Fibroma of tendon sheath.

This report describes four patients with fibroma of tendon sheath. The tumors were slowly enlarging, firm nodules that were adherent to tendon sheaths of the volar aspect of the fingers or palm. One lesion was recurrent. Microscopically, they consisted of lobulated, hyalinized, collagenous masses that contained spindled and stellate fibroblasts and an array of slitlike spaces. There were small pseudopods and separate foci of tumor in adjacent connective tissue. These may explain the propensity of fibroma of tendon sheath to recur.