Androgen receptor in pituitary adenomas of the gonadotroph cell complex

Although androgen receptors have been identified in normal gonadotroph and somatotroph cells of the pituitary, immunohistochemical studies have failed to reveal these receptors in pituitary adenomas so far. Using a monoclonal antibody to androgen receptor in our series of 60 adenomas of the gonadotroph cell complex (20 FSH/LH cell adenomas, 20 null cell adenomas, 20 oncocytic adenomas), only one null cell adenoma showed strong nuclear immunostaining. All the other antibodies were completely negative. The significance of this finding in correlation with clinical data is still unclear, although it may be associated with more rapid tumor growth. In paraadenomous tissue, some normal gonadotrophs expressed the androgen receptor.

Cyclins D1 and D3 and topoisomerase II alpha in inactive pituitary adenomas

The oncogenes cyclin D1 and D3 are overexpressed in many tumors. Topoisomerase II alpha is found in proliferating cells. The immunohistological expression of cyclin D1, cyclin D3, and Topoisomerase II alpha was studied in a collection of 60 clinically inactive surgically removed pituitary adenomas of the follicle-stimulating hormone/luteinizing hormone (FSH/LH) cell complex (20 null cell adenomas, 20 oncocytomas, and 20 FSH/LH cell adenomas) for correlation with other proliferation markers (Ki-67, PCNA) and with clinical data. Whereas cyclin D1 was positive only in one invasive null cell adenoma (1.7%) with some p53-positive nuclei, cyclin D3 was overexpressed in the nuclei of 41 tumors (68%). Topoisomerase II alpha was demonstrated in the nuclei of 42 adenomas (70%) with no significant differences discernible between the three adenoma subtypes. There was no significant correlation to the time of development of tumor symptoms, but a correlation of Topoisomerase II alpha with cyclin D3 and the proliferation marker Ki-67 (Mib1). From these data we conclude that cyclin D3 and Topoisomerase II alpha appear to be additional markers for proliferation which can be used for prognosis index in surgical pathology of the pituitary.

GH-, PRL-, POMC-, beta-TSH-, beta-LH-, beta-FSH-mRNA in gonadotroph adenomas of the pituitary by in situ hybridization in comparison with immunostaining and clinical data

In situ hybridization (ISH) enables the visualization of specific mRNA for pituitary hormones. Our collection consists of 40 surgically removed pituitary adenomas that were classified as follicle stimulating hormone/luteinizing hormone (FSH/LH) cell adenomas by structure and by immunostaining (IH) for all pituitary hormones. All forty adenomas were regarded as clinically inactive. The aim of our study was to examine nonfunctioning adenomas by ISH for demonstration of mRNAs for all pituitary hormones. The results were compared with proliferation markers, invasiveness and clinical data. ISH detected signals for all pituitary hormones at a range of 30% for prolactin (PRL) to 85% for proopiomelanocortin (POMC). mRNA for beta-FSH was detected in 70% and beta-LH mRNA in 43% of adenomas. Thirty-three percent of adenomas revealed negative mRNA detection for beta-LH but positive hormone content. The majority of adenomas (75%) expressed more than two mRNAs simultaneously, mostly the combination of POMC mRNA together with beta-FSH mRNA and one to four others. Comparison with clinical data showed no significant differences except for one adenoma with a high Ki-67 index (> 2.1% positive nuclei). This adenoma showed very high signals for PRL and beta-TSH mRNA.

CD markers in pituitary adenomas

Immunostaining of CD markers in normal pituitary cells has been reported, but a study of these markers in pituitary adenomas has not been done. The expression of CD 3, CD 8, CD 15, CD 20, CD 30, CD 43, CD 45R0, CD 45 R, CD 79 alpha, and VS-38c was investigated in a collection of 65 pituitary adenomas of various types. CD 3 was present in 75%, CD 8 in 18.5%, CD 15 in 12.3%, CD 20 in 66.1%, CD 30 in 10.8%, CD 43 in 10.8%, CD 45 RO in 72.3%, CD 45 R in 16.9%, CD 79alpha in 0% and VS-38 c in 44.6%. Densely granulated GH cell adenomas expressed CD 3, CD 20, CD 45 RO, and CD 45 R, but no other markers. Sparsely granulated GH cell adenomas showed CD 3, CD 8, CD 20, CD 43, and CD 45 RO. Mixed GH/prolactin cell adenomas contained CD 3, CD 8, CD 20, CD 30, CD 45RO, CD 45 R, and VS-38c. Mammosomatotroph cell adenomas were positive only for CD 3, CD 8, CD 20, CD 43, and CD 45 RO. Prolactin cell adenomas expressed CD 3, CD 8, and CD 20. ACTH cell adenomas showed CD 3, CD 15, CD 20, CD 30, CD 45 RO, CD 45 R, and VS-38c. TSH cell adenomas contained CD 3, CD 8, CD 15, CD 20, CD 45 RO, and VS-38c. Gonadotroph cell adenomas were positive for CD 3, CD 8, CD 20, CD 45 RO, CD 45 R, and VS-38c. Alpha-subunit-only adenomas expressed CD 3, CD 8, CD 15, CD 20, CD 30, CD 45 RO, and VS-38c. Plurihormonal adenomas contained CD 3, CD 8, CD 20, CD 30, CD 43, CD 45 RO, CD 45 R, and VS-38c. Oncocytic adenomas were positive for all markers except CD 45 RA and CD 79 alpha. We conclude that the spectra of different adenoma types expressing CD markers varies greatly and that significant correlations do not exist, although noninvasive adenomas appear to express CDs more frequently than invasive adenomas. We have no clear-cut explanations for the various expressions and suggest that it may be a sign of local inter-actions between the immune system and pituitary adenomas.

The expression of the antiproliferative gene ZAC is lost or highly reduced in nonfunctioning pituitary adenomas

The ZAC gene encodes a new zinc-finger protein that concomitantly induces apoptosis and cell cycle arrest and localizes to chromosome 6q24-q25, a well-known hot spot related to cancer. ZAC is highly expressed in the anterior pituitary gland, and its ablation by antisense targeting promotes pituitary cell proliferation. Here we investigate ZAC status in pituitary tumors to evaluate its role in pituitary tumorigenesis. Interest ingly, a strong reduction or absence of ZAC mRNA and protein expres sion was detected in nonfunctioning pituitary adenomas, whereas in clin ically active pituitary neoplasias, the decrease in ZAC expression was variable. Loss of expression was not associated with a mutation of the ZAC gene. Our observations suggest that alternative mechanisms of gene inactivation and/or altered regulation of the ZAC gene occur in nonfunctioning pituitary adenomas.

Histopathological classification of adrenal tumours

Tumours in the adrenals originate from the adrenal cortex, the adrenal medulla or as metastases from extra-adrenal primaries. Differentiating between these three groups is the first task a pathologist has to tackle when dealing with specimens from the adrenal region. Whereas this is possible in every case with total removal of the adrenal tumour it may be impossible in fine needle biopsies of such tumours. The second great problem is the dignity of adrenal tumours, which cannot be determined in many adrenomedullary and some adrenocortical tumours. Immunostainings are helpful but the basic method remains the histopathological examination of paraffin sections. This review gives an update of pathological findings in several adrenal tumour entities, and provides guidelines for the diagnosis of these tumours in the light of recently published data.

Hormone production in pituitary adenomas following external irradiation: an experimental study in rats

INTRODUCTION

The aim of this study was to investigate the hormone production in pituitary gland tumors following fractionated external irradiation in rats.

MATERIALS AND METHODS

Sixty female Wistar rats 3 to 4 month of age at the beginning of the experiments, were subjected to fractionated roentgen-rays exposure, 2 Grays (Gy) daily, either up to 20, 40 or 60 Gy. The animals were sacrificed either 6 month or 1 year after completion of the randomly assigned irradiation protocol.

RESULTS

We found 9 pituitary tumors in 60 irradiated rats (15%). All tumors proved to be adenomas. Immunohistochemical analysis of hormone production in remnants of the normal adenohypophysis revealed immunoreactivity for growth hormone (GH), adrenocorticotropic hormone (ACTH), prolactin (PRL), thyroid-stimulating hormone (TSH), and follicle-stimulating hormone (FSH). In adenomas, 4 cases were immunoreactive for TSH, 4 for GH, 2 for PRL, and 2 for FSH. The tumors were not reactive with anti-ACTH and anti-LH (luteinizing hormone).

DISCUSSION

We concluded that irradiation accelerates the development of pituitary gland adenomas. In our series these tumors were predominantly incidental findings at necropsies after pre-termed follow-up, with a variety of hormone producing tumor cells. However, 4 of 9 tumors in our study were not producing hormones.

Surgical treatment of clinically nonsecreting pituitary adenomas in elderly patients

OBJECTIVE

The goal of this study was to evaluate the efficacy and safety of transsphenoidal pituitary surgery for elderly patients, using improved techniques of the past decade.

METHODS

We retrospectively analyzed 32 surgically treated cases of clinically nonsecreting pituitary adenomas in patients more than 70 years of age (mean, 73.9+/-3.4 yr). These patients were identified in a review of 982 patients with pituitary adenomas who were treated at University Hospital Eppendorf, Hamburg, between January 1991 and November 1999.

RESULTS

The mean preoperative duration of symptoms was 1.9 years (2 wk to 11 yr). The chiasmatic syndrome was present for 27 patients (84.4%). All patients underwent transsphenoidal surgery. Seven patients underwent reoperations. Preoperative assessments of anterior pituitary function revealed growth hormone deficiencies for 21 of 27 patients (77.8%), thyroid insufficiencies for 10 of 30 patients (33.3%), and adrenal insufficiencies for 13 of 29 patients (44.8%). Hypogonadism and hyperprolactinemia were observed for 76.7% and 46.9% of the patients, respectively. All tumors were macroadenomas, ranging from 18 to 50 mm (average, 33.6 mm) in size, including 7 enclosed and 25 invasive adenomas. Complete microscopic tumor resection was achieved in 24 cases, and subtotal removal was performed in 8 cases. There were no severe perioperative complications. In the cases involving hyperprolactinemia, serum prolactin levels were normalized for 8 of 11 patients (72.7%). Normal thyroid function was recovered for 1 of 10 patients (10.0%) with preoperative hypothyroidism. However, growth hormone or adrenal insufficiencies persisted for all patients with preoperative insufficiencies. Visual disturbances were improved for 19 of 23 patients (82.6%). All patients recovered well after surgery, with an average hospital stay of 16.3 days. Histological and immunohistochemical studies demonstrated gonadotroph adenomas in 56.7% of cases, null-cell adenomas in 26.7%, and oncocytomas in 13.3%.

CONCLUSION

Surgical treatment of nonsecreting pituitary adenomas causing visual disturbances is standard, even for elderly patients. In this series, transsphenoidal surgery was a safe procedure, with minimal morbidity and excellent tolerance. Age alone is not a contraindication for active treatment, particularly with transsphenoidal surgery.

Acromegaly associated with a granular cell tumor of the neurohypophysis: a clinical and histological study. Case report

Acromegaly is usually caused by a growth hormone (GH)-secreting pituitary adenoma, and hypersecretion of GH-releasing hormone (GHRH) from a hypothalamic or neuroendocrine tumor accounts for other cases. The authors report on the unusual association of acromegaly with a granular cell tumor of the neurohypophysis. A 42-year-old woman with a 10-year history of acral enlargement, headache, and menstrual abnormalities was referred to our department for a suspected GH-secreting pituitary adenoma. The patient's basal GH levels were mildly elevated at 4.8 microg/L, were not suppressed in response to an oral glucose tolerance test, and increased paradoxically after administration of thyrotropin-releasing hormone. The patient's insulin-like growth factor-1 (IGF-1) level was elevated at 462 microg/L, whereas a magnetic resonance image of the sella turcica revealed an intra- and suprasellar lesion that was compatible with a diagnosis of pituitary adenoma. A transsphenoidal approach to remove the lesion, which was mainly suprasellar, was successful during a second operative attempt, resulting in the clinical and biochemical regression of the patient's acromegaly. Four months postoperatively, the patient's basal GH level was 0.9 microg/L and her IGF-1 level was 140 microg/L. Histological analysis of the operative specimen demonstrated a granular cell tumor of the neurohypophysis, which when stained proved negative for pituitary hormones and GHRH. This case represents the first reported association between a granular cell tumor of the neurohypophysis and acromegaly. Granular cell tumor of the neurohypophysis could be added to the restricted list of neoplastic causes of acromegaly secondary to hypersecretion of a GH-releasing substance.

[Pituitary necrosis. Decreasing incidence due to modern intensive therapy?]

Pituitary necroses develop from the interruption of circulation in the pituitary stalk, especially due to shock, trauma, etc. We studied the incidence, extent, and outcome of necroses in postmortem series from 1991 to 1998 and compared these with the findings in our own study in the 1970s. Necroses were classified into four degrees based on the proportion of anterior pituitary volume: grade I, up to 5%; grade II, 5-10%; grade III, 10-50%; grade IV, more than 50%. The data show a decreased incidence of necrosis, from 7.7% in the 1970s to 3.1% in the 1990s. Scars, indicating former necroses, decreased in incidence from 11.4% to 3.6%. The changes in the four grades of necrosis were: a decrease in grade I from 60% to 41%, a decrease in grade II from 24% to 22%, an increase in grade III from 9% to 17%, and an increase in IV from 8% to 20%. These figures reveal that pituitary necroses became less frequent but more extensive. Necroses of grade IV are generally caused by more than a single cause. The decreased incidence appears to be the consequence of progress in intensive care over the past 20 years, as patients can now survive severe shock longer. The increased frequency of intensive necroses is probably due to the longer period for greater extent of necrosis to develop during intensive care.

Transsphenoidal surgery for pituitary gigantism and galactorrhea in a 3.5 year old child

The management of pituitary macroadenomas which lead to gigantism may require multiple therapeutical approaches, including medical treatment, surgery, and radiation therapy. Transsphenoidal surgery (TSS) during early childhood that achieves total removal of a growth hormone (GH) secreting tumor is rarely reported. The surgeon is confronted with special problems regarding the infantile anatomy. In this case, a 3.5 year old child, the youngest successfully treated by TSS so far, suffered from a GH- and prolactin (PRL) secreting macroadenoma of the pituitary gland. The girl initially presented with an increasing growth rate, later with breast development, and finally, at the age of 2.8 years, with galactorrhea and secretion of blood from the nipples. Increased levels of GH [122 micrograms/l], insulin-like growth factor (IGF-1) [830 micrograms/l], insulin-like growth factor binding protein 3 (IGFBP-3) [8.6 mg/l] and PRL [590 micrograms/l] were found. MRI scans revealed a macroadenoma of 2.7 cm diameter. An eight-week trial of relatively low dose dopamine agonists led to a reduction of PRL, while the GH- and IGF-1 levels remained unchanged; the tumor showed only little shrinkage. Since there was chiasma compression, we opted for early TSS. A complete tumor removal was achieved despite the difficulties of a narrow approach. After TSS, low levels of GH, IGF-1, and PRL documented a complete tumor removal, but persistent diabetes insipidus and anterior lobe deficits resulted from surgery. In summary, if primary medical therapy alone is unable to adequately reduce hormone hypersecretion and tumor size in early childhood, TSS is recommended. Thus, radiation therapy may be reserved for surgical failure.

[A patient with an ACTH-producing pituitary tumor with liver metastasis]

HISTORY AND FINDINGS

A 57-year-old woman had an ACTH-producing pituitary adenoma twice resected, followed by bilateral adrenalectomy for recurrent hypercortisolism. She subsequently developed a secondary postadrenalectomy syndrome (Nelson's tumour) which required further surgery and radiotherapy. The patient now presented for elucidation of a space-occupying lesion in the liver, found incidentally on abdominal ultrasonography.

INVESTIGATIONS

Immunocytochemistry of the liver biopsy revealed ACTH-producing cells that were structurally identical to the cells found in the specimen resected at the previous operation. Changes were also found in the lower thoracic vertebrae, suspicious of metastases, thus suggesting a metastasizing hypophyseal carcinoma. RESULTS AND COURSE: Resection of the primary tumour and subsequent radiotherapy had arrested the corticotropic, thyrotropic, and gonadotropic functions of the pituitary, which had been adequately treated by administration of the corresponding hormones. Ocreotide, bromocriptin or cytostatics were not given because of their reported doubtful efficacy. At the time of diagnosis of the malignancy a curative operation on the liver or palliative embolization of the liver metastases were not possible because of their number and size. The bone metastases were managed palliatively by radiotherapy.

CONCLUSION

No curative treatment has been found for the 66 cases of hypophyseal carcinoma reported so far. Screening investigations in patients with operated pituitary adenoma with the aim of eliciting an early diagnosis of possible malignancy cannot, therefore, be recommended, particularly since renewed tumour growth and local invasiveness do not constitute criteria for the diagnosis of pituitary carcinoma.

Basement membrane proteins and apolipoprotein E in growth hormone secreting adenomas and their correlation to amyloid: an immunoelectron microscopic study

Having previously demonstrated the association of basement membrane components (BMC), as well as apolipoprotein E and amyloid in growth hormone (GH)-producing pituitary adenomas, the aim of this study was to further analyze this relationship at the ultrastructural level. Ultrathin sections from four amyloidotic sparsely granulated monohormonal GH-producing adenomas previously investigated light microscopically were selected. Immunoelectron microscopy was performed, using a single labeling postembedding on-grid Protein-A gold method with antisera directed against laminin, fibronectin and apolipoprotein E. In all four adenomas, anti-laminin, anti-fibronectin, and anti-apolipoprotein E reacted with amyloid fibrils. No BMC were demonstrated between amyloid deposits, making it likely that synthesis and deposition of BMC may be secondary to the deposition of amyloid. The intimate spatial relationship between BMC as well as apolipoprotein E and amyloid fibrils may indicate morphological evidence of a particular arrangement of amyloid components in GH-secreting adenoma amyloid and a pathophysiological link.

Cushing's syndrome due to an ectopic ACTH-secreting pituitary tumour mimicking occult paraneoplastic ectopic ACTH production

A 32-year-old man presenting with typical features of Cushing's syndrome showed baseline cortisol and ACTH values indicating ACTH-dependent disease. Dynamic function tests (dexamethasone, corticotropin releasing hormone (CRH), desmopressin), were suggestive of paraneoplastic ectopic ACTH production. However, inferior petrosal sinus (IPS) ACTH sampling demonstrated a maximum baseline central (363 pmol/l)-peripheral (19 pmol/l) ACTH gradient of 19.1 for the right IPS, conventionally suggestive of Cushing's disease. However, again, IPS ACTH level did not increase after CRH stimulation. Magnetic resonance imaging, while showing no evidence of an intrasellar tumour, revealed an 1.5 x 1.0 cm mass in the left sphenoid sinus which was initially interpreted as most probably being a mucosal polyp. After neurosurgical removal of the tumour, transient secondary adrenal insufficiency was present. The structure and immunostaining characteristics of the tumour demonstrated an ACTH cell adenoma of the pituitary. Ectopic ACTH-secreting pituitary adenomas may cause significant difficulties in differential diagnosis, localisation and appropriate therapy. Thus, although these tumours are rare, they should be included in the list of possible causes of ACTH-dependent Cushing's syndrome.

Markers of function and proliferation in non-invasive and invasive bi- and plurihormonal adenomas of patients with acromegaly: an immunohistochemical study

Twenty-seven plurihormonal and 21 growth hormone- prolactin- (GH- PRL-) mixed cell adenomas obtained from patients with acromegaly undergoing transnasal-transsphenoidal surgery were investigated immunohistochemically for expression of Epidermal Growth Factor (EGF), Transforming Growth Factor alpha (TGF alpha), Insulin-like Growth Factor-1 (IGF-1), Estrogen Receptor-Related Protein (ERRP), Multidrug Resistance Marker (MDRM), Protein Kinase C (PKC), Gs alpha,. Cathepsin D and p53. Five plurihormonal adenomas grew invasively. The panel of markers used in this study represents a selection of functional and proliferative markers thought to be associated with the function and development of pituitary adenomas. Our results imply that the growth factors (EGF, TGF alpha, IGF-1), the cell signalling protein Gs alpha and the MDRM are expressed by both types of pituitary adenomas in a similar pattern. Non-invasive GH-PRL-mixed cell adenomas showed an increased expression of IGF-1, TGF alpha and MDRM compared to non-invasive plurihormonal adenomas. No factor was found which would reliably distinguish between invasive and non-invasive adenomas. We failed to confirm the findings of others that p53 and cathepsin D might be indicators of tumor aggressiveness. A participation of ERRP and PKC in the development of bi- and plurihormonal adenomas with acromegaly appears unlikely, as the immunostains were all negative.

Correlates of long-term hypocortisolism after transsphenoidal microsurgery for Cushing's disease

In Cushing's disease, selective total removal of a corticotroph tumor of the pituitary regularly results in subnormal ACTH- and cortisol plasma levels. The duration of secondary adrenocortical insufficiency varies widely, with an average of 17 months in our patients. The goal of this study is to elucidate the underlying causes for the variation in duration of postoperative hypocortisolism. In this retrospective study, we evaluated 35 patients with postoperative hypocortisolism lasting more than 36 months, and compared them to 51 patients with a duration of less than 36 months. Preoperative data, intraoperative findings, and postoperative results with follow-up evaluations are presented. Extensive pituitary exploration, medial localization of the tumor, and a higher age were associated with increased risk for isolated secondary long-term hypocortisolism. The histological examination of paraadenomateous tissue identified a significantly larger amount of Crooke's cells in long-term cortisol insufficient patients. Previous pituitary surgery increased the risk for hypopituitarism. In some of our patients, the long-term adrenocortical insufficiency resolved after a period of over five years.

Pituitary adenomas in acromegaly: Comparison of different adenoma types with clinical data

Adenoma tissues from 309 patients with active acromegaly was examined by routine light microscopy and immunohistochemistry, and selectively by electron microscopy. All adenomas were immunoreactive for growth hormone. Eighty-seven adenomas were monohormonal (28%), 58 were bihormonal (immunoreactive for growth hormone and prolactin) (19%), and 157 adenomas were plurihormonal (51%), with positivity for glyco-proteins and/or their α-subunit as well. The mean tumor size was significantly greater in monohormonal adenomas than in other adenoma types. There was no difference in invasiveness among the various adenoma types. Younger patients showed invasive tumor growth more often. Patients with densely granulated GH cell adenomas had a significantly longer duration of symptoms compared to patients with other adenoma types. More than half of the patients with sparsely granulated GH cell adenomas had a duration of less than 5 yr. There was no correlation between duration of symptoms and tumor size. The preoperative mean GH level was significantly higher in patients with sparsely granulated GH cell adenomas than in those with mixed GH/PRL cell adenomas. The preoperative mean PRL level was significantly higher in patients with bihormonal adenomas than in those with plurihormonal adenomas. There was an inverse correlation between age and preoperative GH and PRL levels. No linear correlation was found between preoperative basal GH and PRL levels. Monohormonal adenomas presented more often with suprasellar and/or parasellar extension than other adenoma types. Our data suggest a positive correlation between tumor extension and preoperative GH and PRL levels. Patients with plurihormonal adenomas were significantly older than patients with sparsely granulated GH cell adenomas and mixed GH/PRL cell adenomas. No significant difference was found between the various adenoma types and the extent of surgical removal, which depends on the degree of invasiveness, tumor size, and extrasellar tumor extension.

Proliferation markers in different types of clinically non-secreting pituitary adenomas

160 clinically non-secreting pituitary adenomas were examined in regard to their expression of the markers PCNA, bcl2, Ki 67 in the mib-1 modification and p53 which are still under investigation for their relevance to cell proliferation. The series contained 60 null cell adenomas, 60 oncocytomas and 40 gonadotroph adenomas. The groups that showed a definitely negative and definitely positive staining were evaluated in regard to their further characteristics such as size, invasiveness and recurrence. PCNA showed a highly represented immunostaining index throughout the groups, but not correlation between the PCNA index and an increased recurrence rate could be found. The staining for bcl2 was only rarely positive and only in a small number of cells. No correlation with the clinical data could be seen. We found a significant higher rate of staining in the invasive adenomas in the group of null cell adenomas and oncocytomas for Ki 67, especially in those adenomas expressing p53. p53 positivity was restricted to the invasive adenomas but was found only in 20% of all invasive adenomas. These data confirm in a sufficiently large series of clinically endocrine inactive pituitary adenomas, that p53 and Ki67 immunohistology is useful in evaluating the aggressive behavior of clinically silent pituitary adenomas. Nevertheless, negative results do not exclude clinically relevant invasive behavior.

Lymphocytic hypophysitis masking a suprasellar germinoma in a 12-year-old girl--a case report

Case history, light and electron microscopic findings of a case of a lymphocytic hypophysitis in coincidence with a suprasellar germinoma in a 12-year-old girl are reported. The girl presented with a long time case history of diabetes insipidus and subsequent panhypopituitarism. Two years after the diagnosis of diabetes insipidus magnetic resonance imaging (MRI) showed a tumorous enlargement of the sellar content and pituitary stalk. A transnasal exploration was initially performed and revealed a lymphocytic hypophysitis. Light microscopy showed a dense infiltration of mature lymphocytes and plasma cells in the interstitium of the anterior pituitary gland. The stalk area could not be exposed to exclude a germinoma. One year later the lesion relapsed despite dexamethason therapy and a second operation by another neurosurgeon had to be performed. Light microscopy showed lymphocytic infiltrates, fibrosis and necrosis. The diagnosis was a lymphocytic hypophysitis again. Though transcranially exposed only pituitary tissue was removed. No infundibular mass became visible at surgery as shown by MRI. The girl developed five months later multiple cerebral lesions, which revealed to be a germinoma. Lymphocytic hypophysitis in children is very rare and a coincidence with a germinoma has not been described from histopathological aspect until now. The origin of the pituitary infiltration is discussed.

Folliculo-stellate cells in pituitary adenomas of patients with acromegaly

Pituitary adenoma tissue from patients with acromegaly (n = 286) was obtained by surgery and examined for folliculo-stellate cells by immunostaining for S100 protein. The number of immunostained cells varied from one adenoma to another. A hundred and ninety-eight pituitary adenomas (69%) contained S100 protein positive cells corresponding to folliculo-stellate cells (FSC): in 100 cases (35%), only few sparse FSC were found, in 43 cases (15%) FSC were scattered throughout the adenoma, and in 55 cases (19%) there was an abundance of FSC. There were no significant differences regarding sex or age of the patients. The relative amount of FSC vaired among different adenoma types. Plurihormonal adenomas showed the highest FSC density, whereas the majority of monohormonal adenomas contained only few or no FSC. Patients with pituitary adenomas containing scattered FSC had a significantly higher preoperative mean GH level than patients with pituitary adenomas not having FSC. There was a negative correlation between the FSC density in adenoma tissue and the preoperative mean PRL level. There was no correlation between the tumour size and the amount of FSC. Our data indicate no effect of the duration of symptoms on the FSC density and do not suggest a correlation between FSC density and the percentage of a certain hormone-secreting cell type.

Lymphocytic hypophysitis with central diabetes insipidus and consequent panhypopituitarism preceding a multifocal, intracranial germinoma in a prepubertal girl

We report the clinical course of a prepubertal girl with central diabetes insipidus (DI) and consequent panhypopituitarism evolving over a period of 10 years due to lymphocytic hypophysitis and subsequent germinoma. Two years after the diagnosis of central DI was established, MRI revealed a thickened pituitary stalk. Later pituitary enlargement and increasing thickening of the pituitary stalk impinging on the optic chiasm required a trans-sphenoidal biopsy which disclosed active hypophysitis with lymphocytic infiltrates and necrosis. High dose dexamethasone treatment only temporarily halted the disease process. Therefore, stereotactic radiation therapy was performed as a rescue treatment and MRI findings almost reversed. However, the subsequent MRI showed multiple intracranial lesions identified histologically as a germinoma and a standard chemotherapy and radiation was performed.

CONCLUSION

The diagnosis of diabetes insipidus in children requires long-term follow up beyond the pubertal age in order to establish the underlying cause. In contrast to lymphocytic hypophysitis in adults, lymphocytic hypophysitis in prepubertal children may represent the first sign of a host reaction to an occult germinoma.

Reduced expression levels of the cell-cycle inhibitor p27Kip1 in human pituitary adenomas

The molecular mechanisms leading to increased cellular proliferation rates and, thus, tumor formation in the anterior pituitary gland are poorly understood. The cyclin-dependent kinase inhibitor p27Kip1 is a key molecule regulating the G1 phase of the cell cycle in many cell types. Furthermore, it was shown that p27 knock-out mice develop pro-opiomelanocortin-positive pituitary tumors. In an effort to clarify the role of p27 in the normal and tumorous human pituitary, we studied the expression of p27 by immunohistochemistry, using a highly specific mouse monoclonal anti-human p27 antibody. Normal pituitaries and 54 pituitary adenomas (twelve somatotrope adenomas, nine prolactinomas, twelve corticotrope adenomas, three TSH-producing tumors, six gonadotrope adenomas, six null cell adenomas, and six oncocytomas) were analyzed. p27 expression was determined semiquantitatively with regard to both the percentage of positive cells and the intensity of the staining. Normal human pituitaries showed strong expression of p27 in most nuclei. In contrast, the levels of p27 were reduced in the majority of the tumors analyzed. Twenty-two tumors (six somatotrope adenomas, five prolactinomas, four corticotrope adenomas, two TSH-producing tumors, two gonadotrope adenomas, and three null cell adenomas) were completely p27-negative. In 18 tumors, p27 expression was found in < or = 10% of the cells. In the other ten tumors, 11-80% of the cells were p27-positive. In summary, we were able to demonstrate reduced expression levels of the cell-cycle inhibitor p27 in tumors derived from all pituitary cell types. Our data indicate that p27 may be an important regulator of cellular proliferation in the anterior pituitary, the underexpression of which could play a role in pituitary tumorigenesis.

Breast tumors with myofibroblastic differentiation: clinico-pathological observations in myofibroblastoma and myofibrosarcoma

This report describes the clinico-pathological features of myofibroblastic tumors of the breast in six patients. Four women and one man presented with a benign myofibroblastoma. The sixth patient was a woman with myofibrosarcoma. All myofibroblastomas were composed of a fascicular arrangement of spindle cells embedded in dense bundles of collagen. Tumors differed with respect to their proportion of neoplastic cells and collagenous stroma as well as cellular pleomorphism. Based on this variation, the tumors could be subclassified as classic, collagenized, epithelioid and cellular myofibroblastoma. Immunohistological staining confirmed myofibroblastic differentiation by strong expression of either desmin or smooth muscle actin with coexpression of vimentin. In addition, numerous cells reacted with antibodies to CD68. Proliferative activity was rather low in the myofibroblastoma with an average of 0-2 mitotic figures per 10 HPF. DNA cytometric analysis was performed in two cases and showed diploid stem lines with minor S-phase fractions (1% and 3%). In the myofibrosarcoma, cells contained pleomorphic nuclei with some giant cells and numerous mitotic figures (6-7/10 HPF) and had infiltrating margins that were apparent even grossly. Immunohistochemically, tumor cells strongly expressed vimentin, smooth muscle actin and fibronectin. Ultrastructurally, neoplastic cells met the criteria of myofibroblasts, i.e. contained abundant intermediate filaments and myofilament bundles with focal densities as well as fibronexus junctions. DNA cytometric analysis exhibited again a diploid stemline but marked proliferative activity was present as indicated by an S-phase fraction of 20%. In conclusion, in benign myofibroblastoma there may be some cellular pleomorphism but mitotic activity is always low. The malignant counterpart, myofibrosarcoma, is characterized by marked cellular pleomorphism, infiltrating margins and high mitotic rate.

Ganglioglioma of the neurohypophysis with secretion of vasopressin

A patient with a ganglioglioma of the neurohypophysis developed the syndrome of inappropriate antidiuretic hormone secretion (SIADH). We present the case and describe its microscopic and ultrastructural features. Malignant neoplasms were thought to be the main cause of ectopic production of vasopressin. Head trauma, infection, or drugs, however, can also induce hypersecretion of vasopressin. Mechanical compression of the pituitary stalk can lead to an excessive antidiuretic hormone (ADH) release by affecting the inhibitory system. Primary neuroendocrine tumors of the hypothalamic-neurohypophyseal system are extremely rare. We demonstrate the presence of vasopressin in the tumor cells by immunocytochemistry. This represents the first case of SIADH caused by a tumor of the neurohypophysis.

[Amyloid: microscopic demonstration, classification and clinical correlation]

Amyloid is a biophysically defined, biochemically non-uniform protein which is deposited in the tissue, forming a cross-beta configuration. In paraffin sections it is demonstrated using Congo red staining according to Puchtler et al. and a polarizing microscope with a tension-free clean optic system that shows a typical apple-green birefringence. The identification of amyloid has to be followed by immunostaining for AA, ATTR, A lambda, A kappa and A beta 2 microglobulin and possibly further types of amyloids for classification purposes. Considering the localization, expansion and type localized and generalized types probably can be differentiated. The latter should be correlated to a basic disease. The treatment of the basic disease is the only chance for reducing or eliminating the amyloid deposits. In this review, the modern morphological methods for demonstration and both immunohistological and clinical classification of amyloid and amyloidoses are presented. Rare types are mentioned in the tables.