Effect of temozolomide in a patient with recurring oncocytic gonadotrophic pituitary adenoma

The patient was a 70-year-old man with a recurrent pituitary tumor. Three surgeries were performed but the tumor recurred. Based on histologic, immunohistochemical and ultrastructural studies, the diagnosis of oncocytic gonadotrophic pituitary adenoma was made. The tumor was a macroadenoma partly immunopositive for LH. Immunohistochemistry for O6 Methylguanine-DNA Methyl-Transferase (MGMT) showed an admixture of immunopositive and immunonegative cells. After recurrence following operations, the patient was treated with Temozolomide, an imidazotetrazine derivative, DNA-alkylating drug. Following Temozolomide administration the MRI demonstrated significant tumor necrosis. A few months later, the patient died of massive pulmonary embolism. No autopsy was performed. The present case indicates that benign, typically slow-growing pituitary adenomas of oncocytic gonadotrophic type may respond to Temozolomide even when the tumor consists of an admixture of MGMT immunopositive and immunonegative cells.

Identification of lymphatics in the ciliary body of the human eye: a novel "uveolymphatic" outflow pathway

Impaired aqueous humor flow from the eye may lead to elevated intraocular pressure and glaucoma. Drainage of aqueous fluid from the eye occurs through established routes that include conventional outflow via the trabecular meshwork, and an unconventional or uveoscleral outflow pathway involving the ciliary body. Based on the assumption that the eye lacks a lymphatic circulation, the possible role of lymphatics in the less well defined uveoscleral pathway has been largely ignored. Advances in lymphatic research have identified specific lymphatic markers such as podoplanin, a transmembrane mucin-type glycoprotein, and lymphatic vessel endothelial hyaluronan receptor-1 (LYVE-1). Lymphatic channels were identified in the human ciliary body using immunofluorescence with D2-40 antibody for podoplanin, and LYVE-1 antibody. In keeping with the criteria for lymphatic vessels in conjunctiva used as positive control, D2-40 and LYVE-1-positive lymphatic channels in the ciliary body had a distinct lumen, were negative for blood vessel endothelial cell marker CD34, and were surrounded by either discontinuous or no collagen IV-positive basement membrane. Cryo-immunogold electron microscopy confirmed the presence D2-40-immunoreactivity in lymphatic endothelium in the human ciliary body. Fluorescent nanospheres injected into the anterior chamber of the sheep eye were detected in LYVE-1-positive channels of the ciliary body 15, 30, and 45 min following injection. Four hours following intracameral injection, Iodine-125 radio-labeled human serum albumin injected into the sheep eye (n = 5) was drained preferentially into cervical, retropharyngeal, submandibular and preauricular lymph nodes in the head and neck region compared to reference popliteal lymph nodes (P < 0.05). These findings collectively indicate the presence of distinct lymphatic channels in the human ciliary body, and that fluid and solutes flow at least partially through this system. The discovery of a uveolymphatic pathway in the eye is novel and highly relevant to studies of glaucoma and other eye diseases.

Effect of estrogen on the blood supply of pituitary autografts in rats

Estrogens are known to cause pituitary enlargement and lactotroph proliferation. They also modulate pituitary angiogenesis and induce tumor formation. Pituitary grafts, due to the loss of hypothalamic dopamine, also show lactotroph hyperplasia. We investigated the role of estrogen on rat pituitary autograft vascularization by light and transmission electron microscopy, and assessed prolactin (PRL) blood levels, microvessel density (MVD) and cell proliferation using the BrdU labeling index. All adenohypophysial cell types were identified by immunohistochemistry (streptavidin-biotin-peroxidase complex method). The proangiogenic factors, vascular endothelial growth factor (VEGF), its receptor Flk-1, and hypoxia inducible factor-1alpha (HIF-1alpha) were similarly demonstrated. The prevalence of lactotrophs, as well as more intense staining for VEGF, Flk-1 and HIF-1alpha, was noted in those grafts exposed to estrogen, mainly in the area surrounding the central necrotic core. Immunostaining showed Flk-1 expression increased in endothelial cells of the estrogen-exposed grafts as compared with those unexposed. In contrast to the grafts not exposed to estrogen, in the estrogen-exposed grafts, only fenestrated endothelium could be demonstrated, suggesting that estrogen induces fenestration of newly formed capillaries. There was an increase in blood PRL levels in the estrogen-treated groups as compared with controls. Both MVD and BrdU labeling indices were higher in grafts exposed to estrogen, especially after 4 weeks. Our results suggest that estrogen administration not only enhances the expression of proangiogenic factors in the pituitary grafts but also induces their expression at earlier stages, leading to rapid neoformation of purely fenestrated capillaries.

Silent subtype 3 pituitary adenoma: a clinicopathologic analysis of the Mayo Clinic experience

BACKGROUND

Macroadenomas represent 50% of pituitary tumours and are often (30%) nonfunctioning. Their immunophenotype suggests differentiation toward a specific pituitary cell line. A substantial proportion of tumours with particularly aggressive behaviour are so called 'silent subtype 3 adenoma'. Its diagnosis requires ultrastructural confirmation. Although once included among silent corticotroph adenomas, this aggressive, morphologically distinctive tumour is now recognized as a major form of plurihormonal adenoma and, in fact, some patients might present with clinical hormonal excess. The cytogenesis and pathobiology of silent subtype 3 adenomas is unsettled.

OBJECTIVE

We undertook a systematic clinicopathologic examination of the Mayo Clinic experience with this poorly understood tumour.

DESIGN

This retrospective, single institution study found 27 confirmed examples of silent subtype 3 adenoma, a frequency of 0.9% of adenomas. Despite histologic and immunophenotypic variation, their ultrastructural features were diagnostic and the sole basis for case inclusion.

RESULTS

The study group was comprised of 16 men (59%) and 11 women (41%); two patients (7%) had definitive diagnosis of multiple endocrine neoplasia type 1 (MEN1). Three tumours (11%) were discovered incidentally. Nine patients each (38%) presented with headaches or visual field loss. Endocrine hyperfunction was noted in eight cases (30%), including GH excess in five (19%) and clinically significant PRL elevation in three (11%). Hypogonadism was noted in 17 cases (63%) and growth arrest in one (4%). All tumours were macroadenomas; 16 (60%) showed radiographic evidence of invasion. Most tumours were plurihormonal, featuring immunoreactivity for PRL (17), GH (15), TSH (16) or ACTH (3); only one lesion was immunonegative. Although a gross total resection was achieved in 19 cases (70%), re-operation for recurrence(s) was required in seven of these (37%). Follow-up (mean, 69 months) showed a high (59%) rate of persistent or recurrent of tumour. Overall, 14 patients (54%) underwent radiotherapy after surgical treatment: three patients (12%) for substantial residual tumour, eight (31%) as adjuvant therapy and three (12%) for tumour regrowth.

CONCLUSION

Silent subtype 3 adenoma, a plurihormonal tumour, is rare and aggressive in nature. This adenoma must be considered in the differential of often clinically nonfunctioning but plurihormonal adenomas featuring variable cytologic atypia. Electron microscopy is required for confirmation of the diagnosis. The cytogenesis of silent subtype 3 adenoma remains unsettled.

Pituitary adenoma with peliosis: a report of two cases

Peliosis is characterised by multiple blood-filled lakes or cavities within parenchymatous organs. Typically found in the liver, spleen, bone marrow and lymph nodes, it has also been described in other organs such as lungs, kidneys, parathyroids and pancreas. The mechanism responsible for the development of peliosis remains unknown. (1) A 69 year-old man with a 6-year history of acromegaly underwent transsphenoidal surgery for pituitary adenoma. Morphologic findings demonstrated a plurimorphous plurihormonal pituitary adenoma consisting of somatotrophs, lactotrophs and mammosomatotrophs. The tumor contained several blood-filled cavities characteristic of peliosis. (2) A 61-year-old man with a prolactin-producing pituitary adenoma who underwent transsphenoidal surgery. In the tumor, peliosis was noted. Peliosis in a pituitary adenoma is an intriguing finding. The question arises whether it represents vasculogenic mimicry.

Collision tumors of the sella: craniopharyngioma and silent pituitary adenoma subtype 3: case report

Collision tumors of the sella turcica are rare and consist mainly of more than one type of pituitary adenoma, usually a corticotropin- and a prolactin-producing adenoma. The association of a craniopharyngioma and a pituitary adenoma is rare. Herein, we report the first case of an association between craniopharyngioma and silent pituitary adenoma subtype 3. It involved a 12-year-old boy who underwent a frontal craniotomy with surgical removal of a calcified sellar tumor. Histology revealed an adamantinomatous craniopharyngioma; however, by electron microscopy, there was conclusive evidence of adenoma cells showing the ultrastructural features of silent pituitary adenoma subtype 3. Endocrine and neuroimaging as well as detailed immunohistochemical and ultrastructural studies were undertaken. The literature is also reviewed.

Primary pituitary lymphoma: a histological, immunohistochemical, and ultrastructural study with literature review

We report the case of a 62-year-old man with headache and left sixth cranial nerve palsy. A computerized tomography scan revealed an osteolytic process involving the sella turcica and clivus. A partial tumor resection was achieved via an endoscopic transsphenoidal approach. Morphologic investigation revealed a diffuse large B cell lymphoma involving pituitary parenchyma. No systemic disease was found upon staging. Primary pituitary lymphoma is extremely rare. An accurate histologic diagnosis is key to successful treatment and a favorable prognosis. The literature is reviewed.

[The "Zurich Quality Model of Nursing Care", based on the "Quality of Health Outcome Model" (QHOM): a new perspective in measuring quality in nursing care]

Ensuring and maintaining a high level of quality in nursing care becomes more and more important as economic pressure is increasing and personnel is being reduced. The nursing executives of four large Swiss hospitals therefore commissioned a group of nursing scientists and nursing experts with the task of developing a trendsetting model to represent, assess, and interpret the quality of nursing care. The "Quality of Health Outcome Model" (QHOM) served as a basis for development. More than 60 nurses from acute care hospitals and specialized clinics assessed a first draft of the model in hearings and by means of questionnaires. The model integrated earlier attempts at quality screening regarding structures, processes and results, complementing these three elements with a fourth: the patients, whose characteristics influence the results of nursing care remarkably. Thus, the former one-dimensional, linear viewpoint was resolved into a dynamic representation of all four elements, illustrating a specific concept of nursing care. Through the multi-dimensionality of the model the complexity of the nursing process is better represented. The model's core consists of eight exemplary indicators of quality, each of which is relevant to nursing and for each of which criteria and assessment tools have been formulated. The model is seen as a basis and reference for the quality development and first opportunities for clinical application have been succesfully employed. The project can serve as a paradigm of networking amongst hospitals and cooperation between nursing scientists and experts, and of the critical significance of such collaboration to the advancement of nursing quality.

Multiple endocrine neoplasia type 1-associated thyrotropin-producing pituitary carcinoma: report of a probable de novo example

Pituitary carcinomas are exceedingly rare. At present, the sole diagnostic criterion is metastatic spread, either craniospinal or systemic. There is no agreement on a histologic, immunohistochemical, and/or ultrastructural definition. We report a clinically and morphologically well-documented example of pituitary thyrotropin cell carcinoma in a man with multiple endocrine neoplasia type 1 syndrome. The tumor produced thyrotropin, alpha-subunit, and prolactin and, through electron microscopy, was found to consist solely of Thyrotroph cells. Over a protracted course, craniospinal and systemic metastases were noted. The primary and metastatic deposits of this aggressive tumor were studied. To our knowledge, this tumor is the first reported case of thyrotropin cell carcinoma occurring in association with the multiple endocrine neoplasia type 1 syndrome. The literature regarding thyrotropin carcinomas is reviewed. Based on the study of several biopsies during disease progression, we believe that the carcinoma originated de novo without an intermediary adenoma phase.

Immunohistochemical expression of nestin in adenohypophysial vessels during development of pituitary infarction

OBJECTIVES

The aim of this work was to investigate the immunohistochemical expression of nestin, a member of the intermediate filament family, in adenohypophysial vasculature during development and progression of pituitary infarction.

METHODS

Forty-five nontumorous adenohypophyses and 34 pituitary adenomas of various types, all exhibiting acute or healing infarcts, were examined immunohistochemically using the streptavidin-biotin-peroxidase complex method.

RESULTS

In both adenohypophyses and pituitary adenomas without infarction, nestin was expressed in only a few capillaries and endothelial cells. In acute infarcts without a vascular response, no nestin was demonstrable within necrotic capillaries (50 cases). In organizing infarcts, newly formed vessels spreading into necrotic zones showed nestin expression in all capillaries and practically every endothelial cell (25 cases). In the hypocellular, fibrotic scar phase, only a few vessels (4) were apparent, and immunoreactivity was focal and mild.

CONCLUSIONS

Nestin is strongly expressed in newly formed capillaries and is downregulated when infarcts transform to fibrous tissue. Nestin expression may provide valuable insight into the process of pituitary angiogenesis.

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.

Adrenomedullin expression in pituitary adenomas and nontumoral adenohypophyses

Adrenomedullin (ADM) is a novel peptide originally identified in extracts of human pheochromocytoma. It is produced by several tissues, including the pituitary gland. The presence of ADM has been immunohistochemically demonstrated in pathologic pituitary glands, but no systematic study of ADM expression in human pituitary adenomas has been reported. Thus, we investigated ADM immunoexpression in 88 various hormone-secreting and clinically nonfunctioning pituitary adenoma types as well as 30 nontumoral adenohypophyses. Furthermore, ADM immunoreactivity was assessed on a 0 to +3 scale in all samples. We found strong immunoreativity for ADM in normal gonadotrophs also expressing FSH and LH whereas in the other adenohypophysial cell types expression of ADM was mild. Results showed that normal adenohypophyses were strongly immunopositive for ADM (2.18+/-0.11). Our findings demonstrate that ADM expression in the anterior pituitary is diminished in tumors as compared to the normal gland. The physiologic function of ADM is unknown, but it could act as a paracrine or autocrine factor in the adenohypophysis.

Hormonal and morphological study of the pituitaries in reeler mice

Reelin is a neuronal glycoprotein that plays a crucial role in brain layer formation during prenatal development. The reeler mutant mouse lacks Reelin, leading to abnormalities in the neuronal layering of cerebral cortex and cerebellum, producing ataxia, tremor and abnormal locomotion. Reeler mice are reported to have growth retardation and most of them are sterile or unable to bring up their newborns. Since the brain is one of the main regulator of pituitary hormone secretion and no information was reported regarding pituitary function and structure in these mutant mice, we studied pituitary endocrine activity and morphology in reeler mice. Mice were classified in three groups as reeler homozygote (RHM), reeler heterozygote (RHT) or control (CO). Pituitary hormone blood levels were assessed by enzyme immunoassay (EIA) and immunoradiometric assay (IRMA). Animals and their pituitaries were weighted and pituitaries were studied by histology, immunohistochemistry and electron microscopy. Results showed statistically significant differences in body weight and in adrenocorticotropic hormone (ACTH) and luteinizing hormone (LH) blood levels between the three groups. In contrast, growth hormone (GH) blood levels showed a high individual variation and no decrease in reeler groups compared with CO. Morphological studies revealed no differences in pituitary cell types except that somatotrophs appeared to be slightly smaller in RHM and RHT. Although it seems that pituitary hypofunction is not responsible for growth retardation, more studies are needed to obtain a deeper insight into the endocrine status of these mutant mice to elucidate the cause of their low body weight and reproductive behaviour.

A randomized phase 2 trial of combretatstatin A4 phosphate (CA4P) in combination with paclitaxel and carboplatin to evaluate safety and efficacy in subjects with advanced imageable malignancies

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Background: CA4P is the lead compound in a class of agents termed Vascular Disrupting Agents. Phase I studies of CA4P demonstrated toxicities that do not overlap those of chemotherapy. In vitro studies show synergistic cytotoxicity for CA4P and chemotherapy. This study was designed to assess safety, toxicity and tumor perfusion of CA4P at 2 doses when combined with paclitaxel and carboplatin at fixed doses. Methods: A one stage, randomized trial for subjects with imageable tumors by DCE-MRI for perfusion. Subjects received either 45 or 63 mg/m2 CA4P IV on Days 1, 8, and 15, then 200 mg/m2 paclitaxel and AUC 6 carboplatin on Day 2 of each 21 day cycle. After completion of 6 cycles, subjects could continue with CA4P alone. DCE-MRI was measured prior and 24 hours after the first dose of CA4P. Results: 13 subjects were accrued from 3/05–11/05. 78 cycles were administered and 1 subject continues active therapy on cycle 19. The median number of cycles administered was 6. Both 45 and 63 CA4P with paclitaxel/carboplatin were well tolerated. The most frequent adverse events are listed in Table 1 . Grade 3–4 AEs were similar between the two dose groups. Table 1 : Most Frequent AEs by CA4P Dose DCE-MRI data showed a mean reduction in blood flow for both dose groups (46% vs. 19% respectively) confirming CA4P’s tumor vascular disrupting capabilities. Tumor responses were observed and were similar between both dose groups. Best overall response through cycle 6 was 3 PR, and 6 SD. Two subjects with thyroid cancer were randomized to the low dose group and completed cycle 6. The 1st had SD and progressed after cycle 6. The 2nd achieved PR and progressed after 8 cycles. These subjects also had the greatest reduction in tumor blood flow. Ktrans was reduced by 73 and 79% 24 hours post CA4P. Conclusion: These doses of CA4P in combination with paclitaxel and carboplatin were well tolerated, demonstrated anti-tumor activity and reduction of tumor blood flow.

[Table: see text]

No significant financial relationships to disclose.

Pituitary adenoma with tumoral granulomatous reaction

Herein, we report a unique case of an adult male with a corticotrophic pituitary adenoma of silent subtype 1 exhibiting conspicuous idiopathic tumoral noncaseating granulomatous inflammation. The lesion was unassociated with clinical or laboratory evidence of either systemic sarcoidosis or infection. Histochemical and polymerase chain reaction (PCR) studies revealed neither fungi nor tubercle bacilli. We suggest that tumoral production of an as yet uncharacterized antigen may have induced the granulomatous inflammatory reaction.

Temozolomide therapy in a man with an aggressive prolactin-secreting pituitary neoplasm: Morphological findings

Administration of temozolomide to a 46-year-old man with an invasive aggressive prolactin (PRL)-secreting pituitary neoplasm resulted in improvement of the clinical condition and significant decrease of blood PRL levels. Histologic, immunohistochemical, and electron microscopic study demonstrated marked morphological differences in the tumor exposed to temozolomide compared with the unexposed tumor. Necrosis, hemorrhagic areas, accumulation of connective tissue, focal inflammatory infiltration, and neuronal transformation were seen. Immunohistochemical prognostic indicators showed a reduction in growth potential. Based on the clinical, laboratory, and morphological findings, we recommend temozolomide therapy in patients with pituitary tumors not responding adequately to other treatment options.

Pituitary tumor transforming gene overexpression facilitates pituitary tumor development

Intrinsic and extrinsic stimuli result in profound pituitary growth changes ranging from hypoplasia to hyperplasia. Pituitary tumor transforming gene (PTTG) abundance correlates with pituitary trophic status. Mice with Pttg inactivation exhibit pituitary hypoplasia, whereas targeted pituitary PTTG overexpression driven by alpha-subunit glycoprotein (alphaGSU) promoter results in focal pituitary hyperplasia. To test the impact of pituitary hyperplasia on tumor development, we crossbred alphaGSU.PTTG with Rb+/- mice, which develop pituitary tumors with high penetrance. Pituitary glands of resulting bitransgenic alphaGSU.PTTGxRb+/- mice were compared with monotransgenic alphaGSU.PTTG, Rb+/-, and wild-type mice. Confocal microscopy showed that PTTG-overexpressing cells have enlarged nuclei and marked redistribution of chromatin, and electron microscopy of alphaGSU.PTTG pituitaries showed enlarged gonadotrophs with prominent Golgi complexes and numerous secretory granules. These morphological findings were even more remarkable in alphaGSU.PTTGxRb+/- pituitaries. Mice from all four genotypes were sequentially imaged by magnetic resonance imaging to evaluate pituitary volume, and glands from alphaGSU.PTTGxRb+/- mice were the largest as early as 2 months of age (P = 0.0003). Cumulative incidence of pituitary tumors visualized by magnetic resonance imaging did not differ between Rb+/- and alphaGSU.PTTGxRb+/- mice. However, anterior lobe tumors determined after necropsy were 3.5 times more frequent in alphaGSU.PTTGxRb+/- than in Rb+/- mice (P = 0.0036), whereas the frequency of intermediate lobe tumors was similar. In summary, alphaGSU.PTTGxRb+/- pituitary glands exhibit enhanced cellular activity, increased volume, and higher prevalence of anterior pituitary tumors, indicating that changes in pituitary PTTG content directly relate to both pituitary trophic status and tumorigenic potential.