Orbital Giant Cell Tumour in a Paediatric Age Group

Giant cell tumour (GCT) of the bone is generally a benign but locally aggressive tumour that is primarily composed of multinucleated osteoclast-like giant cells with a background of neoplastic mononuclear stromal cells. It predominantly occurs in the epiphysis and metaphysis of the long bones but it can occur in an unusual locations. Giant cell tumour of the skull is rare and GCT of the orbital bones account for less than 1 % of all GCTs. Accurate histopathological diagnosis of GCT and differentiating GCT from other pathological mimickers are important as the GCT has a tendency for local recurrence in incompletely resected cases and in the view of the recently emerging targeted therapy for GCT. Herein we present a case of orbital GCT, which occurred in the left orbital roof in a 6-year-old girl. The tumour was surgically resected and the patient remained with no evidence of residual or recurrent disease after 42 months postoperative follow-up period. In addition, we review the histopathological mimickers of GCT with an emphasis on the pathological diagnostic pitfalls.