Epithelioid hemangioma of bone revisited: a study of 50 cases.

The clinical and pathologic features of 50 epithelioid hemangiomas of bone are analyzed. There were 29 males and 21 females who ranged in age from 10 to 75 (mean 35) years. The tumors arose in long tubular bones (40%), short tubular bones of the distal lower extremity (18%), flat bones (18%), vertebrae (16%), and small bones of the hands (8%). Nine patients (18%) had involvement of more than 1 bone. Radiographically, the lesions were lucent and well marginated. Microscopically, the neoplasms had a lobular architecture and were composed of epithelioid endothelial cells that formed obvious vascular lumina or grew in solid sheets. No hyalinized or solid appearing extracellular myxoid matrix was present. Thirty-five patients were treated with curettage, 13 patients had a local resection and 2 patients only had a biopsy. One patient had local lymph node involvement. Three patients were treated with surgery and radiation therapy. Follow-up information revealed that 4 patients experienced a local recurrence; and 1 patient developed limited involvement of a regional lymph node. Epithelioid hemangioma of bone is a benign lesion that may be multifocal and affect separate tissue and is successfully treated with curettage or marginal en bloc excision.

The SYT-SSX1 fusion type of synovial sarcoma is associated with increased expression of cyclin A and D1. A link between t(X;18)(p11.2; q11.2) and the cell cycle machinery.

A recent large multi-centre study convincingly confirmed previous observations that the SYT-SSX1 fusion type, compared to SYT-SSX2, of synovial sarcoma is associated with a worse clinical outcome. Apart from the clinical impact, this fact also suggests (1) that the SYT-SSX fusion gene may influence molecular mechanisms involved in tumour growth and progression; and (2) that the SYT-SSX1 fusion type has a stronger influence on these mechanisms than SYT-SSX2. The nature of the underlying mechanisms is, however, still unknown. In this study we made use of the SYT-SSX1 vs SYT-SSX2 concept to investigate whether major, tumour relevant, and growth regulatory proteins (e.g. cyclins and cyclin-dependent kinases) may be involved. Using Western blotting analysis on 74 fresh, fusion variant-typed, tumour samples from localized synovial sarcoma, we found a significant correlation between SYT-SSX1 and high expression of cyclin A (P=0.003) and D1 (P=0.025). Our data suggest that SYT-SSX may influence the cell cycle machinery, and that the more aggressive phenotype of the SYT-SSX1 variant is due to an accelerated tumour cell proliferation.