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

We report two cases of a previously unrecognized neoplasm, each characterized by prominent lobular configuration in the subcutaneous tissue. Within the neoplasms were distinctive garland-shaped structures composed of glial fibrillary acidic protein (GFAP) positive cells with indistinct borders, encased in concentric loops of fine collage fibers. In some areas, the neoplastic cells were distributed in small lacunae. The extracellular space between the collagenous tissue and the cells was filled with copious myxoid matrix. One of the neoplasms also demonstrated areas with spindle cells which resembled leiomyoma. Immunohistochemistry was negative for smooth muscle actin (1A4), muscle actin (HHF35), S-100 protein, desmin, cytokeratin, KP1, and epithelial membrane antigen (EMA.) Currently, both patients are free of recurrence or metastasis 2 and 4 years after primary surgical excision. The neoplasms, which we term benign polymorphous mesenchymal tumor of soft parts (BPMT), should be distinguished from ossifying fibromyxoid tumor of soft parts, extraskeletal mesenchymal chondrosarcoma, neoplasms arising in ectopic breast tissue and mixed tumor of the skin.
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PMID:Benign polymorphous mesenchymal tumor (mesenchymal hamartoma) of soft parts. Report of two cases. 918 15

In 1987, a distinctive brain tumor arising in young children was first described. This tumor contained neuroepithelial, peripheral epithelial, and mesenchymal elements, but lacked divergent tissue differentiation characteristic of malignant teratomas. It was originally designated as atypical teratoid tumor, but because of the prominent rhabdoid component, the tumor designation was modified to atypical teratoid/rhabdoid tumors (AT/RT) of infancy and childhood. AT/RTs occur most commonly in infants under 2 years of age, often have central nervous system (CNS) dissemination, do not respond to therapy, and typically are fatal within 1 year. Most are located in the cerebellum (65%), but they may arise at any CNS site. Histologically, various patterns can be present within the same tumor, but they all have a population of rhabdoid cells, and 70% contain fields typical of a primitive neuroectodermal tumor (PNET/medulloblastoma). Less frequently, malignant mesenchymal tissue and/or an epithelial component are found. Necrosis and brisk mitotic activity are common. The immunocytochemical profile is complex, but germ cell markers are consistently negative. Ultrastructural features vary and depend on the site sampled, but whorled bundles of cytoplasmic intermediate filaments are a distinctive finding in cells of the rhabdoid component. The authors report 4 AT/RTs (2 males, 2 females, age range 6 months to 4 1/2 years, 3 cerebellar, 1 cerebral). All cases showed a variety of histologic patterns with necrosis. Typical rhabdoid cells, PNET areas, undifferentiated bland large cell regions, dense connective tissue, and solid clusters of epithelial cells were present. Immunocytochemistry showed strong vimentin reactivity, whereas epithelial membrane antigen, cytokeratin, glial fibrillary acidic protein, S-100 protein, desmin, and smooth muscle actin were present to a lesser extent in most cases. Germ cell markers were negative. Ultrastructurally, many cells contained aggregates of cytoplasmic intermediate filaments, and some cells had a basal lamina on one aspect. Cells with interdigitating cytoplasmic borders were seen and rare cells had microtubules. Cytogenetic studies were normal in 2 cases. Follow-up has shown that 3 children have died of disease (< 1 year after diagnosis) and 1 child is alive with disease (18 months after diagnosis). Separation of AT/RT from PNET based on histopathologic and biologic evaluation is important, because AT/RTs are aggressive tumors with a dismal prognosis and currently there is no effective treatment. Neither clinical signs and symptoms nor radiologic features will distinguish AT/RTs from PNETs.
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PMID:Central nervous system atypical teratoid/rhabdoid tumors of infancy and childhood. 920 2

A tumor in the breast of a 67-year-old male was resected. It was grossly circumscribed and unencapsulated. Histologically, it was composed of plump and long bipolar, spindle cells arranged in fascicular clusters with intervening broad collagen bands. The cells lacked pleomorphism, and no mitotic figures were found. The margin was that of pushing border type. No epithelial component was seen in the tumor. Immunohistochemically, the tumor cells expressed variable reactivity to vimentin, desmin and smooth muscle actin and were negative for S-100 protein and keratin. Electron microscopy showed cell differentiation between fibroblast and smooth muscle cells.
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PMID:Myofibroblastoma of the breast: a case report. 922 74

The canine transmissible venereal tumour is a naturally occurring contagious round-cell neoplasia which is primarily located in the mucous membrane of the external genitalia in dogs of either sex. In order to specify the controversial cytogenetic origin of this round-cell tumour, 14 cases of canine transmissible venereal tumour, formalin- or Bouin-fixed and paraffin-embedded, were subjected to extensive immunophenotypic analysis using reagents specific to a variety of cytoplasmic or surface antigens: lysozyme, ACM1 antigen, vimentin, neuron-specific enolase, glial fibrillary acidic protein, desmin, alpha smooth muscle actin, CD3, IgG, kappa and lambda light chains, and keratin. Lysozyme immunoreactivity was detected in all cases, ACM1 antigen in 11 of 14, neuron-specific enolase in 11 of 14, vimentin in 10 of 14, glial fibrillary acidic protein in 4 of 14 and desmin in 1 of 14. All the sections were negative to keratins, alpha smooth muscle actin and CD3, whereas in five cases, perivascular tumour cells contained Ig G, kappa and lambda light chains. The immunoreactivity to lysozyme and ACM1 antigen supports the hypothesis of a histiocytic immunophenotype for the canine transmissible venereal tumour.
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PMID:Immunophenotype of the canine transmissible venereal tumour. 923 33

We established long-term cultures from skin tumors of nine patients suffering from classical Kaposi's sarcoma (KS). Spindle cells obtained after enzymatic digestion were cultured on gelatin- or fibronectin-coated flasks in DMEM with 15% fetal calf serum, aFGF and heparin. Immunohistochemical staining was positive for MHC class I, laminin, type IV collagen, vimentin, alpha smooth muscle actin (20-40% of cells), caldesmon (20%), calponin (20-40%) and smooth muscle myosin (20-40%), and was negative for common leukocyte antigen, CD4, LFA1, CD34 and cytokeratin. Around 20% of cells up to the third passage in culture expressed the endothelial markers CD36, BMA 120 but were negative for UEA and Fc von Willebrand. Smooth muscle proteins were detected with immunoblotting. Using the polymerase chain reaction, human herpes virus 8 (HHV8) sequences were detected in primary cultures of three out of seven cell lines but were rapidly lost during in vitro passaging. KS-derived cells did not proliferate in serum-free medium, had a normal karyotype and did not grow in soft agar medium. Tumors formed in nude mice injected with KS-derived cells. The tumors were composed of mouse cells and were highly vascularized. Our results suggest that KS-derived cells are heterogeneous: the majority of cells have either a smooth muscle cell or a fibroblastic phenotype. Another minor cell compartment was composed of endothelium-derived cells. KS cells do not possess the characteristics of transformed cells in vitro and may be composed of polyclonal activated cells. Recombinant alpha interferon (rIFN) slightly inhibited the growth of KS-derived cells and increased the expression of MHC class I antigens. While cells were resistant to natural killer (NK) cell-mediated cytotoxicity, they became sensitive to rIFN-primed NK cells. Thus, the antitumor potential of rIFN against KS in vivo could result from immunomodulatory rather than from direct antiproliferative effects.
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PMID:Characterization of in vitro culture of HIV-negative Kaposi's sarcoma-derived cells. In vitro responses to alfa interferon. 924 22

Superficial leiomyosarcomas are infrequent tumors that are very rare in childhood. We report on a 12-year-old white boy with a cutaneous leiomyosarcoma of his left groin. Immunohistochemical study revealed positive immunostaining with antibodies to vimentin, desmin, and smooth muscle actin. The tumor was removed with wide surgical margins.
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PMID:Cutaneous leiomyosarcoma in a child. 926 8

Adenoid basal carcinoma and adenoid cystic carcinoma are rare primary cervical neoplasms occurring in postmenopausal women. They are generally regarded as distinct entities on the basis of their distinctive morphology and a different biological behaviour. Although the separation of these two entities is still mandatory, some rare complex cases may show overlapping pathological features and are difficult to classify. We report a case of composite cervical tumor with both types of carcinoma, an in situ epidermoid carcinoma and a hitherto undescribed clear cell component, each with a different morphology and immunophenotype. The adenoid basal component is mainly immunoreactive for cytokeratin KL1. The adenoid cystic component is strongly stained for smooth muscle actin and is associated with a hyaline stroma immunostained for collagen IV.
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PMID:[Adenoid basal carcinoma and adenoid cystic carcinoma of the uterine cervix]. 929 80

We report the clinical, histopathologic, immunohistologic, and prognostic findings in 19 patients with cutaneous leiomyosarcoma, eight males and 11 females (mean age, 66 years; age range, 41-93 years). The tumors presented mainly as solitary lesions and were located on the head and neck (eight lesions), trunk (four lesions), upper extremities (three lesions), and lower extremities (four lesions). Histopathologically, two predominant growth patterns were observed: nodular (12 cases) and diffuse (seven cases). Neoplasms with a nodular growth pattern were characterized by high cellularity and prominent nuclear atypia, and they showed conspicuous mitoses, several necrotic cells, and sometimes extensive necrotic areas. By contrast, most cutaneous leiomyosarcomas with a diffuse growth pattern revealed low cellularity, well-differentiated smooth muscle cells, inconspicuous mitotic figures, and few or no necrotic cells. Immunohistologic investigations revealed all cutaneous leiomyosarcomas to express vimentin and smooth muscle actin. Pan-muscle actin (HHF-35) was also expressed in most cases (15 lesions). However, only 12 lesions showed positive staining for desmin. Remarkable was the expression of cytokeratins in five lesions. Clinical follow-up revealed local recurrences in five patients (three cases with nodular pattern and two lesions with a diffuse pattern) after a period ranging from 8 months to 3 years after surgical excision. No distant metastases have been observed in our series. We conclude that cutaneous leiomyosarcoma with a diffuse growth pattern may constitute a pitfall in histopathologic diagnosis because of the presence of only subtle criteria for malignancy. Cutaneous leiomyosarcoma may show different immunophenotypes, thus emphasizing the importance of using a large panel of antibodies (smooth muscle actin, HHF-35, desmin, vimentin, cytokeratins, and S-100 protein) in immunohistologic diagnosis. Cutaneous leiomyosarcoma sometimes reveals local recurrences, but it has negligible potential for distant metastases.
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PMID:Cutaneous leiomyosarcoma. 929 73

We report on a locally recurrent vulvar tumor in an 80-year-old woman that we believe represents the first example of malignant transformation of an angiomyofibroblastoma. The tumor was predominantly a typical angiomyofibroblastoma, composed of epithelioid or oval cells with eosinophilic cytoplasm that tended to cluster in small groups and around blood vessels. These areas merged imperceptibly with a high-grade sarcoma that resembled a myxoid malignant fibrous histiocytoma. The tumor cells in the benign areas were diffusely immunoreactive for vimentin; many cells were positive for smooth muscle actin, and focal positivity for muscle actin and desmin was observed. The tumor cells in the sarcomatous areas were diffusely positive for vimentin, but negative for smooth muscle actin, muscle actin, and desmin. No staining for keratin, S-100 protein, or CD34 was noted. Ultrastructural examination of the sarcomatous area showed that the cells had the features of fibroblasts. All previously reported cases of angiomyofibroblastoma have exhibited banal histologic features and have behaved in a benign fashion. This case shows that these tumors may rarely be associated with a malignant component, and the designation "angiomyofibrosarcoma" may be appropriate in such cases.
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PMID:Angiomyofibroblastoma of the vulva with sarcomatous transformation ("angiomyofibrosarcoma"). 929 88

The clinicopathological and immunohistochemical profile of 17 cases of angiomyofibroblastoma (AMF) arising in the genital tract of females is reported. The lesions usually presented as painless masses and were located in the superficial vulvar region (15 cases), canal of Nuck (one case), and perineum (one case) in women ranging in age from 38 to 60 years (median, 46 years). The tumors were well delineated and ranged in size from 2 to 8 cm in greatest dimension. Microscopically, they were composed of spindled and epithelioid mesenchymal cells arranged in cords and nests preferentially arrayed around numerous small to medium-sized vessels. Mitotic activity ranged from 0 to 7 mitoses per 50 high-power fields (HPF) with no abnormal mitotic figures. Minimal nuclear atypia was appreciated. Intralesional fat was present in 12 cases and in two of these cases constituted most of the tumor (lipomatous variant of AMF). Tumor cells expressed vimentin (five of five cases), estrogen receptor protein (six of six cases), progesterone receptor protein (five of six cases), desmin (six of eight cases), CD34 (one of six cases), and smooth muscle actin (one of seven cases). None of the eight women with follow-up of up to 25 years (mean, 7.8 years) after simple excision developed a recurrence. This study confirms the benign nature of AMF, broadens its morphological spectrum to include a lipomatous variant, and proposes an origin from a perivascular stem cell that is capable of myofibroblastic and fatty differentiation.
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PMID:Angiomyofibroblastoma of the female genital tract: analysis of 17 cases including a lipomatous variant. 930 29


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