Giant Cell Tumour of the Tendon Sheath: Analysis of 35 Cases and their Ki-67 Proliferation Indexes.

INTRODUCTION: A giant cell Tumour of the tendon sheath (GCTTS) is a slow-growing benign Tumour originating from the synovial cells of the tendon sheath. It is the second most common Tumour of the hand. The aim of this study was to perform a retrospective clinicopathological evaluation of GCTTS cases and determine whether the proliferative activity of giant cell tumour of tendon sheath is related to its recurrence rate and local aggressiveness.

MATERIALS AND METHODS: The age, gender, Tumour location and diameter, treatment mode, Ki-67 proliferation index, mitotic rate, and recurrence were retrospectively evaluated in 35 patients diagnosed with GCTTS in the Department of Pathology, School of Medicine, Recep Tayyip Erdogan University between 2009 and 2014.

RESULTS: Of the 35 GCTTS cases, 23 were female, and 12 were male. The mean age was 45 y (range 10-70). Sixteen tumours were located in the right hand and 14 in the left hand, and five were in the feet. The mean Tumour diameter was 2.3 cm (0.6-6 cm). All patients underwent marginal excision. The mean postoperative follow-up period was 4 y (range 28 months-5 y). Only six patients showed recurrence. In these cases, the site of GCTTS recurrence was the phalanx of the hand. The mean Ki-67 index in the recurrence cases was 6.5%, whereas it was 2.3% in those without recurrence.

CONCLUSION: The Ki-67 proliferation index and mitotic activity were increased in recurrent cases compared to nonrecurrent cases. Therefore, these parameters may be helpful in predicting recurrence of GCTTS. However, adequate surgical excision and complete removal of the Tumour are important steps to minimize the recurrence rate.