Tenosynovial (extraarticular) chondromatosis: an analysis of 37 cases of an underrecognized clinicopathologic entity with a strong predilection for the hands and feet and a high local recurrence rate.

Tenosynovial chondromatosis is a multinodular cartilaginous proliferation that arises from the tenosynovial membranes. This report describes the clinical, radiologic, and histopathologic findings in 37 cases of this uncommon entity. There were 17 males and 20 females, ranging in age from 20 to 86 years (mean and median age, 46 years). The process involved tenosynovium of the fingers (n = 19), feet (n = 8), wrists (n = 4), ankles (n = 2), hand, not otherwise specified, or palm (n = 2), knee (n = 1), and forearm (n = 1). Signs of disease or symptoms were present for 5 weeks to 18 years (median duration, approximately 2 years) before surgical excision. The two most common complaints were a painless mass and a mass that was mildly tender with pressure. None of the tumors had clinical, radiologic, or histopathologic evidence of articular or bone involvement. Histologically, all tumors consisted of a multinodular cartilaginous proliferation involving tenosynovium and/or subsynovial connective tissue. Mild or moderate atypia, as encountered in chondroma of soft parts and synovial chondromatosis, was a frequent finding. Follow-up information was available for 16 patients (43%). Only two patients with follow-up information remained disease free after their initial surgical procedure. Seven patients had one recurrence and seven patients had two or more recurrences. Tenosynovial chondromatosis appears to be an extraarticular counterpart of synovial (intraarticular) chondromatosis. Our review indicates this process is often confused with chondroma of soft parts, in part, because both entities have a predilection for the hands and feet. Diagnosis of this underrecognized entity is of clinical importance because of the high local recurrence rate.