A. Kasprzynski

[Myoepithelioma of soft tissue -- case report with clinicopathologic, ultrastructural, and cytogenetic findings].

The case of a soft tissue myoepithelioma is presented including clinicopathologic, ultrastructural, and genetic findings. A 30-year-old male patient suffered from a soft tissue tumor within the deep soft tissues of the right lower leg measuring 13.2 x 8.2 x 9 cm. Histologically, the lesion was diagnosed as a myoepithelioma displaying a lobulated architecture with cords and nests of epithelioid and spindle cells without cytologic atypia lying within a fibromyxoid and partly chondroid matrix; immunohistochemistry was positive for pancytokeratin, S100-protein, calponin and partly for GFAP and EMA. Ultrastructural analysis revealed glycogen deposits and cell-membrane-associated plaque structures, whereas true myofilaments could not be identified (with immunohistochemistry being negative for actin). Using comparative genomic hybridization (CGH), a gain of chromosome Y was detected. A loss on 17p could not be detected unambiguously. However, based on the low resolution of CGH a small loss cannot be excluded. The patient was free of disease 25 months following complete tumor resection. Myoepitheliomas/mixed tumors of deep soft tissue represent rare soft tissue lesions that may reach a considerable size and may mimic other soft tissue tumors or sarcomas. Based on a local relapse rate of approximately 20% according to the literature, a complete resection with thorough follow-up should be recommended.

[Identification of genes over-expressed in myxoid/round cell liposarcoma. DNA microarray analysis and immunohistochemical correlation].

Myxoid/round cell liposarcoma are characterized by typical chromosomal translocations. This genetic alteration might result in specific gene-expression profiles in this tumor entity. To identify over-expressed genes in myxoid/round cell liposarcoma DNA microarray analysis was performed on four tumors and four samples of adult fat tissue. Genes ret, cdk4, cyclin D2 and c-myc showed over-expression by means of microarray analysis and Northern blotting. Immunohistochemistry demonstrated cytoplasmic localization of associated proteins in 36 different tumors. The localization of ret was seen in endothelial cells of plexiform vasculature in addition to its accumulation in tumor cells (25% of cases). The results show an over-expression of cdk4, cyclin D2, c-myc and ret on both the transcriptional and protein level in myxoid/round cell liposarcoma. For cyclin D2 and ret this finding has not been reported in this tumor type. The increase of ret on transcriptional level might be explained by its expression in endothelium in intratumoral plexiform blood vessels. For the molecular pathogenesis of myxoid/round cell liposarcoma our findings imply the involvement of these four genes in the deregulation of the cell cycle, especially as cdk4 and cyclin D2 are target genes of c-myc.

Identifikation überexprimierter Gene in myxoid-rundzelligen Liposarkomen

Myxoid/round cell liposarcoma are characterized by typical chromosomal translocations. This genetic alteration might result in specific gene-expression profiles in this tumor entity. To identify over-expressed genes in myxoid/round cell liposarcoma DNA microarray analysis was performed on four tumors and four samples of adult fat tissue. Genes ret, cdk4, cyclin D2 and c-myc showed over-expression by means of microarray analysis and Northern blotting. Immunohistochemistry demonstrated cytoplasmic localization of associated proteins in 36 different tumors. The localization of ret was seen in endothelial cells of plexiform vasculature in addition to its accumulation in tumor cells (25% of cases). The results show an over-expression of cdk4, cyclin D2, c-myc and ret on both the transcriptional and protein level in myxoid/round cell liposarcoma. For cyclin D2 and ret this finding has not been reported in this tumor type. The increase of ret on transcriptional level might be explained by its expression in endothelium in intratumoral plexiform blood vessels. For the molecular pathogenesis of myxoid/round cell liposarcoma our findings imply the involvement of these four genes in the deregulation of the cell cycle, especially as cdk4 and cyclin D2 are target genes of c-myc.

Myoepitheliom des Weichgewebes

The case of a soft tissue myoepithelioma is presented including clinicopathologic, ultrastructural, and genetic findings. A 30-year-old male patient suffered from a soft tissue tumor within the deep soft tissues of the right lower leg measuring 13.2 x 8.2 x 9 cm. Histologically, the lesion was diagnosed as a myoepithelioma displaying a lobulated architecture with cords and nests of epithelioid and spindle cells without cytologic atypia lying within a fibromyxoid and partly chondroid matrix; immunohistochemistry was positive for pancytokeratin, S100-protein, calponin and partly for GFAP and EMA. Ultrastructural analysis revealed glycogen deposits and cell-membrane-associated plaque structures, whereas true myofilaments could not be identified (with immunohistochemistry being negative for actin). Using comparative genomic hybridization (CGH), a gain of chromosome Y was detected. A loss on 17p could not be detected unambiguously. However, based on the low resolution of CGH a small loss cannot be excluded. The patient was free of disease 25 months following complete tumor resection. Myoepitheliomas/mixed tumors of deep soft tissue represent rare soft tissue lesions that may reach a considerable size and may mimic other soft tissue tumors or sarcomas. Based on a local relapse rate of approximately 20% according to the literature, a complete resection with thorough follow-up should be recommended.

Erratum zu: Identifikation überexprimierter Gene in myxoid-rundzelligen Liposarkomen. DNA-Mikroarray-Analyse und immunhistochemische Korrelation

Myxoid/round cell liposarcoma are characterized by typical chromosomal translocations. This genetic alteration might result in specific gene-expression profiles in this tumor entity. To identify over-expressed genes in myxoid/round cell liposarcoma DNA microarray analysis was performed on four tumors and four samples of adult fat tissue. Genes ret, cdk4, cyclin D2 and c-myc showed over-expression by means of microarray analysis and Northern blotting. Immunohistochemistry demonstrated cytoplasmic localization of associated proteins in 36 different tumors. The localization of ret was seen in endothelial cells of plexiform vasculature in addition to its accumulation in tumor cells (25% of cases). The results show an over-expression of cdk4, cyclin D2, c-myc and ret on both the transcriptional and protein level in myxoid/round cell liposarcoma. For cyclin D2 and ret this finding has not been reported in this tumor type. The increase of ret on transcriptional level might be explained by its expression in endothelium in intratumoral plexiform blood vessels. For the molecular pathogenesis of myxoid/round cell liposarcoma our findings imply the involvement of these four genes in the deregulation of the cell cycle, especially as cdk4 and cyclin D2 are target genes of c-myc.

Identifikation überexprimierter Gene in myxoid-rundzelligen Liposarkomen@@@Identification of genes over-expressed in myxoid/round cell liposarcoma: DNA-Mikroarray-Analyse und immunhistochemische Korrelation@@@DNA microarray analysis and immunohistochemical correlation

Myxoid/round cell liposarcoma are characterized by typical chromosomal translocations. This genetic alteration might result in specific gene-expression profiles in this tumor entity. To identify over-expressed genes in myxoid/round cell liposarcoma DNA microarray analysis was performed on four tumors and four samples of adult fat tissue. Genes ret, cdk4, cyclin D2 and c-myc showed over-expression by means of microarray analysis and Northern blotting. Immunohistochemistry demonstrated cytoplasmic localization of associated proteins in 36 different tumors. The localization of ret was seen in endothelial cells of plexiform vasculature in addition to its accumulation in tumor cells (25% of cases). The results show an over-expression of cdk4, cyclin D2, c-myc and ret on both the transcriptional and protein level in myxoid/round cell liposarcoma. For cyclin D2 and ret this finding has not been reported in this tumor type. The increase of ret on transcriptional level might be explained by its expression in endothelium in intratumoral plexiform blood vessels. For the molecular pathogenesis of myxoid/round cell liposarcoma our findings imply the involvement of these four genes in the deregulation of the cell cycle, especially as cdk4 and cyclin D2 are target genes of c-myc.

Myoepitheliom des Weichgewebes@@@Myoepithelioma of soft tissue — case report with clinicopathologic, ultrastructural, and cytogenetic findings: Fallbericht mit klinisch-pathologischen, ultrastrukturellen und zytogenetischen Befunden

The case of a soft tissue myoepithelioma is presented including clinicopathologic, ultrastructural, and genetic findings. A 30-year-old male patient suffered from a soft tissue tumor within the deep soft tissues of the right lower leg measuring 13.2 x 8.2 x 9 cm. Histologically, the lesion was diagnosed as a myoepithelioma displaying a lobulated architecture with cords and nests of epithelioid and spindle cells without cytologic atypia lying within a fibromyxoid and partly chondroid matrix; immunohistochemistry was positive for pancytokeratin, S100-protein, calponin and partly for GFAP and EMA. Ultrastructural analysis revealed glycogen deposits and cell-membrane-associated plaque structures, whereas true myofilaments could not be identified (with immunohistochemistry being negative for actin). Using comparative genomic hybridization (CGH), a gain of chromosome Y was detected. A loss on 17p could not be detected unambiguously. However, based on the low resolution of CGH a small loss cannot be excluded. The patient was free of disease 25 months following complete tumor resection. Myoepitheliomas/mixed tumors of deep soft tissue represent rare soft tissue lesions that may reach a considerable size and may mimic other soft tissue tumors or sarcomas. Based on a local relapse rate of approximately 20% according to the literature, a complete resection with thorough follow-up should be recommended.