A huge giant cell tumour of the extensor tendon sheath of the foot: a case report and literature review

Abstract

Giant cell tumours have a predilection for the hand, where after ganglion cysts, they are the most frequent tumour type. Only 3-5% of giant cell tumours occur in the foot, and even here they tend to occur in the forefoot, with hindfoot giant cell tumours being a rarity. While relatively common overall, their exact nature, as to whether they are truly neoplastic or simply inflammatory, is a subject of significant controversy. They are benign slow growing lesions, best treated with gross total excision under magnification. Despite their subcutaneous nature, they can become markedly infiltrative, and unless completely excised exhibit  ecurrence rates of between 14% and 44%. Factors predictive of recurrence include pressure erosion on X-ray imaging, interphalangeal joint location, concomitant degenerative joint disease, and incomplete excision. We present an adult female patient who presented to our unit with a giant cell tumour extending over the dorsum and medial side of her foot of an alarming size. While the lesion was largely asymptomatic, she was offered surgery for functional reasons. Through the creation of a local flap over the tumour, and using magnification, we were able to achieve a gross total excision. According to our review of the PubMed literature, this is the largest giant cell tumour described in this location, and as such our case report adds value to the world-body of orthopaedic knowledge on the subject.

Key words: Giant cell tumour, Extensor tendons foot