1/6. Clear cell sarcoma of kidney in an adolescent and in young adults: a report of four cases with ultrastructural, immunohistochemical, and dna flow cytometric analysis.Clear cell sarcoma of the kidney is a distinct, highly malignant pediatric neoplasm. Its occurrence in adults is extremely rare and the subject of isolated case reports. We present a series of four cases (three males and one female) identified in an adolescent and in young adults (16, 18, 20, and 25 years) with flank mass (three cases), hematuria (two cases), flank pain (two cases), and hypertension (one case). Three patients had stage III disease and one had stage I disease (National Wilms' Tumor Study staging system). All tumors had predominantly or exclusively the classic histology of a monotonous proliferation of uniform small round cells with evenly distributed fine chromatin, although focal microcyst formation (two cases) and spindled architecture (one case) (variant patterns) were also noted. Therapy in all cases consisted of surgery and chemotherapy with or without radiation. Follow-up data (29-202 months) showed distant metastases in all four cases, including the lung (four cases), bone (two cases), and the liver (two cases). Three patients died of disease at 29, 59, and 63 months (mean, 50.3 months), and one patient is alive with no evidence of disease at 202 months. Ultrastructural features included scattered primitive junctions, short and irregular cytoplasmic extensions, and scant to a moderate amount of mitochondria. Immunohistochemical study (three cases) showed immunoreactivity with vimentin (two cases) and no reaction with cytokeratin, epithelial membrane antigen, S-100 protein, or desmin. Flow cytometric analysis showed diploid dna content in three primary tumors and tetraploidy in one metastatic tumor. The proliferative activity (S-phase fraction) was low to intermediate (mean, 9.8%). Our data suggest that clear cell sarcoma of the kidney in the young adult age group resembles its pediatric counterpart in ultrastructural and immunohistochemical characteristics, proclivity for skeletal and visceral metastasis, dna diploid status with relatively low S-phase, and aggressive clinical course. Clear cell sarcoma of the kidney in adult patients, although rare, must be differentiated from sarcomatoid carcinoma, sarcomas, and round cell tumors because of its unique characteristics in comparison to other renal neoplasms.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
2/6. Newly established clear cell sarcoma (malignant melanoma of soft parts) cell line expressing melanoma-associated Melan-A antigen and overexpressing C-MYC oncogene.Clear cell sarcoma (CCS), malignant melanoma of soft parts, is a rare malignant tumor with a poor prognosis. In this study, a CCS cell line, designated MP-CCS-SY, was established from a metastatic tumor of a 17-year-old Japanese girl that originated in the left achilles tendon. A small number of melanosomes were detected in the cytoplasm by electron microscopy. The melanosomes immunoreacted with two melanoma-associated antibodies, HMB45 and Melan-A. A Western blot demonstrated the existence of a Melan-A antigen in this cell line. Although a t(12;22)(q13;q12), which is characteristic of CCS, was not identified by a chromosomal analysis with conventional banding techniques, fluorescence in situ hybridization analysis with painting probes of chromosomes 12 and 22 revealed the insertion of a chromosome 12 fragment into one of the long arms of chromosome 22. The chimeric EWS/ATF1 transcript was detected by the reverse transcriptase polymerase chain reaction. Extra copies and structural abnormalities of chromosome 8 were observed. Overexpression of c-myc mRNA was detected by Northern blot analysis and may have a role in malignant progression of CCS. The availability of this MP-CCS-SY cell line will help to understand the molecular biology of this malignancy and should be useful as a tool for developing an immunotherapy.- - - - - - - - - - ranking = 5keywords = antigen (Clic here for more details about this article) |
3/6. Perivascular epithelioid cell tumor of the jejunum.Certain HMB-45-positive epithelioid cell tumors have recently been categorized under a unified concept: perivascular epithelioid cell tumor (PEComa). In this report, we describe ajejunal PEComa arising in a 32-year-old woman without other tumors or stigmata of tuberous sclerosis. The tumor consisted of nests of epithelioid cells with clear to granular eosinophilic cytoplasm. The nests were separated by thin fibrovascular septa. The tumor cells were positive for HMB-45 and progesterone receptor, and negative for cytokeratin, epithelial membrane antigen, vimentin, desmin, alpha-smooth muscle actin and CD34. RT-PCR analysis failed to reveal fusion transcript ETW/ATF1, which is characteristic of clear cell sarcoma of the soft parts. She developed a recurrent tumor at the pelvic wall and the left ovary at 13 and 25 months after the first operation, respectively. Each tumor was resected surgically, and no additional therapy was performed. We think the tumor of this case is a malignant form of PEComa because of the clinical history of multiple recurrences and the size of the primary tumor. Our case underscores that to make a correct diagnosis, clinical information and immunohistochemical examination are essential.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
4/6. Primary clear cell sarcoma of the ileum: an uncommon and misleading site.A clear cell sarcoma, arising primarily in the ileum of a 35-year-old man, is reported. Histologically, the neoplasm infiltrated the full thickness of the intestinal wall. It consisted of strands and sheets of round to spindle-shaped cells with clear to eosinophilic cytoplasm, vesicular nuclei and prominent nucleoli. Vascular invasion was present at diagnosis. Tumour cells expressed S-100 protein, melan-A and tyrosinase. They were negative for HMB45, CD117, cytokeratins, epithelial membrane antigen, smooth muscle actin, desmin, CD31, CD34, chromogranin and synaptophysin. reverse transcription-polymerase chain reaction analysis performed on paraffin-embedded tissue showed EWS-ATF1 fusion transcripts representative of the t(12;22) (q13;q12) clear cell sarcoma reciprocal translocation. The patient, who developed liver metastases 2 months after diagnosis, died of disease at 15 months. This case demonstrates that the gastrointestinal tract is a potential site for primary clear cell sarcoma of soft tissues, and, furthermore, that cytogenetics and/or molecular techniques play a central role in the diagnosis.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
5/6. association of the t(12;22)(q13;q12) EWS/ATF1 rearrangement with polyphenotypic round cell sarcoma of bone: a case report.The t(12;22)(q13;q12) chromosomal rearrangement results in an EWS/ATF1 fusion transcript and is associated with clear cell sarcoma (CCS). CCS is an uncommon tumor arising in tendons and aponeuroses of the extremities and shows evidence of melanocytic differentiation at the light microscopic, immunohistochemical, and/or ultrastructural level. Only 5 cases have been reported to arise in bone, none of which had molecular confirmation of the diagnosis. The current report describes a 7-year-old girl with a primary round cell sarcoma of the left humerus showing polyphenotypic differentiation on immunohistochemical analysis. antibodies directed at melanocytic antigens were negative, and there was no evidence of melanocytic differentiation by light microscopy or ultrastructural analysis. cytogenetic analysis revealed rearrangement of the EWS locus within 22q12. RT-PCR and sequence analysis revealed the presence of a fusion transcript bringing together exon 7 of EWS with exon 5 of ATF1, consistent with a type 2 transcript reported in association with CCS. However, given the lack of morphologic features usually present in CCS, a diagnosis of polyphenotypic round cell sarcoma was made. This tumor thus expands the spectrum of neoplasms associated with the t(12;22)(q13;q12) rearrangement.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
6/6. Establishment and characterization of a clear-cell sarcoma (malignant melanoma of soft parts) cell line.A clear cell sarcoma (CCS) cell line, designated as NCS-1, was established in monolayer culture from a xenograft line originating from a metastatic CCS. Marked karyotypic aberrations and tumorigenicity in nude mice revealed the malignant derivation of the NCS-1 cell line. These cells contained abundant glycogen and were amelanotic by light microscopy. By electron microscopy, however, melanosomes in various developmental stages were seen, and some of them were partially melanized. The electron microscopic dopa reaction revealed the presence of tyrosinase activity. Enzyme-linked immunoadsorbent assay revealed that NCS-1 cells expressed a 75-kDa glycoprotein which was identified as a marker of highly differentiated melanoma cells. From these results, NCS-1 cells were found to retain both cytochemical and morphological properties of CCS. Application of NCS-1 cells to a panel of monoclonal antibodies recognizing melanocytic differentiation antigens showed that they corresponded approximately to highly differentiated melanoma cells. In conclusion, the present study strongly supports the close relationship between CCS and malignant melanoma.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |