Granular cell tumor of the neurohypophysis presenting as a third ventricle mass

Granular cell tumors of the neurohypophysis (GCT) are rare benign neoplasms belonging, along with pituicytoma and spindle cell oncocytoma, to the family of TTF1-positive low-grade neoplasms of the posterior pituitary gland. GCT usually present as a solid sellar mass, slowly growing and causing compressive symptoms over time, occasionally with suprasellar extension. They comprise polygonal monomorphous cells with abundant granular cytoplasm, which is ultrastructurally filled with lysosomes. Here we report the case of a GCT presenting as a third ventricle mass, radiologically mimicking chordoid glioma, with aberrant expression of GFAP and Annexin-A, which lends itself as an example of an integrated diagnostic approach to sellar/suprasellar and third ventricle masses.

Co-occurrence of Pituitary Neuroendocrine Tumors (PitNETs) and Tumors of the Neurohypophysis

Between 1996 and 2020, 12,565 cases were enrolled in the German Registry of Pituitary Tumors including 10,084 PitNETs (10,067 adenomas and 19 carcinomas obtained surgically and 193 adenomas diagnosed at autopsy) as well as 69 spindle cell tumors of the neurohypophysis (64 surgical specimens and 5 autopsies). In six patients (1 post mortem and 5 surgical specimens), PitNETs as well as posterior lobe tumors were found in the specimens. Two of the PitNETs were sparsely granulated prolactin-producing tumors, combined in one case with a granular cell tumor and in one case with a pituicytoma. One of the PitNETs revealed that autopsy was a sparsely granulated GH tumor combined with a neurohypophyseal granular cell tumor. Two PitNETs were null cell adenomas combined with a pituicytoma and a spindle cell oncocytoma, respectively. Further, one Crooke cell tumor was combined with a spindle cell oncocytoma. In five cases, the PitNETs were larger than the posterior lobe tumors and accounted for the clinical symptoms. Previously, four cases of co-existing pituitary anterior and posterior lobe tumors were described in the literature, comprising two ACTH PitNETs, one gonadotrophic PitNET and one null cell PitNET, each in combination with a pituicytoma. PitNETs and concomitant granular cell tumor or spindle cell oncocytoma, as observed in our cohort, have not been reported before.

Neuroendocrine changes in the hypothalamic-neurohypophysial system in the Wistar audiogenic rat (WAR) strain submitted to audiogenic kindling

The Wistar audiogenic rat (WAR) strain is used as an animal model of epilepsy, which when submitted to acute acoustic stimulus presents tonic-clonic seizures, mainly dependent on brainstem (mesencephalic) structures. However, when WARs are exposed to chronic acoustic stimuli (audiogenic kindling-AK), they usually present tonic-clonic seizures, followed by limbic seizures, after recruitment of forebrain structures such as the cortex, hippocampus and amygdala. Although some studies have reported that hypothalamic-hypophysis function is also altered in WAR through modulating vasopressin (AVP) and oxytocin (OXT) secretion, the role of these neuropeptides in epilepsy still is controversial. We analyzed the impact of AK and consequent activation of mesencephalic neurocircuits and the recruitment of forebrain limbic (LiR) sites on the hypothalamic-neurohypophysial system and expression of Avpr1a and Oxtr in these structures. At the end of the AK protocol, nine out of 18 WARs presented LiR. Increases in both plasma vasopressin and oxytocin levels were observed in WAR when compared to Wistar rats. These results were correlated with an increase in the expressions of heteronuclear (hn) and messenger (m) RNA for Oxt in the paraventricular nucleus (PVN) in WARs submitted to AK that presented LiR. In the paraventricular nucleus, the hnAvp and mAvp expressions increased in WARs with and without LiR, respectively. There were no significant differences in Avp and Oxt expression in supraoptic nuclei (SON). Also, there was a reduction in the Avpr1a expression in the central nucleus of the amygdala and frontal lobe in the WAR strain. In the inferior colliculus, Avpr1a expression was lower in WARs after AK, especially those without LiR. Our results indicate that both AK and LiR in WARs lead to changes in the hypothalamic-neurohypophysial system and its receptors, providing a new molecular basis to better understaind epilepsy.

Comprehensive Genomic Characterization of A Case of Granular Cell Tumor of the Posterior Pituitary Gland: A Case Report

Granular cell tumors of the pituitary belong to a rare family of neoplasms, arising from the posterior pituitary gland. Although considered benign, they may cause significant morbidity and residual disease after resection can lead to poor clinical outcomes. Currently, there is no known medical therapy for any posterior pituitary gland tumor, in part due to sparse molecular characterization of these lesions. We report data from whole exome sequencing of a case of granular cell tumor of the pituitary, performed under an institutional review board approved protocol. A 77 year-old female underwent resection of an incidentally diagnosed pituitary mass that was causing radiographic compression of the optic nerves with a subclinical temporal field defect and central hypothyroidism. The pathology of the resected specimen demonstrated a granular cell tumor of the posterior pituitary gland. Whole-exome sequencing revealed mutations predicted to be deleterious in key oncogenes, SETD2 and PAX8, both of which have been described in other cancers and could potentially be amenable to targeted therapies with existing approved drugs, including immune checkpoint inhibitors and histone deacetylase inhibitors, respectively. To our knowledge, this is the first comprehensive genomic characterization of granular cell tumor of the posterior pituitary gland. We report mutations in oncogenes predicted to be deleterious and reported in other cancers with potential for therapeutic targeting with existing pharmacologic agents. These data provide new insights into the molecular pathogenesis of GCT of the pituitary and may warrant further investigation.

Acquired forms of central diabetes insipidus: Mechanisms of disease

Most cases of acquired central diabetes insipidus are caused by destruction of the neurohypophysis by: 1) anatomic lesions that destroy the vasopressin neurons by pressure or infiltration, 2) damage to the vasopressin neurons by surgery or head trauma, and 3) autoimmune destruction of the vasopressin neurons. Because the vasopressin neurons are located in the hypothalamus, lesions confined to the sella turcica generally do not cause diabetes insipidus because the posterior pituitary is simply the site of the axon terminals that secrete vasopressin into the bloodstream. In addition, the capacity of the neurohypophysis to synthesize vasopressin is greatly in excess of the body's needs, and destruction of 80-90% of the hypothalamic vasopressin neurons is required to produce diabetes insipidus. As a result, even large lesions in the sellar and suprasellar area generally are not associated with impaired water homeostasis until they are surgically resected. Regardless of the etiology of central diabetes insipidus, deficient or absent vasopressin secretion causes impaired urine concentration with resultant polyuria. In most cases, secondary polydipsia is able to maintain water homeostasis at the expense of frequent thirst and drinking. However, destruction of the osmoreceptors in the anterior hypothalamus that regulate vasopressin neuronal activity causes a loss of thirst as well as vasopressin section, leading to severe chronic dehydration and hyperosmolality. Vasopressin deficiency also leads to down-regulation of the synthesis of aquaporin-2 water channels in the kidney collecting duct principal cells, causing a secondary nephrogenic diabetes insipidus. As a result, several days of vasopressin administration are required to achieve maximal urine concentration in patients with CDI. Consequently, the presentation of patients with central diabetes insipidus can vary greatly, depending on the size and location of the lesion, the magnitude of trauma to the neurohypophysis, the degree of destruction of the vasopressin neurons, and the presence of other hormonal deficits from damage to the anterior pituitary.

A Novel Missense Mutation in Human Receptor Roundabout-1 (ROBO1) Gene Associated with Pituitary Stalk Interruption Syndrome

Pituitary stalk interruption syndrome (PSIS) is characterized by the association of an absent or thin pituitary stalk, an absent or hypoplastic anterior pituitary lobe and an ectopic posterior pituitary (EPP) lobe. The causes of this anatomical defect include both genetic and environmental factors. Molecular genetic defects have been indentified in a small number of patients with PSIS. A 4-year-old boy presented with hypoglycemia and hyponatremia associated with growth hormone, thyroid stimulating hormone, and adrenocorticotropic hormone deficiencies. The patient had right sided strabismus. magnetic resonance imaging images showed pituitary hypoplasia, EPP and absent pituitary stalk. A novel Receptor Roundabout-1 (ROBO1) missense mutation (c.1690C>T, p.Pro564Ser) that may contribute to the disorder was found in this patient and his mother, who also exhibited pituitary abnormalities.

Posterior pituitary dysfunction following traumatic brain injury: review

Neurohypophysial dysfunction is common in the first days following traumatic brain injury (TBI), manifesting as dysnatremia in approximately 1 in 4 patients. Both hyponatremia and hypernatremia can impair recovery from TBI and in the case of hypernatremia, there is a significant association with excess mortality. Hyponatremia secondary to syndrome of inappropriate antidiuretic hormone secretion (SIAD) is the commonest electrolyte disturbance following TBI. Acute adrenocorticotropic hormone (ACTH)/cortisol deficiency occurs in 10-15% of TBI patients and can present with a biochemical picture identical to SIAD. For this reason, exclusion of glucocorticoid deficiency is of particular importance in post-TBI SIAD. Cerebral salt wasting is a rare cause of hyponatremia following TBI. Hyponatremia predisposes to seizures, reduced consciousness, and prolonged hospital stay. Diabetes insipidus (DI) occurs in 20% of cases following TBI; where diminished consciousness is present, appropriate fluid replacement of renal water losses is occasionally inadequate, leading to hypernatremia. Hypernatremia is strongly predictive of mortality following TBI. Most cases of DI are transient, but persistent DI is also predictive of mortality, irrespective of plasma sodium concentration. Persistent DI may herald rising intracranial pressure due to coning. True adipsic DI is rare following TBI, but patients are vulnerable to severe hypernatremic dehydration, exacerbation of neurologic deficits and hypothalamic complications, therefore clinicians should be aware of this possible variant of DI.

Posterior pituitary tumours: the spectrum of a unique entity. A clinical and histological study of a large case series

PURPOSE

In 2017, the WHO established that pituicytoma, granular cell tumour (GCT) and spindle cell oncocytoma (SCO) are posterior pituitary tumours (PPT). Recent data suggests that these tumours probably arise from the pituicytes and may constitute a spectrum of a unique histopathological entity. Our aim is to report the clinical findings and surgical outcomes of 16 patients with PPT. We also evaluated the tissue specimens available in light of current knowledge.

METHOD

Cross-sectional study with retrospective data.

RESULTS

PPT were 7 pituicytomas, 3 GCT and 6 SCO. Patients mean age was 55 years old and 75% were female. Basal hormonal study showed hyperprolactinemia (43.7%) and hypopituitarism (37.5%). There was no case of diabetes insipidus (DI). MRI showed sellar/suprasellar masses with mean size of 19.7mm. PPT was not suspected in any patient. Fifteen patients underwent surgery and complications were common: 20% had perioperative bleeding (one patient died because of a massive haemorrhage), 57.1% hypopituitarism, 35.7% permanent DI and 21.4% underwent a second surgery. Pathological findings shown positivity for thyroid transcription factor 1, vimentin and negativity for cytokeratin and chromogranin A in all specimens evaluated. S100 protein was positive in 88.8% of tumours. Ki67 was ≥ 3% in 66.6% and ranged from 4-7% in SCO.

CONCLUSION

PPT have similar histology, clinical features and are frequently misdiagnosed as nonfunctioning pituitary tumours. However, post-surgical complications including haemorrhage are common. A high clinical suspicion is needed to presume the diagnosis prior surgery and diminish the high morbidity of these tumours.

Critical role of rabphilin-3A in the pathophysiology of experimental lymphocytic neurohypophysitis

Autoimmune hypophysitis (AH) is thought to be an autoimmune disease characterized by lymphocytic infiltration of the pituitary gland. Among AH pathologies, lymphocytic infundibulo-neurohypophysitis (LINH) involves infiltration of the neurohypophysis and/or the hypothalamic infundibulum, causing central diabetes insipidus resulting from insufficiency of arginine vasopressin secretion. The pathophysiological and pathogenetic mechanisms underlying LINH are largely unknown. Clinically, differentiating LINH from other pituitary diseases accompanied by mass lesions, including tumours, has often been difficult, because of similar clinical manifestations. We recently reported that rabphilin-3A is an autoantigen and that anti-rabphilin-3A antibodies constitute a possible diagnostic marker for LINH. However, the involvement of rabphilin-3A in the pathogenesis of LINH remains to be elucidated. This study was undertaken to explore the role of rabphilin-3A in lymphocytic neurohypophysitis and to investigate the mechanism. We found that immunization of mice with rabphilin-3A led to neurohypophysitis. Lymphocytic infiltration was observed in the neurohypophysis and supraoptic nucleus 1 month after the first immunization. Mice immunized with rabphilin-3A showed an increase in the volume of urine that was hypotonic as compared with control mice. Administration of a cocktail of monoclonal anti-rabphilin-3A antibodies did not induce neurohypophysitis. However, abatacept, which is a chimeric protein that suppresses T-cell activation, decreased the number of T cells specific for rabphilin-3A in peripheral blood mononuclear cells (PBMCs). It ameliorated lymphocytic infiltration of CD3+ T cells in the neurohypophysis of mice that had been immunized with rabphilin-3A. Additionally, there was a linear association between the number of T cells specific for rabphilin-3A in PBMCs and the number of CD3+ T cells infiltrating the neurohypophysis. In conclusion, we suggest that rabphilin-3A is a pathogenic antigen, and that T cells specific for rabphilin-3A are involved in the pathogenesis of neurohypophysitis in mice. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Clinical and imaging features of granular cell tumor of the neurohypophysis: A retrospective analysis

The aim of this study was to explore x-ray computed tomography (CT) and magnetic resonance imaging (MRI) characteristics specific to granular cell tumors (GCTs) of the neurohypophysis.The clinical and imaging data of 6 patients with operation-proven GCTs of the neurohypophysis were analyzed retrospectively.There were 6 patients with GCTs of the neurohypophysis confirmed pathologically. Five of the tumors were purely suprasellar lesions distinct from the intrasellar pituitary gland. One tumor was both intra- and suprasellar. Solid tumors were hyperattenuated and enhanced homogeneously on CT, while showing isointensity on T1WI and heterogeneous hypointensity on T2WI, with homogeneous (4/5) or inhomogeneous (1/5) enhancement. The cystic tumor showed hypointensity on T1WI and hyperintensity on T2WI, with ring enhancement. "Star-like crack sign" was seen in 2 larger solid cases. Calcification was absent in all cases.Well-circumscribed intra and/or suprasellar masses, hyperattenuated and homogeneously enhancing on CT, hypointensity on T2WI, rarely seen calcification, should arouse suspicion of GCTs of the neurohypophysis.

Patient With Severe Hyponatremia Caused by Adrenal Insufficiency Due to Ectopic Posterior Pituitary Lobe and Miscommunication Between Hypothalamus and Pituitary: A Case Report

Hyponatremia may be one of the clinical manifestations of adrenal insufficiency (AI) and during the diagnostic workup of hyponatremic patients investigation of AI should be included.We report the case of an 82-year-old patient who was admitted to our hospital with clinical symptoms and laboratory findings of hyponatremia. Following the diagnostic algorithm of hyponatremia we reached the diagnosis of AI. Clinician's attention must focus on the underlying cause of AI which in this case was hidden in a miscommunication between hypothalamus and pituitary due to an ectopic posterior pituitary lobe and became apparent by a pituitary magnetic resonance imaging (MRI) scan. Treatment with oral hydrocortisone resulted in full clinical recovery and electrolyte balance, which was maintained after 7 months of follow-up.Secondary AI is related with hyponatremia through increased ADH secretion. Although a hyponatremic episode may be the first presentation of AI, clinical suspicion is of high importance in order to place the right diagnosis. Disruption of communication between hypothalamus and pituitary is a rare but considerable cause of AI.

Pediatric Central Diabetes Insipidus: Brain Malformations Are Common and Few Patients Have Idiopathic Disease

CONTEXT

Pediatric cohorts of central diabetes insipidus (CDI) have shown varying prevalences for the different causes of CDI, including idiopathic.

OBJECTIVE

The objective of the study was to determine the causes of CDI at a pediatric tertiary care center and to characterize their clinical outcomes.

DESIGN AND SETTING

All patients with CDI at Seattle Children's Hospital were identified and retrospectively analyzed.

PATIENTS

From 2000 to 2013, 147 patients with CDI were encountered (mean age 7 y at diagnosis, mean follow-up 6.2 y).

OUTCOME MEASURES

The different causes of CDI were grouped, and age of diagnosis, anterior pituitary hormone deficiencies (APHDs), and presence of the posterior pituitary bright spot (PPBS) were analyzed. Patients with idiopathic CDI had infundibular thickening measured using a systematic method.

RESULTS

Brain malformations caused 24% of CDI cases, and 12.2% were idiopathic. Four of 22 patients with initially idiopathic CDI were diagnosed with an underlying condition, none occurring later than 2.5 years from diagnosis. APHDs were as common in the brain malformation group as they were in the tumor/infiltrative group (72% vs 85%; P = .09). The PPBS was present in at least 13% of patients and in 19% of those with brain malformations. Patients with idiopathic CDI and stalk thickening on the initial magnetic resonance imaging were more likely to have an underlying diagnosis (40% vs 0%; P = .03).

CONCLUSIONS

Brain malformations were a more common cause of pediatric CDI than previously reported. These patients have a high rate of APHDs, and many have persistence of the PPBS. Idiopathic CDI is an uncommon diagnosis, and none of our patients were diagnosed with Langerhans cell histiocytosis or germinoma for more than 3 years from CDI diagnosis. Providers can consider less frequent magnetic resonance imaging after this time point. A systematic method of infundibular measurement on the initial magnetic resonance imaging may predict an underlying germinoma or Langerhans cell histiocytosis.

Auxologic parameters and response to 2-year therapy with recombinant human growth hormone in growth hormone deficient children with an ectopic posterior pituitary

BACKGROUND

Structural defects of the hypothalamic-pituitary area in MRI are suggested as being a more accurate marker of growth hormone deficiency (GHD) than laboratory assays.

OBJECTIVE

To compare auxological characteristics in GHD children with normal pituitary (NP) function and with ectopic posterior pituitary (EPP), prior to therapy with recombinant human growth hormone (rhGH), extending the follow-up to two years following treatment.

DESIGN

Eighty-six (86) GHD patients were divided into two groups depending on the pituitary MRI: the EPP (23 children, 3.2-16.8 years old) and the NP group (63 children, 3.3-14.8 years old). Height deficits in the population (hSD) and parents (hSD-mpSD) and the change of hSD and bone/chronological age ratio were assessed before and after 12 and 24 months of rhGH therapy.

RESULTS

Height deficits before treatment were significantly greater in EPP compared to NP [median -4.07 (-7.06, -2.75) vs -3.15 (-4.9, -2.35) for hSD, and -3.65 (-7.06, -1.21) vs -1.83 (-4.31, -0.28) for hSD-mpSD; p<0.05]. Bone age was significantly delayed in the EPP group [0.62 (0.27, 0.92) vs 0.75 (0.21, 0.71); p<0.05]; differences remained significant during follow-up. After 12 months of rhGH therapy, EPP showed significantly greater catch-up growth compared to NP [ΔhSD=1.2 (0.42, 2.69) vs 0.74 (0.05, 1.48); p<0.05]. In the 2nd year, height velocity slowed down and was comparable in the two groups. At the conclusion of the study, hSD was similar in both groups, but hSD-mpSD was more deviated in EPP [-1.79 (-3.71, -1.21) vs -1.1 (0.98, -0.07); p<0.05].

CONCLUSIONS

The study showed relevant auxologic differences between EPP and NP children, as well as beneficial effects of rhGH therapy in both groups.

Xanthomatous hypophysitis

We present a 69-year-old woman who presented with chronic headaches and was found to have a pituitary mass on MRI, which was biopsied and said to be lymphocytic hypophysitis. The woman was placed on prednisone and followed with routine eye examinations. Two years later, the lesion gradually increased in size and the woman developed a decrease in peripheral vision in the right eye. An MRI showed abutment of the right optic nerve by the mass. A repeat endoscopic transsphenoidal biopsy/resection of the pituitary lesion was performed. Histopathological analysis of the specimen was consistent with diagnosis of xanthomatous hypophysitis (XH). XH is an inflammatory disorder of the pituitary gland characterized by an infiltration of lipid-laden histiocytes, also known as xanthoma cells. The mass was biopsied and a diagnosis of lymphocytic hypophysitis was made. The woman reported improved visual acuity and peripheral vision postoperatively. One year after the second resection, her visual symptoms worsened. Repeat MRI revealed expansion of the residual pituitary tissue. She was referred to the radiation oncology department for external beam radiation therapy and was placed on a maintenance dose of steroids. Since undergoing radiation therapy, her vision has improved slightly and her 3month MRI revealed stable lesion size. This woman illustrates a rare pituitary pathology presented with a literature review of published patients describing xanthomatous hypophysitis. A discussion of the clinical presentation, epidemiology, etiology, diagnosis, histology and treatment is provided.

[A case of possible immunoglobulin G4-related disease (IgG4-RD) with retroperitoneal fibrosis and central diabetes insipidus due to infundibulohypophysitis]

We report a case of possible immunoglobulin G4-related disease(IgG4-RD)that resulted in complications such as retroperitoneal fibrosis and infundibulohypophysitis. The patient was a 72-year-old male who presented with polyuria and polydipsia. Magnetic resonance imaging(MRI)revealed a thickened pituitary stalk and contrast enhancement with gadolinium. T1-weighted imaging revealed that the posterior pituitary high-signal zone had disappeared. Central diabetes insipidus was diagnosed on the basis of results of the hypertonic saline test. In addition, pressure due to retroperitoneal fibrosis resulted in hydronephrosis and elevated serum IgG4 levels. Because it was determined that the patient could have IgG4-RD, he was administered prednisolone, following which a decrease in the size of the pituitary stalk and retroperitoneal fibrosis was observed. IgG4-RD is characterized by elevated serum IgG4 levels and the infiltration of IgG4-positive plasma cells into various organs, including the central nervous system. Recently, IgG4-RD research teams organized by the Ministry of Health, Labour and Welfare established guidelines for the diagnosis of IgG4-RD. According to these guidelines, this case would fall under the category of "possible IgG4-RD." This case suggested that when infundibulohypophysitis is detected by neuroradiology, further investigation into the possibility of IgG4-RD should be recommended.

Two forensic autopsy cases of death from unexpected lesions of the pituitary gland

Herein, we report the findings of 2 forensic autopsy cases, in which unexpected pituitary lesions were the underlying cause of death. Case 1: A 56-year-old woman was found dead at her home during a cold winter spell. Macroscopic autopsy findings included a difference in the color of blood that filled her left and right cardiac chambers (deep red and dark red, respectively), collapse of both lungs, atrophy of the thyroid gland, and a large tumor arising from the sella turcica. Microscopic examination revealed a pituitary adenoma along with extensive bleeding. The cause of death was considered to be hypothermia, resulting from dysregulation of thermogenesis due to the pituitary adenoma. Case 2: An 86-year-old man with a history of pollakiuria was found dead in a bathtub, with his face and chest submerged in bathwater and his legs positioned outside the bathtub. The macroscopic findings of the autopsy included hyper-inflated lungs, fluid collection in the thoracic cavity, and aspiration of gastric contents in the bronchi. The atherosclerotic changes of the man's coronary and cerebral arteries were considered mild for his age. Microscopic examination showed a marked infiltration of lymphocytes and plasma cells in the posterior pituitary gland, as well as in the liver, pancreas, and submandibular gland. Considering the results of the autopsy and the findings from the investigation conducted at the death scene, we concluded that the man probably lost consciousness following a neurally mediated syncope, which was induced by diabetes insipidus (lymphocytic hypophysitis). After losing consciousness, the man likely fell in the filled bathtub and then drowned. These 2 cases highlight the need for a thorough post-mortem investigation, including a microscopic examination of the pituitary gland. In addition, forensic pathologists should carefully study the pituitary gland in cases where the cause of death is thought to be related to dysfunction of thermoregulation or osmoregulation.

Granular cell tumor of the neurohypophysis: case report and review of the literature

A 54-year-old woman presented with a stalk mass that was discovered incidentally with mild visual fields defect. The mass was operated surgically by the fronto-temporal approach, and histology met the diagnosis of neurohypophesial granular cell tumor (GCT). After surgery, the patient suffered from an irreversible severe bi-temporal visual deficit and an irreversible hypopituitarism. We review the literature and discuss the clinical nature of GCTs, treatment options and outcome. In an effort to avoid the severe complications that may result from surgical removal of neurohypophesial GCT, we discuss also the possibility of choosing the conservative approach with close follow-up. The tumor's firm consistency, tendency to hemorrhage, involving the pituitary stalk and lack of dissection plane from basal brain structure render surgery difficult, and maximal resection often requires sacrificing the stalk. Moreover, small asymptomatic neurohypophysial GCTs are common findings, most probably benign tumors with slow growing nature. Hence, for a neurohypophesial tumor which is suspected to be a GCT, we offer to consider the alternative approach, with close clinical, visual field and radiological study follow up.

[Morpho-functional characteristics of conducting airways and the respiratory portion of rat lung under the conditions of intratracheal infection from the positions of the neuroendocrine regulation of reparative histogeneses]

With the use of light and electron microscopy and immunohistochemistry, the morpho-functional changes in the lungs, the hypothalamus and the neurohypophysis were studied in 45 outbred albino male rats 1, 3, 7 and 14 days after the intratracheal infusion of Staphylococcus aureus strains either possessing anti-lactoferrin activity (ALfA(+)) or lacking it (ALfA(-)). After the infusion of ALfA(+) bacteria, the bronchial wall and the respiratory portion of the lungs demonstrated the destructive changes of tissues, sclerosis phenomena, disturbances of regeneration processes (polypoid outgrowth, metaplasia), while in the neurohypophysis a delay in the release of neurosecretion into the blood from the terminals of nonapeptidergic neurosecretory cells took place. These phenomena were not observed after the infection with ALfA(-)bacteria. The results obtained indicate the disturbances of the structural-functional homeostasis of pulmonary tissues associated with bacterial ALfa, taking place together with the limitations of the hypothalamic neurosecretion.

Variant of lymphocytic infundibulo-neurohypophysitis presenting with unique clinical and radiological features

Lymphocytic hypophysitis (LYH) is a chronic inflammation that primarily affects the pituitary gland. This disorder has recently been classified into lymphocytic adenohypophysitis (LAH), lymphocytic infundibulo-neurohypophysitis (LINH), and lymphocytic infundibulo-panhypophysitis (LIPH) according to the affected area. We report a case of LINH in a 68-year-old woman who presented with diabetes insipidus (DI). In this case, the posterior lobe was affected in both endocrinological assessment and magnetic resonance imaging (MRI) findings. In contrast, the anterior pituitary was not affected in endocrinological assessment but was affected in MRI findings. Indeed, the patient did not develop hypopituitarism. We believed that these clinical and radiological features were unique in regard to the classification of LYH. To confirm the classification of LYH and the distinction from pituitary adenoma, a pituitary biopsy was performed. Based on the pathological and endocrinological assessment, the patient's disorder was finally diagnosed as a variant of LINH. Current evidence recommends that surgical intervention for LYH should be avoided because the natural course of LYH is essentially self-limiting. Therefore, the accumulation of the knowledge of many variants of LYH is important for the preoperative differential diagnosis of pituitary masses. Our clinical observation could be useful for avoiding unnecessary surgical intervention.

[Granular cell tumor of the neurohypophysis observed with hypoglycemic attack]

Granular cell tumor of the neurohypophysis (GCT) occurs as a solitary, small, nodular tumor and rarely grows to a sufficient size to present symptoms. The authors report a case of a 30-year-old man with GCT presenting with hypoglycemic attack. Hypoglycemic attack could be due to dysfunction of the hypothalamus and one of the important symptoms of GCT.

[Endoscopic, posterior transseptal pituitary surgery--learning curve of the surgical technique and equipment in 61 operations]

INTRODUCTION

The removal of hypophyseal tumor by transsphenoidal pituitary surgery using microsurgical instruments was first performed over 100 years ago. Operating techniques for this surgery are constantly being renewed, first by using a microscope and later on with the use of an endoscop. The authors provide an overview of the minimal invasive posterior transseptal-transsphenoidal aproach with the combined utilization of classical techniques with the assistance of the endoscop.

METHOD

Sixty-one patients (33 female, 28 male, 21-84 yrs) were treated for sellar region tumor resection using an endonasal transsphenoidal aproach with the help of an endoscope. Follow ups were performed within 2-21 months.

RESULTS

Total tumor resection was successful in 91.8%, and partial resection in 8.2% of the patients. The rate of complications using the endoscopic method was not higher compared to that of the classical microscopic method. There was no major bleeding in any of the cases. Adverse events such as minor epistaxis occurred in 4.9%, transitional diabetes insipidus in 6.5%, inraoperative CSF leak in 16.67%, postoperative CSF leak in 11.5% and meningitis in 8.2% of the patients. After the operation the pathological hormonal production stoped in all patients except in two patients who were acromegalic. However their GH level normalized and they did not require further treatment, the IGF-1 still remained high.

CONCLUSION

The success of the surgical treatment is based on both, the proficient pre- and postoperative endocrinological care, and the minimal invasive surgical technique. The endoscope was used partially or continuously during the operation for better visualization of the operation field in multiple angles (30 degrees, 45 degrees). It was useful in differentiating between normal and tumorous glandular tissue, and also offered an enhanced view of the intrasellar (via hydroscopy) and parasellar region. Moreover the endoscopic method is able to decrease the operating time, reduce blood loss. In different stages of the surgery, depending on the anatomical and pathological situation, switching back and forth from microscope to endoscope technique, gives us the benefit of a clearer view in each situation.

Ectopic posterior pituitary and stalk abnormality predicts severity and coexisting hormone deficiencies in patients with congenital growth hormone deficiency

Certain pituitary imaging abnormalities are a specific indicator of hypopituitarism. The objective of this study is to compare phenotypical features with radiological findings in patients with congenital growth hormone deficiency (GHD). Magnetic Resonance imaging (MRI) was performed in 103 patients [72 with Isolated GHD (IGHD) and 31 with Combined Pituitary Hormone Deficiency (CPHD)]. Images were assessed for the following abnormalities: (1) small/absent anterior pituitary, (2) thin or interrupted pituitary stalk (PSA), and (3) Ectopic posterior pituitary (EPP), and (4) others. Radiological findings were correlated with the clinical and biochemical parameters. MRI abnormalities were observed in 48.6% patients with IGHD, 93.5% with CPHD. Jaundice, hypoxia, hypoglycemia and breech deliveries were more common in EPP/PSA group. EPP/PSA was observed in 87.1% patients with severe GHD (peak GH < 3 μg/L) as compared to 12.9% with mild to moderate GHD (peak GH: 3-10 μg/L). Amongst CPHD, EPP/PSA was present in 80% of subjects with associated hypocortisolism ± hypothyroidism as compared to 18.2% of subjects with hypogonadism. Over a mean follow up period of 4.5 years, 5.4% of subjects with IGHD and abnormal MRI progressed to CPHD while none of those with normal MRI progressed. This study emphasizes a significant clinico-radiological correlation in Asian Indian GHD patients. MRI abnormalities in the hypothalamic pituitary area, especially EPP/PSA are more common in patients with CPHD and severe GHD. Among CPHD, EPP/PSA predicts association with hypothyroidism or hypocortisolism. IGHD with MRI abnormality may evolve into CPHD.

Necrotizing infundibulo-hypophysitis: an entity too rare to be true?

We report a young woman with sudden and severe retroorbital headache, neck pain, and a large sellar mass extending to the suprasellar cistern. A presumptive diagnosis of non-secreting pituitary macroadenoma undergoing apoplexy was made and transphenoidal surgery performed. Histopathology revealed mononuclear infiltration and marked non-hemorrhagic necrosis of the anterior pituitary consistent with a diagnosis of necrotizing infundibulo-hypophysitis. The possible pathogenesis of this rare variant of hypophysitis is discussed.

Genetic overlap in Kallmann syndrome, combined pituitary hormone deficiency, and septo-optic dysplasia

CONTEXT

Kallmann syndrome (KS), combined pituitary hormone deficiency (CPHD), and septo-optic dysplasia (SOD) all result from development defects of the anterior midline in the human forebrain.

OBJECTIVE

The objective of the study was to investigate whether KS, CPHD, and SOD have shared genetic origins.

DESIGN AND PARTICIPANTS

A total of 103 patients with either CPHD (n = 35) or SOD (n = 68) were investigated for mutations in genes implicated in the etiology of KS (FGFR1, FGF8, PROKR2, PROK2, and KAL1). Consequences of identified FGFR1, FGF8, and PROKR2 mutations were investigated in vitro.

RESULTS

Three patients with SOD had heterozygous mutations in FGFR1; these were either shown to alter receptor signaling (p.S450F, p.P483S) or predicted to affect splicing (c.336C>T, p.T112T). One patient had a synonymous change in FGF8 (c.216G>A, p.T72T) that was shown to affect splicing and ligand signaling activity. Four patients with CPHD/SOD were found to harbor heterozygous rare loss-of-function variants in PROKR2 (p.R85G, p.R85H, p.R268C).

CONCLUSIONS

Mutations in FGFR1/FGF8/PROKR2 contributed to 7.8% of our patients with CPHD/SOD. These data suggest a significant genetic overlap between conditions affecting the development of anterior midline in the human forebrain.

Pituicytomas: radiological findings, clinical behavior and surgical management

BACKGROUND

Pituicytomas are rare low-grade glial neoplasms originating in the neurohypophysis or infundibulum that appear as solid, noninfiltrative masses occupying the sella turcica, the suprasellar space or both. Due to their high tendency to bleed and the possible firmness and adhesion to surrounding structures, preoperative diagnosis of pituicytoma is a goal for the surgeon, but it is actually a challenge because of the absence of distinctive clinical or neuroradiological findings.

METHODS

We report the new cases of three patients who underwent transsphenoidal surgery for suspected pituitary adenomas, which were determined to be pituicytomas at histological and immunohistochemical analysis. We also review previously reported cases of pituicytoma in the literature.

RESULTS

To date, 51 cases of pituicytoma have been reported in addition to our own cases. The natural history and clinical characteristics of this rare tumor are outlined.

CONCLUSIONS

Macroscopic aspects are variable, and final diagnosis is made from the typical histological and immunohistochemical pattern. The therapy of choice is gross total surgical resection since subtotal removal can lead to local regrowth, but the time to recurrence is unpredictable and highly variable. The role of adjuvant therapy is currently undefined.

Posterior pituitary (PP) evaluation in patients with anterior pituitary defect associated with ectopic PP and septo-optic dysplasia

OBJECTIVE

Controversies exist about posterior pituitary (PP) function in subjects with ectopic PP (EPP) and with cerebral midline defects and/or their co-occurrence. We investigate water and electrolyte disturbances in patients at risk for PP dysfunction.

DESIGN

The study was conducted in a single Pediatric Endocrinology Research Unit.

METHODS

Forty-two subjects with childhood-onset GH deficiency were subdivided into five groups: normal magnetic resonance imaging (n=8, group 1); EPP (n=15, group 2); septo-optic dysplasia (SOD) with normal PP (n=4, group 3); EPP and SOD without (n=7, group 4), and with additional midline brain abnormalities (n=8, group 5). At a mean age of 16.0±1.1 years, they underwent a 120 min i.v. infusion with hypertonic 5% saline and evaluation of plasma osmolality (Posm), arginine vasopressin (AVP), thirst score (in groups 1 and 2), and urinary osmolality were performed.

RESULTS

Mean Posm and AVP significantly increased from baseline scores (284.7±4.9 mosm/kg and 0.6±0.2 pmol/l) to 120 min after saline infusion (300.5±8.0 mosm/kg and 10.3±3.3 pmol/l, P<0.0001). Group 5 showed higher mean Posm and lower mean AVP at all time points (P<0.0001). Mean thirst score did not show a significantly different trend between the groups 1 and 2. Urine osmolality was above 750 mosm/kg in all but seven patients after osmotic challenge.

CONCLUSIONS

Patients with midline brain abnormalities and EPP have defective osmoregulated AVP. Patients with EPP and congenital hypopituitarism have normal PP function.

[Management and microsurgical treatment of infundibular dilatations of the posterior communicating artery. Series of nine cases and review of the literature]

INTRODUCTION

The infundibular dilatation (ID) of the posterior communicating (PCom) artery is defined as the conic, triangular or infundibular shaped, less than 3mm wide, origin of the PCom artery from the internal carotid artery. The purpose of this paper is to present the personal experience in the microsurgical management of the ID, to review the literature and to propose some algorithms to improve its clinical and microsurgical management.

MATERIAL AND METHODS

Nine cases of ID have been operated on through a pterional approach. In four patients with subarachnoid hemorrhage (SAH) the ID was considered as the potential source of the bleeding; in four cases the ID was treated after a SAH due to the rupture of an aneurysm; finally, an ID was treated in patient with diagnosis of pseudoxantoma elasticum.

RESULTS

In eight cases the ID was clipped and the Pcom artery subsequently occluded and in the remaining case the ID was associated with a fetal PComA and the ID was reinforced. There were no complications excepting a transitory third cranial nerve paresis. The Glasgow Outcome Scale was 5 in all cases at discharge and one year later.

CONCLUSIONS

The true significance of the ID remains unknown, but in some instances it is necessary to consider its management: 1. In patients with ruptured aneurysms submitted to microsurgical clipping and with an ipsilateral ID, the lesion must be explored and treated; 2. In patients with ruptured aneurysms treated with endovascular procedures or harbouring an ID contralateral to a microsurgically treated aneurysm, the microsurgical indication will be done after considering all risk factors; 3. In patients with SAH and an ID as the only potential source of the bleeding there would be an indication for microsurgical exploration; 4. The incidental finding of an ID should be indication for observation in absence of major risk factors.

Novel heterozygous nonsense GLI2 mutations in patients with hypopituitarism and ectopic posterior pituitary lobe without holoprosencephaly

CONTEXT

GLI2 is a transcription factor downstream in Sonic Hedgehog signaling, acting early in ventral forebrain and pituitary development. GLI2 mutations were reported in patients with holoprosencephaly (HPE) and pituitary abnormalities.

OBJECTIVE

The aim was to report three novel frameshift/nonsense GLI2 mutations and the phenotypic variability in the three families.

SETTING

The study was conducted at a university hospital.

PATIENTS AND METHODS

The GLI2 coding region of patients with isolated GH deficiency (IGHD) or combined pituitary hormone deficiency was amplified by PCR using intronic primers and sequenced.

RESULTS

Three novel heterozygous GLI2 mutations were identified: c.2362_2368del p.L788fsX794 (family 1), c.2081_2084del p.L694fsX722 (family 2), and c.1138 G>T p.E380X (family 3). All predict a truncated protein with loss of the C-terminal activator domain. The index case of family 1 had polydactyly, hypoglycemia, and seizures, and GH, TSH, prolactin, ACTH, LH, and FSH deficiencies. Her mother and seven relatives harboring the same mutation had polydactyly, including two uncles with IGHD and one cousin with GH, TSH, LH, and FSH deficiencies. In family 2, a boy had cryptorchidism, cleft lip and palate, and GH deficiency. In family 3, a girl had hypoglycemia, seizures, excessive thirst and polyuria, and GH, ACTH, TSH, and antidiuretic hormone deficiencies. Magnetic resonance imaging of four patients with GLI2 mutations and hypopituitarism showed a hypoplastic anterior pituitary and an ectopic posterior pituitary lobe without HPE.

CONCLUSION

We describe three novel heterozygous frameshift or nonsense GLI2 mutations, predicting truncated proteins lacking the activator domain, associated with IGHD or combined pituitary hormone deficiency and ectopic posterior pituitary lobe without HPE. These phenotypes support partial penetrance, variable polydactyly, midline facial defects, and pituitary hormone deficiencies, including diabetes insipidus, conferred by heterozygous frameshift or nonsense GLI2 mutations.

Rosai-Dorfman disease involving the neurohypophysis

Rosai-Dorfman disease is a rare, histiocytic proliferative disorder of unknown etiology commonly affecting lymph nodes. Extranodal lesions with or without nodal involvement also occur. We report the case of a 63 year-old woman with disseminated Rosai-Dorfman disease involving the neurohypophysis and associated with adenohypophysial PRL cell hyperplasia.

Transient polyuria related to central diabetes insipidus caused by lymphocytic infundibulo-neurohypophysitis in a patient treated for Graves' disease

A 45-year-old man was hospitalized because of weight loss, finger tremor, thirst, polydipsia and increased urinary frequency. He was diagnosed with Graves' disease (GD) and central diabetes insipidus (CDI). Magnetic resonance imaging revealed the enlarged posterior pituitary with thickened stalk. Histological examination obtained from biopsy of the pituitary revealed lymphocytic infundibulo-neurohypophysitis. He received treatment with thiamazole (MMI) for GD and desmopressin acetate (DDAVP) for CDI. However, DDAVP administration could be discontinued as GD was gradually improved. This course indicates that not only the recovered renal response to arginine-vasopressin but also the immunomodulative effects of MMI might attribute to the improvement of polyuria.

Granular cell tumour of the neurohypophysis: a rare sellar tumour with specific radiological and operative features

Symptomatic granular cell tumours of the neurohypophysis are rare sellar lesions. Preoperative prediction of the diagnosis on the basis of radiological appearance is useful as these tumours carry specific surgical difficulties. This is possible when the tumour arises from the pituitary stalk, rostral to a normal pituitary gland. This has not been emphasized previously.

Spontaneous regression of isolated neurohypophyseal langerhans cell histiocytosis with diabetes insipidus

In pediatric and adolescent patients, the most common causes for a thickened pituitary stalk with central diabetes insipidus are germ cell tumors, lymphocytic infundibuloneurohypophysitis (LIN), and Langerhans cell histiocytosis (LCH). We describe here a 13-year-old girl who had an abrupt onset of polyuria and polydipsia. Magnetic resonance imaging of the brain revealed thickening of the pituitary stalk, and loss of the physiological hyperintense signal of the posterior pituitary gland. Based on a histopathology, she was diagnosed as having LCH. Another LCH lesion was not detected. The prognoses for LCH patients with single-system and single-site are generally good so we decided on only simple observation. The lesion spontaneously regressed 3 months later, resembling a typical self-limiting course of LIN. In conclusion, the present case suggests that 1) radiological differential diagnosis between LIN and LCH is so difficult that histological confirmation is crucial for correct diagnosis, 2) some past cases of histologically-unconfirmed LIN can include LCH, 3) solitary neurohypophyseal LCH can shrink spontaneously up to near remission level.

Pituitary and stalk lesions (infundibulo-hypophysitis) associated with immunoglobulin G4-related systemic disease: an emerging clinical entity

Inflammatory lesions of the pituitary gland are rarely encountered. Recently, the concept of immunoglobulin G4 (IgG4)-related systemic disease was proposed in Japan, and more than 20 cases have been reported as possibly associated with infundibulo-hypophysitis since 2000. We herein review such case reports in the published literature and in the abstracts of scientific meetings. Almost all cases involved middle-aged to elderly men presenting with various degrees of hypopituitarism and diabetes insipidus and demonstrating a thickened pituitary stalk and/or pituitary mass. These structures shrank remarkably in response to glucocorticoid therapy, even in a lower dose range similar to that prescribed as a replacement for adrenocortical insufficiency. Some of the anterior pituitary insufficiencies were also resolved by glucocorticoid administration. The presence of IgG4-related systemic disease and an elevated serum IgG4 level before glucocorticoid therapy were the main clues to a correct diagnosis of IgG4-related infundibulo-hypophysitis. Autoimmunity is suggested but not yet established to play a role in the pathogenesis for IgG4-related systemic disease. The fact that hypertrophic pachymeningitis and para-sinusitis accompanied some cases suggested that both sellar and parasellar structures are involved in the chronic inflammation. We therefore classify this disorder not as a variant form of primary autoimmune hypophysitis but as a secondary form of infundibulo-hypophysitis associated with IgG4-related systemic disease.

[Permeability of rat neurohypophysial blood vessels for neurophysins and ferritin in acute hyperoxia]

The time course of the release of vasopressin-binding (nicotine-stimulated) and oxytocin-binding (estrogen-stimulated) neurophysins (NPs) into the rat pituitary and blood serum has been studied during the convulsive phase of hyperbaric oxygenation (HBO) and the postconvulsive period (PCP). The ultrastructure of the posterior pituitary (neurohypophysis) and the state of the blood-pituitary barrier in the caudal region of the gland have been studied with the use of ferritin as an exogenous marker of vascular permeability.

Histologic study of the human pituitary gland in acute traumatic brain injury

PURPOSE

Approximately 25% of patients with traumatic brain injury (TBI) may develop partial or complete hypopituitarism. The causative mechanisms involved in its development are not clear. To the authors' knowledge, there have been no recent morphologic studies of the pituitary following TBI.

METHODS

To characterize the resultant histologic changes, this study investigated the pituitaries of 42 patients who died following a motor vehicle accident, all from the Mayo Tissue Registry. Twelve patients died instantly at the scene of the accident (Group I) whereas 30 survived between 3 hours and 7 days (Group II). All pituitary specimens were obtained at autopsy, formalin-fixed and paraffin-embedded. Hematoxylin-eosin sections cut in horizontal or sagittal plane were examined light-microscopically.

RESULTS

No infarction was noted in the pituitary specimens from group I. In group II, 13 of 30 (43%) showed acute infarcts of varying size. The extent of infarction in group II ranged from focal to sub-total necrosis involving 90% of the adenohypophysis.

CONCLUSIONS

Underlying adenohypophysial pathology in patients dying after TBI is acute infarction. Loss of large numbers of adenohypophysial cells causes reduced secretion of adenohypophysial hormones and may contribute to post-traumatic hypopituitarism.

Ganglioglioma of the neurohypophysis

The normal infundibulum and neurohypophysis consist entirely of neuronal processes, the neuronal cell bodies of which lie within the supraoptic and paraventricular nuclei of the hypothalamus and supportive glial cells or pituicytes. The finding of neurons within the neurohypophysis is exceedingly rare, as are ganglion cell tumors at this site. In this paper, we report a ganglion cell tumor of the neurohypophysis found incidentally at autopsy. Despite chronic hypertension and the finding of some vasopressin immunoreactivity in lesional neurons, the syndrome of inappropriate antidiuretic hormone secretion (SIADH) was excluded on the basis of normal serum sodium levels. The morphologic and immunohistochemical features of the tumor are presented, cytogenetic considerations are discussed, and literature regarding neuronal lesions of the pituitary gland is reviewed.

Immunoexpression of androgen receptor in the nontumorous pituitary and in adenomas

Little information is available regarding androgen receptor immunoexpression (AR) in the normal and neoplastic human pituitary. Available experimental data links it to primarily gonadotroph cells. We undertook an immunohistochemical study of 41 autopsy-derived normal glands from patients of both sexes and all ages as well as 79 fully characterized pituitary adenomas of all types, the focus being upon AR expression in normal and neoplastic gonadotrophs. Nuclear AR immunoreactivity was noted in gonadotrophs and other normal adeno- and neurohypophysial cells. In addition to its presence in 74% of gonadotroph and 55% of null cell adenomas, lesser proportions of other adenoma types (adrenocorticotropic hormone 50%, prolactin 38%, growth hormone 33%) also exhibited AR immunoreactivity. No staining of thyroid-stimulating hormone adenomas was noted. The physiologic significance of our findings remains to be explored. The literature regarding AR expression in animal and human pituitaries is reviewed.

Remission of congenital diabetes insipidus after eight years

Septo-optic dysplasia (SOD) (De Morsier's syndrome) is a complex developmental disorder marked by variable and often incomplete formation of cranial midline structures, resulting in absence of the septum pellucidum, optic nerve hypoplasia, and hypothalamic-pituitary dysfunction. We describe a patient with SOD who manifested symptoms in the early neonatal period with severe deficiencies of multiple pituitary hormones including anti-diuretic hormone (ADH). Her congenital diabetic insipidus (DI), consequence of an anatomic defect, can be argued to be of the most severe type. Our patient resolved her severe DI 8 years after her initial presentation, suddenly requiring no further medical treatment for DI following longstanding pharmacological replacement of ADH. This is the first report of a patient with SOD with spontaneous resolution of congenital DI.

Anatomic and pathologic spectrum of pituitary infundibulum lesions

OBJECTIVE

The pathologic spectrum of pituitary infundibulum disease is diverse. We reviewed 65 infundibular lesions in 44 adult and 21 pediatric patients and summarized their imaging features and clinical presentation.

CONCLUSION

The spectrum of pathology involving the pituitary infundibulum is broad yet distinct from other pathology in the sella and parasellar region. Pituitary stalk lesions can be grouped into three categories: congenital and developmental, inflammatory and infectious, and neoplastic. Knowledge of the imaging appearance of diseases specific to adults and to children is important for accurate diagnosis and treatment.

Abnormal prion protein in the pituitary in sporadic and variant Creutzfeldt-Jakob disease

By using high-sensitivity Western blotting and immunohistochemistry, pituitary glands from patients with sporadic and variant Creutzfeldt-Jakob disease (sCJD and vCJD, respectively) were analysed for the presence of the protease-resistant form of the prion protein (PrPres). PrPres was detected in a greater proportion of vCJD pituitaries than sCJD pituitaries and was localized predominantly in the neurohypophysis. PrPres was also detected in a recurrent pituitary adenoma from an sCJD patient. Immunohistochemical analysis showed sparse positive labelling, predominantly in folliculostellate cells, in vCJD and sCJD adenohypophyses. The PrPres glycosylation pattern in the vCJD neurohypophyses showed a predominance of the unglycosylated band, which differed markedly from patterns found in all other vCJD tissues. The presence of PrPres in the pituitary of CJD patients at autopsy suggests that human growth hormone-related iatrogenic CJD may have indeed resulted from infectivity in collected pituitaries rather than necessarily from contamination of pituitary pools by adjacent brain tissue.

Contribution of magnetic resonance imaging in non-tumoral hypopituitarism in children

BACKGROUND

Magnetic resonance imaging (MRI) is of paramount importance for evaluating the hypothalamo-pituitary axis in children.

METHODS

We summarize the main points of the MRI technique, and describe the normal appearance of the hypothalamo-pituitary axis as a function of age and pubertal status. The most frequent causes of non-tumoral hypopituitarism include anterior pituitary deficiency (growth hormone deficiency may be isolated or associated with other anterior pituitary hormone deficiencies, with or without other malformations, and related to a known genetic abnormality in some cases), isolated hypogonadotropic hypogonadism and posterior pituitary deficiency with or without anterior pituitary hormone deficiency (central diabetes insipidus may be observed without tumor development).

RESULTS

We describe in detail the appearance of the adenohypophysis, the pituitary stalk and the neurohypophysis, correlations with hormone deficiencies, the abnormalities that may be associated and progression over time for each condition.

CONCLUSION

An accurate description of hypothalamo-pituitary axis abnormalities is necessary for accurate diagnosis and prognosis evaluation, with certain features suggestive of particular diseases and some prognostic data correlated with phenotype.

[Optic nerve hypoplasia associated to ectopic neurohypophysis]

Hypoplasia of the optic nerve is a rare congenital anomaly of unknown etiology that is a frequent cause of blindness in children. It can present in isolation or associated to other malformations of the central nervous system. Magnetic resonance is the technique of choice for the study of this condition; it enables both the hypoplasia of the nerve and the possible associated malformations to be demonstrated. We present a case of optic nerve hypoplasia associated to ectopic neurohypophysis.

Idiopathic central diabetes insipidus in children and young adults is commonly associated with vasopressin-cell antibodies and markers of autoimmunity

OBJECTIVES

Autoimmune targeting of hypothalamic-neurohypophyseal structures in children and young adults with posterior pituitary and anterior pituitary dysfunction, as well as pituitary stalk involvement, are not yet completely understood.

DESIGN

We aimed to (1) evaluate the presence of circulating vasopressin-cell autoantibodies (AVPc-Abs) in young patients with central diabetes insipidus (CDI), (2) detect organ-specific autoantibodies as markers of autoimmunity, and (3) define the relationship between immune markers and neuroimaging findings.

PATIENTS

Twenty patients were evaluated at a median age of 16.3 years. Twelve patients had idiopathic CDI, six had Langerhans cell histiocytosis (LCH) and two had germinoma. AVPc-Abs were evaluated in 40 healthy children. Magnetic resonance imaging (MRI) of the hypothalamic-pituitary region was performed longitudinally in all subjects.

MEASUREMENTS

Circulating arginine vasopressin (AVP), protein tyrosine phosphatase (IA2), glutamic acid decarboxylase (GAD), 21-hydroxylase (21-OH), endomysium antibodies (EMA), parietal cell (PCA), thyroid peroxidase (TPO), thyroglobulin (TG) and TSH-receptor (TSHr) autoantibodies were evaluated.

RESULTS

Circulating AVPc-Abs were found in 15 patients (75%), nine with idiopathic CDI, four with LCH and two with germinoma; the pituitary stalk was involved in most of them. Five patients with idiopathic CDI showed a persistence of AVPc-Abs during follow-up and one became positive subsequently. Serum IA2 autoantibodies were demonstrated in 14 patients (70%) and 21-OH autoantibodies in three of them.

CONCLUSION

In idiopathic CDI, circulating AVPc-Abs suggest an autoimmune involvement of the neurohypophyseal system. The identification of AVPc-Abs in subjects who could have either idiopathic CDI or LCH or germinoma, however, indicates that AVPc-Abs cannot be considered a completely reliable marker of autoimmune CDI. Thus, close clinical and MRI follow-up are needed because AVPc-Abs may mask germinoma or LCH.

Participation of the subfornical nucleus in hypothalamic-neurohypophyseal axis activation during the early phase of endotoxic shock

During the early phase of endotoxic shock the hypothalamus is activated and neurohypophyseal hormone secretion is increased. In order to study the participation of the subfornical organ (SFO) in this response we lesioned the nucleus and determined hormone secretion and c-fos expression in the paraventricular and supraoptic nuclei after administration of lipopolysaccharides (LPS) in rats. LPS significantly increased the number of cells showing Fos immunoreactivity in the paraventricular and supraoptic nuclei of the hypothalamus (p < 0.05) and also caused an increase in plasma levels of vasopressin and oxytocin (p < 0.05). SFO lesion significantly reduced LPS-induced Fos immunoreactivity (p < 0.05) and hormone secretion (p < 0.05). We conclude that the SFO participates in the activation of the hypothalamic-neurohypophyseal axis in the early phase of endotoxic shock.