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

• Published in: Human pathology 1996-10, Vol.27 (10), p.1060-1065
• Main Authors: Hirakawa, Naoya, Naka, Takahiko, Yamamoto, Ichiro, Fukuda, Toshiro, Tsuneyoshi, Masazumi
• Format: Article
• Language: English
• Subjects: bcl-2; Biological and medical sciences; Chromosomes, Human, Pair 18; cytogenetic abnormality; Cytogenetics; Diseases of the osteoarticular system; Female; fluorescence in situ hybridization; Humans; Immunohistochemistry; In Situ Hybridization, Fluorescence; Male; Medical sciences; paraffin-embedded tissue; Proto-Oncogene Proteins c-bcl-2 - analysis; Proto-Oncogene Proteins c-bcl-2 - biosynthesis; Sarcoma - chemistry; Sarcoma - pathology; Sarcoma, Synovial - chemistry; Sarcoma, Synovial - pathology; Soft Tissue Neoplasms - chemistry; Soft Tissue Neoplasms - pathology; soft tissue sarcomas; synovial sarcoma; Tumors of striated muscle and skeleton; X Chromosome
• ISSN: 0046-8177; 1532-8392
• DOI: 10.1016/S0046-8177(96)90284-1

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.