1/7. A new human pleomorphic rhabdomyosarcoma cell-line, HS-RMS-1, exhibiting MyoD1 and myogenin.A number of human cell lines derived from alveolar or embryonal rhabdomyosarcoma (RMS) have been described. To our knowledge, however, no cell line established from pleomorphic RMS has been reported. We describe here the establishment and characterization of a new human cell line, HS-RMS-1, which originated from a typical pleomorphic RMS arising in the gluteal muscle of a 26-year-old man. HS-RMS-1 cells had pseudotetraploid complex karyotypes with no specific abnormalities. Both in vitro and in vivo the cells on light microscopic examination exhibited pleomorphic features with immunopositive reaction for myogenic antigens including MyoD1 and myogenin, although no Z band-like structures were detected electron-microscopically. RT-PCR demonstrated the expression of MyoD1 and myogenin in HS-RMS-1 cells at the mRNA level, and direct sequencing analysis revealed cDNAs of MyoD1 and myogenin identical to those previously reported. This cell line, HS-RMS-1, established from pleomophic RMS will be useful for further studies including the molecular aspects of human RMS.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
2/7. Primary CD30/Ki-1 positive anaplastic large cell lymphoma of skeletal muscle with der(17)t(1;17)(q11;p11).CD30/Ki-1 positive anaplastic large cell lymphoma (Ki-1 ALCL) frequently exhibits extranodal disease and chromosomal t(2;5)(p23;q35). An 11-year-old girl presented with an intramuscular tumor of the right upper arm. Tumors of the chest wall, left arm and leg, hepatomegaly, pleural effusion, and enlarged lymph nodes then developed. The intramuscular tumor and pleural effusion showed a diffuse infiltration of large atypical cells with abundant amphophilic cytoplasms. The tumor cells were positive for CD30, CD2, CD45RO, and p80, but were negative for other T-cell, B-cell, and myeloid cell antigens. She was diagnosed as having Ki-1 ALCL with a T-cell origin. Cytogenetic studies showed an abnormal karyotype including a der(17)t(1;17)(q11;p11). She received seven cycles of intensive chemotherapy followed by an autologous peripheral blood stem cell transplantation, and has been in complete remission for more than two years. The primary involvement of skeletal muscle is quite uncommon in ALCL, and an abnormal karyotype including t(1;17)(q11;p11) has not been reported previously. Since a high frequency of aberrations of 1p36/1q12 or 17p13.3 was detected in sarcoma cells, the presence of suppressor genes is suggestive in these sites.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
3/7. Myxofibrosarcoma with an infiltrative growth pattern: a case report.Myxofibrosarcoma, also known as a myxoid variant of malignant fibrous histiocytoma, is one of the most common sarcomas in the extremities of elderly people and is characterized by a high frequency of local recurrence. We report a case of myxofibrosarcoma, intermediate grade, involving the thigh along the fascial plane and between the muscles without the formation of an apparent nodular lesion. On microscopic examination, the tumor lacked areas of necrosis and pronounced cellular pleomorphism, but it was highly cellular with proliferation of spindle cells which contained large elongated, hyperchromatic and irregularly shaped nuclei, slightly eosinophilic cytoplasm and indistinct cell margins, arranged in both interlacing fascicles and a storiform pattern. Immunohistochemically, many of the tumor cells showed intense reactivity to vimentin and CD34. More than 20% of the cells were positive for p53 protein and the MIB-1 labeling index was approximately 30%. desmin, alpha-smooth muscle actin, muscle-specific actin, S-100 protein, cytokeratin, epithelial membrane antigen, bcl-2 protein and neurofilament were negative. The absence of a discrete mass lesion and diffuse infiltrative nature precluded early recognition of tumor. Seven years after hindquarter amputation, the patient has been alive without evidence of local recurrence or distant metastasis. This case indicates that myxofibrosarcoma can demonstrate a highly infiltrative growth pattern. It is possible that this infiltrative nature is associated with a high rate of local recurrence of the tumor. A careful radiological examination of the extension of the tumor prior to surgery is mandatory considering the infiltrative nature of myxofibrosarcoma.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
4/7. Extraocular muscle metastasis 16 years following primary prostate carcinoma.An 83-year-old man with a history of localized prostate carcinoma treated 16 years prior with transurethral partial prostatectomy and radioactive seed implants presented with a 2-month history of right globe proptosis. Computed tomography demonstrated a right medial rectus mass. serum prostate specific antigen (PSA) level was normal. Tumor biopsy revealed poorly differentiated carcinoma with diffuse staining of tumor cells with PSA and prostatic acid phosphatase. This case demonstrates that prostate carcinoma may metastasize to an extraocular muscle many years after treatment of the primary tumor and may not be accompanied by elevated serum PSA. Immunohistochemical stains are helpful in establishing the diagnosis.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
5/7. Chordoid tumor: a light, electron microscopic, and immunohistochemical study.Chordoid tumor--synonymous with chordoid sarcoma, parachordoma, and peripheral chordoma--is a very rare neoplasm with histologic similarity to chordoma that is found outside the axial skeleton. A soft tissue chordoid tumor in the gluteus maximus muscle of a 42-year-old man is presented. This tumor had morphologic features identical to a chordoma: nodular growth with vacuolated cytoplasm and myxomatous stroma by light microscopy, positive immunoreaction for cytokeratin and epithelial membrane antigen by immunohistochemistry, desmosomes, intercellular lumina lined with microvilli, and the presence of basal lamina material by electron microscopy. Two similar cases have been reported in the English literature.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
6/7. Symplastic leiomyoma of the scrotum. A case report.Mesenchimal tumors of the scrotum are rare lesions. Here, we describe a case of symplastic leiomyoma of the scrotum, in a 49-year old man. This is the third case reported in the world literature. Grossly, the lesion is a white-gray nodule, with fasciculated pattern, on sectioning. Histologically, the neoplasm is formed by whorling bundles of fusiform cells, which have atypical nuclei, with occasional cytoplasmatic inclusions. Mitoses are absent. The muscolar nature of the lesion is demonstrated by positivity for Masson-trichrome stain and for actin and desmine antigens.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
7/7. Localized muscle wasting as an initial symptom of skeletal muscle lymphoma.A 25-year-old man who developed painless muscle wasting and weakness of only the right thigh, was eventually shown to have systemic lymphoma with muscle infiltration. The patient was initially misdiagnosed as focal inflammatory myopathy, and he had a partial response to steroid therapy. Immunohistochemical analysis of the biopsied muscle and the subcutaneous tumor revealed the infiltrating cells with a positive macrophage-associated marker (CD68) and negative T- or B-cell-associated antigens, leading to the final diagnosis of true histiocytic lymphoma. Although skeletal muscle lymphoma is extremely rare, it should be considered in the differential diagnosis of localized muscle wasting.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |