Biomedical subjects

B W Scheithauer

Publications and source records attributed to B W Scheithauer.

At least 91 records · Page 5Linked to original sources

PubMed1999

Pituitary adenylate cyclase-activating polypeptide inhibits transforming growth factor-beta1-induced apoptosis in a human pituitary adenoma cell line.

Pituitary adenylate cyclase-activating polypeptide (PACAP) was originally isolated from hypothalamic tissues based on its ability to stimulate cAMP production in cultured anterior pituitary cells. Recent studies have suggested a functional role for PACAP in the apoptosis of brain cells. However, the role of PACAP in regulating apoptosis in human pituitary adenomas has not previously been examined. Analysis of the cultured human pituitary adenoma cell line HP75, which expresses all three major PACAP receptors, showed that both PACAP-38 and PACAP-27 inhibited TGF-beta1-induced apoptosis. Treatment with the PACAP receptor antagonists PACAP 6-38 (PACAP type I receptor antagonist) and (p-chloro-D-Phe(6), Leu(17))-VIP (PACAP type II receptor antagonist) blocked the effects of PACAP-38 on the inhibition of transforming growth factor-beta1 (TGF-beta1)-induced apoptosis, confirming the specificity of the role of PACAP. Treatment with forskolin but not phorbol 12-myristate 13-acetate (PMA) also inhibited TGF-beta1-induced apoptosis. TGF-beta1 treatment was associated with an increase in mitogen-activated protein kinase (MAP kinase) when analyzed by Western blotting, but PACAP inhibition of TGF-beta1-induced apoptosis was not associated with activation of MAP kinase. Immunocytochemical analysis of the cell cycle cyclin-dependent kinase inhibitor p27 showed that treatment with TGF-beta1, forskolin, PMA, and PACAP increased p27 expression in cultured HP75 cells. These results indicate that PACAP is a highly specific inhibitor of TGF-beta1-induced apoptosis in the HP75 human pituitary adenoma cell line and that PACAP, TGF-beta1, forskolin, and PMA all stimulate expression of the TGF-beta-regulated cell cycle protein p27 in the HP75 human pituitary adenoma cell line. The HP75 cell line can be used as a model to study the regulation of apoptosis in human pituitary cells.

Adenoma↗

PubMed1999

Chordoid glioma of the third ventricle: confirmatory report of a new entity.

The term "chordoid glioma" was recently introduced to denote a circumscribed, apparently low-grade neoplasm arising in or preferentially involving the third ventricle of middle-aged women. We report biopsy and postmortem findings in a 60-year-old woman with symptoms of forgetfulness, headache, and lethargy. Neuroimaging showed a contrast-enhancing third ventricular mass with obstructive hydrocephalus. The tumor was subtotally resected. Microscopically, it consisted of clusters and strands of epithelioid cells in a mucoid matrix. Its margins were remarkably discrete and showed little tendency to infiltrate surrounding brain parenchyma. The majority of neoplastic cells were glial fibrillary acidic protein (GFAP) and vimentin positive, whereas S100 protein labeled only individual cells. Stains for epithelial membrane antigen (EMA) and cytokeratin were nonreactive. There was no evidence of neuroendocrine differentiation or expression of estrogen and progesteron receptors. Lymphoplasmacellular infiltrates were noted throughout the lesion and at the tumor-brain interface. The MIB-1 labeling index averaged 1.5%. At present, chordoid glioma is considered a glial neoplasm of uncertain histogenesis with distinct clinicopathologic features.

Biomarkers, Tumor↗

PubMed1999

Chemotherapy for advanced CNS ependymoma.

BACKGROUND: The role of chemotherapy in recurrent ependymoma is poorly defined. This study was performed to help clarify the benefits of chemotherapy in this setting. PATIENTS AND METHODS: We retrospectively reviewed the charts of patients with advanced ependymoma of the CNS who received chemotherapy in our institution between 1974 and 1993, inclusive. Sixteen consecutive patients were treated with regimens containing either nitrosourea, platinum, or other combinations exclusive of nitrosourea or platinum. No patient received nitrosourea and platinum concurrently. Two methods were used to define response. The first was a direct comparison of radiographic images before and after chemotherapy more than one month apart. A second broader definition of response that employed four other criteria in addition to imaging studies (symptoms, signs, performance status, and neurologic functional status) was also used. RESULTS: Results were as follows (response rate by imaging studies followed by response rate by scoring in parenthesis): Platinum-based chemotherapy resulted in a 67% (83%) response rate with 33% (0%) remaining stable. Nitrosourea-based regimens resulted in a 25% (60%) response rate with 50% (10%) remaining stable. When combinations other than platinum or nitrosourea were used, 11% (22%) responded and 56% (44%) remained stable. Relative differences in response rates between chemotherapy regimens persisted when the data were analyzed by grade. Median time to progression was 6, 10, and 3 months, respectively. CONCLUSION: Platinum-based chemotherapy regimens appear to result in higher response rates with lower rates of progression than nitrosourea-based regimens. Other regimens that do not include cisplatinum or nitrosourea appear to be even less effective.

Adolescent↗

PubMed1999

Distribution and regulation of proconvertases PC1 and PC2 in human pituitary adenomas.

Pituitary adenomas are members of the family of neuroendocrine cells and tumors which have secretory granules containing chromogranins/secretogranins and other proteins. Pituitary adenomas express the neuroendocrine specific proconvertases PC1 (also known as PC3) and PC2, which are important for the proteolytic processing of chromogranins/secretogranins molecules. We examined the distribution of PC1 and PC2 in primary cultures of 20 pituitary adenomas and analyzed the regulation of the proconvertase mRNAs and proteins by various secretagogues including hypothalamic hormones and phorbol ester to determine the role of PC1 and PC2 in CgA processing in pituitary adenomas. Although PC2 was present in all adenomas, there was a differential distribution of PC1 with PRL adenomas expressing lower levels of PC1 compared to other adenoma types by RT-PCR analysis, in situ hybridization and immunostaining. Treatment of primary cultures of pituitary adenomas with phorbol 12-myristrate 13-acetate (PMA) resulted in an increase in pancreastatin (PST) secretion in most pituitary adenomas and increased PC1 mRNA and protein expression in gonadotroph adenomas, but not in other types of adenomas. Analysis of a human pituitary adenoma cell line, immortalized by recombinant defective adenovirus (HP75), which expressed chromogranin A, FSH, PC1 and PC2 showed that PST was secreted by these immortalized cells. Treatment with TGF beta 1 resulted in an increase in PST secretion and in PC1 mRNA and protein. These results indicate that a) there is a differential distribution of PC1 in human pituitary adenomas with PRL adenomas expressing very little PC1 mRNA and protein and b) that PC1 expression in gonadotropin hormone-producing adenomas is regulated by PMA and TGF beta 1. These findings support the observation that chromogranin A is a substrate for the endoproteinase PC1 in human pituitary adenoma cells.

Adenoma↗

PubMed1999

Prolactin-producing pituitary adenoma and carcinoma with neuronal components--a metaplastic lesion.

Recent studies indicate that cells of various epithelial tumors are capable of transformation to neurons. Observing both neurons and neuropil in two prolactin-producing adenohypophyseal tumors, one benign and one malignant, we sought to assess their cellular differentiation, the presence of nerve growth factor receptor, and expression of the dopamine receptor gene using immunocytochemistry, electron microscopy, and in situ hybridization. Light and electron microscopy clearly revealed cells morphologically transitional between adenoma/carcinoma cells and neurons. Large neurons lacked proliferative activity. Neurons in varying number showed immunoreactivity for pituitary hormones including prolactin, growth hormone and alpha subunit in the adenoma and prolactin alone in the carcinoma. The distribution of nerve growth factor receptor staining was similar. In both tumors, in situ hybridization showed mRNAs for prolactin and dopamine receptor within adenohypophyseal cells and neurons. Our results indicate that the occurrence of neurons and neuropil in growth hormone and prolactin-producing pituitary tumors appears to be the result of metaplasia. The process is not limited to benign tumors and may be due to the production of tropic substances by the adenohypophysial cells, which by paracrine/autocrine mechanisms result in transformation of adenoma cells to nerve cells.

Adenoma↗

PubMed1999

Pituitary hyperplasia.

Comprehensive article summarizing more than 25 years of experience with pituitary hyperplasia in surgical material. Morphologic forms of hyperplasia--diffuse and nodular--are defined and, for comparison, the normal morphology, frequency and intraglandular distribution of cell types are briefly reviewed. All cell types can give rise to hyperplasia, although their frequency, extent and clinical importance widely vary. Somatotroph hyperplasia is rare; it is limited to cases of GHRH overproduction by extrapituitary endocrine neoplasms and sporadic examples of gigantism. Prolactin cells display the highest propensity for non-neoplastic proliferation. Physiologic hyperplasia occurs in pregnancy and lactation. Pathological hyperplasia is mostly secondary to other, neoplastic or non-neoplastic, space occupying processes. Idiopathic lactotroph hyperplasia is very rare. The much-disputed corticotroph hyperplasia is infrequent cause of pituitary dependent Cushing's disease. Despite difficulties of diagnosis in fragmented biopsies, several well-documented cases prove the existence of corticotroph hyperplasia which is nearly always nodular. Thyrotroph hyperplasia, secondary to hypothyroidism, a treatable condition, is not expected to occur in surgical material, yet several cases have been identified. Operated lesions are massive nodular leading to significant pituitary enlargement thereby mimicking TSH- or PRL-producing adenoma. Hyperprolactinemia is a frequent concomitant of severe thyrotroph hyperplasia. Gonadotroph hyperplasia and proliferation of pars intermedia derived POMC cells are not likely to occur in surgical material and have no clinical significance. Adenoma formation may rarely be associated with any type of pituitary hyperplasia.

Adrenocorticotropic Hormone↗

PubMed1999

Expression of von Hippel-Lindau protein (VHL-P) in nontumorous and adenomatous human pituitaries.

We studied the presence of von Hippel-Lindau protein (VHL-P) in 7 nontumorous pituitaries and 68 pituitary adenomas by immunocytochemistry using a polyclonal antibody which detects both normal and mutated forms. In nontumorous pituitary VHL-P was variable expressed in the cytoplasm of most adenohypophysial cells. In addition, weak diffuse staining was noted in the posterior lobe. Among the 53 VHL-P immunopositive adenomas (78%), 32 showed only cytoplasmic, 7 only nuclear, and 14 both cytoplasmic and nuclear immunoreactivity. In densely (8 cases) and sparsely (7 cases) granulated somatotroph adenomas nuclear and weak cytoplasmic immunoreactivity were common; all 4 sparsely granulated lactotroph adenomas had only moderate cytoplasmic immunostaining; all 7 functioning corticotroph adenomas presented intense cytoplasmic immunoreactivity and 4/7 showing nuclear immunostaining as well; all 3 silent subtype 1 adenomas were negative; 7 3/4 silent subtype 2 and 4/7 silent subtype 3 adenomas exhibited only cytoplasmic immunoreactivity; thyrotroph adenomas showed variable patterns from negative in 1/7, to only cytoplasmic in 2/7, nuclear alone in 2/7, or both in 2/7. Only weak, focal cytoplasmic immunoreactivity was noted in gonadotroph adenomas of female (2/4) and male (1/5) type. Lastly, all 4 null cell and 8 oncocytic adenomas showed moderate to intense cytoplasmic immunoreactivity. It can be concluded that the majority of pituitary adenomas express the VHL-P with variable distributions and intensity in different tumor types. The frequent localization of VHL-P in the nuclei of somatotroph adenomas, the least vascularized tumor type, suggests a possible inhibitory role of VHL-P in pituitary angiogenesis.

Adenoma↗

PubMed1999

Detection of p16, RB, CDK4, and p53 gene deletion and amplification by fluorescence in situ hybridization in 96 gliomas.

Inactivation of the p53 gene is a common early event of astrocytoma tumorigenesis. Alternatively, since the p16, retinoblastoma (RB), and CDK4 genes have been implicated in malignant progression, detection of losses or amplifications of these genes in gliomas could be diagnostically, prognostically, and therapeutically important. We obtained smear preparations from 96 diffuse gliomas and 10 nonneoplastic specimens. Dual-color fluorescence in situ hybridizations using paired probes for CEN9/p16, CEN8/RB, CEN17/p53, and CEN12/CDK4 were performed and revealed expected frequencies of abnormalities, except for p53 losses, which were low (7%). The latter supports the concept that p53 inactivation usually occurs by mitotic recombination. Detected abnormalities of the p16/RB/CDK4 pathway were highly associated with astrocytic differentiation and were univariately associated with decreased patient survival. However, only patient age and histologic classification retained statistical significance on multivariate analysis. We conclude that in diffuse gliomas, p16/RB/CDK4 abnormalities are markers of astrocytic phenotype. Thus, their detection by fluorescence in situ hybridization may have diagnostic usefulness in cases with equivocal morphologic features. Although our numbers are small, we find no additional prognostic significance to these genetic abnormalities one age, grade, and oligodendroglial histology are taken into account.

Adult↗

PubMed1999

The blood-brain barrier in primary CNS lymphomas: ultrastructural evidence of endothelial cell death.

The vasculature of 24 primary CNS B-cell lymphomas that were not related to acquired immunodeficiency syndrome was systematically studied by electron microscopy. Seven low-grade astrocytic tumors were included for comparison. Classical electron microscopy features of apoptosis were found in lymphoma cells of 21 of 22 subjects. Capillaries of gliomas and lymphomas showed changes reported previously: variability of endothelial cell (EC)-thickness and number, basal lamina thickness and duplication, and fenestrations. Primary CNS B-cell lymphoma ECs showed two distinctive populations of electron-dense and electron-lucent cells. The electron-dense ECs occurred in 38% of all capillaries, with changes consisting of chromatin condensation in bizarre and contracted nuclei, cytoplasmic shrinkage with markedly increased electron density, and dilatation of the endoplasmic reticulum. We interpreted these changes as indicative of apoptosis. Cell death eventually resulted in complete disintegration of the endothelium with frank discontinuities of the EC component of the blood-tumor barrier in capillaries and postcapillary venules. Another population of ECs had increased cell volume, conspicuous cytoplasmic electron lucency, dispersed organelles, scattered vesicles, and apical stress fibers. We interpreted these changes as indicative of cellular regeneration. Individual apoptotic ECs often lay next to normal or regenerating ECs. Neither type of EC change was observed in gliomas, which also lacked perivascular neoplastic lymphocytic cuffing. We believe that these populations of ECs, which have not been described in other disorders affecting the blood-brain barrier, may be induced by cytokines released from necrotic and/or apoptotic tumor lymphocytes and may explain the unusual imaging characteristics of primary CNS B-cell lymphomas treated with corticosteroids.

Adrenal Cortex Hormones↗

PubMed1999

Immunohistochemical staining for ganglioside GD1b as a diagnostic and prognostic marker for primary human brain tumors.

Immunohistochemical staining intensity for ganglioside GD1b was determined for 108 human neuroectodermal tumors. Most of the tissue elements that immunostained were tumor cells; only a few axons and occasional neurons reacted in some specimens. All pilocytic astrocytomas stained very positively, whereas none of the ependymomas and only 11% of primitive neuroectodermal tumors, 20% of glioblastomas, and 28% of anaplastic astrocytomas showed more than faint staining. A similar association between grade and immunostaining was seen in tumors containing an oligodendrogliomatous component, but reactivity was not as strong as in astrocytic tumors or primitive neuroectodermal tumors. Results of Cox regression showed significant associations between immunostaining intensity and survival for all cases taken together (P = 0.007); for the group consisting of astrocytomas, oligoastrocytomas, and oligodendrogliomas (P = 0.002); and for astrocytomas alone (P = 0.04). Results were also significant using a proportional hazards model controlling for patient age (all cases P = 0.005; astrocytomas only P = 0.02), but not when controlling for tumor grade. Our results indicate that immunohistochemical staining for GD1b is correlated with tumor grade and that it may be of prognostic utility in some primary human brain tumors, especially astrocytomas.

Astrocytoma↗

PubMed1999

Primary melanocytic neoplasms of the central nervous systems.

Primary melanocytic neoplasms of the central nervous system (CNS) consist of a spectrum ranging from well-differentiated melanocytoma to its overtly malignant counterpart, melanoma. Diagnostically difficult intermediate lesions lie between these extremes. Clinicopathologic features of 33 cases were studied to define histologic appearances, diagnostic criteria, and the clinical behavior of lesions along this spectrum. Seventeen cases were well-differentiated, solitary leptomeningeal tumors classified as melanocytomas. They contained variably pigmented melanocytic cells arranged in tight nests, sheets, or fascicles. Mitotic rates ranged from zero to one per 10 high-power fields (HPFs), with most having zero per 10 HPFs. All tumors were immunoreactive for HMB-45 and S-100 protein and negative for epithelial membrane antigen. MIB-1 staining was low (<1-2%). Nuclei were regular, often with small, eosinophilic nucleoli. These lesions arose predominantly in the spinal canal (65%) in patients ranging in age from 17 to 73 years. None recurred after surgical resection. In contrast to these benign lesions, there were 13 cases with histologic and cytologic features consistent with those of malignant melanoma. These cases contained larger, cytologically atypical, pigmented tumor cells growing in loose nests or sheets, often with CNS invasion or necrosis. Some contained bizarre, pleomorphic nuclei; others were densely cellular and mitotically active, but less pleomorphic. Mitotic rates (mean, 5.7 per 10 HPFs) and MIB-1 labeling indices (mean, 8.1%) were higher than those of melanocytomas. Melanomas occurred at spinal (38%), posterior fossa (38%), and supratentorial (23%) levels in patients ranging in age from 15 to 71 years. After resection, 8 of 13 lesions recurred, with four being fatal (mean survival, 14 months). Of five totally resected melanomas, four did not recur (mean follow-up, 26 months). Three intermediate-grade melanocytic tumors could not be classified as melanocytoma or melanoma. All showed sheetlike growth patterns, microscopic CNS invasion, and occasional mitoses. MIB-1 staining ranged from 1% to 4%. One tumor recurred after 17 months; one patient was lost to follow-up after 5 months; and the third died after surgery. Although melanocytic tumors represent a spectrum of lesions, certain histopathologic features are helpful in predicting biologic behavior.

Adolescent↗

PubMed1999

Cellular proliferation in pilocytic and diffuse astrocytomas.

Using quantitative image analysis, we evaluated the MIB-1 labeling index (LI) in a large population of pilocytic (n = 131) and diffuse astrocytomas (n = 140), explored its significance as a prognostic predictor of survival, and compared it to other commonly accepted predictors, including grade and its histologic determinants, atypia, mitoses, endothelial proliferation, and necrosis. Diffuse astrocytomas were graded according to the St Anne-Mayo scheme and included 45 grade 2, 50 grade 3, and 45 grade 4 astrocytomas. In pilocytic astrocytomas, mean, median, and range of MIB-1 LIs were 1.1, 0.9, and 0-3.9%, respectively. In diffuse astrocytomas, these values were 2.3, 2, and 0-7.6% in grade 2; 6, 4.4, and 0.1-25.7% in grade 3; 9.1, 6, and 0.3-36% in grade 4. There was a significant difference in the distribution of MIB-1 LIs between pilocytic and diffuse grade 2 astrocytomas (p < 0.001), between grade 2 and grade 3 (p < 0.001), and between tumors of grade 3 and 4 (p = 0.014). Among pilocytic astrocytomas there was no association between survival and MIB-1 LI or any histologic parameter. In diffuse astrocytomas, MIB-1 LI was significantly correlated with grade as well as with mitotic activity (<0.001) and survival. While in diffuse astrocytomas of all grades, necrosis was the strongest factor associated with survival, in tumors of grades 2 and 3 the MIB-1 LI preceded other histologic parameters and, on multivariate analysis, remained the only feature predictive of survival. Grade 3 astrocytomas with a single "solitary" mitosis had a significantly lower MIB-I LI than did grade 3 tumors with >1 mitosis and, compared to the latter, had a significantly longer survival (p = 0.013), one not significantly different from patients with grade 2 astrocytomas. These findings suggest that the cutoff point between grade 2 and 3 in the St. Anne-Mayo scheme may not be optimal and may need to be revised.

Adolescent↗

PubMed1999

Glycolipid markers of astrocytomas and oligodendrogliomas.

Neutral glycolipids and gangliosides were analyzed in 149 astrocytomas (A), 46 oligodendrogliomas (O), and 21 oligoastrocytomas (OA) to determine if specific glycolipids correlate with histologic diagnosis and grade. Positivity for asialoGM1 (GA1) and negativity for paragloboside by immuno-TLC correlated with histological diagnosis of O and OA, whereas the reverse pattern correlated with A. High levels (over 5 microg hexose per mg dry weight) of CMH generally correlated with an O component, but the association was not as strong as for either GA1 presence or paragloboside absence. Pilocytic astrocytomas and pleomorphic xanthoastrocytomas had high proportions (> 15%) of globoside, low ratios (< 0.5) of GD1a: GD1b, and identifiable ceramide trihexoside (CTH). Three gangliosides of the 1b pathway were progressively lost with increasing grade of A, but a similar correlation with grade was not seen in O or OA. A high proportion of cases expressing sialosylparagloboside (3'LM1; 6'LM1) were grade 4 A. Glycolipids are synthesized by glycosyltransferases that add specific sugars to the nascent oligosaccharide. Correlation of specific glycolipids with histological diagnoses and grades indicate that these tumor types express specific patterns of glycosyltransferases, several of which have been cloned. It is possible that critical genes coding for these enzymes are deleted, overexpressed, or mutated in certain tumor types and grades, thus leading to the patterns of glycolipids that we found to be associated with these tumors.

Adolescent↗

PubMed1999

Aggressive enterogenous cyst with extensive craniospinal spread: case report.

OBJECTIVE AND IMPORTANCE: Considered benign and malformative in nature, enterogenous cysts are predominantly spinal lesions. Although recurrences have been reported, especially in the rare intracranial examples, craniospinal dissemination has never been described. CLINICAL PRESENTATION: We report a 63-year-old woman who presented 16 years previously with a histologically typical enterogenous cyst of the cerebellum. Fourteen years after its incomplete excision, numerous supratentorial, infratentorial, and spinal subarachnoid cysts were detected. A histological examination revealed multiple enterogenous cysts without evidence of malignancy. Ki-67 (MIB-1) proliferative indices were less than 1% in all except one specimen, wherein it was 4%; immunohistochemistry demonstrated rare p53 protein overexpression. INTERVENTION: During the last 2 years, four subtotal resections of spinal enterogenous cysts have been performed for progressive paraplegia, pain, paresthesia, and bladder dysfunction. Considering the multiple recurrences and progressive neurological deficits, craniospinal radiation therapy was given. CONCLUSION: To our knowledge, this is the first report of widespread craniospinal dissemination associated with the incomplete resection of an enterogenous cyst. Although a rare complication, it emphasizes the advantages of early, aggressive surgery.

Bone Diseases↗

PubMed1999

Leptin and leptin receptor expression in normal and neoplastic human pituitary: evidence of a regulatory role for leptin on pituitary cell proliferation.

Leptin is a circulating hormone secreted by adipose and a few other tissues. The leptin receptor consists of a single transmembrane-spanning polypeptide that is present as a long physiologically important form as well as in several short isoforms. Recent studies have suggested that the anterior pituitary may have a role in the regulatory effects of leptin in animal models. To test this possibility in human pituitaries, we examined the expression of leptin and OB-R in normal and neoplastic pituitaries, and the possible functions of leptin in the pituitary were also analyzed. Leptin was present in 20-25% of anterior pituitary cells and was expressed in most normal anterior pituitary cells, including ACTH (70% of ACTH cells), GH (21%), FSH (33%), LH (29%), TSH (32%), and folliculo-stellate cells (64%), but was colocalized with very few PRL cells (3%), as detected by double labeling immunohistochemistry with two different antileptin antibodies. In addition, leptin expression was detected by RT-PCR in some pituitary tumors, including ACTH (three of four), GH (one of four), null cells (two of four), and gonadotroph (one of four) tumors as well as in normal pituitary. Immunohistochemical staining showed greater immunoreactivity for leptin in normal pituitaries compared to adenomas. Treatment of an immortalized cultured anterior pituitary cell line, HP75, with leptin stimulated pancreastatin secretion in vitro. Leptin also inhibited cell growth in the human HP75 and in the rat pituitary GH3 cell lines. Both long (OB-Rb) and common (OB-Ra) forms of the leptin receptor messenger ribonucleic acid and leptin receptor protein were expressed in normal and neoplastic anterior pituitary cells. These findings show for the first time that leptin is expressed by most human anterior pituitary cell types and that there is decreased leptin protein immunoreactivity in pituitary adenomas compared to that in normal pituitary tissues. We also show that OB-Rb is widely expressed by normal and neoplastic anterior pituitary cells, implicating an autocrine/paracrine loop in the production and regulation of leptin in the pituitary.

Animals↗

PubMed1999

Clinicopathological characteristics of atypical teratoid/rhabdoid tumor.

The clinicopathological features of atypical teratoid/rhabdoid tumor, a new entity among malignant pediatric brain tumors, and the differential diagnosis from primitive neuroectodermal tumor (PNET)/medulloblastoma, and germ cell tumor are described. Histologically, atypical teratoid/rhabdoid tumor is defined as a polymorphous neoplasm often featuring rhabdoid, PNET, epithelial, and mesenchymal components. Atypical teratoid/rhabdoid tumors usually include PNET components and occur mainly in the posterior fossa, so mimic medulloblastoma. Atypical teratoid/rhabdoid tumor is characterized by the cytogenetic finding of monosomy 22 rather than i(17q). The tumor is similarly mistaken for PNET at supratentorial sites. Germ cell tumors also enter into the differential diagnosis due to their histological immunophenotypic diversity, particularly features indicative of epithelial and mesenchymal differentiation. Nonetheless, the remarkable spectrum of tissues that typify teratoma is absent in atypical teratoid/rhabdoid tumor. The same is true of germ cell marker in tumor tissues and serum. The prognosis of atypical teratoid/rhabdoid tumor is far less favorable than that of PNET/medulloblastoma of malignant or germ cell tumor. Meta-analysis of 133 cases, including 15 new and 118 reported cases, confirm that atypical teratoid/rhabdoid tumor is as a clinicopathological entity and emphasizes the necessity for distinguishing this unique tumor from other pediatric central nervous system neoplasms.

Adolescent↗

PubMed1999

Development of postoperative fibromatosis after resection of an intraspinal meningioma. Case report.

The authors report the case of an adult female patient who developed a paraspinous thoracic fibromatosis (desmoid tumor) after undergoing resection of an intraspinal thoracic meningioma that was complicated by postoperative wound infection. To the best of the authors' knowledge, this is the first report of such a tumor occurring after resection of a spinal meningioma. Awareness of the development of postoperative fibromatosis and recognition of its association with wound sepsis is important. Although rare, this distinctive lesion should be considered in the differential diagnosis of the apparent rapid regrowth of otherwise indolent lesions including meningioma.

Female↗

PubMed1999

Hemangioma of spinal nerve root.

OBJECT: Hemangiomas of the spinal nerve roots are rare. Only 12 cases have been reported in the literature, all since 1965. These lesions occurred in adults, primarily in males, and were located in the cauda equina. Of the 12 lesions, eight were cavernous hemangiomas. The authors report here the clinicopathological features of 10 cases of hemangioma of the spinal nerve root, nine of which were of the capillary type. METHODS: The group included six men and four women who ranged in age from 40 to 62 years. The majority of patients presented with pain and weakness. One patient also experienced worsening of pain during menses. In all cases, gadolinium-enhanced magnetic resonance imaging or computerized tomography myelography demonstrated a discrete intraspinal extramedullary mass. Administration of contrast agent resulted in uniform, intense enhancement. A gross-total resection was achieved in all but one case; in most cases, it was necessary to sacrifice the parent nerve root. Preoperative symptoms and signs improved in nine cases. On histological examination, all but one tumor, a spindle-cell hemangioendothelioma, were shown to be ordinary capillary hemangiomas. Two lesions exhibited a cavernous component, and five showed a partly solid growth pattern resembling juvenile capillary hemangioma. In all cases, the relationship with the nerve root was histologically confirmed. The tumor-nerve relation varied. The intact nerve was displaced by the epineurial mass in three cases. The fascicles appeared separated in six cases, and individual nerve fibers were seen throughout one lesion with endoneurial involvement. CONCLUSION: . Hemangiomas of spinal nerve roots pose a challenging diagnostic problem. Knowledge of their existence is relevant in that they may mimic tumors and are amenable to surgical treatment.

Adult↗