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Query: UMLS:C0027651 (tumor)
 685,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Neuroblastoma (NB), primitive neuroectodermal tumor (PNET), Ewing's sarcoma and rhabdomyosarcoma (RMS) are solid malignant tumors in childhood. Microscopically these tumors are grouped as small-round-cell tumors, and a different diagnosis is sometimes difficult. Cell surface membrane antigen, cytoskeletal protein and N-myc amplification and over-expression were analyzed in these cell lines and tumor tissues for the accurate diagnosis. NB and PNET could be distinguished from Ewing's sarcoma and RMS by the panel of monoclonal antibodies against cell surface membrane antigens. The cytoskeletal protein analysis is useful for the diagnosis of RMS and leiomyosarcoma. Alpha-smooth muscle actin and/or desmin were demonstrated in the S-type (epithelial-like) cells in 3 NB cell lines, suggesting the differentiation pathway of NB into smooth muscle cells. N-myc amplification and over-expression were observed in NB cell lines as well as one RMS cell line. The occurrence of N-myc amplification and over-expression in the RMS cell line cautions us against using N-myc as a distinguishable marker for NB.
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PMID:[Analysis of surface membrane antigens, cytoskeletal proteins and N-myc oncogene in pediatric solid malignant tumors, their diagnostic usefulness and relevant problems]. 132 30

We immunohistochemically investigated the distributions of components of the basement membrane (BM) (type IV collagen and laminin) and alpha smooth muscle actin in twelve primary pleomorphic adenomas of the parotid gland, as compared with six recurrent benign pleomorphic tumors (recurrent type). There were no differences between the two types of the tumor in the distributions of the BM components and actin, whereas the recurrent type of tumor have numerous myxochondroid areas histologically. The localization of type IV collagen in the tumor tissue was almost the same as that of laminin. Actin was identified in the occasional myoepithelial cell. In the tumor tissues, the components of BM were most densely localized in the areas surrounding solid clusters of epithelial cells, outer cells of glandular structures and occasional cells in the myxoid area, but the stroma of the myxochondroid areas did not take up stain. BM was densely defined between the tumor capsule and epithelial cells, but the tumor capsule was not bordered by myxochondroid areas with BM. These results suggest that loss of BM between the capsule and myxochondroid areas may be one of the causes of postoperative recurrence of pleomorphic adenomas.
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PMID:[Immunohistochemical study of basement membrane in pleomorphic adenomas of the parotid gland: comparison between primary treated tumor and recurrent tumor]. 133 8

A unique bronchial tumor is reported. The tumor grew as an endobronchial polyp and obstructed the right main bronchus. Histologically the lesion consisted of two different types of neoplastic cells; epithelial small cell nests and atypical spindle-shaped cells. Immunohistochemical studies with a panel of antibodies showed that the small cell nests were immunoreactive for epithelial and neuroendocrine markers. The spindle-shaped cells showed positive staining for smooth muscle actin. Epithelial markers were also positive focally in the spindle cells. Electron microscopy confirmed that the spindle-shaped cells had both epithelial and mesenchymal features. Based on these results, the tumor was considered to be a unique combination of small cell and spindle cell carcinoma.
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PMID:A combined small cell and spindle cell carcinoma of the lung. Report of a unique case with immunohistochemical and ultrastructural studies. 133 11

This report describes the histologic and immunohistologic features of an intraductal myoepithelial tumor that developed in the breast of a 61-year-old woman. Histologically, the tumor proliferated intraductally, with both a comedo or doughnut pattern and a solid pattern containing narrow fibrovascular cores, mimicking what appeared to be a conventional intraductal carcinoma. No fine papillary or arborizing growth or cribriform formation was observed. Tumor cells at the ductal peripheral zone were polygonal and clear with abundant glycogen in the cytoplasm; they were transformed into nonclear cells with slightly eosinophilic cytoplasm toward the center of the involved ducts. Occasionally, nonclear cells were elongated, with a centrally located cigar-shaped nucleus. These elongated or spindle cells tended to show a fascicular and streaming pattern similar to that of a smooth muscle tumor. Immunohistochemically, alpha smooth muscle actin (alpha-SM-actin) and S-100 protein were expressed in most of the nonclear cells. While clear cells also had a positive reaction for S-100 protein, they were mostly negative or barely positive for alpha-SM-actin. Epithelial membrane antigen (EMA) was also positive in a certain number of polygonal cells. These results support the myoepithelial nature of the present tumor, and some cells might also be immunologically differentiated into ductal epithelial cells. In addition to cytological atypia, frequent mitoses, and central necrosis within ducts, there was a minimal but evident stromal invasion, suggesting histological malignancy in this peculiar tumor.
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PMID:Intraductal growth of malignant mammary myoepithelioma. 133 12

We report a case of ovarian leiomyomata, bilateral and massive, in a 21-yr-old woman. Primary leiomyoma of the ovary is a very rare tumor and is usually small, unilateral, and concomitant with uterine leiomyomata. To our knowledge, this is the first report in the English literature of bilateral ovarian leiomyomata. We document the smooth muscle origin of the tumors with immunohistochemical studies that show appropriate staining with antibodies to vimentin, muscle specific actin, desmin, smooth muscle actin, and collagen type IV. The available literature is reviewed. The characteristics of both typical and atypical ovarian leiomyoma and theories of its origin are discussed.
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PMID:Bilateral massive ovarian leiomyomata in a young woman: a case report with review of the literature. 134 26

A detailed immunohistochemical study has been carried out on 63 breast lesions with epitheliosis, ductal carcinoma in situ and clinging carcinoma (lobular cancerization), using antibodies directed against keratins 5/14 and 14, 15, 16, 18, 19, vimentin, smooth muscle actin, collagen IV and laminin. The results have shown that epitheliosis on the one hand and ductal in situ and clinging carcinoma on the other are immunohistochemically different epithelial lesions. Epitheliosis appears to be epithelial hyperplasia with keratin 5/14 and keratin 14, 15, 16, 18, 19-positive cells. Compared to epitheliotic cells tumor cells of clinging carcinoma, lobular cancerization and ductal carcinoma in situ expressed only luminal keratins 14, 15, 16, 18, 19 in 85% of the cases studied; whereas in 15% there was a basal keratin expression. From our results we conclude that the clinging carcinoma (lobular cancerization) represents the initial morphological step in the development of ductal carcinoma in situ and thus may be interpreted as a minimal ductal neoplasia. With the immunohistochemical demonstration of basal and luminal keratins it may be possible in individual cases to differentiate between benign and malignant in situ lesions of the breast.
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PMID:An immunohistochemical study of the breast using antibodies to basal and luminal keratins, alpha-smooth muscle actin, vimentin, collagen IV and laminin. Part II: Epitheliosis and ductal carcinoma in situ. 138 27

We analyzed 46 gastrointestinal stromal tumors (GISTs) using a panel of antibodies to determine the frequency of smooth muscle differentiation and the relationship of immunophenotype to histopathologic features and clinical behavior. Thirty-six GISTs were classified as benign or malignant based exclusively on clinical behavior; a 2-year minimum follow-up was required for benign lesions. GISTs were immunopositive in the following categories: vimentin 45 of 46, desmin nine of 45, muscle-specific actin (MSA) 36 of 46, alpha-smooth muscle actin (SMA) 34 of 46, chicken gizzard actin-7 zero of 38, cytokeratin two of 46, S100 protein six of 46, glial fibrillary acidic protein (GFAP) zero of 46, synaptophysin zero of 46, and chromogranin one of 46. At least one muscle marker was positive in 39 of 46 tumors. Five GISTs were MSA positive/SMA negative, and three were MSA negative/SMA positive. All desmin-positive cases reacted with MSA or SMA. Eight GISTs were positive for vimentin, MSA, SMA, and desmin, whereas seven were vimentin positive only. Compared with the latter, the former tended to be smaller, less often necrotic, and clinically benign (p less than 0.05 for each). All vimentin-positive only GISTs were malignant. Immunohistochemical features did not correlate with tumor site, cellularity, nuclear pleomorphism, or mitotic rate. Benign GISTs were less cellular than were malignant GISTs (p less than 0.05), but they did not differ statistically in degree of nuclear pleomorphism, necrosis, mitotic rate, or size. We conclude that (a) 85% of GISTs react with at least one muscle antibody; (b) immunohistochemical features are unrelated to anatomic site; (c) SMA is, in effect, as sensitive as MSA, whereas desmin is less sensitive; and (d) simultaneous vimentin, MSA, SMA, and desmin positivity correlates with a benign outcome.
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PMID:Muscle differentiation and clinicopathologic features of gastrointestinal stromal tumors. 141 3

Inflammatory pseudotumor is a pathologic term used to describe reactive, pseudoneoplastic phenomena, which reportedly occur in many parts of the body. Clinicopathologic and immunohistochemical findings in six cases of inflammatory pseudotumor of the major salivary glands are described. All six lesions involved the parotid gland. There were three men and three women affected, with a median age of 72.5 years. All patients presented with a swelling of several months' duration in the parotid region. Five patients were alive and free of tumor at an average of 3.2 years after surgical removal, and one patient was lost to follow-up. The lesions were firm, discrete nodules, grossly described as homogenous yellow-gray tissue. Histologically, all lesions contained a diversified admixture of four histological elements: (a) myofibroblasts, (b) histiocytes, (c) plasma cells, and (d) lymphocytes. Results of immunohistochemical studies showed a biphasic spindle cell population of myofibroblasts and histiocytes with variable staining characteristics for KP-1(CD-3), smooth muscle actin, muscle-specific actin, and vimentin. These findings are in agreement with the concept that inflammatory pseudotumor is a fibroinflammatory lesion with an abundant component of myofibroblastic/fibrohistiocytic elements.
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PMID:Inflammatory pseudotumors of the major salivary glands. Clinicopathologic and immunohistochemical analysis of six cases. 141 8

Cellular neurothekeoma is a recently recognized benign cutaneous neoplasm, which is currently regarded as being of nerve sheath origin and is thought to represent a variant of conventional neurothekeoma (dermal nerve sheath myxoma). Nine new cases presenting predominantly in adolescents or young adults are described. Morphologically they were characterized by short fascicles or small nests of palely eosinophilic epithelioid or spindle-shaped cells which ramified in an ill-defined manner between dermal collagen bundles. Myxoid matrix was absent or sparse. Scattered normal mitoses and multinucleate giant cells were often present. Immunohistochemically all nine cases were strongly NK1/C3 positive, seven were weakly NSE positive and three were smooth muscle actin positive. Staining for S-100 protein, PGP 9.5, epithelial membrane antigen and desmin was negative in all cases. In view of its distinctive architecture and immunophenotype, both of which are totally different from conventional neurothekeoma, it is proposed that cellular 'neurothekeoma' is a separate discrete entity which may represent an epithelioid variant of pilar leiomyoma.
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PMID:Cellular 'neurothekeoma': an epithelioid variant of pilar leiomyoma? Morphological and immunohistochemical analysis of a series. 158 88

Two groups of cells, one rounded or oval and the other spindle-shaped, were found in a case of plexiform fibrohistiocytic tumor. Immunohistochemistry was strongly positive for alpha smooth muscle actin in most cells of both types but stronger in the spindle-shaped cells, suggesting a myofibroblastic origin. This was in correlation with electron microscopic findings which revealed fibroblasts, myofibroblasts and some undifferentiated mesenchymal cells. However, factor XIIIa was negative suggesting that this tumor does not originate from dermal dendrocytes.
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PMID:Plexiform fibrohistiocytic tumor. 166


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