1/12. Cerebellar medullomyoblastoma with advanced neuronal differentiation and hamartomatous component.This report describes an unusual medullomyoblastoma which developed in the cerebellar vermis of a 6-year-old girl. Histological investigation showed a highly cellular and predominantly undifferentiated tumor. Myogenic differentiation was prominent in clusters of large tumor cells with eosinophilic cytoplasm and immunoreactivity for desmin and myoglobin. Electron microscopy revealed the presence of immature Z-bands. Immunohistochemically, numerous cells showed incipient expression of myoblastic marker antigens, supporting the view that medulloblastomas and related primitive neuroectodermal tumors possess the potential for non-neural differentiation. In addition, there was evidence of advanced neuronal differentiation, with expression of neuron-specific enolase, synaptophysin, retinal S-antigen, and the formation of ganglioid tumor cells. Occassional neoplastic cells expressed glial fibrillary acidic protein without morphologically detectable astrocytic differentiation. Associated with the neoplasm was brain tissue containing clusters of neuronal cells and focal accumulations of immature oligodendroglia-like cells which expressed neuronal marker antigens. This unusual component resembled a hamartomatous lesion and would support the hypothesis that the cerebellar medullomyoblastoma originated from a teratomatous or malformative lesion. Alternatively, this component may constitute the end stage of advanced neuronal differentiation of a primitive neuroectodermal tumor.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
2/12. Granular cell tumour of the larynx.A granular cell tumour may present as clinically innocuous lesions on the vocal cords and the diagnosis is usually made by histopathology. However, the granular cells characteristic of this tumour may not be obvious and accompanying epithelial hyperplasia may be interpreted by the pathologist as invasive squamous cell carcinoma. Good communication between pathologist and surgeon is required to ensure that clinically benign lesions on the vocal cords are not misdiagnosed. The diagnosis of granular cell tumour can be confirmed by immunocytochemical staining for S100 antigen.- - - - - - - - - - ranking = 0.33333333333333keywords = antigen (Clic here for more details about this article) |
3/12. granular cell tumor of the esophagus.A case of granular cell tumor of the esophagus in a 50-year-old man is reported. Gastrointestinal endoscopy revealed a round, sessile, non-ulcerated white-yellow elevated tumor at the lower third of the esophagus. biopsy revealed a granular cell tumor. Immunohistochemical staining demonstrated that granules in the cytoplasm of tumor cells were positive for S-100 protein and negative for carcinoembryonic antigen. An electron microscopic study revealed that tumor cells were closely packed in clusters, surrounded by basal lamina and collagen fibers. Most cells contained dark cytoplasm filled with electron-dense granules. These granules resembled lysosomes and phagosomes. In a few cells with clear cytoplasm, some mitochondria and poorly developed endoplasmic reticulums were seen. Fibrillar internal materials, myelin-like figures and a premature angulate body were observed in the clear cytoplasm. The lesion has remained unchanged in gross appearance and in size for twenty-three months without any treatment.- - - - - - - - - - ranking = 0.33333333333333keywords = antigen (Clic here for more details about this article) |
4/12. Alveolar soft part sarcoma: immunological evidence of rhabdomyoblastic differentiation.Two cases of alveolar soft part sarcoma have been studied immunocytochemically using antisera against epithelial membrane antigen, lysozyme, keratins, S-100 protein, desmin, vimentin, fetal myosin, slow myosin, alpha-skeletal muscle actin, alpha-smooth muscle actin and myoglobin. The neoplastic cells were negative with all antisera employed with the exception of the alpha-skeletal muscle actin antiserum which stained the cytoplasm of numerous neoplastic elements, including the crystalloid rods, typical cytoplasmic inclusions of these tumours. It is suggested that the presence of this protein indicates rhabdomyoblastic differentiation of these tumours.- - - - - - - - - - ranking = 0.33333333333333keywords = antigen (Clic here for more details about this article) |
5/12. Malignant granular cell tumor. Report of a case with special reference to carcinoembryonic antigen.A case of malignant granular cell tumor and its histochemical and electron-microscopic characteristics are reported. This case showed, in addition to the well-known distribution of this type of tumor in subcutaneous fat, mediastinum, retroperitoneum and lungs, multiple foci in the myocardium. Contrary to recent studies reporting the presence of carcinoembryonic antigen (CEA) in benign and malignant granular cell tumors, this case is CEA-negative. We suggest that the reported CEA-reactivity in this type of tumor is probably due to cross-reacting antibodies against antigens, presumably associated with lysosomes.- - - - - - - - - - ranking = 2keywords = antigen (Clic here for more details about this article) |
6/12. Congenital gingival granular cell tumor with smooth muscle cytodifferentiation.Congenital epulis of the newborn is a rare benign congenital gingival granular cell tumor (GGCT) of unknown histogenesis which occurs most commonly on the gingiva of the anterior maxillary alveolar ridge in girls. The granular cells in this entity are histologically indistinguishable from those in extragingival granular cell tumors, known historically as granular cell myoblastoma (GCM), which occur at any age and appear to be of Schwann cell origin. Ultrastructural, histochemical, and immunohistochemical features of three GGCT were examined and compared to three GCM and a granular cell ameloblastoma. This is the first instance in which the ultrastructure of granular cells in a congenital epulis showed evidence of smooth muscle differentiation. carcinoembryonic antigen-like immunoreactivity was localized in granular cells from all granular cell tumors studied, but S-100 protein was present only in GCM. The smooth muscle ultrastructural features and the lack of S-100 protein in GGCT strongly suggest a different histogenesis from that of GCM. The GGCT is likely derived from a primitive gingival perivascular mesenchymal cell with the potential for smooth muscle cytodifferentiation.- - - - - - - - - - ranking = 0.33333333333333keywords = antigen (Clic here for more details about this article) |
7/12. Giant myofibroblastoma of the male breast.Myofibroblastoma of the breast is a rare, benign neoplasm, seen predominantly in men. The gross appearance is that of a well-circumscribed nodule, characteristically small, seldom exceeding 3 cm. We report a case of giant myofibroblastoma measuring 10 cm and weighing 169 g in the breast of an 83-year-old man. light microscopic, immunohistochemistry, and electron microscopic features are described. Histologically, these neoplasms may exhibit a varied cellularity that can be misinterpreted as sarcoma. However, they lack marked cellular pleomorphism, tumor necrosis, and mitosis and are characteristically composed of plump and long bipolar, spindly cells arranged in swirling fascicles with intervening broad collagen bands. As we report, immunostaining is strongly positive for vimentin, desmin, and muscle common antigen and negative for cytokeratins and S-100-associated protein. Electron microscopy shows predominantly cells suggestive of myofibroblastic differentiation. The patient has remained free of disease 2 years after mastectomy.- - - - - - - - - - ranking = 0.33333333333333keywords = antigen (Clic here for more details about this article) |
8/12. Meningeal myofibroblastoma.Myofibroblastoma is a recently described benign mesenchymal tumor. Only one case has been reported previously in the CNS. We report a second case of myofibroblastoma arising in the meninges in a 70-year-old woman who presented with visual changes. The histologic appearance was characterized by alternating areas of spindled and rounded cells separated by collagen and amianthoid fibers. Immunostaining demonstrated strong vimentin and focal smooth-muscle actin positivity; staining for epithelial membrane antigen, cytokeratin, S-100, desmin, myosin, glial fibrillary acidic protein, and factor viii-related antigen was negative. Ultrastructurally, the myofibroblasts had features of both smooth-muscle cells and fibroblasts. Differentiating the benign myofibroblastoma from more aggressive meningeal sarcomas and meningeal meningiomas is important. The tumor most likely arises from myofibroblasts that probably reside in the meninges.- - - - - - - - - - ranking = 0.66666666666667keywords = antigen (Clic here for more details about this article) |
9/12. Epstein-Barr virus (EBV)-associated smooth-muscle tumor arising in a post-transplant patient treated successfully for two PT-EBV-associated large-cell lymphomas. Case report.The association of Epstein-Barr virus (EBV) with smooth-muscle tumors was recently reported in the setting of acquired immunodeficiency syndrome (AIDS) and post-transplantation. We report a case of an EBV-associated smooth-muscle tumor arising in a post-transplant (PT) patient who previously was treated successfully for two EBV-associated PT large-cell lymphomas. A 4-year-old girl required cardiac transplantation for dilated cardiomyopathy when she was aged 23 months. Her PT regimen included cyclosporine, azothiaprine, and diltiazem. At 16 months PT, she presented with anemia, guaiac-positive stools, and an abdominal mass diagnosed as diffuse large-cell lymphoma of B-cell phenotype. Immunosuppressive therapy was reduced, and interferon and i.v. immunoglobulin were initiated. She rapidly developed signs of rejection, and a cardiac biopsy was performed, revealing grade IIIB rejection. Subsequently, immunosuppressive therapy increased. At 23 months PT, a biopsy was done of a large pelvic mass that was diagnosed as immunoblastic large-cell lymphoma. After treatment with chemotherapy and retinoic acid, the size of the mass markedly decreased. Follow-up computed tomography scan revealed multiple liver nodules. A needle biopsy of the liver showed a smooth-muscle tumor of indeterminate grade. Both the lymphomas and the smooth-muscle tumor contained EBV within > 95% of tumor cells by Epstein-Barr (EBER1) in situ hybridization, were of strain type A by Epstein-Barr nuclear antigen-2 (EBNA-2) polymerase chain reaction (PCR) and contained an identical 30 base-pair deletion (amino acids 346-355) of the latent membrane protein (LMP)-1 oncogene by PCR analysis. Notably, the initial large-cell lymphoma and the subsequent immunoblastic lymphoma each contained a unique p53 mutation, suggesting that they were distinct. These data suggest that the same virus contributed to the pathogenesis of both the malignant lymphomas and the smooth-muscle tumor.- - - - - - - - - - ranking = 0.33333333333333keywords = antigen (Clic here for more details about this article) |
10/12. Mammary myofibroblastoma with leiomyomatous differentiation.An unusual example of mammary myofibroblastoma in a 36-year-old woman was reported. The central portion resembled mammary myofibroblastoma or solitary fibrous tumor of other sites and showed reactivity for CD34 and muscle-specific actin, with few cells staining for desmin. The peripheral portion resembled leiomyoma and showed strong reactivity for actin and desmin but only focal staining for CD34. We interpret this tumor as mammary myofibroblastoma showing frank peripheral leiomyomatous differentiation. Although closely related to solitary fibrous tumor, mammary myofibroblastoma appears slightly different because of its consistent slant toward myoid differentiation in the form of actin and variable desmin reactivity as opposed to the rare and sparse immunohistochemical expression of myoid features by solitary fibrous tumors of other sites. This case demonstrates this phenomenon carried to an extreme, a feature not previously documented in mammary myofibroblastoma. It is of interest to note the modulation of the antigenic profile with the differentiation process, that is, loss of CD34 and gain of desmin accompanying the myoid differentiation.- - - - - - - - - - ranking = 0.33333333333333keywords = antigen (Clic here for more details about this article) |
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