Synovial Sarcoma : Prognosis
Prognosis of Synovial Sarcoma: The overall 5-yr survival rate ranges from 64% to 76%. Heavily calcified synovial sarcomas (as seen in this example) have a better prognosis with 80% long-term survival. The favorable prognostic features include young age (15 years or younger), distal extremity lesions, size < 5 cm, fewer than 15 mitoses/10 HPF, heavy calcification, negative surgical margins, and lower stage. Adverse prognostic features are necrosis in >50% of the tumor, tumor size > 5 cm, high mitotic index, rhabdoid cells, and aneuploidy. The prognostic significance of microscopic subtypes is not clear. Some studies have found a more indolent behavior for biphasic synovial sarcomas as compared to monophasic subtype. Others disagree with this notion. The relative proportion of epithelial and spindle cell components in biphasic tumors is also of no prognostic relevance. Tumors with poorly-differentiated areas behave more aggressively and metastasize early. Therefore, thorough sampling of the tumor is essential.