References

A case of trigger finger in a fourteen-year-old child, presenting as locking in extension is reported. At operation a tumour arising from the superficials tendon was found and removed. Reports of tumours causing trigger finger are very rare. Iqbal (1982) reported a case of triggering in flexion due to a fibrous histiocytoma arising from the profundus tendon. Oni (1984) reported a fibroma of the tendon sheath as causing triggering. Case Report A fourteen-year-old boy presented with a five month history of locking of the left index finger in full extension. The finger could be passively unlocked. Clinically a small nodule on the superficialis tendon could be felt moving in the palm on flexion and extension of the finger. At operation a small, pedunculated tumour, measuring lcm in length was found arising from the superficialis tendon to the left index finger (Figure 1). Histology showed this to be either a calcifying aponeurotic fibroma or soft part chondroma. Both are benign lesions which can be histologically indistinguishable. Post operatively the patient had no problems and at follow-up the pre-operative symptoms of triggering had completely disappeared. Discussion Trigger fingers normally occur with locking in flexion, although locking in extension has been reported, usually in adults (Fahey 1954). The same author also noted that triggering of a digit, other than the thumb, is very rarely seen in a child. Although the thickening of the flexor tendon, usually profundus, has been described as a “turnout- ” this was felt to be a bunching of the tendon due to stenosis of the fibrous flexor sheath (Huesto