Tenosynovial haemangioma of the finger.

Haemangiomas developing in the hand in relation to tendon and the tenosynovium (tendon sheath) are very rare. To our knowledge only three cases have been described arising in relation to the tenosynovium of the tendons of the hand, only one of which showed infiltration of the underlying tendon. We report the case of a 16-year-old right hand dominant student who presented to her family doctor with a swelling on her left little finger. An MRI scan was arranged which confirmed a soft tissue lesion between the flexor tendons and the proximal phalanx of the left little finger, with appearance similar to giant cell tumour of the tendon sheath. Surgical exploration demonstrated a dark red fleshy tumour that appeared to infiltrate the flexor digitorum sub-limis tendon, and extend around either side of the proximal phalanx. For complete excision of the lesion the infiltrated sublimis tendon and a part of the A2 pulley were sacrificed. There was no resultant bow-stringing of the profundus tendon. Histologically the tenosynovium was expanded by a vascular lesion consisting of dilated, thin-walled vascular channels within fibrous tissue; the appearances were consistent with those of a synovial haemangioma of the flexor tendons. Our case illustrates the pitfalls in diagnosis and the invasive potential of a synovial haemangioma. A complete surgical excision is critical to prevent recurrence.