Extraorbital giant cell angiofibroma.

A number of intriguing fibrovascular mesenchymal proliferations with benign or low grade malignant potential have recently been described. Giant cell angiofibroma was introduced as an entity by Dei Tos et al. in 1995 and initially considered to be a lesion of the orbit. We describe an extraorbital example, indicating that giant cell angiofibroma is not confined to the orbit. Immunologically, giant cell angiofibroma is positive for CD 34, bcl-2 and vimentin, and negative for epithelial and muscle markers, and S-100. The tumor shares several morphological and immunological properties with giant cell fibroblastoma and solitary fibrous tumor, yet it features a histology sufficiently characteristic to allow its categorization as a separate entity. The recommended treatment is complete but conservative excision. Metastases have not been reported.