title: Calcifying/ossifying synovial sarcoma: a clinicopathologic and molecular study of 5 cases.
abstract: 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.
  
  
  OBJECTIVE
  The aim was to report clinicopathological features and molecular analysis of 5 cases of calcifying/ossifying SS.
  
  
  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.
  
  
  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.
authors: Department of Pathology and Microbiology, Section of Histopathology, Aga Khan University Hospital, Karachi, Pakistan.
authors: Nasir
authors: N
authors: Ud Din
authors: Amanda
authors: A
authors: Hopkins
authors: Aisha
authors: A
authors: Memon
authors: Zubair
authors: Z
authors: Ahmad
authors: Rashida
authors: R
authors: Ahmed
mesh_terms: D000293:Adolescent; D000328:Adult; D014408:Biomarkers, Tumor / Q000032:analysis; D002113:Calcification, Physiologic; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013584:Sarcoma, Synovial / Q000473:pathology*; D062606:Tertiary Care Centers; D055815:Young Adult
chemical_list: D014408:Biomarkers, Tumor