1/3. t(9;22)(q22-31;q11-12) is a consistent marker of extraskeletal myxoid chondrosarcoma: evaluation of three cases.Three cases of extraskeletal myxoid chondrosarcoma with typical histologic and ultrastructural features were investigated cytogenetically. All three cases showed a reciprocal chromosome translocation characterized as t(9;22)(q22-31)(q11-12), thus confirming the findings in three previously karyotyped cases of extraskeletal myxoid chondrosarcoma in the literature. These data add significantly to the evidence of t(9;22) being diagnostic for extraskeletal myxoid chondrosarcoma. Other previously published cases with a range of complex karyotypes were less well defined morphologically. In cases with limited diagnostic material this karyotype might facilitate distinction from myxoid liposarcoma, which consistently shows t(12;16). Clear cell sarcoma, ewing's sarcoma/primitive neuroectodermal tumor, and desmoplastic round cell tumor also show involvement of chromosome 22 with formation of a hybrid gene between the Ewing's sarcoma gene on band q12 and a transcription factor gene. Whether rearrangement of the Ewing's sarcoma gene is also present in extraskeletal myxoid chondrosarcoma is not clear at present. Cloning of the (9;22) translocation might provide important clues to the pathogenesis of this type of chondrosarcoma.- - - - - - - - - - ranking = 1keywords = karyotype (Clic here for more details about this article) |
2/3. Round cell liposarcoma with the insertion (12;16)(q13;p11.2p13).cytogenetic analysis of a short-term culture from a round cell liposarcoma revealed ins(12;16)(q13;p11.2p13) as a sole abnormality in all metaphase cells studied. This chromosome rearrangement, thus far not described in liposarcomas, leads to recombination of bands 12q13 and 16p11.2 and, thus, seems to be the equivalent of t(12;16)(q13;p11), a translocation that is highly specific for the myxoid type of liposarcoma. Our case represents the fourth fully karyotyped round cell liposarcoma that displays a cytogenetic rearrangement of bands 12q13 and 16p11, thus supporting the concept that round cell liposarcoma is related to myxoid liposarcoma and constitutes its poorly differentiated form. The fact that ins(12;16) was the only detectable chromosome aberration suggests that the presence of secondary cytogenetic aberrations is not a prerequisite for the development of a round cell histology in liposarcoma.- - - - - - - - - - ranking = 0.33333333333333keywords = karyotype (Clic here for more details about this article) |
3/3. Tumor karyotype differentiates lipoblastoma from liposarcoma.lipoblastoma is a rare benign pediatric soft tissue tumor that may be difficult to distinguish from a myxoid liposarcoma clinically or histologically. The authors present a case of a progressively growing, locally invasive soft tissue tumor in a child. Tissue culture for cytogenetic study showed a breakpoint in the long arm of chromosome 8. A review of the literature showed seven case reports of lipoblastoma karyotype, six of which had a similar breakpoint in chromosome 8. This distinguishes it from the histologically alike myxoid liposarcoma, the karyotype of which typically contains the clonal anomaly t(12;16)(q13:p11). The authors recommend that when performing a biopsy of a childhood adipose tumor with unusual features, such as progressive or invasive growth, that fresh tissue be submitted for cell culture. The tumor karyotype will, in most cases, aid in differentiating lipoblastoma from myxoid liposarcoma.- - - - - - - - - - ranking = 2.3333333333333keywords = karyotype (Clic here for more details about this article) |