Aneurysmal fibrous histiocytoma: an unusual variant of cutaneous fibrous histiocytoma.

Aneurysmal fibrous histiocytoma (AFH) (Santa-Cruz DJ, Kyriakos M. Aneurysmal ('Angiomatoid') fibrous histiocytoma of the skin. Cancer 1981;47:2053-2061) is a distinct but poorly recognized clinicopathological variant of cutaneous fibrous histiocytoma (CFH) that may result from the slow extravasation of blood into the tumour. The resulting lesion can have a very different clinicopathological appearance resulting in diagnostic confusion. We describe a patient with an AFH that presented as a pigmented nodule on the foot and discuss clinical recognition and histological differentiation from other tumours.