Calcifying/ossifying synovial sarcoma: A clinicopathologic and molecular study of 5 cases

• Main Authors: Nasir Ud Din, Amanda Hopkins, Aisha Memon, Zubair Ahmad, Rashida Ahmed
• Format: Article
• Language: English
• Published: Wolters Kluwer Medknow Publications 2015-01-01
• Series: Indian Journal of Pathology and Microbiology
• Subjects: Calcifying; favorable prognosis; ossifying; synovial sarcoma
• Online Access: http://www.ijpmonline.org/article.asp?issn=0377-4929;year=2015;volume=58;issue=1;spage=55;epage=58;aulast=Din

Background: Synovial sarcoma (SS) is a soft tissue sarcoma with a generally aggressive behavior. Calcifying/ossifying SS is a rare variant associated with a favorable prognosis. Aim: The aim was to report clinicopathological features and molecular analysis of 5 cases of calcifying/ossifying SS. Materials and Methods: Record of 370 cases of SS reported in the section of Histopathology, of a tertiary care Hospital, between 2002 and 2011 were retrieved. Five cases exhibiting extensive calcification and ossification were identified. Immunohistochemistry was performed using Flex technique. Molecular analysis of these 5 cases was performed later at the collaborative Hospital abroad, by reverse transcription polymerase chain reaction. Results and Conclusions: The ages of the patients ranged from 13 to 44 years (mean age 27 years; female to male ratio 1.6:1). The duration of symptoms ranged from 5 months to 5 years. Histologically, 4 were monophasic, and 1 was biphasic. Three cases exhibited extensive calcification and two extensive ossification. Immunohistochemical stain (epithelial membrane antigen was positive in all 5 cases, CKAE1/AE3 (3/4), Bcl2 (4/4), S100 (4/4), CK7 (2/2), CD99 (1/3) and vimentin (2/2). Intact RNA was obtained from 3 cases, all of which were positive for the SYT/SSX fusion transcript. Follow-up was available in 4 cases and ranged from 19 months to 85 months (mean 50 months). Local recurrence was seen in 2 cases. In conclusions, we report clinicopathologic features of 5 cases of calcifying/ossifying SS. The duration of symptoms and mean age of patients is similar to the literature. A slight female predominance was seen in contrast to a male predominance described in the literature. The clinical course of our cases validates the favorable prognosis of this rare type of SS.