TENDON SHEATH TUMORS - A PATHOLOGICAL-STUDY OF THE RELATIONSHIP BETWEEN GIANT-CELL TUMOR AND FIBROMA OF TENDON SHEATH

Thirty-nine soft tissue lesions occurring on the distal aspect of the limbs have been selected because of histological features consistent w ith those recognized for giant cell tumour of tendon sheath or fibroma of tendon sheath. In spite of the frequent occurrence of such lesions at the stated sites, they were rarely correctly diagnosed pre-operati vely. Using a scoring system to grade specified histological features, a blind evaluation to re-classify these 39 lesions was undertaken. Th is resulted in 29 cases of giant cell tumour of tendon sheath, six fib romas of tendon sheath and four 'transitional stage' lesions. Despite the heterogeneous morphology of these categories, there were no signif icant differences in the clinical features of affected patients. The e xistence of a 'transitional stage' lesion, combined with the homogeneo us clinical picture of all categories, supports the concept that fibro ma of tendon sheath is the end and sclerosing stage of giant cell tumo ur of tendon sheath, probably consequent on progressive vascular impai rment. There is a need for pathologists to recognize the transitional stage lesions so as to avoid their inclusion with other diagnostic ent ities. For this group the name 'giant cell tumour of tendon sheath-tra nsitional stage lesion' is suggested.