Orbital giant cell angiofibroma: immuno-histochemistry and differential diagnosis

A 57-year-old woman presented with a 16-month history of a slowly growing mass in the medial aspect of her right lower eyelid. On radiologic examination, the mass was seen to extend into the anterior orbit. Initial attempt at excision was complicated by problems with hemostasis and only a portion was removed. Histopathologic examination revealed a giant cell angiofibroma, which was subsequently excised.

Giant cell angiofibroma is a benign spindle cell neoplasm characterized by multinucleated giant cells and pseudovascular spaces with a propensity to occur in the anterior soft tissues of the orbit of middle-aged adults. It is part of a wide differential diagnosis of tumours that can be separated by various histologic and immunohistochemical features, which are discussed in the report. It is important to consider it preoperatively because the vascular nature of this tumour may create problems with hemostasis during excision.