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.
Second Department of Pathology, Faculty of Medicine, Kyushu University, Fukuoka, Japan.
N
N
Hirakawa
T
T
Naka
I
I
Yamamoto
T
T
Fukuda
M
M
Tsuneyoshi
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