Peritendinous nodules in overlap syndrome.

Peritendinous nodules were observed in 4 patients with overlap syndrome. In all cases they were multiple, minute and located around the flexor tendons of the forearms and the extensor tendons of the hands. Similar nodules were also found on the extensor aspect of elbows, dorsum of the feet, hamstring muscles and Achilles tendons. Common histologic features were inflammatory granuloma with scattered areas of fibrinoid necrosis, mononuclear cell infiltration and occasional vasculitic lesions. Multiple peritendinous nodules should be considered another clinical feature of overlap syndrome.