[Histopathology of the hypothalamus and the neural lobe of hypophysis in suicide victims]

Histologic studies of the hypothalamus and neurohypophysis revealed that in young (17-35 y. o.) suicide victims, there are degenerative changes in the supraoptic and paraventricular nuclei and partial destruction by inflammation of the neurohypophysis. Simultaneously foci of micromalaic and the gatuering of azurophilic material in neuronal perikarya around the cerebral blood vessel and the leptomeninges. The degenerated neurones contain great vacuoles, often filled with lipofuscin. The probable pathogenic mechanism of the observed changes is discussed with its influence on mood-lowering leading to suicide.

Central precocious puberty in multisystem Langerhans cell histiocytosis: a case report

The authors describe a girl with multisystem Langerhans cell histiocytosis (LCH) who developed central precocious puberty (CPP). At the age of 19 months she presented with otorrhea and polypoid formations in the ear canal; polyps were removed and LCH suspected. She subsequently developed diabetes insipidus with a documented lesion of the pituitary stalk; she received chemotherapy and began therapy with l-desamino-8-D-argininevasopressin. Growth hormone deficiency was diagnosed at the age of 4.4 years and GH replacement therapy started. The patient has been off therapy for LCH since the age of 6. Signs of pubertal development appeared at 7.5 years (bone age 8 years) and gonadotropin-releasing hormone analog (GnRHa) treatment was started. During the observation period she developed central hypothyroidism. Development of CPP during LCH is extremely rare; to the authors 'knowledge, no patient has been described so far. The authors believe that CPP was secondary to LCH and did not represent a casual finding, even in the absence of hypothalamic-pituitary axis involvement. The presence of preceding lesions producing excessive cytokine levels, with damage on the neurosecretory apparatus that inhibits the GnRH pulse generator, represents the most intriguing hypothesis. The possibility of CPP development should be considered during the follow-up of these patients.

[Corticotroph microadenomas of the pituitary stalk. Diagnostic and therapeutic difficulties]

Thirteen percent of the pituitary adenomas in our series have been corticotroph adenomas. Most have been microadenomas located in the adenohypophysis, more often laterally than posteromedially. In a few rare cases, the corticotroph cells of the pars tuberalis gave rise to an adenoma. Only 16 cases of pituitary stalk adenomas have been published to date. We report here three new cases among a series of 150 patients who underwent surgery for corticotroph adenomas (2% incidence as in the literature). There was no difference in the clinical or biological presentation of intrasellar and pituitary stalk adenomas. This location must be systematically searched on the MRI, but a negative exploration cannot excluded the diagnosis of pituitary stalk adenoma like in intrasellar ones. Two anatomical entities seems to be separated. Some stalk adenomas developed preferentially in the supradiaphragmatic space (one in our series) and are accessible for selective resection. Others develop within the pituitary stalk itself and sometimes in the pars distalis (two patients in our series) which requires section of the pituitary stalk with hypophysectomy if the lower limit is not clearly seen during surgery. The subfrontal or pterional access is the approach of choice for suprasellar tumors. These approaches remain controversial for pituitary stalk adenomas because of the poor visibility of the pituitary stalk and the floor of the third ventricle. The transnasosphenoidal approach with extension to the sphenoidal planum and opening of the optochiasmatic cisterna appears to be the best alternative for surgical removal of these adenomas.

Clinical and molecular analysis of three families with autosomal dominant neurohypophyseal diabetes insipidus associated with a novel and recurrent mutations in the vasopressin-neurophysin II gene

OBJECTIVE

To test further the hypothesis that autosomal dominant neurohypophyseal diabetes insipidus (adFNDI) is caused by heterozygous mutations in the vasopressin-neurophysin II (AVP-NPII) gene that exert a dominant negative effect by producing a precursor that misfolds, accumulates and eventually destroys the neurosecretory neurons.

METHODS

Antidiuretic function, magnetic resonance imaging (MRI) of the posterior pituitary and AVP-NPII gene analysis were performed in 10 affected members of three unreported families with adFNDI.

RESULTS

As in previously studied patients, adFNDI apparently manifested after birth, was due to a partial or severe deficiency of AVP, and was associated with absence or diminution of the hyperintense MRI signal normally emitted by the posterior pituitary, and with a heterozygous mutation in the AVP-NPII gene. In family A, a transition 275G-->A, which predicts replacement of cysteine 92 by tyrosine (C92Y), was found in the index patient, but not in either parent, indicating that it arose de novo. The six affected members of family B had a transversion 160G-->C, which predicts replacement of glycine 54 by arginine (G54R). It appeared de novo in the oldest affected member, and was transmitted in a dominant manner. In family C, six of 15 living affected members were tested and all had a novel transition, 313T-->C, which predicts replacement of cysteine 105 by arginine (C105R). It, too, was transmitted in a dominant manner. As in other patients with adFNDI, the amino acids replaced by the mutations in these three families are known to be particularly important for correct and efficient folding of the precursor.

CONCLUSIONS

These findings are consistent with the malfolding/toxicity hypothesis underlying the pathogenesis of adFNDI. Moreover, they illustrate the value of genetic analysis in all patients who develop idiopathic diabetes insipidus in childhood, even if no other family members are affected.

Preoperative location of the pituitary bright spot in patients with pituitary macroadenomas

BACKGROUND AND PURPOSE

The purpose of this study was to determine the location of the pituitary bright spot in patients with pituitary macroadenomas before surgery.

METHODS

A total of 54 patients with pituitary macroadenomas were retrospectively included in this study. Nonenhanced spin-echo T1-weighted MR images were reviewed to identify the location of the high-intensity-signal posterior pituitary lobe that indicates antidiuretic hormone (ADH) storage. Images were acquired with a 1.5-T machine by using 3-mm-thick contiguous sections in two or three orthogonal planes and a 300 x 512 matrix.

RESULTS

The bright spot corresponding to ADH storage was identified in 44 (81%) patients. Two groups of patients were defined by the height of the macroadenoma: Group A patients (n = 27) had pituitary macroadenomas less than 20 mm in height, and group B (n = 27) had macroadenomas 20 mm or larger. In group A, the bright spot was identified in 25 patients (93%); it was located in the sella in 24 of these cases (96%). In group B, the bright spot was identified in 19 patients (70%); it was in an ectopic location in 14 of these cases (74%).

CONCLUSION

MR imaging can be used to depict the pituitary bright spot in most patients with pituitary macroadenomas before surgery. The bright spot is usually identified at its expected location within the sella in patients with pituitary macroadenomas less than 20 mm in height, whereas an ectopic location is common when pituitary macroadenomas are larger more than 20 mm.

MRI evaluation of the diaphragmal opening: using MRI parallel to the transsphenoidal surgical approach

Twenty-six adult diaphragma sellae and infundibulae were examined by MRI parallel to the transsphenonidal surgical plane with attention given to the diaphragmal opening. The diaphragmal opening was observed in 11 cases (42.3%). The anteroposterior diame ter of the opening ranged from 4.0 to 14.0 mm (mean 8.8 mm), and the lateral diameter ranged from 6.0 to 14.0 mm (mean 9.5 mm). In the cases of open diaphragma sellae, the infundibulum tended to be located in the posterior part of the diaphragma sellae but this was not statisticallysignificant. On MRI parallel to the transsphenoidal surgical approach, the anatomy of the dia phragma sellae was well evaluated.

Depletion of neurohypophyseal content of vasopressin in septic shock

OBJECTIVES

To assess the mechanisms underlying the inappropriately low plasma vasopressin levels reported in septic shock.

DESIGN

Prospective case series.

SETTING

A 26-bed general medical intensive care unit at a university hospital.

PATIENTS

Septic shock patients.

MEASUREMENTS AND MAIN RESULTS

In three consecutive patients with septic shock, plasma vasopressin levels, circulating vasopressinase activity, baroreflex sensitivity, and neurohypophyseal vasopressin content were assessed. Plasma vasopressin concentration was unexpectedly within normal range in two patients (1.6 pg/mL and 1.8 pg/mL) and increased in one (16 pg/mL). In all cases, vasopressinase activity was undetectable, baroreflex sensitivity was decreased, and the high signal intensity of the posterior lobe of the pituitary gland on T1-weighted magnetic resonance images was absent. Magnetic resonance imaging and plasma vasopressin levels normalized after recovery from shock in the patient who survived.

CONCLUSION

These data suggest that in septic shock, inappropriately low plasma levels of vasopressin are at least partly related to a depletion of vasopressin stores in the neurohypophysis.

Effects of aging on vasopressin production in a kindred with autosomal dominant neurohypophyseal diabetes insipidus due to the DeltaE47 neurophysin mutation

Postmortem examinations of the hypothalamus of patients with autosomal dominant neurohypophyseal diabetes insipidus (adNDI), which have been reported only on persons dying between the ages of 37-87 yr, reveal the presence of the arginine vasopressin (AVP)-producing parvocellular neurons but the absence of 95% of the expected AVP-producing magnocellular neurons. To determine whether the clinical course of adNDI is compatible with the hypothesis that the neuropathologic findings are attributable to a progressive loss of magnocellular neurons beginning in early life, we performed posterior pituitary magnetic resonance imaging and water deprivation tests, including plasma ACTH measurements, on 17 affected members of a kindred with the deltaE47 neurophysin mutation whose ages ranged from 3 months to 54 yr. Nine adult nonaffected members (ages, 20-56 yr) underwent these tests as controls. All six children undergoing magnetic resonance imaging demonstrated a posterior pituitary hyperintense signal (PPHS). Eight of nine affected adults showed an absent or barely visible PPHS, whereas eight of nine age-matched nonaffected adults produced a normal size PPHS. During water deprivation tests, infants concentrated their urine normally, and a 3-month-old infant produced a high plasma AVP level of 15.7 pmol/liter. By school age, affected children were no longer able to concentrate their urine or prevent hypernatremia. Affected adults became dehydrated; their median plasma AVP level was less than 1.0 pmol/liter, but their median fasting plasma ACTH was 2-fold greater than the level of nonaffected adults (10.0 vs. 5.0 pmol/liter; P = 0.008). These results suggest that adNDI is a progressive disease associated with chronic loss of the magnocellular neurons that supply AVP to the posterior pituitary but preservation of the parvocellular neurons that supply AVP and CRH to the median eminence and stimulate ACTH production during hypernatremia.

Changes in the epithelium of Rathke cleft cyst associated with inflammation

OBJECT

Rathke cleft cysts (RCCs) are composed of tall, well-differentiated, ciliated columnar epithelia. Their structures are altered by hyperplasia or squamous metaplasia, but their cause remains unknown.

METHODS

The authors studied pathological findings and anterior pituitary function in 20 patients harboring RCCs. They classified RCC epithelium as either single (a single ciliated columnar cell lining or a flattened cuboidal cell lining) or stratified (a stratified ciliated columnar cell lining, basal cell hyperplasia, columnar cell hyperplasia, or squamous metaplasia). Inflammation was classified as acute, subacute, chronic, or end stage. The epithelial cell lining was observed in 13 specimens obtained during surgery (six specimens contained single and seven contained stratified epithelia). Inflammation had penetrated the cyst epithelium or subjacent stroma in 10 patients, and the stage of inflammation correlated well with the type of epithelia group: early stages of inflammation in the single epithelium group and chronic or end-stage inflammation in the stratified epithelia (p = 0.0027). The adenohypophysis was identified in 21 surgical specimens. Postoperatively, growth hormone (p = 0.019), cortisol (p = 0.027), and thyroid-stimulating hormone (p = 0.039) responses significantly worsened as the inflammation progressed. The presence of diabetes insipidus correlated well with advanced stages of neurohypophysitis (p = 0.025).

CONCLUSIONS

Epithelial stratification in the RCC is caused by inflammation that may extend into the adjacent adenohypophysis or neurohypophysis and overwhelm the hypophysis, resulting in panhypopituitarism. Transsphenoidal excision may represent the best choice for treatment, at least for cases of RCC in which there is partial impairment of hypophysial function.

Hypothalamo-neurohypophysial magnocellular neuroendocrine system of field voles after acute heat or cold stress

Hypothalamo-neurohypophysial magnocellular neuroendocrine system (H-NH MC NES) of field voles was described in normal conditions and after acute heat or cold stress. 60 mature males of field voles were used for examinations after 2 weeks of adaptation to stable conditions of laboratory keeping. 10 animals were the controls. Another group of 25 field voles were subjected to sudden cold of -15 degrees C for 3 hours. The third group of 25 field voles were subjected to sudden heat of +32 degrees C for 3 hours. Neurosecretory material in paraffin 6 microns sections was stained with paraaldehyde fuchsin (fixed in Bouine fluid in the modyfication of Bock et al. 1968) and tigroid was stained with toluidine blue (fixed in Carnoy fluid). Routine staining with hematoxylin and eosin was used for comparison. It was found that H-NH MC NES in field voles has similar body structure as that described in many reports for laboratory H-NH MC NES of rodents. Supraoptic nucleus (SON) consisted of large multipolar neurocytes and paraventricular nucleus (PVN) consisted of slightly smaller neurocytes. PVN also included areas with small neurocytes. Acute heat or cold stress evoked enhanced concentration of neurosecret in SON and PVN and in the remaining H-NH MC NES structures of field voles simultaneously a decrease of tigroid contents was observed in neurocytes of SON and PVN after heat stress.

August 2001: Sellar/suprasellar mass in a 59-year-old woman

The August 2001 COM. Symptomatic granular cell tumors (GCTs) of the neurohypophysis are rare lesions. They are generally regarded as benign neoplasms, although detailed descriptions of the natural course of the tumors are limited to a few cases. We report on a 59-year-old woman with a large GCT of the neurohypophysis and rapid onset of symptoms. Although lacking definitive signs of malignancy, the tumor showed nuclear polymorphism, proliferative activity, evidence of a mutation of the tumor suppressor gene p53 as well as expression of the apoptosis-inhibiting protein bcl-2. These indices may be useful in defining more precisely the clinicopathological prognosis for neurohypophyseal GCTs.

Spectrum of different types of hypophysitis: a clinicopathologic study of hypophysitis in 31 cases

Hypophysitis has been histologically classified into five types: lymphocytic hypophysitis (LYH), granulomatous hypophysitis (GRH), xanthogranulomatous hypophysitis (XGH), xanthomatous hypophysitis (XH), and necrotizing hypophysitis. The present study evaluated 31 cases of hypophysitis to clarify their characteristic clinicopathologic features. The lesions were histologically classified into four groups: LYH (22 cases) including lymphocytic adenohypophysitis (LAH) (19 cases) and lymphocytic infundibuloneurohypophysitis (LINH) (3 cases), GRH (5 cases), XGH (2 cases), and XH (2 cases). In each group, the pituitary gland showed lymphocytic infiltration associated with focal or diffuse hypophysial destruction of variable severity and fibrosis. Histologic and clinical overlap among different types of hypophysitis, especially between LAH and LINH, suggest that these entities may have similar etiologic background and/or represent different stages of the same lesion. Considering the sampling sites and clinical manifestations, LAH may not usually involve the neurohypophysis, but LINH may often extend to the adenohypophysitis. A selective loss of adrenocorticotropic hormone-positive cells was seen in two patients with LAH despite only very slight lymphoplasmacytic infiltration. This suggests that there may be at least two causative mechanisms for hypopituitarism in hypophysitis: nonspecific destruction of all types of adenohypophysial cells by severe inflammation and selective destruction of specific adenohypophysial cells.

Hyperintensity of posterior pituitary on MR T1WI in a boy with central diabetes insipidus caused by missense mutation of neurophysin II gene

We present a 10-year old boy with central diabetes insipidus (CDI) showing hyperintensity in a normal-sized posterior pituitary on magnetic resonance (MR) T1-weighted image (T1WI). He complained of nocturnal enuresis and polyuria. Daily urine volume increased to 4 to 5 L, and AVP plasma level was very low. Polymerase chain reaction (PCR)-amplified exons of the arginine vasopressin (AVP)-neurophysin (NP) II gene were sequenced. Nucleotide-1884 guanine in Exon 2 was substituted with thymine, which induced a substitution of glycine for valine at amino acid position 65 in the NP II moiety. However, MR imaging showed hyperintensity in the posterior pituitary on T1WI. These results suggest that the MR findings of the posterior pituitary in CDI may vary.

Pituicytoma: ultrastructural evidence of a possible origin from folliculo-stellate cells of the adenohypophysis

Pituicytoma is a rare neoplasm occurring in the sellar and suprasellar regions. The tumor is currently considered to arise from the pituicyte, a specialized glial cell of the posterior lobe and the stalk of the pituitary gland. The authors describe a case of pituicytoma, focusing on the ultrastructural features. The patient was a 79-year-old woman with hypopituitarism and visual disturbances. Immunohistochemically, the tumor showed strong and diffuse positivity for vimentin, and EMA and GFAP were focally detectable. Ultrastructurally, the lesion was composed of elongated cells containing in the Golgi area aggregates of intermediate filaments in a concentric pathway (fibrous body), and secretory granules. These features intermediate between a pituicytoma and a pituitary adenoma suggest that "pituicytomas" may also arise from the specialized stromal folliculo-stellate cells of the adenohypophysis, which are able to differentiate into endocrine cells.

Ependymoma of the neurohypophysis

There are two reported cases of ependymomas arising in the pituitary fossa; one in a human, the other in a horse. Both died during their stay in hospital. The case presented here is the first published case of a patient who is well 3 months after surgery.

Intrasellar pituicytoma in a patient with other endocrine neoplasms

Considered a neoplasm of pituicytes, pituicytoma is a rare and distinct type of glioma that arises in the suprasellar space and within the sella turcica. Only 12 previously reported cases of pituicytoma are documented in the literature. We report an intrasellar pituicytoma in a 66-year-old man presenting with symptoms and radiologic appearance indistinguishable from a nonfunctional pituitary adenoma. The patient also had a medical history significant for parathyroid adenomas and follicular carcinoma of the thyroid. The intrasellar tumor had morphologic features of a pituicytoma, with interlacing fascicles and a storiform pattern much like a benign fibrous histiocytoma. Immunoreactivity for S100 was strong, but the tumor lacked intercellular collagen type IV. The differential diagnosis of a low-grade spindle cell lesion of the sellar space is discussed, and the literature is reviewed. A summary of the clinical and pathologic features of this case, as well as the 12 previously reported cases, is presented.

Metachronous neurohypophysical immature teratoma occurring 10 years after total resection of pineal mature teratoma

An 18-year-old boy presented with an immature neurohypophysial teratoma occurring 10 years after total resection of a mature pineal teratoma through an occipital transtentorial approach in 1989. Thorough histological examination had revealed a mature teratoma. He developed panhypopituitarism and diabetes insipidus in 1999. Magnetic resonance imaging revealed a suprasellar tumor occupying the third ventricle. This tumor was totally resected through a frontobasal approach. Histological examination revealed an immature teratoma. This tumor occurred in a different site from the initial tumor and was considered to be de novo and thus a so-called metachronous germ cell tumor. Patients with completely resected mature teratoma require extended follow-up, including periodic magnetic resonance imaging, because of the risk of such a metachronous germ cell tumor.

Lymphocytic hypophysitis: report of an unusual case of a rare disorder

A 36-year-old non-pregnant woman presented with a four-month history of progressive visual deterioration and amenorrhea. The latest gestation was 6 years earlier. Hormonal study revealed central diabetes insipidus, hypopituitarism, and slightly increased prolactin level. Ophthalmologic examination showed bilateral hemianopsia. In the magnetic resonance imaging an intrasellar mass with supra and retrosellar extension was found. The mass showed a polylobular aspect with heterogeneous signal within the tissue. The normal neurohypophysis could not be identified. Pterional craniotomy was performed. The pathological examinations revealed fibrous tissue with heavy inflammatory infiltrate composed of lymphocytes and plasma cells, islands of eosinophilic epithelial cells stained positively for chromogranin, GH, ACTH, and PRL and negatively for antibodies directed against HLA-II antigens. This case of lymphocytic hypophysitis was not related to pregnancy and involved the neurohypophysis. We discuss the features that can help to make a preoperative differential diagnosis.

MR imaging of central diabetes insipidus: a pictorial essay

Central diabetes insipidus (DI) can be the outcome of a number of diseases that affect the hypothalamic-neurohypophyseal axis. The causes of the condition can be classified as traumatic, inflammatory, or neoplastic. Traumatic causes include postoperative sella or transection of the pituitary stalk, while infectious or inflammatory causes include meningitis, lymphocytic hypophysitis, and granulomatous inflammations such as sarcoidosis and Wegener's granulomatosis. Various neoplastic conditions such as germinoma, Langerhans cell histiocytosis, metastasis, leukemic infiltration, lymphoma, teratoma, pituitary adenoma, craniopharyngioma, Rathke cleft cyst, hypothalamic glioma, and meningioma are also causes of central DI. In affected patients, careful analysis of these MR imaging features and correlation with the clinical manifestations can allow a more specific diagnosis, which is essential for treatment.

An unusual MR presentation of the neurohypophyseal "bright spot" in pituitary dwarfism

Abnormalities of the hypothalamo-hypophyseal axis are frequently associated with pituitary deficiency. We describe a previously unknown morphological presentation of the ectopic posterior neurohypophyseal "bright spot."

Pituicytoma: primary astrocytic tumor of the pars nervosa in aging Fischer 344 rats

We describe 2 cases of a relatively rare tumor diagnosed as pituicytoma in the pars nervosa of rat pituitary. This tumor was spontaneously noted in one 110-week-old female and one 109-week-old male Fischer 344 (F344)/DuCrj rats during 2-year carcinogenicity studies. Although no gross abnormality of the pituitary was detected in the female rat, whitish discoloration and enlargement of the pituitary were observed in the male. Histopathologically, neoplastic cells in both animals possessed pale eosinophilic, often abundant irregular cytoplasm with nuclei of variable size. The tumor cells were arranged in the spindle or sheet cell pattern with indistinct cell boundaries and showed compression or invading proliferation of surrounding tissues. Prominent pleomorphism of the cells was noted in the tumor in the female rat, and mitotic figures were detected in several portions of the tumor in the male rat. Small-sized cells having scanty cytoplasm with deeply staining nuclei seen in the mass were suspected to be microglia. Moreover, isolated single native pars distalis cells were distributed throughout the tumor masses. Immunohistochemically, cytoplasmic foot process of the tumor cells showed a positive immunoreactivity for glial fibrillary acidic protein. On the basis of morphologic characteristics and glial fibrillary acidic protein staining, this tumor is consistent with astrocytoma.