Angiofibroma of soft tissue: report of two cases and review of literature

Angiofibroma of soft tissue is a recently described tumor, which showed the distinctive histological features. Because of the presence of prominent vascular network, the tumor was easily misdiagnosed as low grade malignant soft tissue lesions. Herein, we present two cases of angiofibroma of soft tissue in a 57-year-old female and a 37-year-old male, respectively. Histologically, both of them were composed of abundant branching vessels and bland spindle cells with variably collagenous to myxoid background. In addition, in case 1, few scattered atypical multinucleated cells could be observed in the tumor, whereas the case 2 demonstrated the obvious capsule invasion. Immunohistochemical staining showed that the two was consistently diffusely positive for vimentin and Bcl-2, focally positive for EMA, and negative for cytokeratin, actin(SM), ALK, S-100, CD31, CD34, MUC4, CD99, CD68 and desmin. Ki-67 proliferation index was less than 1%. Our present cases served to further broaden the morphologic profile of the tumor. It was necessary for being familiar with this neoplasm to avoid overdiagnosis.