Posterior Pituitary Research Articles

Bilateral Correlational Behavior of Pyroglutamate Aminopeptidase I Activity in Rat Photoneuroendocrine Locations During a Standard 12:12 h Light–Dark Cycle

We previously described the circadian variation and bilateral distribution of pyroglutamate aminopeptidase I (pGluPI) activity levels in photoneuroendocrine locations of adult male rats during a standard 12:12 h light–dark cycle. However, the correlational analysis between such locations has not yet been studied. This may provide new data about the unilateral and bilateral functional interaction between photoneuroendocrine locations under light and dark conditions. We analyzed the correlations between locations of a photoneuroendocrine circuit consisting of retina, anterior hypothalamus, superior cervical ganglion, and pineal gland, as well as other related photoneuroendocrine locations: posterior hypothalamus, anterior pituitary, posterior pituitary, occipital cortex, and serum. In particular, we analyzed the correlations between the left retina or the right retina versus the rest of the locations, as well as the correlations between the left and right sides of paired structures at the different time points selected from 12 h light and 12 h dark periods. Also, the profiles of correlational results were compared with the corresponding mean levels. The results demonstrate the complexity of asymmetrical brain behavior. The correlation profile did not always parallel the profile observed with the mean activity values. The diurnal behavior of correlations with the left or right retina differed from one location to another. Likewise, the diurnal variation of correlations between the left and right sides of the paired structures differed between them. Particularly, while most correlations between the left versus right sides of paired structures showed positive values, that of the posterior hypothalamus showed a negative value at 13 h of light period. In addition, except the posterior hypothalamus, most paired locations only correlated significantly with right retina at 07 h of the light period. The results demonstrate the dynamic complexity of brain asymmetry, which represents a challenge for understanding its functional meaning.

Real-time intraoperative ultrasound imaging of the posterior pituitary gland during endoscopic endonasal approach.

Pituitary adenomas are amongst the most common benign central nervous system tumors, and often require resection via an endoscopic endonasal approach (EEA). Two of the most common associated complications are central diabetes insipidus (DI) and syndrome of inappropriate antidiuretic hormone secretion (SIADH). Both are thought to be caused by manipulation of the posterior pituitary gland (PPG), making intraoperative visualization and preservation of this structure critical. Intraoperative endoscopic endonasal ultrasound (IEUS) may present an optimal tool for this purpose. This study aims to describe the appearance and morphology of the PPG on IEUS. This study included all pituitary adenoma surgeries during which IEUS was utilized and the PPG was visualized between 1/1/2022, and 12/31/2023. Demographic, clinical, pathological, and radiological data were retrospectively collected. The PPG was described as either hypoechoic, isoechoic, or hyperechoic as compared to the anterior pituitary gland and adenoma, and the morphology of the PPG was further classified as ellipse or crescent shaped. The PPG was hypoechoic in all 43 cases included in our final cohort (100.0%). Morphologically, the PPG appeared elliptical in 27 cases (62.8%), and crescent shaped in 16 cases (37.2%). The PPG can typically be visualized by IEUS as a hypoechoic structure immediately anterior to the posterior wall of the sella turcica, with elliptical morphology being the most common appearance. These characteristics can be used by the skull base surgeon to more confidently identify the position and morphology of the PPG intraoperatively for its' preservation.

Arginine vasopressin deficiency (central diabetes insipidus) with partial empty sella: a case report

BackgroundArginine vasopressin deficiency (central diabetes insipidus) is defined as a reduction in the release of arginine vasopressin (AVP) resulting in a variable degree of polyuria. Partial empty sella refers to an enlarged sella turcica that is not completely filled by pituitary gland. It can be either primary or secondary and its manifestation ranges from asymptomatic cases to isolated posterior pituitary, isolated anterior pituitary or both anterior and posterior pituitary dysfunctions. Diabetes insipidus caused by a partially empty sella is rare.Case presentationThe patient, an 18-year-old Ethiopian woman who presented with long standing headache, increased urination, increased thirst, absence of menses and weight loss. Urine and serum osmolality was done and suggested diabetes insipidus. On further workup, brain magnetic resonant imaging was done and partially empty sella was diagnosed.ConclusionDiabetes insipidus secondary to partially empty sella is uncommon. In patients presenting with headache and anterior or posterior pituitary dysfunction, empty sella should be considered, whether partial or complete.

8431 Triphasic response of pituitary stalk post anoxic injury in a mechanically ventilated patient

Abstract Disclosure: P. Henriquez Feliz: None. H. Neizer: None. E. Alshdifat: None. F. Abdulkarim: None. T. Mazhude: None. T. Zahra: None. Introduction: A phenomenon may manifest wherein the pituitary undergoes a triphasic response following an inciting event. Phases include diabetes insipidus (DI) followed by Syndrome of inappropriate Antidiuretic Hormone (ADH), and finally a recurrence of DI. Research has established that this is a common complication to neurosurgical interventions but there are limited reports following anoxic brain injury. This case demonstrates a potential pituitary stalk injury after an anoxic brain injury. Case: Unknown 30 year old male found by EMS with pulseless electrical activity cardiac arrest likely from polysubstance use. Returned of spontaneous circulation after 30 minutes in the emergency department. Total downtime unknown. Managed by Intensive Care Unit. Scans were negative. Initial blood work showed eunatremia with a specific gravity (sg) 1.068 and serum osmolarity (Sosm) 311. Eventually, developed hypernatremia, 163 mmol/L, and a urine osmolarity (Uosm) of 428 mosm, raising concern for central DI (CDI). Responded to hypotonic fluids not requiring desmopressin at that time. On day 10, developed severe hyponatremia 113 mmol/L with a Uosm of 774, suggesting ADH mediated response or excessive free water intake. Sodium normalized after managed with fluid restriction. On day 16, patient developed hypernatremia, 178 mmol/L, and Uosm of 869 mosm. Suggestive of CDI recurrence. Treated with desmopressin and hydrocortisone. Discussion: Changes in water-electrolyte balances may occur after anoxic brain injury. The mechanism is believed to arise from axonal shock due to disruptions in vascular supply leading to unregulated release of ADH from degenerating posterior pituitary, causing oliguria and hyponatremia, and subsequent permanent DI from loss of neurons. These stages may last 5-7 days on initial phase, and the second phase can extend anywhere from 2-14 days. In this case, phases one and two lasted four and three days, respectively. It is important to acknowledge that timelines may vary based on management initiation and recognition of transition between stages. CDI treatment involves hypotonic fluids with desmopressin. Our patient was initially managed with free water due to low suspicion for CDI. During shift towards suspected second phase, Uosm increased, urine output and sodium dropped significantly. However, it is uncertain whether this was due to axonal injury causing SIADH or a consequence of hypotonic fluids causing increased response of ADH. As predicted during triphasic response, patient became oliguric with a net negative fluid balance of >10L and Uosm of 869. Therefore, desmopressin was started with good response. Further follow up was unattainable as neurological status deteriorated preceding to brain death. Most cases reported showed hypoattenuation lesion of posterior pituitary on MRI; MRI would have been required to determine if there was injury to the pituitary in this case. Presentation: 6/2/2024

12227 The Battle Between Central And Nephrogenic Diabetes Insipidus

Abstract Disclosure: A.A. Luzuriaga Chavez: None. J.P. Hidalgo: None. A. Rao: None. N. Patel: None. Diabetes insipidus (DI) is a rare disorder characterized by excessive polyuria and polydipsia. The two main types include central diabetes insipidus (CDI), which results from antidiuretic hormone (ADH) deficiency and nephrogenic diabetes insipidus (NDI), defined by ADH resistance in the renal tubules. It can be challenging to distinguish between different types of DI in a critically ill patient. A 68-year-old female with a past medical history of hypertension, bipolar disorder came to the ER for complaints of chills and shortness of breath. She was transferred to the intensive care unit (ICU) for septic shock secondary to pneumonia and left pleural effusion. A chest tube was placed with improvement in her breathing and she was transferred out of the ICU. Four days later, the patient developed altered mental status, fevers and ICU was reconsulted due to concern for meningitis. A lumbar puncture was done with negative results but the brain MRI revealed ischemic sites involving both medial parietal cortices extending into both occipital poles, consistent with acute ischemia. Furthermore, the patient developed an increased urine output of 200ml per hour with a negative balance of 2.7L, increased sodium of 150, serum osmolality of 313 and urine osmolality of 196. The patient received desmopressin 1 mcg q 6 hrs with the persistence of hypernatremia. Upon further questioning, the patient had been on lithium therapy in the past for bipolar disorder. Amiloride 2.5mg BID was added to the treatment regimen. The patient’s hypernatremia and urine output improved and she was discharged on both amiloride and desmopressin to follow up for dose adjustments as needed. DI has a prevalence of 1 in 25000. Acquired CDI secondary to lesions in the hypophysis or hypothalamus highlights the major role of the central nervous system in regulating water homeostasis. This case report describes CDI developing after a stroke. Ischemia can cause hypoperfusion of osmoreceptors in the hypothalamus and posterior pituitary. Lithium can be frequently associated with NDI, usually seen in 20 to 40% of patients. Different mechanisms of action include lithium interference in renal collecting tubules by increasing cAMP in response to ADH and down-regulation of aquaporin-2 expression, which is accepted to be reversible with the cessation of the therapy. However, long-term treatment with lithium likely results in permanent NDI. Our patient had a history of lithium therapy which contributed to the development of symptoms of NDI and responded to a combination of desmopressin and amiloride. The successful therapy enforces the diagnosis of both a central and a peripheral pathology. Central and nephrogenic DI, despite stemming from distinct underlying causes, may concurrently manifest in critically ill patients. This case report emphasizes the need for physicians to evaluate for multiple causes of DI in a patient with water disturbances. Presentation: 6/1/2024

8380 Pituitary Stalk Interruption Syndrome, A Rare Cause of Panhypopituitarism

Abstract Disclosure: F. Abdulkarim: None. E. Alshdifat: None. P. Henriquez Feliz: None. J. Vargas-Jerez: None. T. Zahra: None. Pituitary Stalk Interruption Syndrome, A Rare Cause of Panhypopituitarism Faridat Abdulkarim, MD. Esra’a Alshdifat, MD. Pamela Henriquez Feliz, MD. Julia Vargas- Jerez, MD. and Tasneem Zahra, MD. Introduction: Pituitary stalk interruption syndrome (PSIS) is a rare congenital pituitary anatomical abnormality with reported incidence of 0.5 per 100,000 live births. It is characterized by the triad of thin or interrupted pituitary stalk, absent or ectopic posterior lobe and hypoplastic or aplastic anterior lobe seen on MRI. The anterior pituitary function is usually impaired however the posterior pituitary is usually intact and normal. We report a case of a Now 34-year-old Female who presented to the endocrine clinic with underdeveloped sexual characteristics. MRI done was consistent with PSIS. This is the second case of PSIS we report from our Institution. Case Presentation: A Now 34-year -old Hispanic American Female presented to our endocrine clinic with underdeveloped secondary sexual characteristics. She had panhypopituitarism, including Growth hormone deficiency and was treated with growth hormone from early childhood until age 13-14 years. She re-presented to our clinic at the age of 28 years after being lost to follow up for many years. On physical examination, she was 175cm tall, weighed 89.4kg and BMI 29.1kg/m2Patient has pre-pubertal breast, tanner stage 1, no axillary hair, small external genitalia with scanty pubic hair. Hormonal analysis revealed Estradiol <5 pg/mL (low), FSH 0.4 IU/L (low), LH <0.3 IU/L (low), Progesterone 0.1ng/mL (Low), Testosterone <2.5 ng/dL (8.4- 48.1ng/dl) Prolactin 22.3ng/mL (3.4-24.1 ng/ml), TSH 0.88uIU/mL (0.27-4.20), Free T4 0.5ng/dl (0.9-1.8) , ACTH 7.7pg/mL (7.2-63.3), Baseline AM Cortisol 0.7ug/dL (6.0-18.4) and 5.5 ug/dL after Cosyntropin test, IGF-1 17ng/mL (83-280). Urinalysis revealed normal specific gravity. Chromosome analysis with Normal Karyotype 46XX. Pelvic US revealed Markedly diminutive uterus and ovaries. MRI of the pituitary was highly suggestive of PSIS. She is currently being treated with levothyroxine and hydrocortisone Conclusion: PSIS is a rare congenital abnormality. Fortunately has good prognosis, however if left undiagnosed/untreated has high mortality mainly from Adrenal insufficiency and Myxedema coma. The patient discussed above, has underdeveloped sexual characteristics and primary amenorrheaLaboratory finding consistent with Panhypopituitarism with Normal prolactin which is the case in most patient with PSIS. Imaging revealed atrophic uterus and ovaries, and MRI revealed Findings which are highly suggestive of PSISShe previously had problems with outpatient clinic visits and medication compliance. However, she is currently compliant with hormonal replacement therapy which is the mainstay of treatment. Presentation: 6/3/2024

6379 Clonidin does not stimulate copeptin release

Abstract Disclosure: G. Binder: None. K. Weber: None. A. Peter: None. R. Schweizer: None. Background: Copeptin is secreted in isomolar amounts along with arginine vasopressin peptide from the posterior pituitary. Its stability makes it a perfect candidate for a biomarker of AVP deficiency. In children, the infusion of arginine and bolus of insulin stimulate copeptin; the respective stimulation test could be an alternative to the water deprivation test. Here, we retrospectively studied the effect of clonidine on copeptin release. Design and patients: This is a monocentric retrospective analysis of donated residual serum samples from 42 children with suspected of GH deficiency who underwent clonidine stimulation between 2020 and 2023. Measurements: Copeptin was measured in baseline, 30-, 60-, 90- and 120-min samples by BRAHMS Copeptin proAVP Kryptor immunofluorescence assay. GH was measured using an in-house RIA calibrated against the WHO International Reference Preparation 98/574. Results: According to the test results (clonidine and arginine test), there were 20 patients with GHD and 16 without GHD. No patient had polyuria-polydipsia syndrome. Median age was 6.7 years (quartiles; 5.6-7.8), the median height was -2.92 SDS (-3.42- -2.34), and the median BMI was-0.29 SDS (-1,32 - +0,16). The median baseline level of copeptin was 5,6 pmol/l (3.4-9.6). Median copeptin mildly decreased to 4.5 pmol/l (3.0-10.0) after 30 min; this change was not significant (P=0.45). Thereafter, median values remained low at 4.6, 4.6 and 4.6 pmol/l (60, 90 and 120 min). There was no correlation between baseline copeptin levels and the diagnosis of GHD. Conclusion: The clonidine stimulation test does not stimulate copeptin release and is therefore not suitable for the assessment of AVP deficiency in children. Presentation: 6/2/2024

8129 A Case of Pituitary Stalk Interruption Syndrome Presenting With Panhypopituitarism

Abstract Disclosure: A. Salvat: None. M. Sevilla: None. Background: Pituitary stalk interruption syndrome (PSIS) is a rare congenital abnormality characterized by the classic triad of a thinned or interrupted pituitary stalk, an ectopic or absent neurohypophysis, and a hypoplastic or absent anterior pituitary gland. Clinical manifestations vary and can include neonatal hypoglycemia, short stature, cryptorchidism, and delayed puberty. Symptoms can present at birth or later in life with variable degrees of hormone deficiency. Clinical case: A 25-year-old male with hypothyroidism (on levothyroxine since age 13) presented for evaluation of hypogonadotropic hypogonadism. At birth, he was diagnosed with bilateral cryptorchidism and had frequent hypoglycemic episodes. During his childhood and early teenage years, his growth paralleled of his peers. However, at age 18, he experienced a growth spurt with unusually long arms and legs. He never developed secondary sexual characteristics. Physical examination showed blood pressure of 109/62 mmHg, height 193 cm, weight 76 kg, Tanner stage 1 pubic hair, microphallus, and nonpalpable testicles. The initial labs were consistent with panhypopituitarism: FSH 0.14 mIU/mL (0.95–11.95 mIU/mL), luteinizing hormone <0.09 mIU/mL (0.57–12.07 mIU/mL), total testosterone <4 ng/dL (240–871 ng/dL), prolactin 30.31 ng/dL (3.46–19.40 ng/dL), AM cortisol <1 ug/dL (3.7–19.4 ug/dL), ACTH 14 pg/mL (6–50 pg/mL ), cortisol levels 60 minutes after consyntropin stimulation test of 3.6 ug/dL (3.7–19.4 ug/dL), IFG-1 <16 ng/mL (63–373 ng/mL), TSH 7.24 uIU/mL (0.35–4.94 uIU/mL), free T4 0.53 ng/dL (0.70–1.48 ng/dL). Karyotype 46, XY, inv (9) (p12q13). The whole exome sequencing testing was negative. Pituitary magnetic resonance imaging showed hypoplasia of the anterior pituitary gland, ectopic location of the posterior pituitary gland at the expected base of the pituitary infundibulum anterior to the mammary bodies, and hypoplastic or absent pituitary infundibulum, findings suggestive of pituitary stalk interruption syndrome. Scrotal ultrasound showed no testicular or epididymal tissue within the scrotum. DEXA scan showed osteoporosis associated with a long history of non-treated testosterone deficiency. The levothyroxine was adjusted, and the patient was started on intramuscular testosterone, calcium, and vitamin D to manage the hypogonadism and improve the bone mineral density. Conclusion: Diagnosis of PSIS is often delayed due to its variable presentation and age of onset. Although this condition is considered rare, it should be in the differential diagnosis of patients presenting with panhypopituitarism. Early identification of deficient hormones, as well as prompt initialization of hormone replacement therapy, is essential to prevent serious complications associated with these deficiencies, such as adrenal crisis, osteoporosis, diminished quality of life, delayed puberty, and infertility. Presentation: 6/3/2024

6469 Supplement Misadventures: A Case Of Acute Heart Failure, Cardiogenic Shock, And Hormonal Dysregulation Secondary To Surreptitious Use Of Multiple Hormonal Supplements

Abstract Disclosure: K.N. Grennan: None. S. Thota-Kammili: None. A.L. McKenna: None. C.G. Coyle: None. S.L. Samson: None. Introduction: Supplement misuse in the bodybuilding community is prevalent. With the availability of internet ordering and purchasing, patients have access to hormonal supplements without prescription or regulation. Here we present the case of a patient on self-administered hormonal supplements who presented in acute heart failure leading to cardiogenic shock in the setting of concurrent thyroid, adrenal, and gonadal axis dysfunction. Case Description: A 28-year-old male with no significant medical history was transferred to our hospital after presenting to an outside emergency room with dyspnea, cough, nausea, and a subjective fever. He developed acute hypoxic respiratory failure requiring intubation. Echocardiogram performed showed an ejection fraction (EF) of 10%. He was started on two vasopressors and methylprednisolone 1 g daily for two days, due to concern for myocarditis versus giant cell arteritis. Hormonal work-up showed TSH 0.02 mIU/L (normal range 0.3-4.2), free T4 0.4 ng/dL (0.9-1.7), total T3 48 ng/dL (80-200), FSH <0.3 IU/L (1.2-15.8), LH <0.2 IU/L (1.3-9.6), ACTH <5.0 pg/mL (7.2-63), cortisol 1.7 mcg/dL (2.5-12), estradiol 171 pg/mL (8.0-35), total testosterone 1730 ng/dL (240-950), and prolactin 47 ng/mL (4.0-15.2). He received 10 mg dexamethasone at the outside facility. A medication bag found by his family included online purchases of non-prescribed testosterone cypionate and enanthate, liothyronine, anastrozole, and clomiphene. None were medical grade. He was also taking the anabolic steroid clenbuterol for 3 days prior. Echocardiogram on day 3 of admission showed an improved EF of 36%. Cardiac magnetic resonance imaging (MRI) showed a papillary fibroelastoma and myocarditis. Patient was weaned off vasopressors and the ventilator. He was discharged on levothyroxine 50 mcg daily and hydrocortisone 10 mg twice daily for outpatient reassessment. Transesophageal echocardiogram confirmed diagnosis of papillary fibroelastoma. One month Endocrinology clinic follow-up showed no evidence of posterior pituitary, thyroid, or adrenal axis dysfunction or growth hormone excess, but he continued to have gonadal axis suppression with elevated prolactin and estradiol, the latter thought to be secondary to conversion from testosterone. Pituitary MRI showed no micro or macroadenoma. His EF recovered to 50%. He is pending surgical removal of the aortic valve fibroelastoma. Discussion: With hormonal supplements easily accessible online, it is important for physicians to counsel patients about the dangers of misuse. This case highlights a previously healthy 28-year-old man who presented in critical condition with cardiogenic shock and hypothalamic-pituitary axis dysfunction from supplements he purchased online. There should be targeted educational interventions regarding the harm of supplements aimed at the bodybuilding community to prevent similar cases. Presentation: 6/2/2024

7422 Adipsic Diabetes Insipidus Following Pituitary Macroadenoma Resection

Abstract Disclosure: J. Chippior: None. L. Ghalib: None. A 44 year-old female with a PMH of primary hypothyroidism, and a pituitary macroadenoma that was lost to follow up, presented to the ED with a chief complaint of an acute headache and decreased visual acuity involving the right eye over the past year. Patient was found to have a large, homogenous suprasellar mass with the largest dimension measuring 6.3 cm in size, and causing displacement of the optic chiasm. Initial hormonal workup was most notable for elevated prolactin at 128 ng/ml (3.3-26.7 ng/ml), which was slightly lower than when it was previously measured 10 years ago. The patient was taken to the OR for transsphenoidal endoscopic partial resection, but within 24 hours of post-op, she developed hypernatremia at 153 mmol/dL (135-145 mmol/dL) that was suspected to be secondary to diabetes insipidus (DI). In addition, she also suffered several small strokes involving her right midbrain and basal ganglia. She required multiple doses of DDAVP throughout her stay and this was ultimately continued upon discharge. Unfortunately, as follow up MRI had shown residual tumor within the third ventricle, she returned for a 2nd resection but once again suffered additional post-operative complications. The patient experienced additional strokes involving the right frontal and parietal lobes, and her DI became more labile than before, with her serum sodium peaking at 172 mmol/dL. Despite such a high degree of hypernatremia, she did not demonstrate any signs of thirst or any desire to access free water, even after her post-stroke encephalopathy had largely resolved. With less than 100 severe cases documented over the past four decades, it was suspected that the patient had a rare form of DI known as “adipsic DI”. Osmoreceptors within the hypothalamus can trigger the release of ADH or stimulate thirst, with the former requiring a smaller change in serum osmolality to generate such a response. Pituitary surgery involves manipulation of the infundibulum and any inadvertent severing can prevent ADH’s ability to travel from the hypothalamus to the posterior pituitary, subsequently leading to DI. The majority of patients with post-op DI increase their free water intake and subsequently do not develop hypernatremia. Those with adipsic DI lack this compensatory mechanism which leads to the electrolyte disturbance, and carries a higher risk of morbidity and mortality than those with typical DI. Following her second surgery, our patient was discharged with DDAVP once again but this time with a higher dose and frequency. She’s had numerous hospital readmissions since then for altered mental status in the setting of hypernatremia as she still struggles to meet her free water intake and continuously relies on her family for reminders. Though her case is certainly not typical, it highlights the added complexity of managing adipsic DI as it relies not only on DDAVP replacement, but replicating what is supposed to be an innate behavior. Presentation: 6/3/2024

8138 Pituitary Stalk Interruption Syndrome (PSIS) in a patient with Isolated Hypogonadotropic Hypogonadism

Abstract Disclosure: A. Thomson: None. R. Osman: None. Pituitary Stalk Interruption Syndrome in a Patient with Isolated Hypogonadotropic Hypogonadism Pituitary Stalk Interruption syndrome (PSIS) is a rare cause of hypopituitarism, characterized by a radiologic constellation of thin or interrupted pituitary stalk, hypoplasia, or aplasia of the anterior lobe and with the presence of an ectopic posterior pituitary (EPP). It is most commonly associated with isolated growth hormone deficiency (IGHD) and is often diagnosed in childhood. We present one case of a patient with isolated hypogonadotropic hypogonadism in adulthood, subsequently found to have an PSIS on MRI. A 45 year old male patient presented to our clinic with hypogonadism. He gradually started developing decreasing libido, fatigue, and loss of erections. He had normal puberty and childhood growth, and has fathered one child. He denied history of anosmia or visual symptoms. Subsequent hormonal testing showed: morning Total Testosterone: 145 ng/dl (normal 264-916 ng/dl), Free testosterone 1.5 pg/ml (normal 6.8-21.5 pg/ml), LH 1.1 mIU/ml (normal 1.7-8.6 mIU/ml) and FSH of 3.6 mIU/ml (normal 1.5-12.4 mIU/ml). Prolactin was minimally elevated at 21 ng/ml (normal 4.0 - 15.2 ng/ml). Thyroid, IGF-1, cortisol, and ferritin levels were within normal limits. Repeat levels showed similar findings. He denied ever taking any form of exogenous testosterone. His pituitary MRI revealed a small volume of anterior pituitary tissue, measuring 0.2cm x 0.7cm x 0.7cm, without discrete pituitary adenoma, a hypoplastic midline stalk measuring 1.3 mm in AP diameter (nl 2-3 mm), with a T1 hyperintense nodularity measuring 0.6cm x 0.4cm along the posterior aspect of the sella turcica consistent with EPP. No additional structural abnormality or any mass lesions were identified. He was subsequently started on replacement testosterone therapy and his symptoms resolved. PSIS usually presents in childhood with IGHD. Patients may have other pituitary hormone deficiencies and congenital central nervous system defects, although panhypopituitarism is rare. There have been reports in children with delayed puberty and isolated hypogonadotropic hypogonadism who have been found to have PSIS. Only one othercase of an adult female patient exhibiting hypogonadotropic hypogonadism as the only manifestation of PSIS has been documented in the literature. Our case highlights the potential for an adult male to present later in life with hypogonadotropic hypogonadism as a manifestation of PSIS. The marginally elevated prolactin level may be due to lack of inhibition of hypothalamic dopamine on lactotroph cells within the pituitary caused by the EPP, although it is doubtful that this has clinical significance. This is a rare presentation of PSIS, clinicians should be mindful ofthis radiological constellation and the potential for isolated hypogonadotropic hypogonadism presenting unusually in the adulthood. Presentation: 6/3/2024

Posterior pituitary tumors and other rare entities involving the pituitary gland.

Non-neuroendocrine tumors account for around 10% of all primary neoplasms of the sella. If meningiomas, craniopharyngiomas, and germ cell tumors are excluded, the remaining lesions include a broad spectrum of uncommon, benign, and aggressive, often diagnostically challenging lesions. This review aims to summarize the essential clinicopathological features of tumors of the posterior pituitary gland, infundibulum spectrum expressing thyroid transcription factor 1, and primary sellar atypical rhabdoid teratoid tumor, and provide the criteria for their diagnosis and management.

Estrogen-dependent oxytocin expression in the hypothalamus and estrogen-dependent vasopressin in the median eminence.

The posterior pituitary (PP) hormones oxytocin (OXT) and arginine vasopressin (AVP) are synthesized within the hypothalamic nucleus and released from the PP into systemic circulation. Hypothalamic AVP projects its axons into the external layer of median eminence (eME) and regulates anterior pituitary hormone secretion during stress responses. Although similar as PP hormones, we demonstrate distinct regulatory roles of estrogen in hypothalamic OXT and AVP dynamics. OXT dynamics in the hypothalamus exhibit sex-dependent variations and that estrogen may influence dynamic OXT level changes, as observed in OXT-mRFP1 transgenic rats. Estrogen was also observed to modulate dynamic changes in AVP levels in the axon terminals of eME in female AVP-eGFP transgenic rats. Although OXT and AVP are produced within the similar hypothalamic region, both exhibit distinct dynamics within the hypothalamus. Estrogen acts on the hypothalamus, and further effects of estrogen replacement therapy can be expected.

A New Biomarker Copeptin in Determining Disease Severity in COVID-19.

Copeptin is released from the posterior pituitary gland into systemic circulation in response to various stimuli, including stress. We aimed to evaluate the role of copeptin in determining the severity of the disease in patients with COVID-19. The study was conducted prospectively in two centers between June 1, 2022, and October 1, 2022. Severe and mild-moderate COVID-19 patients were compared in terms of clinical, laboratory and imaging findings, and serum copeptin levels at hospitalization. A total of 90 patients were included in the study; 45 patients were in severe disease groups. Dyspnea, loss of appetite, and loss of smell were significantly more common in the severe disease group (p<0.001, p=0.025, and p<0.001, respectively). Among the tomography findings, the consolidation frequency was similar in both groups (p=0.259). C-reactive protein (CRP), D-dimer, ferritin, lactate dehydrogenase (LDH), procalcitonin, troponin and copeptin levels were higher in the severe group (p<0.05); hemoglobin, total protein and vitamin D levels were lower (p=0.05). The area under the curve (AUC) values for severe disease were 0.643 for copeptin (p=0.019), 0.656 for CRP (p=0.011), 0.684 for procalcitonin (p=0.004), 0.657 for ferritin (p=0.01), 0.72 for D-dimer (p=0), 0.688 for troponin (p=0.002), and 0.672 for age (p=0.005). In our study, copeptin was identified as a new prognostic biomarker indicating the severity of the disease in patients with COVID-19.

New diagnostic criterion for a 3% hypertonic saline infusion test for the differential diagnosis of diabetes insipidus and primary polydipsia

AIM: To determine the value of urine osmolality when conducting a test with 3% hypertonic sodium chloride solution, which allows for the differential diagnosis of diabetes insipidus (DI) and primary polydipsia (PP).METHODS: An interventional cross-sectional study was conducted at the (Endocrinology Research Center. The study included 90 patients with polyuria-polydipsia syndrome from September 2021 to September 2023. All patients underwent sequential two tests with osmotic stimulation: 3% hypertonic saline infusion test and a water deprivation test. The final diagnosis was established based on the results of a fluid deprivation test, the patient’s anamnestic data (previous operations, diseases of the hypothalamic-pituitary region, the presence of mental illnesses), MRI data (the presence of a hyperintense signal from the posterior pituitary on T1-weighted images, a detected tumor or infiltrative formation of the hypothalamic-pituitary area, presence of Rathke’s pouch cyst).RESULTS: 48 patients with a final diagnosis of DI and 42 with a final diagnosis of PP were analysed. A cut-off point for urine osmolality during infusion test with 3% hypertonic saline was found: values less than or equal to 377 mOsm/kg support the diagnosis of DI, and values higher than 377 mOsm/kg support the diagnosis of PP. The sensitivity of the criterion is 89%, 95% CI (77%; 97%), specificity — 98% (87%; 100%), PPV — 98% (88%; 100%), NPV — 89% (76%; 96%), accuracy 93% (86%; 98%).CONCLUSION: The proposed criterion for differential diagnosis has comparable diagnostic accuracy in relation to the differential diagnosis of DI and PP, while the safety of the test may be higher.

Expression of the apelin system in the porcine pituitary during the oestrous cycle and early pregnancy and the effect of apelin on LH and FSH secretion

Reproductive success requires considerable energy investment. Research has shown that some adipokines, i.e. the hormones produced in adipose tissue, affect reproductive functions by influencing all structures of the hypothalamic-pituitary-ovarian axis. Apelin is a recently identified member of the adipokine family. To the best of the authors' knowledge, this is the first study to investigate the gene and protein expression of the apelin system (the apelin hormone and the apelin receptor, APJ) in the anterior (AP) and posterior (PP) pituitary lobes of the domestic pig during different phases of the oestrous cycle (days 2 to 3, 10 to 12, 14 to 16, and 17 to 19) and in early pregnancy (days 10 to 11, 12 to 13, 15 to 16, and 27 to 28). It was also assumed that apelin participates in the regulation of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) secretion and influences Akt, MAPK/Erk1/2, and AMPK signalling pathways in the AP during the oestrous cycle. Apelin, APJ mRNAs and proteins were detected in both pituitary lobes. Apelin was identified in gonadotropes, somatotropes, lactotropes, and thyrotropes. The study also revealed that apelin and APJ mRNA/protein levels fluctuate during the oestrous cycle and early gestation. Apelin affects basal, GnRH- and/or insulin-stimulated gonadotropin secretion in some phases of the cycle, as well as the phosphorylation of Akt, MAPK/Erk1/2, and AMPK proteins in AP cells. These findings suggest that apelin may be produced locally in the pituitary and that this gland is receptive to apelin's action. The study also suggest that apelin may influence female reproductive functions by controlling the release of LH and FSH from AP cells, and that it affects Akt, MAPK/Erk1/2, and AMPK signalling pathways.

Hypophisitis in pregnant women with persistent diabetes insipidus in the outcome

Autoimmune/lymphocytic hypophysitis is one of the rare causes of central diabetes insipidus in adults and is most common among women in the second or third trimester of pregnancy. Numerous studies have shown that lymphocytic hypophysitis is characterized by a very variable clinical signs with the development of neurological symptoms, visual disturbances and hypopituitarism with partial or complete loss of pituitary function, as well as a number of features in magnetic resonance imaging (MRI). Isolated lymphocytic indibuloneurohypophysitis occurs in fewer cases and involves the posterior lobe and stalk of the pituitary gland with a clinical presentation of diabetes insipidus. The above clinical case describes the development of hypophysitis in a pregnant woman with a predominant lesion of the posterior pituitary gland and an outcome in diabetes insipidus, which persists 6 years after pregnancy and childbirth. In the article some aspects of the differential diagnosis of diabetes insipidus in pregnant women, as well as instrumental diagnosis and treatment approaches of hypophysitis are discussed.

Stimulation Therapy to Induce Mothers: Protocol for a Multicenter Randomized Controlled Trial.

More than 1 million women have their labor induced in the United States each year, and synthetic oxytocin infusion is the most common method used. However, compared to spontaneous labor, medical induction is resource intensive, has increased obstetric risks, and is associated with less successful breastfeeding. In contrast to the endogenous oxytocin hormone, which is released in a pulsatile fashion in the brain, synthetic oxytocin is continuously infused intravenously, resulting in important limitations related to efficacy, safety, and cost. Akin to spontaneous labor contractions, infant suckling of the breast nipple is known to stimulate the pulsatile release of endogenous oxytocin from the posterior pituitary gland. Nipple stimulation therapy via an electric breast pump similarly stimulates endogenous oxytocin release and may be a favorable inpatient method for patients undergoing labor induction. This study aims to examine whether inpatient nipple stimulation therapy is an efficacious labor induction method that increases the likelihood of spontaneous vaginal delivery and sustained breastfeeding and determine whether it is a cost-effective approach. This is a multicenter, pragmatic, open-label, parallel-group randomized controlled trial of nulliparous patients with singleton gestations ≥36 weeks undergoing labor induction. This trial compares inpatient nipple stimulation therapy via an electric breast pump versus immediate synthetic oxytocin infusion without nipple stimulation. This trial including 988 nulliparas will provide adequate statistical power to detect clinically meaningful differences in delivery mode and breast milk as the sole source of nutrition for newborns at hospital discharge or 72 hours after birth. The project received pilot funding in 2021 and full funding in 2023. Enrollment for this study began in November 2021 at a single site, and as of May 2024, recruitment is underway at 3 study sites. It is anticipated that enrollment will be completed by late 2026. Successful completion of this trial will provide rigorous data to determine whether inpatient nipple stimulation therapy with an electric breast pump can improve the way we induce labor and positively impact breastfeeding success and early infant nutrition through lactation. ClinicalTrials.gov NCT05079841; https://clinicaltrials.gov/study/NCT05079841. DERR1-10.2196/63463.

Circadian copeptin and oxytocin profiles in anorexia nervosa: Exploring the interplay with neurohypophysis opioid tone.

Neurohypophysis (NH) function in eating disorders (ED) remains poorly elucidated. Studies on vasopressin and oxytocin display inconclusive findings regarding their levels and associations with psychological complications in ED. The profile of opioid tone, a crucial NH activity regulator, is also unknown. To characterise the circadian profile of NH hormones and NH opioid tone using positron emission tomography/MRI (PET/MRI) imaging in patients with ED compared to healthy controls. Twelve-point plasma circadian profiles of copeptin and oxytocin, alongside nutritional and psychological scores, were assessed in age-matched female participants: 13 patients with anorexia nervosa restrictive-type (ANR), 12 patients recovered from AN (ANrec), 14 patients with bulimia nervosa and 12 controls. Neurohypophysis PET/MRI [11C] diprenorphin binding potential (BPND) was evaluated in AN, ANrec and controls. Results revealed lower copeptin circadian levels in both ANR and ANrec compared to controls, with no oxytocin differences. Bulimia nervosa exhibited elevated copeptin and low oxytocin levels. [11C] diprenorphin pituitary binding was fully localised in NH. Anorexia nervosa restrictive-type displayed lower NH [11C] diprenorphin BPND (indicating higher opioid tone) and volume than controls. In ANR, copeptin inversely correlated with osmolarity. Neurohypophysis [11C] diprenorphin BPND did not correlated with copeptin or oxytocin. Copeptin demonstrated significant group differences, highlighting its potential diagnostic and prognostic value. Oxytocin levels exhibited conflicting results, questioning the reliability of peripheral blood assessment. Increased NH opioid tone in anorexia nervosa may influence the vasopressin or oxytocin release, suggesting potential therapeutic applications.

Ectopic Posterior Pituitary and Its Associations with Extrapituitary Intracranial Anomalies.

Posterior pituitary ectopia is a very rare entity in the development of the pituitary gland. Several factors and multiple genes are associated with this entity causing both pituitary and extrapituitary abnormalities. Pituitary abnormalities can be various endocrine problems and extrapituitary abnormalities can be optic nerves and cerebellar hypoplasia, heterotopia, and abnormal vessels. This pictorial review represents the imaging manifestations of extrapituitary intracranial anomalies that can be associated with posterior pituitary ectopia.