Overexpression of bcl-2 protein in synovial sarcoma: a comparative study of other soft tissue spindle cell sarcomas and an additional analysis by fluorescence in situ hybridization.
The expression of bcl-2 protein was analyzed in 19 synovial sarcomas and 29 additional soft tissue spindle cell sarcomas as controls by the immunohistologic staining of paraffin-embedded specimens; 15 of 19 (79%) synovial sarcoma cases were positive, but all other spindle cell sarcomas were negative including 20 leiomyosarcomas, 4 malignant peripheral nerve sheath tumors, and 4 fibrosarcomas. In 4 cases of bcl-2-positive synovial sarcoma (3 biphasic and 1 focally glandular type), bcl-2 protein staining was much stronger in the spindle cells than in the epithelial cells. A fluorescence in situ hybridization (FISH) analysis with centromeric and whole chromosome painting probes for chromosome 18 and X was performed on 7 synovial sarcomas. The six cases of bcl-2-positive synovial sarcoma consisted of five cases with the t(X; 18) and one case with tetrasomy of chromosome 18 and X. It has been speculated that bcl-2 protein expression is caused by the 14; 18 translocation and other abnormalities of chromosome 18. This study thus showed the feasibility of such a correlation between bcl-2 protein expression and the characteristic cytogenetic abnormality in the synovial sarcoma-X; 18 translocation. In addition, bcl-2 protein also appears to be a characteristic marker of synovial sarcoma and is thus considered to be potentially useful in distinguishing synovial sarcoma from other spindle cell sarcomas.
Hirakawa
N
N
Second Department of Pathology, Faculty of Medicine, Kyushu University, Fukuoka, Japan.
Naka
T
T
Yamamoto
I
I
Fukuda
T
T
Tsuneyoshi
M
M
D002887:Chromosomes, Human, Pair 18; D003582:Cytogenetics; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000032:analysis / Q000096:biosynthesis*; D012509:Sarcoma / Q000737:chemistry* / Q000473:pathology; D013584:Sarcoma, Synovial / Q000737:chemistry* / Q000473:pathology; D012983:Soft Tissue Neoplasms / Q000737:chemistry* / Q000473:pathology; D014960:X Chromosome
D019253:Proto-Oncogene Proteins c-bcl-2