Pituitary Lesions Research Articles

Metastatic pituitary lesion

Metastatic lesion of pituitary is a rare condition and is diagnosed in 1.8-4% of cases. Monitoring and treatment of such patients is a complex task and requires increased attention from a multidisciplinary team of specialists. The authors represent three patients with metastatic pituitary lesion who underwent neurosurgical treatment at the National Research Center of the National Research Institute of Endocrinology with subsequent pathomorphological confirmation of the diagnosis. The primary tumors were breast cancer, lung carcinoid, and clear cell kidney cancer. Two patients had distant metastases other than the pituitary gland. The clinical manifestation consisted in the appearance of symptoms of panhypopituitarism, chiasmal syndrome and mass effect in all cases. The follow-up period after surgical treatment was 0.25-2.5 years. Progression of the underlying disease was noted in two patients. One of them carried out stereotactic radiosurgical treatment and stereotactic oriented irradiation. One patient has a stable condition.

Long-Term Quality of Life Among Patients Undergoing Endoscopic Pituitary Gland Surgery.

Introduction/Objectives: The endoscopic approach to skull base lesions is widely regarded as less invasive and associated with reduced morbidity, offering favorable outcomes, particularly in terms of short-term quality of life (QOL). However, to date, long-term assessments of both nasal function and tumor-related QOL remain limited. To evaluate patients' long-term nasal- and tumor-related QOL after endoscopic endonasal resection of pituitary tumors and to detect predictors for poor postoperative QOL. Study Design: This study was a prospective cohort study. Methods: All patients with pituitary adenomas who underwent trans-sphenoidal surgery at Tel Aviv Sourasky Medical Center between 2014 and 2021 were recruited. Recruited patients completed the Anterior Skull Base Disease-Specific QOL (ASBS-Q) questionnaire and the Sinonasal Outcome Test 22 (SNOT-22) questionnaire before surgery and 1, 2, and 3-5 years after surgery. Clinical data were collected and analyzed. Results: The study included 43 patients (18 women). No significant decrease was observed in tumor-related quality of life (QOL) scores, measured by ASBS-Q and SNOT-22, throughout the 5-year follow-up period. SNOT-22 score differences from the preoperative baseline at years 1, 3, and 5 were 0.81 [-4.84-6.58], 3.35 [-4.32-11.02], and 3.73 [-2.22-9.68], respectively, with no statistically significant changes. ASBS-Q scores similarly showed no significant changes over time. Subgroup analyses revealed that tumor characteristics (secreting vs. non-secreting, size), surgical factors (intraoperative cerebrospinal fluid leak, gross tumor resection, use of nasoseptal flap), and endocrine remission did not significantly impact QOL (p > 0.05 for all variables). Conclusions: Our study demonstrated that patients who underwent endoscopic pituitary lesion resection maintained high nasal- and tumor-related quality of life over a 5-year follow-up period. However, given the limitations of our study, further multi-center studies with larger patient populations are warranted to validate these results.

5086 Approaching the Enigma: Unveiling a Pituitary Stalk Lesion with Imaging and Hormonal Patterns

Abstract Disclosure: N. Rodriguez-Morales: None. P. Guido: None. Background: Pituitary stalk lesions (PSL) pose a diagnostic dilemma for endocrinologists. Multiple studies have attempted to associate hormonal imbalances and imaging patterns to a specific etiology (1,2). However, the diagnosis remains a mystery on many occasions. We describe a case of secondary hypogonadism and central DI attributed by a PSL. Clinical Case: A 39-year-old male presented with symptoms of hypogonadism and polyuria. Initial workup was consistent with secondary hypogonadism; decreased free and total testosterone levels (1.8 pg/dL and 9 ng/dL, n>35 pg/dL, n>250 ng/dL), LH (0.2 mIU/mL, n>1.5 mIU/mL), and FSH (<0.7 mIU/mL, n>1.6 mIU/mL). The remaining anterior pituitary hormones were within normal limits. The patient was also polyuric (6.5L urine output in 24hr). HgbA1c was normal. Urine Na, urine Osm demonstrated water diuresis (13 mmol/L and 54 mOsm/kg, respectively). A water deprivation test was performed. Initial urine Osm after water restriction was 119 mOsm/kg, which more than tripled to 575 mOsm/kg after administration of desmopressin, diagnostic of central DI. Pituitary MRI showed a well-circumscribed thickening of the pituitary stalk (6x6x5mm), with uniform enhancement. Evaluation for etiology to rule out germ cell tumor, lymphoma, sarcoidosis, opportunistic infection, tuberculosis, Langerhans cell histiocytosis showed a normal serum hCG, HIV, ACE, LDH, AFP. A lumbar puncture demonstrated normal cytology and was negative for AFB. Whole body bone scintigraphy and chest X-ray were normal. Pituitary deficits were treated with hormone replacement (testosterone and desmopressin), and a repeat MRI showed a stable lesion. Conclusion: Noninvasive testing is key to the evaluation of a pituitary stalk lesion. Careful consideration of inflammatory, infectious, and neoplastic etiologies along with attention to pituitary deficits is very important. Our patient most likely has a craniopharyngioma based on data from other case series (1,2). This case serves to bring additional data to the body of literature on this complicated clinical scenario.

7239 Natural history of cystic pituitary lesions

Abstract Disclosure: B. Graner: None. D.Z. Erickson: None. D. Donegan: None. Introduction: Pituitary lesions are a common incidental finding on brain MRI, the majority of which are cystic. The natural history and management of cystic pituitary lesions have not been clearly established. Purpose: The purpose of this study is to determine the natural history of incidentally identified cystic pituitary lesions, risk factors for growth and the proportion of patients who develop clinically significant symptoms requiring surgical intervention. Methods: Pituitary MRI reports between 01/01/2015 and 12/31/2022 in patients aged 18 years and older were searched for using Dig Our Radiology Information System (DORIS) using the words “cyst” or “cystic.” Additional inclusion criteria included a follow-up pituitary MRI of at least one year duration, clinical evaluation by Endocrinology, and the presence of a cystic pituitary lesion. Patients with non-contrast exams, excessive pituitary hormone secretion, and surgery within 1 year of presentation were excluded. Patient demographics, imaging characteristics of the lesion and clinical outcomes were collected. All pituitary MRI exams were reviewed by a single neuroradiologist. Results: A total of 157 MRIs in 56 patients with a mean age of 48 ±15 years were included, 39 (70%) were female. The mean follow-up was 2.3 ± 1.4 years. The most common indication for MRI was headache (n= 18, 32%). There was no significant difference in mean maximum (max) diameter at last follow-up compared to baseline (7.45 ±4.23 vs 7.04 ±4.35 mm, p=0.06) or mean cyst volume (197.08 ±252.68 vs 201.43 ±326.18 mm3). Nine (16%) of the lesions increased in volume with a mean change in volume of 105 ±133.64 mm3/yr, note 11 (20%) decreased volume and 36 (64%) remained the same size. Using univariate logistic regression, the odds of cyst growth was greater the larger the max diameter (p= 0.03) or volume was at baseline (p= 0.02)/ Female sex (p=0.32), age at diagnosis (p=0.70) or whether the lesion was thought to be a Rathke cleft cyst or a cystic adenoma (p=0.80) were not associated with increased odds of growth. The risk of growth was higher (42 vs 9%, p=0.016) and the volume change per year was greater (67.2 ±134 vs -7 ±28 mm3, p=0.04) in those with a baseline max diameter of >10 mm. Surgery was performed in 4 patients (7%), 3 of which demonstrated lesion growth (baseline size 12-15 mm and growth rates of 59-341mm3/yr). Pathology revealed one Rathke cleft cyst, one cystic adenoma and fibrotic pituitary changes. The fourth surgical patient opted for resection at an outside facility without a demonstrated increase in size (Rathke cleft cyst). Conclusion: The majority of incidentally found cystic pituitary lesions do not increase after an average follow-up 2-3 years. Growth necessitating surgical intervention was only required in 5% of patients over the study period. A pituitary cyst >10 mm at diagnosis was associated with an increased risk of growth and therefore warrants closer follow-up. Presentation: 6/1/2024

7667 Cushing’s Puzzle: Echinococcal Pituitary Cyst In A Rare Encounter

Abstract Disclosure: E. Sari: None. F. Erenler: None. Introduction: Echinococcus is a rare parasitic infection endemic in the Mediterranean, Middle East, South America and Africa, which can cause cystic disease in several organs. Central nervous system involvement is known to comprise 1-2% of all cystic echinococcal disease. Hereby, we report a case of an opportunistic pituitary echinococcus infection in a patient with hypercortisolism due to adrenocortical adenoma with initial misdiagnosis of Cushing’s disease. Clinical Case: A 40-year-old South American female with poorly controlled T2DM on oral agents and hypertension presented to the ER with abdominal pain and subsequent CT of the abdomen with contrast showed a right adrenal mass measuring up to 2.8 cm. A follow up CT with adrenal protocol confirmed 3.3 cm right adrenal mass, 46 HU in precontrast images with >50% washout. Review of records revealed that a recent MRI brain with contrast was performed for headache evaluation and showed an incidental 5x7x4 mm lesion in the pituitary gland. Endocrinology evaluation revealed 24-hour urine volume 1800 mL, elevated free cortisol levels 277.6 mcg/24hr (RR: 4.0-50.0 mcg/24hr), creatinine of 0.67g/24hr (RR: 0.50-2.15g/24hr). 1 mg dexamethasone suppression test showed AM cortisol of 28.7 mcg/dL. ACTH was elevated at 67 pg/mL (RR: 6-50 pg/mL). FSH, LH, and GH were normal. Presumed diagnosis of ACTH-dependent hypercortisolism was made and she underwent bilateral inferior petrosal sinus sampling with confirmed successful cannulation but this was inconclusive due to low ACTH levels. Follow-up MRI of the pituitary gland showed T1 bright, T2 isointense circumscribed lesion measuring 7x6x3 mm at anterior pituitary gland with a thin rim of peripheral enhancement consistent with cystic features. She underwent transsphenoidal resection of the pituitary lesion and the pathology specimen showed parasites consistent with echinococcosis. Infectious disease was consulted, and the patient started on albendazole. Post-operative laboratory evaluation was notable for persistently elevated AM cortisol, 24-hour urine free cortisol levels, and low ACTH levels, confirming ACTH independent hypercortisolism. She underwent right adrenal nodule resection and pathology was consistent with adrenocortical adenoma. Post-adrenalectomy AM cortisol levels were < 2 mcg/dL, indicating the resolution of hypercortisolism along with substantiating the diagnosis of primary adrenocortical hyperfunction. Conclusion: To the best of our knowledge, this is the first case report of an opportunistic echinococcus infection presenting as a pituitary lesion in the setting of Cushing Syndrome. We would like to highlight the importance of recognizing opportunistic infections, including Echinococcus as a potential etiology in the setting of hypercortisolism, especially for patients from endemic regions. Presentation: 6/2/2024

9242 SOX11 mutations cause hypogonadotropic hypogonadism through both hypothalamic and pituitary level deficits

Abstract Disclosure: B. Sun: None. S. Stockman: None. M. Stamou: None. L. Plummer: None. K. Salnikov: None. D. Kotan: None. K. Topaloglu: None. S.B. Seminara: None. R. Balasubramanian: None. AbstractPurpose: Human SOX11 mutations cause Coffin-Siris Syndrome (CSS) which is clinically characterized by aplasia or hypoplasia of the distal phalanx/nail of the fifth digit, developmental delay, cognitive impairment, and distinctive facial features. Recent studies show hypogonadotropic hypogonadism (HH) occurs in ∼20% of patients with SOX11 mutations. The genotypic-phenotypic spectrum of SOX11 mutations in patients presenting with Idiopathic Hypogonadotropic Hypogonadism (IHH) is unknown. Methods: Exome sequencing data from 1810 unrelated IHH probands (anosmic and normosmic forms) were reviewed for SOX11 rare sequence variants (RSVs) [minor allele frequency <0.1%]. Rare variant association analysis (RVAS) and domain-based enrichment for SOX11 RSVs was performed between the IHH and gnomAD population cohort. RSVs predicted as pathogenic/likely pathogenic by ACMG criteria were deemed as pathogenic RSVs and detailed phenotypic analysis was undertaken for these variants. Results: A total of 4 pathogenic SOX11 RSVs were identified in 5 IHH cases. RVAS analysis showed that SOX11 inactivating RSVs (frameshift/non-sense) across the entire protein was enriched in the IHH cohort (2 RSVs in 3 IHH cases (p.S303X [de-novo]; p p.S345Afs*13); p<0.0001) while SOX11 missense RSVs was enriched only within the SOX11-HMG domain (2 RSVs in 2 IHH cases (p.G84D [de-novo]; p.P114S; p=0.003). Phenotypic review of individuals with pathogenic SOX11-RSVs revealed a spectrum of endocrine defects including: anosmic and normosmic forms of IHH, growth-hormone (GH) deficiency, neuroimaging defects (pituitary microadenoma and hypothalamic mass), and hypothyroidism. Additionally, we also identified a pathogenic SOX11 HMG domain RSV in a patient with functional HH (p.R100Q). CSS-associated features were present in almost all individuals with pathogenic SOX11 RSVs. Conclusions: This study validates SOX11 mutations as causal for IHH and reiterates the critical importance of the SOX11-HMG domain in disease pathogenesis. The spectrum of endocrine abnormalities in SOX11-related human disorders includes IHH, functional HH, GH deficiency, pituitary lesions, and hypothyroidism. The association of congenital anosmic and normosmic forms of IHH, functional HH, and anatomic abnormalities of the pituitary gland suggest that the pathogenesis of HH in SOX11-disorder may stem from both hypothalamic and pituitary level deficits. Presentation: 6/1/2024

6626 Fertility considerations in Klinefelter Syndrome complicated by hypogonadotrophic hypogonadism

Abstract Disclosure: M. Govinna: None. S. Sarlos: None. C.A. Allan: None. R. Giri: None. Background: Klinefelter syndrome (KS) remains underdiagnosed with less than 50% of men ever diagnosed and >90% of diagnoses only occurring when fertility is sought. MicroTESE (microscopic testicular sperm extraction) is now successful in 47-69% [1]. Optimal timing of the procedure is uncertain. Case: A 14-year-old male student with a history of renal stones (normal genitourinary tract anatomy) and anxiety presented with a six-day history of new onset headaches and transient visual blurring. MRI scan showed a 2.1cm pituitary lesion with local mass effect and minimal compression of the optic chiasm. Pre-operative pituitary panel: FSH 29.8 IU/L (1.2 - 5.2 IU/L); LH 8.8 IU/L (2.0 - 8.0 IU/L); testosterone 10.9 nmol/L (0.7 - 17.6 nmol/L). Remainder of anterior pituitary function was normal; no AVP deficiency. On examination, Tanner stage P4 G4, testicular volumes 5-6ml (right) and 6-8ml (left) (expected range 15-20ml). Height 175cm (75th centile) and weight 60.1kg (63rd centile). Transsphenoidal resection (TSS) of the pituitary lesion was performed. Intraoperative appearances were suggestive of craniopharyngioma adherent to the pituitary stalk, with stalk transection to achieve complete resection. Post-operatively AVP-deficiency, hypocortisolism and secondary hypothyroidism required replacement therapy. Histopathology was subsequently consistent with Rathke’s cleft cyst. Karyotype testing confirmed 47 XXY genotype (Klinefelter syndrome). Post-TSS FSH and LH levels were 0.7IU/L (1.2 - 5.2 IU/L) and 0.3 IU/L (2.0 - 8.0 IU/L); with testosterone <0.1 nmol/L (0.7 - 17.6 nmol/L), consistent with hypogonadotrophic hypogonadism superimposed on a background of primary hypogonadism. Testosterone replacement therapy was commenced following discussion regarding potential future fertility options. Discussion: This diagnosis of KS highlights the importance of thorough assessment of pubertal development and testicular examination. Small testes with hypergonadotrophic hypogonadism in the context of pituitary pathology should trigger further assessment. Fertility preservation procedures in prepubertal and adolescent boys with KS remain controversial [2]. This patient represents a unique scenario whereby he is LH and FSH deficient post TSS. Whilst prior treatment with hCG does not increase sperm retrieval in non-mosaic KS [3] there may be a role for gonadotrophin therapy prior to undertaking microTESE in our patient. To date, there are no reported cases.

6626 Fertility considerations in Klinefelter Syndrome complicated by hypogonadotrophic hypogonadism

Abstract Disclosure: M. Govinna: None. S. Sarlos: None. C.A. Allan: None. R. Giri: None. Background: Klinefelter syndrome (KS) remains underdiagnosed with less than 50% of men ever diagnosed and >90% of diagnoses only occurring when fertility is sought. MicroTESE (microscopic testicular sperm extraction) is now successful in 47-69% [1]. Optimal timing of the procedure is uncertain. Case: A 14-year-old male student with a history of renal stones (normal genitourinary tract anatomy) and anxiety presented with a six-day history of new onset headaches and transient visual blurring. MRI scan showed a 2.1cm pituitary lesion with local mass effect and minimal compression of the optic chiasm. Pre-operative pituitary panel: FSH 29.8 IU/L (1.2 - 5.2 IU/L); LH 8.8 IU/L (2.0 - 8.0 IU/L); testosterone 10.9 nmol/L (0.7 - 17.6 nmol/L). Remainder of anterior pituitary function was normal; no AVP deficiency. On examination, Tanner stage P4 G4, testicular volumes 5-6ml (right) and 6-8ml (left) (expected range 15-20ml). Height 175cm (75th centile) and weight 60.1kg (63rd centile). Transsphenoidal resection (TSS) of the pituitary lesion was performed. Intraoperative appearances were suggestive of craniopharyngioma adherent to the pituitary stalk, with stalk transection to achieve complete resection. Post-operatively AVP-deficiency, hypocortisolism and secondary hypothyroidism required replacement therapy. Histopathology was subsequently consistent with Rathke’s cleft cyst. Karyotype testing confirmed 47 XXY genotype (Klinefelter syndrome). Post-TSS FSH and LH levels were 0.7IU/L (1.2 - 5.2 IU/L) and 0.3 IU/L (2.0 - 8.0 IU/L); with testosterone <0.1 nmol/L (0.7 - 17.6 nmol/L), consistent with hypogonadotrophic hypogonadism superimposed on a background of primary hypogonadism. Testosterone replacement therapy was commenced following discussion regarding potential future fertility options. Discussion: This diagnosis of KS highlights the importance of thorough assessment of pubertal development and testicular examination. Small testes with hypergonadotrophic hypogonadism in the context of pituitary pathology should trigger further assessment. Fertility preservation procedures in prepubertal and adolescent boys with KS remain controversial [2]. This patient represents a unique scenario whereby he is LH and FSH deficient post TSS. Whilst prior treatment with hCG does not increase sperm retrieval in non-mosaic KS [3] there may be a role for gonadotrophin therapy prior to undertaking microTESE in our patient. To date, there are no reported cases.

8474 SOX11 mutations cause hypogonadotropic hypogonadism through both hypothalamic and pituitary level deficits

Abstract Disclosure: B. Sun: None. S. Stockman: None. M. Stamou: None. L. Plummer: None. K. Salnikov: None. D. Kotan: None. K. Topaloglu: None. S.B. Seminara: None. R. Balasubramanian: None. AbstractPurpose: Human SOX11 mutations cause Coffin-Siris Syndrome (CSS) which is clinically characterized by aplasia or hypoplasia of the distal phalanx/nail of the fifth digit, developmental delay, cognitive impairment, and distinctive facial features. Recent studies show hypogonadotropic hypogonadism (HH) occurs in ∼20% of patients with SOX11 mutations. The genotypic-phenotypic spectrum of SOX11 mutations in patients presenting with Idiopathic Hypogonadotropic Hypogonadism (IHH) is unknown. Methods: Exome sequencing data from 1810 unrelated IHH probands (anosmic and normosmic forms) were reviewed for SOX11 rare sequence variants (RSVs) [minor allele frequency <0.1%]. Rare variant association analysis (RVAS) and domain-based enrichment for SOX11 RSVs was performed between the IHH and gnomAD population cohort. RSVs predicted as pathogenic/likely pathogenic by ACMG criteria were deemed as pathogenic RSVs and detailed phenotypic analysis was undertaken for these variants. Results: A total of 4 pathogenic SOX11 RSVs were identified in 5 IHH cases. RVAS analysis showed that SOX11 inactivating RSVs (frameshift/non-sense) across the entire protein was enriched in the IHH cohort (2 RSVs in 3 IHH cases (p.S303X [de-novo]; p p.S345Afs*13); p<0.0001) while SOX11 missense RSVs was enriched only within the SOX11-HMG domain (2 RSVs in 2 IHH cases (p.G84D [de-novo]; p.P114S; p=0.003). Phenotypic review of individuals with pathogenic SOX11-RSVs revealed a spectrum of endocrine defects including: anosmic and normosmic forms of IHH, growth-hormone (GH) deficiency, neuroimaging defects (pituitary microadenoma and hypothalamic mass), and hypothyroidism. Additionally, we also identified a pathogenic SOX11 HMG domain RSV in a patient with functional HH (p.R100Q). CSS-associated features were present in almost all individuals with pathogenic SOX11 RSVs. Conclusions: This study validates SOX11 mutations as causal for IHH and reiterates the critical importance of the SOX11-HMG domain in disease pathogenesis. The spectrum of endocrine abnormalities in SOX11-related human disorders includes IHH, functional HH, GH deficiency, pituitary lesions, and hypothyroidism. The association of congenital anosmic and normosmic forms of IHH, functional HH, and anatomic abnormalities of the pituitary gland suggest that the pathogenesis of HH in SOX11-disorder may stem from both hypothalamic and pituitary level deficits. Presentation: 6/1/2024

7405 A Case of Pituitary Apoplexy in Pregnancy

Abstract Disclosure: Y. Esaki: None. G.E. Vates: None. I. Shafiq: None. Pituitary apoplexy is a rare cause of headache during pregnancy. The prevalence of pituitary apoplexy during gestation and the peripartum period is estimated to be 1 in 10,000 term pregnancies. Approximately 42-47% of these patients were known to have a pituitary lesion especially history of prolactinoma. Here we report a pregnant female developing pituitary apoplexy after discontinuation of dopamine agonist. A 27-year-old female was initially diagnosed with prolactinoma with elevated prolactin of 158.1 ng/ml (3.0-300 ng/ml). MRI revealed a 1.3 cm x 1.5 cm x 1.4 cm pituitary mass with solid and cystic components. Treatment with cabergoline 0.25 mg twice weekly was started. After 2 years of treatment, prolactin was 74.2 ng/ml and the size of the adenoma decreased to 1.0 cm x 1.2 cm x 1.3 cm. One year later, she became pregnant at age 30 and discontinued cabergoline after 7 weeks of gestation. At 12 weeks of gestation, she presented to the Emergency Department for 3 days of severe headaches associated with emesis. The ED work up includes prolactin > 2,000 ng/ml. MRI head without contrast demonstrated an interval increase in size to 1.5 cm x 1.7 cm with hemorrhagic component. Urgent evaluation by a Neuro-ophthalmologist revealed no clinical evidence of optic neuropathy. Blood work showed AM cortisol 2.3 mcg/dl (4.0-22.0 mcg/dl), TSH 0.5 mIU/L (0.4-0.5 mIU/L), FT4 0.6 ng/dl (0.8-1.8 ng/dl). Cabergoline 0.25 mg twice weekly was restarted to control the size of the tumor as well as hydrocortisone and levothyroxine for central adrenal insufficiency and hypothyroidism respectively. Four weeks later, she was 17 weeks pregnant. MRI showed a further increase in the size of the adenoma, now measuring 1.8 cm x 2.0 cm x 1.3 cm. The lesion now extended into the suprasellar cistern, affecting the optic chiasm. She underwent the transsphenoidal resection of the pituitary adenoma at 18 weeks of gestation due to the increase in size of the tumor. The final pathology was consistent with pituitary adenoma, lactotroph cell type, WHO grade 1. MRI obtained 3 months post-operation showed no residual T1 hyperintense tumor signal. There was a cyst-like expansion of the sella turcica with a decreased mass effect on the optic chiasm. She delivered her healthy baby at 40 weeks and 5 days via vaginal delivery. She received stress dose steroid during labor, then was discharged home with hydrocortisone 10 mg twice daily. She is doing well following the delivery and breastfeeding the baby. This case illustrates a rare case of pituitary apoplexy during pregnancy in a patient with prolactinoma. Pituitary apoplexy should be considered as a differential diagnosis when pregnant patients develop an acute, severe headache, especially those with an underlying pituitary adenoma. It is critical to assess and treat the hormonal deficiencies. For prolactinoma, pharmacological therapy can be initiated. Surgery is considered if the medical therapy fails. Presentation: 6/3/2024

8155 Isolated Hypothalamic-Pituitary Langerhans' Cell Histiocytosis in Adult Patients

Abstract Disclosure: A. Vu: None. M. Aguilera: None. J. Shakil: None. R. Al-Ward: None. Introduction: Langerhans cell histiocytosis (LCH) is an infiltrative disease due to clonal proliferation of immature dendritic cells mainly affecting children and seen in adults in less than 30% of cases. It can present as localized or with systemic manifestations, with isolated hypothalamic-pituitary lesions being exceptionally rare. Our report adds to the limited published literature by presenting two cases of isolated hypothalamic-pituitary LCH diagnosed in adults. Furthermore, one of the cases reveals a rare association with papillary thyroid cancer (PTC). Case 1: 35-year-old woman with no past medical history presented with 4 year history of amenorrhea and weight gain and more recently, polyuria and polydipsia. Further investigations showed hypogonadotropic hypogonadism, central hypothyroidism, and mildly elevated prolactin. She couldn’t complete water deprivation test due to extreme thirst. A dedicated pituitary MRI showed marked infundibular enlargement, concerning for hypophysitis. An extensive workup including assessments for autoimmune etiology, sarcoidosis, infections, and low-grade tumors, did not identify a definitive etiology. A PET scan was obtained (to rule out LCH and Erdheim Chester disease), which showed increased uptake in the pituitary stalk. Due to otherwise negative workup, transsphenoidal biopsy of the pituitary lesion was done. Post-procedure, diabetes insipidus (DI) was diagnosed due to elevated sodium while fasting for the procedure. Tissue examination revealed increased histiocytes and lymphocytes, and a positive BRAF V600E mutation confirming LCH as the underlying diagnosis. Case 2: 26-year-old male with history of LCH limited to the skull, in remission for 8 years after chemotherapy, presented with 4-week history of polyuria, polydipsia and weight loss. A 24-hour urine collection resulted in 6.5L of urine. During water deprivation test, there was notable increase in serum sodium, serum osmolarity, and urine osmolarity. Initial pituitary MRI was normal, but subsequent imaging revealed the loss of the posterior pituitary bright spot. PET scan showed focal FDG avidity in the right lower thyroid lobe, confirmed on fine needle aspiration as PTC with BRAF mutation. He underwent total thyroidectomy and is currently receiving chemotherapy for LCH recurrence. Discussion: LCH is infrequent in adults, presenting with variable manifestations based on affected organs. In the multifocal form, the hypothalamic-pituitary axis is involved in 5-50% of cases. Our report describes two unique cases with only four other reported cases of isolated hypothalamic-pituitary axis LCH in adults. Central diabetes insipidus can be seen before the diagnosis or as the disease progresses. Pituitary biopsy, although invasive, should be considered when the diagnosis is not clear. The association of PTC with a BRAF mutation is extremely rare and has been reported. Presentation: 6/2/2024

9363 Spontaneous Cushing Disease Remission Induced By Pituitary Apoplexy

Abstract Disclosure: J.E. Esquivel Vargas: None. F. Ruiz Salazar: None. A.B. Santos Rojo: None. Background: Spontaneous remission of Cushing disease is rare, and it is mainly due to apoplexy of a pituitary tumor. Clinical case: 14-year-old female presented with clinical features of Cushing syndrome. Initial tests were consistent with Cushing disease (CD): elevated 24h urinary cortisol (235µg/24h, n<90µg/24h), abnormal 1 mg dexamethasone overnight test (cortisol after 1 mg dex 3.4µg/dL, n<1.8µg/dL), and elevated ACTH-concentrations (83.5 pg/mL, n 10-60pg/mL). Pituitary adenoma was suspected, and the patient was referred for a transsphenoidal resection of the adenoma. While waiting for surgery the patient presented to the Emergency department with a headache and clinical signs of meningism. Computed axial tomography of the central nervous system was performed, and no structural alterations were found. The symptoms subsided with analgesia. One month later she presented again to the Emergency department with clinical findings of acute adrenal insufficiency (cortisol level of 4.06 µg/dL), and she was noted to have spontaneous biochemical remission associated with resolution of her symptoms of hypercortisolism. Nuclear magnetic resonance imaging was performed describing a 2.6 x 1.8mm hypointense pituitary lesion, suggestive of cerebrospinal fluid, which could be a remnant of a pituitary microadenoma. For that reason, spontaneous CD remission induced by pituitary apoplexy (PA) was diagnosed. The patient has been managed conservatively since the diagnosis and remains in clinical and biochemical remission until the present time after 10 months of follow up. Conclusion: There are 3 unique aspects of our case: the early age of onset of symptoms, the spontaneous remission of CD due to PA which has been rarely reported in the medical literature, and the patient presented a microadenoma because there are less than 10 clinical case reports of PA associated with microadenoma. Presentation: 6/1/2024

8411 Ectopic ACTH-dependent Cyclical Cushing’s Syndrome- the Art of Hide-and-seek

Abstract Disclosure: H. Mon: None. A. Kapoor: None. S. Qureshi: None. M. Martineau: None. K. Meeran: None. Case report: A 72-years-old lady was admitted with hypokalaemia, hyperglycaemia with metabolic alkalosis with background hypertension, type2 diabetes, osteoporosis and right-sided breast cancer treated with chemotherapy and radiotherapy 3years ago. She was previously seen in Endocrinology Clinic for similar episode and deemed not having Cushing’s or Conn’s syndrome on workup. During this admission, although there was no obvious Cushingoid appearance, there was refractory hypokalaemia. On further exploration, there were previous admissions with similar episodes in UK and in her home country, within the same year, a few months apart. Therefore, endocrinology workup was conducted for suspected cyclical Cushing’s syndrome. It demonstrated raised 24-hour urinary free cortisol of 5643 nmol/24hour (reference range 0-164 nmol/24hours), unsuppressed low dose dexamethasone suppression test with cortisol level of 800 nmol/L and increased ACTH level of 429 ng/L. MRI (pituitary) showed no pituitary lesion with probable empty sella and CSF filled. However, CT (thorax) showed enlarging lesion (previously from 1cm to 1.6cm) in the left lower lobe, concerning lung metastasis or primary lung malignancy. PET scan showed left lower lobe nodule having low-grade activity with likelihood of indolent malignancy and appearances of physiologic adrenal hyperplasia. Management: Given persistently high cortisol levels during admission with ongoing hyperglycaemia and refractory hypokalaemia, metyrapone was started and titrated accordingly. Her clinical condition including potassium and cortisol levels effectively responded to metyrapone. Gallium scan was booked for detail localization with ongoing lung MDT (multidisciplinary team meeting) and neuroendocrine tumour MDT.However, after starting metyrapone, she had type 1 respiratory failure, not responding to initial antibiotics. After excluding other possible respiratory aetiologies, empirical treatment for Pneumocystosis pneumonia (PCP) was initiated, after which blood test for Beta-D-glucan was found out to be significantly raised, supporting the presumptive diagnosis. Conclusion: Our case highlighted the following interesting points 1. diagnostic challenges, due to the fluctuating nature of cyclical Cushing’s syndrome, presenting with recurrent hypokalaemia. 2. the interesting nature of likely ACTH-dependent cyclical Cushing’s syndrome, progressing into florid Cushing’s syndrome, with efficacy to metyrapone 3. rare and compelling combination of 3 conditions of Cyclical Cushing’s syndrome, being ectopic ACTH-dependent and complicated by Pneumocystosis pneumonia (PCP). Presentation: 6/1/2024

6791 Pituitary Apoplexy as Presentation of Atypical Teratoid/Rhabdoid Tumor

Abstract Disclosure: S.I. Babli: None. H. Alkubedan: None. N.M. Ali: None. R. Alqawahmed: None. M.M. Elhassan: None. Introduction: Pituitary apoplexy occurs in a pituitary adenoma; it migh occur in other less common types of tumors. The atypical teratoid/rhabdoid tumor (ATRT) is a very aggressive malignant tumor of the central nervous system and has a poor prognosis. It is rare to occur in adult and in the sellar region. Clinical Case: 32 years old male presented to ER with 4 days history of fever, headache and vomiting. He was conscious but confused. Vital signs Temperature 39 C, BP 120/80, HR 110 beats/min and Saturation of 95 %, Possibility of meningoencephalitis was raised, patient Brain CT showed Sellar and suprasellar mass with compression over the optic chiasma and invasion to the left cavernous sinus. Patient suddenly developed Generalize tonic-clonic convulsion and hypotension. He received IV midazolam, intubated and was started on noradrenaline and hydrocortisone, he was admitted to ICU as a case of meningoencephalitis and started on Ceftriaxone, Vancomycin and Acyclovir. Cerebrospinal fluid analysis showed RBC 175/cumm, WBC 20/cumm with 20% polymorph and 80% mononuclear cells, Protein 1.38 g/l (0.24-0.49) glucose 7.9 mmol/l with plasma glucose of 10 mmol/l. Repeated Brain CT showed Sellar and suprasellar mass with compression over the optic chiasma and invasion to the left cavernous sinus and with minimal heterogenicity and increased density suggestive of hemorrhagic components. Endocrine history revealed weight gain but no history to suggest acromegaly, Cushing’s syndrome or hypogonadism . Examinations: Patient was intubated and sedated BP 90/60 on Maximum inotropic support. Left oculomotor nerve palsy, Bilateral papilledema, he was having acanthosis nigricans with no signs of acromegaly, CS or hypogonadism. Laboratory finding: WBC17 with neutrophilia, Hgb 14.7 g/dl plt 360 Na 140 mmol/l, creatnin 180 mmol/, FT4 6.2 pmol/l, TSH 0.015, PROLACTINE 22, IGF1 29 ng/ml (41-246) Free testosterone index 2.13 (33-106), LH 0.5, FSH 0.3 .Patient had TTS and histopathology showed: SMARCB1 deficient malignant neoplasm, consistent with sellar atypical teratoid rhabdoid tumor. Post OP, patient had Ventilator associated pneumonia and recurrent attacks of seizures despite multiple antiepileptic medications. Patient was evaluated by medical and radiation oncologists but due to his general condition the treatment was postpone. One month after TSS, he developed intractable seizure new Brain CT showed interventricular haemorrhage with hydrocephalus and marked enlargement of hyperdense pituitary lesion which suggests haemorrhage. External ventricular drain was inserted but patient arrested and died. Conclusions: ATRT of the CNS usually affects young children. In the literature review performed in adults, only nine cases have occurred in the sellar or suprasellar region. Survival is variable in the different cases reported in the literature, with a mean of 26 months. Presentation: 6/2/2024

6570 Treatment of Cushing’s With Levoketoconazole: A Case Series

Abstract Disclosure: N. Chamorro-Pareja: None. M. Haines: None. L.E. Dichtel: Consulting Fee; Self; Lumos Pharma. Research Investigator; Self; Recordati, NovoNordisk, Perspectum Ltd, Lumos Pharma, Pfizer, Inc.. Stock Owner; Self; Marea Therapeutics. Other; Self; Third Rock Ventures. B.M. Biller: Consulting Fee; Self; Xeris Pharmaceuticals, Recordati Rare Diseases, Sparrow, Lundbeck. Background: Endogenous Cushing’s syndrome (CS) is a rare condition of excess cortisol secretion; the most common cause is a pituitary corticotroph tumor (Cushing’s disease [CD]). Medical treatment for CD is primarily used to control hypercortisolism in patients with persistent or recurrent disease after transsphenoidal surgery (TSS). Levoketoconazole (LKCZ), a steroidogenesis inhibitor, was FDA approved in January 2022 for CS treatment. This reports 3 cases of patients who were treated with LKCZ for recurrent CS. Clinical Cases: Case 1: 44-year-old (yo) male (M) with a history of CD with urinary free cortisol (UFC) >26x upper limit of normal (ULN) who was treated preoperatively with ketoconazole (KCZ) 1000 mg/day with UFC improved to 6x ULN. KCZ was discontinued at TSS, and he achieved remission post-operatively. He was lost to follow-up and re-presented after several years with worsening hypertension, muscle weakness, edema, and anxiety with UFC 28x ULN and a recurrent pituitary lesion on MRI. He declined repeat TSS and underwent radiation therapy (RT) and medical treatment. LKCZ was initiated at 150 mg twice daily (BID) and increased to 300 mg BID. At LKCZ 300 mg BID, he had a low UFC and mild nausea but an adequate serum morning cortisol (10.4 ug/dL, ref:6-18.4 ug/dL); LKCZ was reduced to 150 mg BID with resolution of symptoms (sxs) and normal UFC. Case 2: 56 yo M with a history of CD (UFC >3x ULN) who underwent 2 TSSs and RT over 10 years prior with eventual remission, but later recurred. Sxs included brain fog and mood disturbances. He achieved control with pasireotide but discontinued due to abnormal liver function tests. He was then treated with KCZ 400 mg/day but remained hypercortisolemic (LNSC 1.1x ULN) and was interested in trying a new medication, so was switched to LKCZ 150 mg BID with significant improvement of sxs and normalization of LNSC. Case 3: 54 yo F with presumed cyclic CD (negative whole-body and octreotide scans) with UFC 1.7x ULN and LNSC 3x ULN. TSS was performed with negative pathology; she had persistent hypercortisolemia and sxs including insomnia, fatigue, and mood disturbances. She was intolerant to and/or uncontrolled on 4 medications, including KCZ at 1000 mg/day that was discontinued due to a rash. She was started on LKCZ 150 mg BID and achieved normal LNSC and UFC after about 1 month. The drug was discontinued due to the development of a rash similar to that with KCZ. Conclusion: LKCZ is a new option for the treatment of CS in patients whose disease persists after TSS. These 3 patients had improvement of sxs and normalization of cortisol levels while on LKCZ, although one patient discontinued LKCZ due to a rash that was previously experienced with KCZ. The other two patients are being carefully monitored for liver function test elevation, QTc abnormalities and adrenal insufficiency with no issues to date. To our knowledge, this is the first case series of CS patients treated clinically with LKCZ. Presentation: 6/1/2024

8104 Rare Case Of Ectopic Cushing’s Syndrome Secondary To Metastatic Parotid Pleomorphic Adenocarcinoma

Abstract Disclosure: B.S. Neutel: None. P. Manroa: None. Background: Pleomorphic adenocarcinoma of the parotid gland is a rare malignancy and ectopic ACTH secretion from these tumors is very rarely described. We report a case of ectopic Cushing’s syndrome (CS) in such a patient and describe the clinical course. Clinical Case: A 69-year-old female with left parotid pleomorphic adenocarcinoma status post surgery and adjuvant radiotherapy presented to her local hospital approximately 7 months after initial treatment with proximal muscle weakness and near-syncope. Workup revealed profound hypokalemia at 1.6 mmol/L (n 3.5-5.3 mmol/L) along with new-onset hypertension (BP 175/110 mm Hg) and hyperglycemia with a HbA1c 6.5 % (n <5.7%), as well as metabolic alkalosis with a bicarbonate level of >40 mmol/L (n 22-32 mmol/L). A CT scan showed multiple liver metastases and a biopsy confirmed metastatic parotid pleomorphic adenocarcinoma. She was then transferred to our comprehensive cancer center for further management. She reported muscle weakness, easy bruising, and facial edema. She denied acne, hirsutism, or abdominal striae. Endocrine workup revealed a random cortisol of 56 mcg/dL (n 3-18 mcg/dL) and ACTH of 378 pg/mL (n 7.2-63.3 pg/mL). Her AM cortisol level remained unsuppressed at 79.2 and 59.4 mcg/dL (n< 1.8 mcg/dL) after 1 mg and 8 mg overnight dexamethasone suppression tests respectively. Late-night salivary cortisol was 7.9 mcg/dL (n <0.112 mcg/dL). An MRI of the sella was negative for any pituitary lesions. After stabilizing her clinical condition and correcting electrolyte abnormalities, she was started on chemotherapy with paclitaxel and carboplatin by the oncologist. Based on clinical suspicion of ectopic CS, ketoconazole was started and titrated upwards with rapid improvement of blood pressure, hypokalemia, and hyperglycemia. She was discharged home and antihypertensives were tapered off. ACTH staining on the liver biopsy was unable to be performed due to paucity of the specimen. A Ga-68-DOTATATE PET CT revealed increased radiotracer uptake in the liver lesion suggestive of SSTR 2 receptor positivity. Despite initial clinical improvement, her disease progressed with widespread liver, lymph node, and osseous metastases within 3 months necessitating escalating doses of ketoconazole, spironolactone, and potassium supplementation. The patient elected to pursue hospice care due to intolerance to chemotherapy and passed away shortly afterward. Conclusion: Although ectopic CS caused by parotid pleomorphic adenocarcinoma is rare, prompt recognition and treatment is necessary because ectopic ACTH production is associated with poor prognosis in these patients. Presentation: 6/3/2024

8653 A Rare Cause of a Pituitary Mass

Abstract Disclosure: L. El Musa Penna: None. W. Medina-Torres: None. L.R. Sepulveda-Garcia: None. I.C. Arroyo Gomez: None. J. Segarra-Villafane: None. Z. Maisonet -Feliciano: None. M. Ramirez: None. L.A. Gonzalez-Rodriguez: None. M. Alvarado: None. J. Feneque González, MD: None. M. Marcos Martínez, MD: None. M. Correa Rivas: None. Pituitary gland masses are the second most common tumor of the central nervous system (CNS) across all age group, as per Central Brain Tumor Registry in the United States. Most common lesions are adenomas, which can be categorized as functional and non-functional based on the presence of hormonal hypersecretion. In the differential diagnosis, there is also craniopharyngiomas, Rathke’s cleft cysts, pituitary hyperplasia, inflammatory lesions, malignancy and abscess. Pituitary abscess is a rare condition, and only 0.2-0.6% of pituitary lesions are diagnosed as abscesses.This is the case of a 42-year-old female with history of hypothyroidism, chronic sinusitis with nasal polyps, severe asthma, and chronic steroid use complicated by iatrogenic adrenal insufficiency and osteonecrosis of the hips bilaterally, who was evaluated for intractable headaches. On brain imaging was found with a pituitary macroadenoma. She denied any symptoms suggesting hypersecretion of hormones and was scheduled for transsphenoidal surgery. All hormonal work up was found within normal limits, except for prior iatrogenic adrenal insufficiency due to multiple systemic steroids courses to treat asthma exacerbation throughout her life.During surgery, upon mass resection, purulent secretions were found. Frozen section was done intraoperatively, showing respiratory epithelium, pus and actinomyces species. All infectious material was removed. Infectious Diseases services was consulted and patient was promptly started on IV antibiotics. Blood cultures were negative, and patient remained afebrile. Final pathology confirmed the presence of respiratory epithelium, actinomyces colonization and a fibrous capsule with acute and chronic inflammation. Special stains report was negative for fungi. She was discharge to continue home infusion of antibiotic regimen to complete 8 weeks of treatment.There is no specific imaging finding to identify pituitary abscesses so, most of them, are diagnosed intraoperatively. They can arise from hematogenous spread or from adjacent tissues or structures (ie. patient with meningitis or sinusitis). The condition is considered a life-threatening however, the majority of cases have a chronic course. Based on different reports, theses abscesses have a higher female predominance; the age range is between 12 to 76 years and the average period between onset of symptoms and diagnosis is 8 months on average. Most pituitary abscesses are sterile, however most common organisms isolated are: Gram-positive cocci (Staphylococcus and Streptococcus), and Gram-negative organisms such as Neisseria, Escherichia coli and Corynebacterium. The rarity of cases often leads to delayed diagnosis and treatment initiation, contributing to increased morbidity and mortality. Presentation: 6/2/2024

7521 Unmasking of PCOS after Microprolactinoma Treatment

Abstract Disclosure: F. Erenler: None. B. Aydogan Mathyk: None. Background: PCOS and prolactinomas are two of the leading causes of secondary amenorrhea. Hirsutism is a common finding for both diagnosis and can be the presenting symptom. We are presenting a case of secondary amenorrhea, initially diagnosed with microprolactinoma without signs of hyperandrogenism, which progressed to overt PCOS after prolactinoma treatment. Case: A 22-year-old female with history of Hashimoto’s hypothyroidism presented with secondary amenorrhea. Patient was on combined oral contraception pills (COC) for menstrual regulation and discontinued them with a desire of natural cycles. After the discontinuation of COC, her menstrual cycles did not return for four months and patient was subsequently found to have a microprolactinoma with prolactin (PRL) level 70.6 ng/mL - high (nl: 2.8-29.2 ng/mL), LH 6.1 mIU/mL (follicular phase: 1.9-12.5 mIU/mL), FSH 2.4 mIU/mL - low (follicular phase: 2.5-10.2 mIU/mL), androstenedione 132 ng/mL (follicular phase: 51-213 ng/mL), testosterone 36 ng/mL (nl: 2-45 ng/mL), AMH 33 ng/mL - high (nl: 1.02-14.63 ng/mL), DHEA-S 241 mcg/dL (nl: 44-286 mcg/dL), HCG neg. MR Sella showed a 0.5 cm hypoenchancing pituitary lesion, confirming the diagnosis of prolactinoma. Patient was started treatment with cabergoline 0.25 mg twice a week and PRL level trended down to 3.9 ng/mL. With normalization of PRL, patient started complaining of new onset hirsutism without return of her menses. Ferriman Gallway score was 8. Further workup showed elevated androgen markers: LH 25.7 mIU/mL - high (follicular phase: 1.9-12.5 mIU/mL), FSH 5.0 mIU/mL (follicular phase: 2.5-10.2 mIU/mL), PRL 4.7 ng/mL -low (nl: 4.8-23.2 ng/mL), androstenedione 341 ng/mL -high (41-262 ng/mL), E2 63.4 pg/mL (nl: 12.5-160 pg/mL), AMH 22.3 ng/mL – high (nl: 1.23-11.61 ng/mL), testosterone 94.7 ng/mL - high (nl: 10-55 ng/mL), DHEA-S 261 mcg/dL (nl:110-431.7 mcg/dL). ACTH stimulation test pursued to rule out NCAH and17-OH progesterone levels were within normal range after stimulation. Pelvis US obtained due to high suspicion for PCOS and was consistent with polycystic ovaries. The diagnosis of PCOS confirmed by Rotterdam criteria. Patient has phenotype A PCOS by the definition of NIH 2012 consensus. Conclusion: Hyperprolactinemia and pituitary adenomas can cause secondary amenorrhea. In our case, the treatment of hyperprolactinemia with cabergoline unmasked the underlying PCOS. The clinical and biochemical manifestation of PCOS became apparent following the removal of prolactin’s suppressive effect on GnRH. Presentation: 6/2/2024

Observations from the first 100 cases of intraoperative MRI – experiences, trends and short-term outcomes

BackgroundWe sought to analyze, in well-defined clinical setting, the first 100 patients treated at the intraoperative MRI (iMRI) hybrid surgical theatre at our facility in a population-based setting to evaluate which pathologies are best approached with iMRI assisted surgeries, as this is not yet clearly defined.MethodsPatients undergoing surgery in the 3T iMRI hybrid surgical theatre at our neurosurgical department between December 2017 to May 2021 were included after informed consent. Demographic, clinical, surgical, histological, radiological and outcome parameters, as well as variables related to iMRI, were retrospectively collected and analyzed. Patients were subdivided into adult and pediatric cohorts.ResultsVarious neurosurgical procedures were performed; resection of tumors and epileptic foci, endoscopic skull base procedures including pituitary lesions, deep brain stimulation (DBS) and laser interstitial thermal therapy (LITT). In total, 41 patients were pediatric. An iMRI scan was carried out in 96% of cases and led to continuation of surgery in 50% of cases, mainly due to visualized remaining pathological tissue (95.2%). Median time to iMRI from intubation was 280 min and median total duration of surgery was 445 min. The majority of patients experienced no postoperative complications (70%), 13 patients suffered permanent postoperative deficits, predominantly visual.ConclusionHerein, we demonstrate the first 100 patients undergoing neurosurgery aided by iMRI at our facility since introduction. Indications for surgery differed between pediatric and adult patients. The iMRI was utilized for tumor surgeries, particularly adult low-grade gliomas and pediatric tumors, as well as for epilepsy surgery and DBS. In this heterogenous population, iMRI led to continuation of surgery in 50%. To establish the benefit in maximizing the extent of resection in these brain pathologies future studies are recommended.Clinical trial numberNot applicable.

Adenomas hipofisarios y adenomas funcionantes

Functioning pituitary adenomas (FPAs) are the most common pituitary lesions. They represent approximately 15% of all intracranial neoplasms, with prolactinomas accounting for 60% of FPAs. Its clinical manifestations are related to hypersecretion and/or local symptoms due to the tumor's mass effect, such as headache, visual disturbances, and/or hypopituitarism. The main clinical syndromes associated with pituitary hyperfunction include hyperprolactinemia with secondary hypogonadism, acromegaly, Cushing's syndrome, and secondary hyperthyroidism. Diagnosing FPA involves demonstrating an excess in hormone secretion through biochemical tests followed by imaging tests to localize the tumor. Magnetic resonance imaging (MRI) with contrast is the test of choice for this purpose. In regard to treatment, surgery is the first-line option for most FPAs except for prolactinomas, which usually respond well to dopamine agonists.