A case of synovial bursitis on the buttock

A 61-year-old man presented with a subcutaneous tender cyst in the ischial region. We performed partial excision of the cyst, and the pathological findings showed fibrin deposits on the wall covered with several layers of synovial cells. The cyst was diagnosed as synovial bursitis. No recurrence has been observed nine months after the operation. Due to the rare occurrence of synovial bursitis and thus limited opportunity for dermatologists to encounter, it is important for dermatologists to be aware of the characteristic clinical and pathological features of synovial bursitis for appropriate diagnosis.