1/130. Malignant peripheral nerve sheath tumor with perineurial cell differentiation (malignant perineurioma).A unique case of malignant peripheral nerve sheath tumor (MPNST) with perineurial cell differentiation occurring in a 63-year-old woman in a subcutis of the forearm is described. The tumor contained cellular and myxoid areas. The neoplastic cells were fusiform with distinct cell borders. They were arranged in storiform pattern and in wavy parallel cell cords in the cellular areas. Focally, a pleomorphism and mitotic activity (including atypical mitoses) similar to those of malignant fibrous histiocytoma were seen. The myxoid parts contained haphazardly oriented cells and scarce lipoblast-like multivacuolated cells mimicking a liposarcoma. In the differential diagnosis, myxoid liposarcoma, dermatofibrosarcoma protuberans, malignant fibrous histiocytoma and low-grade fibromyxoid sarcoma were considered. Immunohistochemically, perineurial differentiation was indicated by the diffuse expression of epithelial membrane antigen and focal reactivity for CD34. The tumor was negative with antibodies to S-100 protein, Leu-7, CD68 (KP1), vimentin and cytokeratin AE1/AE3. Ultrastructure of tumor cells revealed features of MPNST. No recurrence occurred in the patient during 2 years follow up.- - - - - - - - - - ranking = 1keywords = cell (Clic here for more details about this article) |
2/130. Solitary malignant peripheral nerve sheath tumor of the pancreas.Primary malignant peripheral nerve sheath tumors of the pancreas are rare. This is a report of a 72 year-old African male who presented with an 8 lb. weight loss and anorexia. A computed tomography (CT) scan revealed a 12 cm mid pancreatic mass. An 85% pancreatectomy (with splenectomy) was performed. Immunohistopathologic and ultrastructural (electron microscopy) evaluation established the schwann cell origin of this neoplasm. The clinical management and pathologic findings are discussed in this report as well as a review of the literature.- - - - - - - - - - ranking = 0.076923076923077keywords = cell (Clic here for more details about this article) |
3/130. Intraosseous epithelioid malignant peripheral nerve sheath tumor of the phalanx. Case report.We report the first case of intraosseous epithelioid malignant peripheral nerve sheath tumor (MPNST) occurring in the phalanx. The patient was a 50-year-old Japanese man with an intramedullary lytic lesion of the proximal phalanx. Microscopically, the tumor was composed of epithelioid cells or polygonal cells, forming large cell nests with central necrosis. Most tumor cells were diffusely and strongly immunopositive for S-100 protein and vimentin, and negative for cytokeratin, epithelial membrane antigen, carcinoembryonic antigen, alpha-smooth muscle actin, and HMB-45. laminin-positive material was discontinuously demonstrated between the individual tumor cells. Electron microscopy showed prominent external lamina. Our case indicated that laminin is useful for differentiating epithelioid MPNST from metastatic carcinoma and malignant melanoma.- - - - - - - - - - ranking = 0.38461538461538keywords = cell (Clic here for more details about this article) |
4/130. Cellular schwannoma mimics a sarcoma: an example of a potential pitfall in aspiration cytodiagnosis.Cellular schwannoma, a variant of benign schwannoma, is characterized by marked nuclear pleomorphism and hyperchromasia and may be overdiagnosed as a malignancy in fine-needle aspiration specimens. We report the aspiration cytology findings of a case of cellular schwannoma that arose in the parapharyngeal region of a 50-yr-old woman.- - - - - - - - - - ranking = 0.076923076923077keywords = cell (Clic here for more details about this article) |
5/130. Cutaneous sclerosing perineurioma with cryptic NF2 gene deletion.Sclerosing perineurioma is a recently described variant of perineurioma that characteristically occurs in the fingers and palms of young adults. We report a cutaneous sclerosing perineurioma with preservation of the axons and schwann cells in the center of the whorls of perineurial cells, a feature that previously was reported to be typically absent in these lesions. Additionally, clonal chromosomal abnormalities of chromosome 10 and a cryptic deletion of the 5'BCR and NF2 loci on chromosome 22 were present. These findings further support the hypothesis that a gene on chromosome 22 may play a role in the pathogenesis of perineurioma. The NF2 gene is a logical candidate because of its involvement in other nerve sheath tumors.- - - - - - - - - - ranking = 0.15384615384615keywords = cell (Clic here for more details about this article) |
6/130. Pathologic causes of the superior oblique click syndrome.PURPOSE: To describe the clinical features in two patients with superior oblique click syndrome and the pathologic causes of their symptoms. DESIGN: Two observational case reports. PARTICIPANTS: Two patients. methods: The clinical histories, results of physical examinations, treatment, and pathologic findings in two patients with superior oblique click syndrome are reviewed and analyzed with reference to the literature. MAIN OUTCOME MEASURES: Relief of symptoms. RESULTS: Both patients were operated on; one was found to have a schwannoma and the other a giant cell tumor of tendon sheath as causes of their symptoms. Symptoms were relieved by removal of the lesions and have not recurred. CONCLUSION: Definite pathologic lesions may cause the superior oblique click syndrome.- - - - - - - - - - ranking = 0.076923076923077keywords = cell (Clic here for more details about this article) |
7/130. Molecular analysis of malignant triton tumors.Triton tumors are rare variants of malignant peripheral nerve sheath tumor (MPNST) with muscle differentiation, often seen in patients with neurofibromatosis 1 (NF1). Individuals affected with NF1 harbor mutations in the NF1 tumor suppressor gene and develop neurofibromas and MPNSTs. The NF1 gene is expressed in schwann cells and its expression is lost in schwannian neoplasms, suggesting a role in malignant development. Separately, there is evidence that p53 suppressor gene mutations are involved in MPNSTs. To determine the role of the NF1 and p53 genes in the development of the malignant Triton tumor we examined 2 such tumors, 1 from a 3-year-old boy without clinical manifestations of NF1 and another from a 24-year-old man with NF1. Histological analysis of these tumors showed both neural and muscle differentiation with S-100 and desmin immunoreactivity, respectively. Reverse transcribed rna polymerase chain reaction (RT-PCR) of NF1 mRNA showed NF1 expression in the sporadic tumor. Strong nuclear immunoreactivity for p53 was observed throughout the malignant population in both tumors. This was confirmed by loss of heterozygosity for p53 in the non-NF1 patient, suggesting that p53 is involved in both hereditary and sporadic Triton tumors. The finding of preserved NF1 gene expression in the non-NF1-related Triton tumor suggests that different genetic events predispose to the development of this rare neoplasm in sporadic cases.- - - - - - - - - - ranking = 0.076923076923077keywords = cell (Clic here for more details about this article) |
8/130. Intraneural angiosarcoma and angiosarcoma arising in benign and malignant peripheral nerve sheath tumours: clinicopathological and immunohistochemical analysis of four cases.AIMS: Angiosarcomatous differentiation represents the least common form of heterologous differentiation in malignant peripheral nerve sheath tumours (MPNST), and is seen most frequently in patients with neurofibromatosis type 1. More rarely, it has been reported in patients without stigmata of neurofibromatosis, or in benign nerve sheath tumours and peripheral nerves. This study was undertaken to confirm this rare association. methods AND RESULTS: Four cases of angiosarcoma arising in a peripheral nerve, in a long-standing schwannoma and in two MPNST are described. Immunohistochemical studies were performed on paraffin sections with the alkaline phosphatase-antialkaline phosphatase method. An intraneural high-grade epithelioid angiosarcoma arose in the left posterior tibial nerve of a 78-year-old man, a well to moderately differentiated angiosarcoma was seen in an ancient schwannoma of the lateral neck in a 73-year-old women, and an angiosarcoma of varying grades of differentiation developed in a recurrent MPNST in the thigh of 38-year-old man. In addition a high-grade MPNST in the axillary region of a 30-year-old man showed foci of heterologous high-grade angiosarcomatous differentiation. The neural and endothelial lines of differentiation were confirmed in each case by positive immunohistochemical staining for neural and endothelial markers, respectively. In all cases tested, the neural differentiated cells stained immunohistochemically positive for antibodies against vascular endothelial growth factor. CONCLUSIONS: This study confirms the rare association of angiosarcoma arising in peripheral nerves, as well as in benign and malignant peripheral nerve sheath tumours.- - - - - - - - - - ranking = 0.076923076923077keywords = cell (Clic here for more details about this article) |
9/130. Low-grade malignant perineurioma of the paravertebral column, transforming into a high-grade malignancy.A demarcated 6 x 5 cm right paravertebral tumor at the level of T6 in a 39-year-old male was removed surgically. Histologically, the tumor consisted of monomorphous benign-looking, low-cellular spindle cells embedded in desmoplastic stroma. Ten years later, the tumor recurred locally with metastasis to systemic organs, including the occipital skin. Malignancy was histologically evident by the increased cellularity, cellular atypia and mitotic activity. The patient died of respiratory failure at the age of 49. Retrospectively reviewed, the primary lesion was low-grade fibrosarcoma-like spindle cell tumor, with secondary transformation into a highly malignant form. The differential diagnoses included sclerosing epithelioid fibrosarcoma, low-grade fibromyxoid sarcoma and malignant peripheral nerve sheath tumor. Immunohistochemically, the spindle cells in the primary and recurrent tumors consistently expressed epithelial membrane antigen, vimentin, type 4 collagen and laminin. The tumor cells in the present case showed a differentiation toward perineurial cells, which are normally positive for these immunohistochemical markers. Hence, the appropriate diagnostic term should be 'malignant perineurioma', a subtype of malignant peripheral nerve sheath tumor.- - - - - - - - - - ranking = 34.73339718498keywords = spindle cell, spindle, cell (Clic here for more details about this article) |
10/130. Extraneural retiform perineuriomas. A report of four cases.We present here four cases of extraneural perineurioma (EP), which occurred in 31, 32, 42 and 43 year old women in the left hand, right arm (2 cases) and right axillary regions, respectively. All tumors were well circumscribed, with a thin capsule. They were 2, 2, 1.5 and 1.5 cm in the largest diameter. Microscopically all tumors had a distinctive appearance composed of interconnected cords of cells which ran in a parallel fashion or formed a characteristically looking cellular lattice. These cords were composed of cells with tapered to stellate shaped nuclei having one or two inconspicuous nucleoli. The space between the cells of the lattice was edematous and empty looking, or it was composed of myxoid matrix, or it was filled with characteristically looking globular deposits of collagen extracellular matrix. These globular deposits of collagen extracellular matrix often indented the nuclei, giving them a stellar appearance. Immunohistochemically all tumors reacted positively with antibodies to epithelial membrane antigen. antibodies to smooth muscle actin, muscle-specific actin, S-100 protein, cytokeratin AE1/AE3, cytokeratin CAM 5.2, and HMB-45 gave uniformly negative immunohistochemical results.- - - - - - - - - - ranking = 0.46153846153846keywords = cell (Clic here for more details about this article) |
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