Cavernous Research Articles

Arterial spin labeling could detect the occlusion of inferior petrosal sinus for cavernous sinus dural AVF

Abstract Several reports indicate that arterial spin labeling (ASL) magnetic resonance imaging (MRI) is useful for the diagnosis, identification of cortical venous reflux, and assessment of therapeutic effect in dural arteriovenous fistula (dAVF). However, there is no reports indicating the utility of ASL in the identification of venous sinus obstruction. We herein report the case of a 72-year-old woman presented with diplopia and right trigeminal neuralgia due to bilateral CS-dAVF. Digital subtraction angiography (DSA) showed temporal occlusion of the inferior petrosal sinus (IPS) and ASL indicated hyperintense signal in the IPS. The ASL signal could indicate venous stasis soon after the occlusion based on the serial changes of IPS patency and occlusion observed in the Digital subtraction angiography.

Analysis of the impact of a rhinologist-assisted endoscopic approach on a single neurosurgeon’s outcomes in transsphenoidal resection of pituitary adenomas

ObjectivesDetermine the improvements in outcomes of transsphenoidal pituitary adenoma resection following addition of a skull base rhinologist to the neurosurgical team. DesignAll patients that underwent transsphenoidal resection of pituitary adenoma were identified. Demographic data, Otolaryngology (ENT) involvement, initial adenoma size, extent of resection, hormonal secretion status, visual field exam, post-operative DI, CSF leak, recurrence, need for nasoseptal flap (NSF), re-operation rate were all collected. A linear-regression model adjusteds for confounders. SettingA single academic institution Participants271 patients who underwent transsphenoidal surgery between 2015 and 2020.Main Outcome MeasuresThe main outcome measures were Extent of Resection and Endocrinologic remission. ResultsOf the 271 patients identified, 228 (84 %) patients had macroadenomas, one-third of patients presented with bitemporal hemianopsia, and 27 % (72) were hormonally active. For these and demographics there were no statistically significant differences between the microscopic or endoscopic approach (EEA) groups. For patients with cavernous sinus invasion of >50 %, EEA was more likely to achieve gross total resection (GTR) (OR 2.6; p<0.001). For patients who had prior sellar surgery, EEA was 2.5x more likely to get a GTR (p=0.05). The EEA approach resulted in an extra hospital day (1–2 vs 2–3 p<0.05) and surgery lasted an additional hour (1.17 vs 2.5, p<0.05), but did not require fat grafts or lumbar drains on a routine basis. ConclusionsWhile the operating time and LOS were longer, the EEA approach performed by two specialized co-surgeons demonstrates superior value for adenomas that have had a prior surgical attempt or with significant cavernous sinus invasion.

Origin and Course Cavernous Internal Carotid Artery Branches from the Endoscopic Endonasal Perspective: Cadaveric Study and Analysis Clinical Implications.

Endoscopic endonasal approaches to treat cavernous sinus lesions require detailed knowledge of the origin, course, and anatomic variations of the branches of the cavernous internal carotid artery (cICA) because inadvertent avulsion can cause intraoperative ICA injury. We aim to study the origin and course of the branches of the cICA from an endoscopic endonasal perspective and relate these branches to surgically relevant anatomic references. Sixty sides of 30 formalin-fixed specimens were dissected to identify the origin and course of cICA branches, including the inferolateral trunk (ILT), the meningohypophyseal trunk (MHT), anterior and inferior McConnell's capsular arteries (MCAs), and the superolateral trunk (SLT). The ILT and MHT were bilaterally in all specimens, whereas the anterior and inferior MCAs were identified in 28% and 25% of dissected sides, respectively. The SLT was only found in 3% of sides dissected. The MHT was the most proximal branch of the cICA, and its origin was an average of 8.9 mm anterior to the foramen lacerum and 3.8 mm superior to the sellar floor. The ILT was the second most proximal branch of the cICA, which originated 6.4 mm from the MHT on average. The anterior and inferior MCAs were present in 28% and 25% of specimens, respectively. The SLT, when present, was the second most proximal branch of the cICA, which originated at a mean height of 2.7 mm from the sellar floor. Overall, complete ILT and MHT were identified in 68% and 77% of cases, respectively. The MHT and ILT are constant branches of the cICA, with the MHT originating from the medial cICA posterior bend 4 mm superior to the sellar floor and 9 mm anterior to the foramen lacerum, whereas the ILT arises from the lateral horizontal cICA, 2.3 mm superior to the sellar floor and 6 mm anterior to the MHT.

Stand-alone transarterial flow diversion for treatment of carotid cavernous fistulas

ObjectiveCarotid-cavernous fistulas (CCFs) are rare arteriovenous communications allowing blood to flow from the carotid artery into the cavernous sinus. Although currently coil and/or liquid embolization remain the preferred treatment methods for CCFs, flow diverters (FD) stents represent a viable alternative to traditional embolization techniques. This study explores both the technical aspects and rationale behind using FD stents as a stand-alone treatment approach for CCFs. MethodsThe study includes records of 7 patients with CCFs treated at two comprehensive stroke centers from 2019 to 2023. Patients treated with FD stenting in conjunction with coil and/or liquid embolization were excluded from the study. ResultsFive patients were diagnosed with direct CCFs and 2 patients with indirect CCFs. Six patients were treated with the Surpass Evolve FD stent and 1 patient with the Pipeline FD stent. DSA follow-up was performed for an average duration of 14.4 months following FD placement. Complete fistula obliteration with no residual shunting was observed in all patients. Furthermore, all patients experienced a complete resolution of symptoms following treatment. ConclusionsThe authors’ experiences suggest the efficacy and safety of FD stenting as a stand-alone treatment option for CCFs. Compared to embolization, FD stents can better preserve the parent vessel and promote healing with less associated mass effect. Despite being a retrospective self-assessment with a relatively small sample size, to the authors’ knowledge, this study represents the largest individual case series of patients with CCF treated with stand-alone FD stenting.

PATTERNS OF RADIOTHERAPY PRACTICE FOR FUNCTIONING PITUITARY TUMOURS - A SURVEY OF UK CENTRES

Abstract AIMS Pituitary adenomas are benign tumours that are classified as functioning or non-functioning based on the production of excess pituitary hormones. Functioning adenomas (FA) typically present as hypersecretory syndromes including acromegaly and Cushing’s disease. In FA, radiotherapy is used when surgery fails to achieve hormone normalisation and/or when medical treatment does not control hormone excess. In the absence of prospective studies that clearly define the optimal radiotherapy technique in FA, it is expected that there will be variability in practice. A survey of UK neuro-oncology centres was undertaken, aiming to establish the extent of this variability in FA. METHOD A survey was distributed electronically to 20 neuro-oncology departments across the UK. Data were collected on patient numbers, radiotherapy indications, techniques, dosing, and target volume delineation. RESULTS Responses were received from eight centres (40% response rate), treating a total of approximately 32 FA per annum. There was variability in techniques employed to treat FA. While four centres treated most FA with IMRT, two treat most with stereotactic radiosurgery (SRS), and two with fractionated stereotactic radiotherapy (fSRT). The most common dose used for IMRT treatment was 45Gy in 25 fractions (n=7), with 50.4Gy in 28 fractions, 50Gy in 30 fractions and 54Gy in 30 fractions also reported. Use of margins around residual disease (n=5) and inclusion of involved cavernous sinuses and surgical tract (n=3) within clinical target volumes also varied. Most centres (n=7) would agree to a change in target volume delineation practices for the purpose of a clinical trial in FA. CONCLUSION This survey found that there is variability in radiotherapy dosing, technique, and target volume delineation practices for radiotherapy to FA across the UK. All centres but one would accept changes in their practice within the context of a prospective clinical trial of radiotherapy for FA.

Classification, angioarchitecture and treatment outcomes of medullary bridging vein-draining dural arteriovenous fistulas in the foramen magnum region: a multicenter study.

This study aimed to classify medullary bridging vein-draining dural arteriovenous fistulas (MBV-DAVFs) located around the foramen magnum (FM) according to their location and characterize their angioarchitecture and treatment outcomes. Patients with MBV-DAVFs diagnosed between January 2013 and October 2022 were included. MBV-DAVFs were classified into four groups. Jugular vein-bridging vein (JV-BV) DAVF: located in proximity to jugular fossa, Anterior condylar vein (ACV)-BV DAVF: proximity to anterior condylar canal, Marginal sinus (MS)-BV DAVF: lateral surface of FM and Suboccipital cavernous sinus (SCS)-BV DAVF: proximity to dural penetration of vertebral artery. Twenty patients were included, three JV-BV, four ACV-BV, three MS-BV and ten SCS-BV DAVFs, respectively. All groups showed male predominance. There were significant differences in main feeders between JV (jugular branch of ascending pharyngeal artery) and SCS group (C1 dural branch). Pial feeders from anterior spinal artery (ASA) or lateral spinal artery (LSA) were visualized in four SCS and one MS group. Drainage pattern did not differ between groups. Transarterial embolization (TAE) was performed in three, two, one and two cases and complete obliteration was obtained in 100%, 50%, 100% and 0% in JV, ACS, MS and SCS group, respectively. Successful interventions without major complications were finally obtained in 100%, 75%, 100%, and 40% in JV, ACS, MS and SCS group, respectively. JV-BV DAVFs were successfully treated using TAE alone. SCS-BV DAVFs were mainly fed by small C1 dural branches of vertebral artery often with pial feeders from ASA or LSA, and difficultly treated by TAE alone.

Fluorescence detection of pituitary neuroendocrine tumour during endoscopic transsphenoidal surgery using bevacizumab-800CW: a non-randomised, non-blinded, single centre feasibility and dose finding trial [DEPARTURE trial

Achieving endocrine remission by gross total resection is challenging in pituitary neuroendocrine tumours (PitNETs) with cavernous sinus invasion. This study aims to assess the safety, feasibility, and optimal dose for intraoperative fluorescence imaging as an added instrument to discriminate PitNET from surrounding tissue using bevacizumab-800CW, targeting vascular endothelial growth factor A (VEGF-A). In part I, dose-escalation (0-4∙5-10-25mg) was performed in 4 groups of 3 patients with PitNETs Knosp grade 3-4. In part II, after interim analysis, the 10mg and 25mg groups were expanded to a total of 6 patients. Quantitative fluoroscence molecular endoscopy consisted of wide field fluorescence molecular endoscopy and multi-diameter single fiber reflectance / single fiber fluorescence spectroscopy. Mean fluorescence intensity (MFI) of the fresh surgical specimen was calculated and VEGF-staining was performed. Eighteen patients were included. All doses were well tolerated. Three serious adverse events were registered, but none were tracer-related. Part I showed an adequate in-vivo tumour-to-background ratio for both 10mg (TBR 2∙00 [1∙86, 2∙19]) and 25mg (TBR 2∙10, [1∙86, 2∙58]). Part II revealed a substantially higher MFI in the 25mg group. With both 10mg and 25mg a statistically significant difference between tumour and surrounding tissue was detected (p < 0∙0001). All surgical specimens had VEGF-A expression. This study demonstrates the safety and feasibility of quantitative fluorescence molecular endoscopy during PitNET surgery. Both 10mg and 25mg bevacizumab-800CW result in clear differentiation in-vivo, with improved contrast ex-vivo (MFI) in the 25mg group. NCT04212793 / Study Details| Detection of PitNET Tissue During TSS Using Bevacizumab800CW| ClinicalTrials.gov.

A pituitary gland squeezed upward by intrasellar kissing carotid arteries: Mimicking a pituitary microadenoma

Background: Intrasellar kissing carotid arteries are a rare variant in which bilateral internal carotid arteries run very near each other at their cavernous sinus portion. We encountered a woman with the pituitary gland mimicking a pituitary microadenoma because the pituitary gland was compressed bilaterally by intrasellar kissing carotid arteries. Case Description: A 61-year-old woman with a chronic headache underwent magnetic resonance imaging, which revealed a sellar mass measuring 10.2 mm in height, 8.2 mm in length, and 4.0 mm in width at the midintercarotid level. Blood levels of all pituitary and target-organ hormones were within normal range. The height and superior convex shape of the sellar mass suggested that it was a nonfunctioning microadenoma, which was monitored over the past 16 years. A recent three-dimensional reconstruction of magnetic resonance angiography clearly showed that the pituitary gland was squeezed upward, compressed bilaterally, and extended superiorly by intrasellar kissing carotid arteries. Conclusion: The pituitary gland can be squeezed upward by intrasellar kissing carotid arteries and mimic pituitary tumor.

Retinal vascular abnormality of non-perfusion and neovascularization in a toddler with neurofibromatosis type 1.

This report describes the case of a 13-month-old boy diagnosed with neurofibromatosis type 1, who presented with retinal vascular abnormalities including extensive non-perfusion and neovascularization. We also discuss the observed changes following photocoagulation treatment. A 13-month-old boy presented to the Department of Ophthalmology at Peking University People's Hospital with a reduction in the width of the left palpebral fissure for the past 6 months. The boy exhibited more than six café-au-lait spots larger than 5 mm in diameter on his trunk and legs. Fundus examination of the left eye revealed significant neovascularization in the temporal periphery of the retina, with late leakage and non-perfusion also noted temporally in fluorescein angiography (FA). Magnetic resonance imaging of the brain and orbits showed an enlarged left sphenoid body, a widened left cavernous sinus, and a large plexiform neurofibroma. Laser treatment was performed on the left eye. Five months later, the neovascularization was controlled. Careful fundus examinations and systemic reviews, especially FA, are essential. Timely laser treatment is crucial for controlling disease progression and preventing retinal detachment.

Circumferential exposure of the cavernous sinus and parasellar region through a combined open and endoscopic endonasal transcavernous approach, a morphometric study.

Although recent trends currently favor the endoscopic endonasal transcavernous approach (EETA) over the pretemporal transcavernous approach (PTA) for certain cavernous sinus pathologies, dedicated assessment of the surgical exposure and maneuverability is wanting. Toward this aim, this morphometric study quantifies these variables within four cavernous sinus compartments by comparing the PTA, EETA, and a combined approach to achieve a circumferential dissection (EETA-PTA). In five latex-injected specimens, exposure volumes of the EETA, PTA, and circumferential EETA-PTA approaches were quantified; the latter combined the most conservative options of both the endoscopic and open approaches. Two clinical cases illustrate the combined approach. EETA-PTA provided the largest volume of exposure (65.6% vs 35% PTA vs 44.6% EETA, P = 0.01) and eliminated the need to mobilize the ICA or cross cranial nerves. Although EETA and PTA approaches afforded comparable exposure volumes along the entire cavernous sinus (34.9 vs 44.6%), the EETA better exposed medial and inferior compartments (whereas the PTA exposed larger volumes in the lateral and superior compartments. The combined EETA-PTA yielded 66% of total cavernous sinus exposure volumes and eliminated the need to mobilize the ICA or cross cranial nerves. Our methodology aligns with strategies that use a modular concept to divide the skull base into compartments for maximal safe resection. Excluding soft tumors, the EETA is preferred for medial and inferior lesions and the PTA for superior and lateral lesions. A staged combined EETA-PTA may safely yield a 360-degree access for extensive multi-compartment lesions that span neurovascular structures within the cavernous sinus.

LONG-TERM NATURAL HISTORY OF GIANT NULL CELL PITUITARY ADENOMA.

Pituitary adenomas that extend to the ventricular system are extremely rare. We present a 5-year natural history of a giant null cell pituitary adenoma with invasion into the cavernous sinus extending to the third ventricle. MRI series that were available could be useful for neurosurgeons, ophthalmologists, and endocrinologists as well as radiologists. Patients with the diagnosis of pituitary adenoma that are certain according to the radiological and clinical examination should be consulted by a neurosurgeon experienced in endoscopic endonasal surgery, a neuroendocrinologist, and an ophthalmologist. The surgery postponement in such cases results in disability and quality of life worsening. At that time, the surgery of giant pituitary adenomas demands high skills, and the risk of postoperative complications is high. The proper treatment modality including earlier surgery seems to be favorable for patient outcome.

7248 Spliceosome component TCERG1 regulates the aggressiveness of somatotroph adenoma

Abstract Disclosure: K. Kim: None. The role of the spliceosome in the development of pituitary tumors is not well understood, despite preliminary studies indicating abnormal expression of oncogenic splicing variants in these neuroendocrine tumors. We aimed to identify differentially expressed spliceosome components in growth hormone (GH)-secreting pituitary tumors and investigate their roles in pathogenesis.We performed transcriptome analysis of 20 somatotroph adenomas and 6 normal pituitary tissues to select dysregulated spliceosome components. Clinical characteristics were analyzed based on gene expression in 64 patients with acromegaly. GH secreting pituitary adenomas were confirmed by 75 g oral glucose tolerance and immunohistochemical staining. Proliferation, invasion, and hormonal activity of GH secreting pituitary adenoma cells were investigated after modulating gene expression.TCERG1 expression was significantly higher in somatotroph adenomas than in normal cells (log2 fold change 0.59, adjusted P=0.0002*). Genotype-phenotype analysis revealed that patients with higher TCERG1 expression had lower surgical remission rates than those with lower expression (63.64% vs. 95.45%, P=0.009*). TCERG1 expression was significantly higher in groups with cavernous sinus (CS) invasion or Ki67 index over 1.5 (2.06 vs. 1.65, P=0.011*; 2.02 vs. 1.66, P=0.043*). TCERG1 overexpression led to a 16.91% increase in proliferation after 72 h (P&amp;lt;0.001*) and a 249.47% increase in invasion after 48 h in GH3 cells (P=0.026*). Conversely, TCERG1 silencing significantly decreased cell proliferation (10.15% at 72 h, P&amp;lt;0.001*) and invasion (96.87% at 48 h, P=0.029*). Vimentin was increased, but E-cadherin was decreased in both TCERG1 overexpressed GH3 cells and somatotroph adenomas. And TCERG1 silence reversed the expression of the genes (CDH2, SNAI1, ZEB2, and VIM) in GH3 cells. Additionally, GH secretion increased when TCERG1 was overexpressed in GH3 cells. Spliceosome machinery provide novel insights into the pathogenesis of GH-secreting pituitary tumor and highlight the potential role of TCERG1 as a therapeutic target. Presentation: 6/2/2024

12526 Acromegaly Secondary to Sparsely Granulated Adenoma

Abstract Disclosure: D. John: None. M. Kinaan: None. J. Titus: None. K. Lamar: None. The most common pathological finding in acromegaly is a densely granulated adenoma which is composed of large round eosinophilic cells with prominent nucleoli and spherical nuclei that closely resemble a somatotroph cell. Less common finding is a sparsely granulated adenoma that is composed of sheets of poorly cohesive, pleiomorphic nuclei, chromophobic cells. We present a case of a 58-year-old gentleman presenting to our endocrine clinic for evaluation of a pituitary macroadenoma. The patient was hospitalized for nausea, vertigo, headaches, and blurring of vision. CT brain at that time showed a pituitary mass measuring 2.4 x 1.6 x 1.7 cm centered in the right cavernous sinus and inseparable from the pituitary gland. Hormonal work-up in the hospital was remarkable for high GH level. IGF-1 level was not done. Patient was advised to follow-up with neurosurgery as outpatient and no emergent surgery was planned. In the clinic, patient denied symptoms of DI, adrenal insufficiency or hypothyroidism. He has history of hypogonadotropic hypogonadism and was on testosterone therapy, but he stopped it since his hospitalization. On physical examination, he was noted to have macroglossia, deep voice, prominent jawbone, and soft tissue swelling in the hands and feet. Patient did not have any visible joint swelling. He stated he did not notice these changes personally and that he’s always been a “big guy” and always had a deep voice since he was a teenager. Repeat hormonal workup (done at 8 AM) showed: normal CMP, ACTH, cortisol, prolactin, TSH, T4, and T3. Testosterone was low with LH and FSH inappropriately within the normal reference range consistent withhypogonadotropic hypogonadism. IGF-I was elevated at 628ng/mL with a Z score of 3.9. These findings were consistent with acromegaly. He underwent surgery for tumor resection and pathology report showed that about 40% of the cells demonstrated weak immunoreactivity for GH, and rare (less than 1%) prolactin-positive cells were present within the tumor. The specimen was negative for TSH, ACTH, FH, and LH immunostains. Immunostain for CAM5.2 showed predominantly perinuclear dot-like immunoreactivity. The *MIB1 proliferation index is about 1%. The findings were consistent with a sparsely granulated gonadotrophic adenoma, which may demonstrate aggressive behavior. Postoperative MRI showed postoperative changes with residual pituitary tissue (normal gland vs. residual tumor). Postoperative cortisol &amp;gt;16. Postoperative GH dropped from 4.39 to 2.69 after 1 month. After 3 months, patient was doing well with no symptoms. However, IGF1 level (&amp;gt;400) showing that surgery was not curative. Currently he is awaiting gamma knife radiation therapy with possible medical therapy afterwards. Our case will provide an overview of the specific management considerations for these tumor and how they differ from densely-granulated tumors. Presentation: 6/3/2024

7392 Unilateral Adrenal Embolization In Cushing Disease-A Lifesaving Emergent Procedure

Abstract Disclosure: M. Sadiq: None. B. Irshad: None. A. Haider: None. Case presentation: A 59-year-old female was diagnosed with Cushing Disease (CD) thirteen years ago with symptomatic hypercortisolism. Hypokalemia and elevated 24-hour urine cortisol (392 ug/24 hr, n 0-50 ug/24 hr) were noted at the time of diagnosis. Following LDDST, morning cortisol was 30.5 ug/dl, and HDDST showed greater than 50% suppression. A pituitary macroadenoma with bilateral cavernous sinus extension was noted on MRI Sella. Due to cavernous sinus invasion, she was not considered a surgical candidate and underwent Gamma knife radiation. 24-hour urine cortisol decreased significantly (20 ug/24 hours). Two years follow-up MRI brain showed an empty Sella and AM cortisol was noted to be normal at 12.2 ug/ dl with no evidence of AI. She was lost to follow-up and reestablished almost ten years after her initial gamma knife and was symptomatic from hypercortisolism. 24-hour urine cortisol at 85.4 mcg/24 hr, abnormal salivary cortisol x 2 (0.24 and 0.20 mcg/dl n &amp;lt; 0.09 mcg/dl) confirming hypercortisolism. MRI of Sella showed recurrent adenoma with bilateral sellar masses. She was referred to Neurosurgery and was started on Ketoconazole and Paseriotide once-monthly injections. She developed new onset diastolic heart failure &amp; upper GI bleeding, requiring hospitalization. High ACTH level of 668 pg/ml (n. 6.6- 65 pg/ ml). 8 am cortisol was 107.6 ug/dl which was suppressed to 16.1 after 8 mg overnight Decadron. Repeat Gamma knife was planned but due to her decline, it was decided to do unilateral adrenal artery embolization to reduce hypercortisolism. IR-guided adrenal artery embolization of the left middle &amp; inferior adrenal arteries was performed. She required stress dosing of HC post-embolization which was tapered off while monitoring 8 am cortisol which started to rise &amp; 24-hour cortisol levels were noted to be normal (51.2 mcg/24 H) on post-embolization day eight. Gamma knife radiation treatment was performed a month later after which she was noted to have GWS and required Hydrocortisone 15/10 mg twice daily, which she has been taking to date. 24-hour urine cortisol remains normal at 11.8 mcg/24 h. Discussion: Treatment for CD is primarily surgical. Radiotherapy is a second-line alternative in tumors that are non-amenable to surgery. Radiotherapy takes time to achieve its full effect. Cushing Disease patients with significant hypercortisolism and resultant complications require urgent treatment. Unilateral Adrenalectomy is described in literature to curb the cortisol burden . Similarly Unilateral Adrenal artery embolization offers less invasive approach to treat patients considered unfit for surgery. Conclusion: Unilateral adrenal artery embolization can be considered a bridging treatment in CD to reduce cortisol burden and improve the metabolic profile following which a more definitive treatment such as repeat surgery or radiotherapy can lead to long-term remission. Presentation: 6/1/2024

7883 Atypical Presentation of Macroprolactinoma: Discordantly Low Serum Prolactin and Therapeutic Challenges

Abstract Disclosure: S. Hossain: None. M.S. Hossain: None. B. Gautam: None. S.C. Kumar: None. H. Liao: None. D.S. Rosenthal: None. Introduction: Pituitary tumors are categorized as microadenomas (&amp;lt;1 cm) and macroadenomas (&amp;gt;1 cm) with prolactinomas being one of the most common causes. The mean prevalence of prolactinomas is 10 per 100,000 in men and 30 per 100,000 in women. Serum prolactin levels corresponds to the size of the prolactinoma and any discrepancy should be treated with caution as that may indicate co-existence of pluripotent cells. We present a patient who presented with visual field defect and headaches, found to have a pituitary macroadenoma with discordantly low serum prolactin level compared to the size of adenoma, prompting a change in the treatment course. Case Presentation: A 42 year old male with no past medical history was seen as an endocrinology consult requested by neurosurgery for frequent headaches and visual problems for 1 year. Vital signs were normal, with negative orthostatic drop of blood pressure. He had prominent bitemporal hemianopsia confirmed by formal visual field testing by Ophthalmology. No galactorrhea or features suggestive of acromegaly or hyperthyroidism. He complained of erectile dysfunction but appeared to have normal male secondary sexual characteristics. MRI of brain showed a suprasellar mass measuring 3.8 x 2.6 x 2.2 cm with mass effect on the optic chiasm, hypothalamus with extension and infiltration into the right cavernous sinus. Lab results showed elevated prolactin of 1343.5 ng/ml confirmed by serial dilution, low serum testosterone level of 134 ng/dl and inappropriately normal FSH and LH. Complete blood counts, comprehensive metabolic panel, TFT, ACTH, cortisol and IGF-1 were normal. Patient was started on bromocriptine and he noticed improvement in his field of vision and acuity within one week of starting therapy. He continued to show sustained improvement in vision and resolution of his headaches at the one-month mark. MRI 2 months from starting bromocriptine showed modest reduction in size of the tumor to 2.1 x 2.3 x 2.4 cm with continued mass effect on the optic chiasm. Prolactin level decreased to 69.3 ng/ml. Therefore, although there was some improvement in visual fields, surgical resection was recommended to alleviate the mass effect on the optic chiasm. Conclusion: Our case highlights the significance of identifying discrepancies between the size of a prolactinoma and serum prolactin levels. Expected prolactin level from a prolactinoma similar in size to our case would be &amp;gt;3000 ng/ml when ours was 1343.5ng/ml. Despite undergoing treatment and lowering of prolactin levels our patient's pituitary adenoma did not significantly reduce in size after two months of treatment with bromocriptine and the mass continued to exert pressure on the optic chiasm. This suggests possible presence of pluripotent cells in addition to prolactin-producing cells within the tumor. The recommended course of action was surgical resection of the mass. Presentation: 6/1/2024

6400 An Unusual Presentation of Silent Corticotroph Pituitary Macroadenoma

Abstract Disclosure: N. Mon: None. V. Lohano: None. B. Williams: None. N. Lehman: None. R. Kulkarni: None. S.L. Mokshagundam: None. Silent Corticotroph Pituitary Adenomas (SCA) are a rare group of nonfunctioning pituitary adenomas (NFA) comprising 3-6% of all pituitary adenomas and up to 20% of corticotroph adenomas. SCA are biologically and clinically distinct from Cushing disease and NFA. SCA present with headache, visual field impairment, hypopituitarism, and pituitary apoplexy. We present a case of SCA with the initial presentation of syncope with undetectable ACTH and very low AM cortisol level.A 67 year-old-female was incidentally found to have a pituitary macroadenoma in MRI brain for syncope work up in 2017. MRI reported 1.4 x 1.2 x 1.3 cm sellar mass with suprasellar extension, minimal mass effect on the optic chiasm and no cavernous sinus invasion. Initial labs showed ACTH &amp;lt;5 (7.2-63.3 pg/mL), AM cortisol 0.8 (6-28ug/dl), Prolactin 101.1 (3.3-27 ng/mL), TSH 0.08 (0.34-5.60 uIU/mL), Free T4 0.6 (0.58-1.64 ng/dL), FSH 1.7 (2-5 mIU/mL), LH &amp;lt;0.2 (1-13 mIU/mL), IGF-1 33 ( 41-279 ng/mL). ACTH stimulation test: cortisol 0.5 ug/dl at baseline, 5.8 ug/dl at 60min. She was diagnosed with panhypopituitarism and hyperprolactinemia due to stalk effect. Hydrocortisone and Levothyroxine (LT4) were started. She underwent pituitary macroadenoma resection for optic chiasm decompression in 2017. Pathology reported pituitary neuroendocrine tumor (pitNET), but no immunostaining was done at that time. Follow up MRI in 2019 showed residual pituitary tumor. In 2023, she endorsed headaches, mood changes, fatigue and weight gain. Physical exam was unremarkable except BMI 34.75. Prolactin, Free T4, IGF-1 were normal. MRI in 2023 revealed recurrent and enlarging pituitary adenoma (1.9 x 1.4 x 1.6 cm) with suprasellar extension, abutting the optic chiasm, and left cavernous sinus invasion with internal carotid artery encasement. She underwent revision transsphenoidal resection of pituitary tumor to decompress the optic chiasm with plan for subsequent focused radiation to the cavernous sinus portion. Postoperative period was uneventful and hydrocortisone and LT4 were continued on discharge. Final pathology reported silent corticotroph lineage pitNET with low Ki67, immunostaining positive for TPIT, CAM5.2, and negative for ACTH. ACTH-negative SCA are a rare subtype and more likely to have lower ACTH levels, and multiple microcysts on MRI than ACTH-positive SCA. New WHO classification of pitNET highlights the histological typing and subtyping based on immunostaining of pituitary lineage transcription factors as the cornerstone for accurate classification. SCA are more biologically aggressive tumors with a high propensity of recurrence and resistance to conventional treatment. TPIT and ACTH immunostaining significantly improved the diagnosis of SCA and thereby close clinical follow up for early recognition and management of SCA recurrence. Absence of serum markers of recurrence makes this challenging. Presentation: 6/1/2024

7078 Diagnostic Obstacles in Thyroid-Stimulating Hormone-Secreting Pituitary Adenoma (TSH-oma): A Case Report

Abstract Disclosure: V.A. Mendpara: None. P.P. Rao: None. M.D. Lundholm: None. Background: Thyroid-stimulating hormone-secreting pituitary adenoma (TSH-oma) is a rare cause of hyperthyroidism, forming 0.5-3% of all functioning pituitary tumors and &amp;lt;1% of hyperthyroid cases. Here, TSH secretion is autonomous and unresponsive to the normal negative feedback of thyroid hormones, leading to inappropriate TSH, T4 and T3 elevation. In the absence of clinical symptoms it can be difficult to distinguish between thyroid hormone resistance (THR) and lab errors. Clinical Case: A 44-year-old Swahili-speaking female with a history of type 2 diabetes was admitted for hypoglycemia requiring insulin adjustment. In her workup, thyroid function tests were obtained, revealing normal or low TSH (0.28 mIU/L) and high free T4 levels (2.7 ng/dL). At outpatient follow-up, repeat labs showed elevated TSH, T3 and FT4 (5.22 mIU/L, 377 ng/dL and 4.7 ng/dL, respectively). She reported weight loss, occasional palpitations, and chronic insomnia but denied other symptoms. Graves' antibodies (TSI, TSHR Ab) were negative. On exam, she had a 30-40 gm, smooth, non-tender thyroid without adenopathy, and a BMI of 23 kg/m2. The initial differential diagnosis included TFT lab error, THR or TSH-oma. A FT4 by equilibrium dialysis was high at 7.8 ng/dL (1.1-2.4 ng/dL). N-telopeptide (NTX) and sex hormone-binding globulin (SHBG) were elevated, consistent with a true hyperthyroid state. Genetic testing for THR posed time and cost barriers. Elevated alpha-subunit levels (87 ng/mL, normal ≤1.8 ng/mL) with normal levels of other pituitary hormones prompted a pituitary MRI, unveiling a 4.7 cm suprasellar bilobed pituitary mass abutting the optic chiasm and invading the cavernous and sphenoidal sinuses. She denied peripheral vision loss or headaches. Hyperthyroidism was managed with methimazole until surgical intervention for the TSH-oma. A transsphenoidal resection was performed with histopathological confirmation of a TSH-staining pituitary adenoma. She was started on levothyroxine for central hypothyroidism thereafter. Discussion: It is challenging to find the cause of abnormal TFTs when patients are asymptomatic and the differential includes THR, lab errors or TSH-oma. Inaccurate diagnosis can lead to delays in care or unnecessary thyroid ablation or pituitary surgery. Conversely, early identification and appropriate treatment of TSH-omas can prevent neurological and endocrinological complications, such as optic chiasm compression, visual disturbances, headache and hypopituitarism. Despite a lack of convincing symptoms of hyperthyroidism, we used confirmatory labs (NTX, SHBG) to rule in biochemical hyperthyroidism along with alpha-subunit testing and pituitary MRI to solidify the TSH-oma diagnosis, leading to surgical intervention. This case highlights the vital steps in the diagnosis of a TSH-oma, emphasizing the need for logical evaluation and differentiation of this rare condition. Presentation: 6/1/2024

6553 Remission of Cushing’s Disease on Day 6 Post Transsphenoidal Surgery

Abstract Disclosure: M.N. Abdou: None. H. Alhumaidi: None. Background: Current recommendations for steroids replacement in the immediate post-operative (post op) period after transsphenoidal surgery (TSS) for patients with Cushing’s Disease (CD) are heterogenous and can be misleading. Monitoring daily morning cortisol for 72 hours post TSS with replacing steroids only after detecting low morning cortisol or signs of adrenal insufficiency (AI) has been mentioned in several studies. While some studies recommend either empiric steroids replacement on discharge regardless of status of remission or longer hospital stay for closer cortisol monitoring, others recommended monitoring for 3-4 days and starting steroids on discharge only if morning cortisol was &amp;lt; 415 nmol/L. Case: 60 years old female with a history of type 2 diabetes mellitus, hypertension and dyslipidemia was referred for an evaluation of a pituitary macroadenoma. She had an incidental finding of a pituitary mass measuring 25 mm on a CT brain obtained after a fall 3 months prior to her current visit. MRI pituitary gland revealed a 25x23x22 mm suprasellar mass with cavernous sinus invasion. She reported weight gain and worsening of diabetes control over the 2 years prior to her presentation. On exam, weight was 80 kg, BMI 32.5, BP 110/69, vital signs were otherwise normal. She had central obesity, facial plethora, and frontal hair thinning. Hormonal workup showed elevated 1 mg dexamethasone suppression test: 341 nmol/L (&amp;lt;55). 24h UFC was also high 233 nmol/24 hours (38-208). Morning cortisol 15.5 mcg/dl (6-18) with ACTH 228 pg/ml (7.2-63.3). Prolactin 581 mIU/L (58-418). FSH and LH were at the premenopausal range. TSH, FT4, and IGF-1 were normal. HBA1C 8%. Results were consistent with CD with central hypogonadism and mild elevation of prolactin likely due to stalk effect. Patient was admitted to the hospital for TSS. She had no surgical complications, and no steroids were used to monitor remission. Daily morning cortisol was measured after the surgery, readings were (1631, 668, 469, 224, 318, 110 nmol/l) day 1-6 (D1-D6) post op. She was started on oral Hydrocortisone (HC) 15 mg in the morning and 10 mg in the afternoon on D6 post op after documentation of cortisol level of 110 nmol/l. She was vitally stable and had no signs of AI before starting steroids. 1 day after starting oral HC she developed hypotension and hyponatremia. IV HC 100 mg was given immediately followed by 50 mg every 6 hours. Blood pressure improved with stress dose steroids. She was discharged home on HC 20 mg three times daily, tapered to reach 15, 10 over a period of 2 weeks. Conclusion: We present a case of CD that had a nadir morning cortisol on D6 post op in whom a diagnosis of fatal AI would have been missed if recommendations from some studies were followed. This case highlights the importance of prolonged monitoring for adrenal insufficiency if steroids were not used after surgery for CD. Presentation: 6/1/2024

6797 Pituitary Apoplexy as initial Presentation of IgG4-Related hypophysitis

Abstract Disclosure: M. Alameri: None. A. Alnuaimi: None. Introduction: IgG4-related hypophysitis is a rare disease due to IgG4 lymphoplasmacytic infiltration of the pituitary gland. It can either be isolated or part of a multisystemic disease. We report a rare case of pituitary apoplexy as first manifestation of IgG4-RD. Case report: A 27-year-old previously healthy male presented to emergency department with severe headache, nausea, vomiting and visual impairment. CT brain showed a large sellar suprasellar mass of 3cm with thick rim enhancement. Blood test showed evidence of central adrenal insufficiency, central hypothyroidism and secondary hypogonadism. Patient was started on hormone replacement therapy for central adrenal insufficiency and central hypothyroidism. Pituitary magnetic resonance imaging (MRI) demonstrated a 3.1 x 2.4 x 2.4 cm well-defined large sellar suprasellar mass with thick rim enhancement with intrinsic heterogeneous T2 signal with hypointense T1 signal on fat-suppressed post contrast imaging consistent with necrotic haemorrhagic suggestive of pituitary apoplexy and background of hypophysitis. Upward displacement of optic chiasm was noted without involvement of cavernous sinus. The patient was initially treated with high-dose steroids aiming for reduction of the pituitary mass. However, eventually, he underwent transsphenoidal surgery due to alternated level of consciousness. Pituitary histopathology showed that vast majority of the tissue is necrotic. A small fragment of viable anterior pituitary tissue is present, which measures up to 5.5 mm in greatest dimension which exhibited marked chronic inflammation, predominantly comprised of small lymphocytes. Plasma cells were present and staining with IgG/IgG4 revealed two high-power fields with clusters of approximately 25 and 50 IgG4 positive plasma cells, respectively. Blood test showed elevated blood IgG4 levels of &amp;gt;2.60 g/L (normal reference range 0.03-2.01 g/L). Case was discussed at Endocrine MDT meeting which agreed that blood tests result along with histopathology findings were in keeping with IgG4-Related hypophysitis as per the Mayo Clinic, Leporati and Japan-Korea proposed criteria. Because blood IgG4 levels were elevated, a systemic evaluation was performed. No evidence of other systemic disease found. High dose steroid therapy was initiated, which reduced remnant inflammatory sellar changes. Discussion and conclusion: IgG4-related pituitary disease should be considered as differential diagnosis in unusual presentations of pituitary apoplexy in the context of sellar suprasellar hypophysitis. Presentation: 6/2/2024

6619 An Unlikely Cause of Oligomenorrhea: Acromegaly Secondary to a Sparsely Granulated, Somatotroph-Lactotroph Adenoma

Abstract Disclosure: S.I. Alicea: None. Y. Wu: None. J. Marquez: None. C.S. Botero Suarez: None. M. Kinaan: None. Introduction: Acromegaly most commonly presents as a pituitary tumor that causes excessive production ofgrowth hormone (GH); and rarely due to excess of GHRH or ectopic production of GH. Approximately 15% of surgically removed pituitary adenomas represent GH-producing neoplasms, and about 5% are bihormonal, secreting both GH and prolactin (PRL). We present a case of an unexpected presentation of oligomenorrhea which ended up with the diagnosis of acromegaly secondary to plurihormonal mixed somatotroph-lactotroph sparsely granulated adenoma. Case Description A 32-year-old female with history of prediabetes was referred to our clinic by her gynecologistfor evaluation of oligomenorrhea which was initially attributed to polycystic ovarian syndrome.She reported menarche at age 10 and has experienced irregular menses and periods of amenorrhea over the years. Physical exam revealed macroglossia, a widened thickened nose, acanthosis nigricans in the neck skin folds, facial hair thickening, and significant thickening of all fingers, toes and soft tissues. Given physical exam findings, we evaluated the patient for acromegaly and lab testing revealed markedly high IGF I, mildly elevated prolactin, and hemoglobin A1C of 5.7%. An MRI of the brain with IV contrast revealed a heterogeneously enhancing pituitary macroadenoma measuring 2.9 x 2.9 x 2.2 cm with suprasellar extension resulting in mass effect on the optic chiasm without definite cavernous sinus extension. She was started on Cabergoline 0.5mg twice weekly temporarily and underwent pituitary transsphenoidal resection. Pathology results revealed tumor cells that were positive for Chromogranin and Cam5.2. About 10% of cells showed immunoreactivity for Prolactin and negative for TSH, ACTH, FSH, LH and immunostains. There was also weak focal (about 2%) immunoreactivity for GH. Occasional mitotic figures were present. The MIB-1 proliferation index was 3%. The reticulin stain demonstrates loss of acinar architecture, supporting the diagnosis. Aside from transient sodium fluctuations consistent with triphasic response, she had no long-lasting postoperative complications. One month after her surgery, her IGF I level and hemoglobin A1C are trending down and she reports symptomatic relief. She continues follow up in our clinic. Discussion This patient has acromegaly secondary to a mixed somatotroph-lactotroph sparsely granulated adenoma. Sparsely granulated adenomas are more common in younger populations, can be more aggressive, and are less responsive to somatostatin analogs. Early detection and treatment is imperative in the prevention of complications secondary to the disease. Our case will closely examine the differences in the clinical, prognostic, and pathologic features of sparsely- vs. densely granulated adenomas. We will also discuss the effects of acromegaly on gonadal function. Presentation: 6/1/2024