[Myoblastic myoma of the tendon of long flexor of the thumb]

The case history of a female patient with flexion contracture of the thumb, having been caused by a tumour originated in the tendon of musculus flexor pollicis longus and histologically classified as a myoblastic myoma is presented. After a complete resection of the tumour and substitution of the originated defect of the tendon the function of the right hand became possible to a full extent and no signs of a relapse may be seen four years after the operation.