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Sidiropoulos M, Syro LV, Rotondo F, Scheithauer BW, Penagos LC, Uribe H, Ramirez MDP, Horvath E, Goth M, Kovacs K. Melanoma of the sellar region mimicking pituitary adenoma. Neuropathology 2012; 33:175-8. [DOI: 10.1111/j.1440-1789.2012.01331.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Salehi F, Scheithauer BW, Kovacs K, Horvath E, Syro LV, Sharma S, Manoranjan B, Cusimano M. O-6-methylguanine-DNA methyltransferase (MGMT) immunohistochemical expression in pituitary corticotroph adenomas. Neurosurgery 2012; 70:491-6; discussion 496. [PMID: 21822153 DOI: 10.1227/neu.0b013e318230ac63] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND O-6-methylguanine-DNA methyltransferase (MGMT) is a DNA repair enzyme that counteracts chemotherapeutic cytotoxicity of alkylating agents such as temozolomide. Low levels of MGMT expression have been shown to correlate with longer survival in glioma patients treated with temozolomide. The same is true in pituitary adenomas. OBJECTIVE We investigated the immunohistochemical expression of MGMT in a variety of corticotroph adenoma subtypes to determine the potential utility of temozolomide as a therapeutic agent. METHODS The tumors consisted of 40 cases of adrenocorticotropin-secreting pituitary tumors in Cushing disease, 12 Crooke cell adenomas, and 7 subtype I silent corticotroph adenomas. Staining for MGMT was assessed by light microscopy; nuclear reactivity was estimated semiquantitatively as present in < 10%, 10% to 25%, 25% to 50%, 50% to 75%, and > 75% of cells. RESULTS Immunoexpression showed no correlation with patient age, sex, tumor size, invasiveness, or recurrence in patients with Cushing disease. Among adrenocorticotropin-secreting adenomas associated with Cushing disease, most invasive (60%) and recurrent (86%) tumors showed low MGMT immunopositivity, defined as < 25%. Most (75%) Crooke cell adenomas exhibited an MGMT immunoreactivity of ≤ 50%. All subtype I silent corticotroph adenomas showed < 10% MGMT staining. CONCLUSION Our descriptive findings of low MGMT expression in adrenocorticotropin-producing pituitary adenomas, particularly aggressive tumors, suggest that they may be suitable candidates for temozolomide therapy.
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Baborie A, Daousi C, Javadpour M, Das K, White H, Macfarlane I, Kovacs K, Horvath E. A clone of elusive parents: gonadotroph adenoma-female type. Ultrastruct Pathol 2012; 36:85-8. [PMID: 22471430 DOI: 10.3109/01913123.2011.642465] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
A 69-year-old woman presented with visual disturbance. Perimetry testing revealed a bitemporal hemianopia. Brain MRI demonstrated a 2.2-cm gadolinium-enhancing pituitary mass. Previously she had been treated for hypothyroidism, hypertension, and dyslipidemia. She had hyperprolactinemia. Endoscopic transsphenoidal debulking improved her visual field defects. Histology showed a chromophobic adenoma. Electron microscopy showed elongated, polar cells with long, slender processes. The small uniform secretory granules were peripherally disposed, collecting heavily within cell processes. Based on electron microscopical characteristics the tumor is consistent with an ACTH-negative female gonadotroph adenoma. The parent cell of this rare variant of a pituitary adenoma is yet unknown.
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Syro LV, Scheithauer BW, Kovacs K, Toledo RA, Londoño FJ, Ortiz LD, Rotondo F, Horvath E, Uribe H. Pituitary tumors in patients with MEN1 syndrome. Clinics (Sao Paulo) 2012; 67 Suppl 1:43-8. [PMID: 22584705 PMCID: PMC3328811 DOI: 10.6061/clinics/2012(sup01)09] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
We briefly review the characteristics of pituitary tumors associated with multiple endocrine neoplasia type 1. Multiple endocrine neoplasia type 1 is an autosomal-dominant disorder most commonly characterized by tumors of the pituitary, parathyroid, endocrine-gastrointestinal tract, and pancreas. A MEDLINE search for all available publications regarding multiple endocrine neoplasia type 1 and pituitary adenomas was undertaken. The prevalence of pituitary tumors in multiple endocrine neoplasia type 1 may vary from 10% to 60% depending on the studied series, and such tumors may occur as the first clinical manifestation of multiple endocrine neoplasia type 1 in 25% of sporadic and 10% of familial cases. Patients were younger and the time between initial and subsequent multiple endocrine neoplasia type 1 endocrine lesions was significantly longer when pituitary disease was the initial manifestation of multiple endocrine neoplasia type 1. Tumors were larger and more invasive and clinical manifestations related to the size of the pituitary adenoma were significantly more frequent in patients with multiple endocrine neoplasia type 1 than in subjects with non-multiple endocrine neoplasia type 1. Normalization of pituitary hypersecretion was much less frequent in patients with multiple endocrine neoplasia type 1 than in subjects with non-multiple endocrine neoplasia type 1. Pituitary tumors in patients with multiple endocrine neoplasia type 1 syndrome tend to be larger, invasive and more symptomatic, and they tend to occur in younger patients when they are the initial presentation of multiple endocrine neoplasia type 1.
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Rotondo F, Cusimano M, Scheithauer BW, Coire C, Horvath E, Kovacs K. Atypical, invasive, recurring Crooke cell adenoma of the pituitary. Hormones (Athens) 2012; 11:94-100. [PMID: 22450349 DOI: 10.1007/bf03401542] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
We report the case of a 49-year-old woman presenting with Cushing disease and visual disturbance. An atypical, aggressive, invasive pituitary tumor regrew despite several surgeries. Detailed morphologic investigation by histology, immunohistochemistry and electron microscopy documented a Crooke cell adenoma, a rare form of ACTH-producing pituitary tumor. Recognition of such adenomas is of importance given their aggressive behavior and tendency to recur. More studies are needed to explain the pathobiology of this not invariably functional pituitary adenoma.
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Ortiz LD, Syro LV, Scheithauer BW, Rotondo F, Uribe H, Fadul CE, Horvath E, Kovacs K. Temozolomide in aggressive pituitary adenomas and carcinomas. Clinics (Sao Paulo) 2012; 67 Suppl 1:119-23. [PMID: 22584716 PMCID: PMC3328813 DOI: 10.6061/clinics/2012(sup01)20] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Temozolomide is an alkylating agent used in the treatment of gliomas and, more recently, aggressive pituitary adenomas and carcinomas. Temozolomide methylates DNA and, thereby, has antitumor effects. O6-methylguanine-DNA methyltransferase, a DNA repair enzyme, removes the alkylating adducts that are induced by temozolomide, thereby counteracting its effects. A Medline search for all of the available publications regarding the use of temozolomide for the treatment of pituitary tumors was performed. To date, 46 cases of adenohypophysial tumors that were treated with temozolomide, including 30 adenomas and 16 carcinomas, have been reported. Eighteen of the 30 (60%) adenomas and 11 of the 16 (69%) carcinomas responded favorably to treatment. One patient with multiple endocrine neoplasia type 1 and an aggressive prolactin-producing adenoma was also treated and demonstrated a good response. No significant complications have been attributed to temozolomide therapy. Thus, temozolomide is an effective treatment for the majority of aggressive adenomas and carcinomas. Evidence indicates that there is an inverse correlation between levels of O6-methylguanine-DNA methyltransferase immunoexpression and therapeutic response. Alternatively, high-level O6-methylguanine-DNA methyltransferase immunoexpression correlates with an unfavorable response. Here, we review the use of temozolomide for treating pituitary neoplasms.
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Manoranjan B, Syro LV, Scheithauer BW, Ortiz LD, Horvath E, Salehi F, Kovacs K, Cusimano MD. Undifferentiated sarcoma of the sellar region. Endocr Pathol 2011; 22:159-64. [PMID: 21681665 DOI: 10.1007/s12022-011-9166-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Malignancies lacking specific features of cellular maturation are termed "undifferentiated" and represent 5-10% of all human tumors. They are encountered at a variety of sites but do not, as a rule, arise in the sellar region. A 39-year-old male with a history of testicular seminoma and an unsuccessful biopsy of a third ventricular neoplasm, presented with visual disturbances and memory loss. Light microscopically, the tumor consisted entirely of undifferentiated spindle cells. No germ cell component was noted. An exhaustive immunohistochemical study found immunoreactivity for vimentin and desmin, but for no other myoid markers. Polymerase chain reaction showed no X;18 translocation. Based upon these studies, a diagnosis of "undifferentiated sarcoma" was made. Our case, being highly unusual among reported sellar neoplasms, underscores the difficulties inherent in the differential diagnosis of undifferentiated neoplasms.
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Nosé V, Ezzat S, Horvath E, Kovacs K, Laws ER, Lloyd R, Lopes MBS, Asa SL. Protocol for the examination of specimens from patients with primary pituitary tumors. Arch Pathol Lab Med 2011; 135:640-6. [PMID: 21526962 DOI: 10.5858/2010-0470-sar1.1] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
In an effort to improve the diagnosis of pituitary tumors, we propose a synoptic approach to pituitary pathology reporting that will provide clear information to endocrinologists, neurosurgeons, neuropathologists, and surgical pathologists to advance the diagnosis and classification of pituitary adenomas.
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Moshkin O, Syro LV, Scheithauer BW, Ortiz LD, Fadul CE, Uribe H, Gonzalez R, Cusimano M, Horvath E, Rotondo F, Kovacs K. Aggressive silent corticotroph adenoma progressing to pituitary carcinoma: the role of temozolomide therapy. Hormones (Athens) 2011; 10:162-7. [PMID: 21724542 DOI: 10.14310/horm.2002.1307] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Temozolomide (TMZ) has recently been recommended as a novel approach in the management of aggressive pituitary tumors. Herein, we present the case of a 43-year-old man with a 20-year history of silent subtype 2 pituitary corticotroph adenoma. Nine surgical resections and radiotherapy had failed to provide a cure. Morphological evaluation of the tumor revealed a mildly pleomorphic adenoma, the cells of which showed low-level cell proliferative activity with Ki67, increased topoisomerase II alpha index and conclusive O-6-methylguanine-DNA methyltransferase (MGMT) as well as vascular endothelial growth factor (VEGF) immunoreactivity. Given its aggressive behavior and failure of conventional therapy, TMZ was administered. The treatment was continued even after MGMT immunopositivity was identified, but failed to decrease MGMT immunoexpression and exerted no morphologic effect. Examination of the lesion after TMZ therapy showed neither morphologic nor immunohistochemical alterations. In our case, TMZ administration, despite changing the TMZ dosing regimen to prompt a drug response, was incapable of depleting MGMT stores.
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Salehi F, Scheithauer BW, Kros JM, Lau Q, Fealey M, Erickson D, Kovacs K, Horvath E, Lloyd RV. MGMT promoter methylation and immunoexpression in aggressive pituitary adenomas and carcinomas. J Neurooncol 2011; 104:647-57. [DOI: 10.1007/s11060-011-0532-6] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2010] [Accepted: 01/31/2011] [Indexed: 01/08/2023]
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36
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Rotondo F, Quintanar-Stephano A, Asa SL, Lombardero M, Berczi I, Scheithauer BW, Horvath E, Kovacs K. Adenohypophysitis in rat pituitary allografts. Int J Exp Pathol 2010; 91:445-50. [PMID: 20586813 DOI: 10.1111/j.1365-2613.2010.00723.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
The histological, immunohistochemical and ultrastructural alterations in 81 pituitary allografts from Lewis rats transplanted beneath the renal capsule of Wistar rats were investigated. Intrasellar pituitaries of rats bearing allografts were also examined. Recipient rats were sacrificed at various time points after transplantation. Two days after transplantation, the central portion of the allografts demonstrated ischaemic necrosis. A week later, massive mononuclear cell infiltrates consisting primarily of lymphocytes and to a lesser extent, macrophages, plasma cells and granulocytes became prominent. At about three to four weeks after transplantation, the mononuclear cell infiltrate diminished; the surviving adenohypophysial cells, mainly prolactin (PRL) cells, increased in number and necrosis was replaced by connective tissue. No histological changes were noted in the intrasellar pituitaries of rats bearing allografts. Immunohistochemistry demonstrated that the surviving adenohypophysial cells were mainly PRL-producing cells. Electron microscopy revealed adenohypophysial cell destruction, a spectrum of inflammatory cells and, in late phase, accumulation of fibroblasts and collagen fibres. PRL cells were the prominent cell types; they increased in number. It appears that pituitary allografts are 'foreign' and evoke an immune response, suggesting that they may be used as an experimental animal model for morphological investigation of the development and progression of adenohypophysitis, a rare disease occurring mainly in young women often associated with pregnancy.
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Rotondo F, Sharma S, Scheithauer BW, Horvath E, Syro LV, Cusimano M, Nassiri F, Yousef GM, Kovacs K. Endoglin and CD-34 immunoreactivity in the assessment of microvessel density in normal pituitary and adenoma subtypes. Neoplasma 2010; 57:590-3. [PMID: 20845998 DOI: 10.4149/neo_2010_06_590] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
UNLABELLED Vascularization is a prerequisite of tumor growth, invasion and metastasis. In the present work, microvessel density was assessed by quantitating using two different endothelial cell biomarkers, endoglin (CD-105) and CD-34. Fifty endocrinologically active and 36 clinically nonfunctioning pituitary adenomas, all surgically resected, as well as 10 autopsy-derived normal adenohypophyses were investigated by immunohistochemistry. The results showed that in every pituitary adenoma type endoglin, an assumed biomarker of proliferating endothelial cells, immunostained fewer vessels than CD-34 which revealed immunopositivity in all capillaries. Differences in endoglin versus CD-34 immunoexpression indicate varying degrees of vascularity in pituitary adenoma subtypes. The low levels of endoglin immunoexpression in pituitary tumors exposed to long-acting somatostatin analogs and dopamine agonists are consistent with the view that these agents inhibit angiogenesis. KEYWORDS immunohistochemistry, endoglin, CD34, microvascular density, angiogenesis, pituitary.
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Salehi F, Scheithauer BW, Moyes VJ, Drake WM, Syro LV, Manoranjan B, Sharma S, Horvath E, Kovacs K. Low immunohistochemical expression of MGMT in ACTH secreting pituitary tumors of patients with Nelson syndrome. Endocr Pathol 2010; 21:227-9. [PMID: 21061089 DOI: 10.1007/s12022-010-9138-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
MGMT expression in tumors has been correlated with response to treatment with temozolomide therapy. Few medical therapies are available for Nelson syndrome, and the efficacy of such therapeutics remains limited. The aim of the present study was to assess immunohistochemical expression of MGMT in ACTH-secreting pituitary adenomas of patients with Nelson syndrome. Our material consisted of eight specimens from ACTH-secreting pituitary adenomas of patients with Nelson syndrome. Immunohistochemical staining for MGMT was performed using the streptavidin-biotin-peroxidase complex method. MGMT immunoreactivity was assessed microscopically and recorded as an estimated percentage of nuclear MGMT immunostaining (0 = none, 1=<10%, 2=<25%, 3=<50%, 4=>50%). Five of the eight specimens (65%) exhibited no MGMT immunoreactivity, with two out of eight cases (25%) showing slight MGMT staining (<10%) and one out of eight cases (12%) demonstrating moderate MGMT positivity (<25%). Patient male/female ratio was 3:5, with average patient age being 62.4 (range 57–66). Our findings suggest that temozolomide therapy may be of potential use in patients with Nelson syndrome, as these tumors express absent/low levels of MGMT. Absent or low MGMT staining in brain and other neoplasms has been shown to correlate with successful treatment with temozolomide, and recent reports of aggressive pituitary adenomas suggest similar outcomes.
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Lau Q, Scheithauer B, Kovacs K, Horvath E, Syro LV, Lloyd R. MGMT immunoexpression in aggressive pituitary adenoma and carcinoma. Pituitary 2010; 13:367-79. [PMID: 20740317 DOI: 10.1007/s11102-010-0249-0] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Recent case reports have documented the efficacy of temozolomide therapy in some aggressive pituitary adenomas and pituitary carcinomas resistant to multimodality therapy. Evidence suggests that low O6-methylguanine-DNA methyltransferase (MGMT) immunoexpression correlates with response to temozolomide chemotherapy. Herein, we aimed to study MGMT immunoexpression in a spectrum of pituitary tumors, indolent, aggressive and malignant. A literature review of the use of temozolomide in pituitary tumors was also performed. Immunohistochemistry for MGMT was performed on 60 pituitary tumors identified in the Mayo Clinic Tissue Registry and the consultation files of one of us (BWS). The group included 30 pituitary carcinomas (15 ACTH, 10 PRL, 1 FSH/LH, 1 TSH, 1 silent subtype 3 and 2 null cell). Tissue from recurrences was available in 17 cases. In addition, 30 functionally different pituitary adenomas were studied, including 15 invasive and 15 non-invasive adenomas. Overall, 32 cases of pituitary tumors (54%) demonstrated low MGMT immunoexpression. This included 17 of 30 (57%) carcinomas, 9 of 15 (60%) invasive adenomas, and 6 of 15 cases (40%) of non-invasive pituitary adenomas. There was no significant change in MGMT immunoexpression between primary and recurrent tumors. Prolactin-producing carcinomas had the highest proportion of tumors (80%) with low expression. A significant proportion of pituitary adenomas and carcinomas demonstrate low MGMT immunoexpression. In an effort to anticipate the likelihood of a temozolomide response, all cases of aggressive pituitary tumors should be assessed for MGMT expression.
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Rotondo F, Khatun N, Scheithauer BW, Horvath E, Marotta TR, Cusimano M, Kovacs K. Unusual double pituitary adenoma: A case report. Pathol Int 2010; 61:42-6. [DOI: 10.1111/j.1440-1827.2010.02613.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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41
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Syro LV, Ortiz LD, Scheithauer BW, Lloyd R, Lau Q, Gonzalez R, Uribe H, Cusimano M, Kovacs K, Horvath E. Treatment of pituitary neoplasms with temozolomide: a review. Cancer 2010; 117:454-62. [PMID: 20845485 DOI: 10.1002/cncr.25413] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2010] [Revised: 03/10/2010] [Accepted: 04/07/2010] [Indexed: 11/10/2022]
Abstract
Temozolomide, an orally administered alkylating agent, is used to treat malignant gliomas. Recent reports also have documented its efficacy in the treatment of pituitary adenomas and carcinomas. Temozolomide methylates DNA and thereby exhibits an antitumor effect. O⁶-methylguanine-DNA methyltransferase (MGMT), a DNA repair enzyme, removes alkylating adducts induced by temozolomide, counteracting its effects. The authors of this review conducted a Medline database search regarding temozolomide in the treatment of pituitary tumors. Demographic characteristics, tumor types, and therapeutic responses were noted in all patients. Data regarding MGMT immunoexpression, which was documented in some studies, were correlated with information regarding clinical and radiologic responses. To date, there have been 19 reported cases of adenohypophyseal tumors treated with temozolomide, including 13 adenomas and 6 carcinomas. Ten of those 13 adenomas responded favorably, and 2 nonresponsive tumors had high-level MGMT immunoexpression. All 6 carcinomas responded to therapy, but data regarding MGMT expression were available for only 3 patients, and each had low MGMT expression. In 2 adenomas, morphologic studies were performed both before and after the patients received temozolomide. The responsive tumor had necrosis, hemorrhage, fibrosis, and neuronal differentiation. The nonresponsive tumor had no changes. There have been no reported complications attributable to temozolomide. The current results indicated that temozolomide is efficacious in the treatment of aggressive pituitary adenomas and pituitary carcinomas. Evidence indicated that low-level MGMT immunoexpression is correlated with a favorable response. A significant proportion of pituitary adenomas and carcinomas had low MGMT immunoexpression.
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Fealey ME, Scheithauer BW, Horvath E, Erickson D, Kovacs K, McLendon R, Lloyd RV. MGMT immunoexpression in silent subtype 3 pituitary adenomas: possible therapeutic implications. Endocr Pathol 2010; 21:161-5. [PMID: 20480258 DOI: 10.1007/s12022-010-9120-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
The objective of the study was to assess O(6)-methylguanine-DNA methyltransferase (MGMT) immunoreactivity in pituitary adenomas of silent subtype 3 as a potential indicator of temozolomide susceptibility. The Mayo Clinic Anatomic Pathology Database was searched for all cases of silent subtype 3 pituitary adenoma. Each of the 23 cases identified had been confirmed on the basis of histology, immunohistochemical staining for pituitary hormones, as well as on diagnostic ultrastructural criteria. Unstained microscopic sections were immunostained for MGMT and were semiquantitatively assessed. Of the 23 tumors examined, 18 (78%) showed no MGMT immunoreactivity. The remaining five (22%) showed immunoreactivity in < or =50% of tumor cells. Among eight of the most clinically aggressive tumors in this study, six (75%) lacked MGMT immunoreactivity. The observed lack of or low-level expression of MGMT by this distinctive, clinically aggressive form of pituitary adenoma suggests potential efficacy of treatment with the alkylating agent temozolomide.
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43
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Horvath E, Coire CI, Kovacs K, Smyth HS. Folliculo-stellate cells of the human pituitary as adult stem cells: examples of their neoplastic potential. Ultrastruct Pathol 2010; 34:133-9. [PMID: 20455662 DOI: 10.3109/01913121003662247] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Two unique, formerly unrecorded sellar neoplasms were observed in two women of 60 and 63 years of age. One lesion consisted of small epithelial cells and the other was a large-cell oncocytic tumor, yet they had the same simple cytoplasmic organization with dominance of polyribosomes and a sprinkle of glycogen. Striking markers shared by the neoplasms: (1) network of typical pituitary follicles, and (2) unexpected similarity to fetal human pituitary tissue at different gestational ages of 6 and 10-12 weeks. The latter showed appreciable endocrine differentiation. The assumed parent cell is the folliculo-stellate cell as pluripotent adult stem cell.
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Coiré CI, Smyth HS, Rosso D, Horvath E, Kovacs K. A double pituitary adenoma presenting as a prolactin-secreting tumor with partial response to medical therapy. Case report. Endocr Pathol 2010; 21:135-8. [PMID: 20058099 DOI: 10.1007/s12022-009-9104-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Double pituitary adenomas are difficult to recognize pre-operatively as only a single mass may be appreciated on imaging. We present herein a giant prolactin-secreting pituitary adenoma in a middle-aged man that had responded partially to dopamine agonist therapy. The excised specimen demonstrated a double adenoma. The prolactin-producing one displayed the expected morphological changes resulting from medical therapy, while the other, a gonadotroph adenoma, did not. The failure of tumor shrinkage can be attributed to the presence of a double adenoma, a previously unreported cause of failure of medical therapy in prolactinoma.
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Möstl K, Hinaidy B, Loibi C, Szekely H, Horvath E, Bürki F. Zur Entero-Pathogenität boviner Coronaviren unter Feldbedingungen1,2. ACTA ACUST UNITED AC 2010. [DOI: 10.1111/j.1439-0450.1984.tb01358.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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46
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Salehi F, Kovacs K, Scheithauer BW, Cantelmi D, Horvath E, Lloyd RV, Cusimano M. Immunohistochemical expression of pituitary tumor transforming gene (PTTG) in pituitary adenomas: a correlative study of tumor subtypes. Int J Surg Pathol 2010; 18:5-13. [PMID: 20106827 DOI: 10.1177/1066896909356105] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
OBJECTIVE We investigated the correlation between immunohistochemical expression of the pituitary tumor transforming gene (PTTG) and pituitary adenoma subtype. METHODS Pituitary adenomas (n = 89) were stained for PTTG using the streptavidin-biotin-peroxidase complex method and a monoclonal PTTG antibody. RESULTS PTTG staining was found to be cytoplasmic with a pronounced paranuclear expression pattern. Reactivity was highest in growth hormone (GH) adenomas as compared with other tumors, including prolactin (PRL), follicle-stimulating hormone/luteinizing hormone/alpha subunit, as well as adrenocorticotrophic hormone-secreting adenomas. PRL adenomas exhibited the lowest expression levels. Among GH adenomas, untreated tumors demonstrated significantly higher PTTG levels than octreotide-treated examples. Although dopamine agonist-treated PRL adenomas tended to show lower expression levels, statistical significance was not reached. CONCLUSIONS Our finding that PTTG was differentially expressed in pituitary adenoma subtypes suggests a cell-specific function for PTTG. Moreover, treatment of GH adenomas with somatostatin analogues lowered PTTG expression. Further investigation into mechanisms mediating cell-specific expression of PTTG is warranted.
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Salehi F, Scheithauer BW, Moyes VJ, Drake WM, Syro L, Manoranjan B, Sharma S, Horvath E, Kovacs K. Low immunohistochemical expression of MGMT in ACTH secreting pituitary tumors of patients with Nelson syndrome. FASEB J 2010. [DOI: 10.1096/fasebj.24.1_supplement.954.16] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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48
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Sharma S, Rotondo F, Kovacs K, Horvath E. Ultrastructural differences in the endoplasmic reticulum among various pituitary tumor types. FASEB J 2010. [DOI: 10.1096/fasebj.24.1_supplement.565.18] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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49
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Mohammed S, Cusimano MD, Scheithauer BW, Rotondo F, Horvath E, Kovacs K. O-methylguanine-DNA methyltransferase immunoexpression in a double pituitary adenoma: case report. Neurosurgery 2010; 66:E421-2; discussion E422. [PMID: 20087113 DOI: 10.1227/01.neu.0000363852.77126.ad] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVE Double pituitary adenomas in surgical cases are rarely reported. The incidence in published surgical specimens ranges from 0.4% to 1.3%. We present a treatment dilemma of a double adenoma that had differential O-methylguanine-DNA methyltransferase (MGMT) reactivity. CLINICAL PRESENTATION A 48-year-old man presented with acromegaly and a recurrent pituitary adenoma. He had elevated growth hormone (GH) and elevated insulin-like growth factor blood levels and hyperprolactinemia. INTERVENTION Subtotal transsphenoidal resection was performed. Morphologic examination disclosed 2 histologically distinct tumors, including a GH adenoma and a prolactin adenoma. Immunohistochemistry revealed Ki-67 labeling indices of 1% and 2%, respectively. Of significant note was MGMT immunopositivity in the GH adenoma and lack of staining in the prolactin adenoma. CONCLUSION This is the first clinical instance in which MGMT was assessed in double adenomas of the pituitary. The 2 tumors showed significant differences in reactivity that could impact chemotherapeutic management. The adenomas underwent recurrence, a feature that reflects their invasive nature and the possibility that chemotherapeutic intervention may be required in the future. Response to temozolomide use is anticipated with respect to the prolactin adenoma but would likely not benefit the GH cell adenoma of our patient.
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Roncaroli F, Scheithauer BW, Horvath E, Erickson D, Tam CK, Lloyd RV, Kovacs K. Silent subtype 3 carcinoma of the pituitary: a case report. Neuropathol Appl Neurobiol 2009; 36:90-4. [PMID: 19811617 DOI: 10.1111/j.1365-2990.2009.01043.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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