Cellular Angiofibroma of the Perianal Space: MR Imaging and Pathologic Correlation

ABSTRACT

A variety of benign and malignant tumor can occur in the perianal space. Among them, cellular angiofibroma is a rare tumor that belongs to fibroblastic/myofibroblastic tumors of the WHO classification, sometimes called as "angiomyofibroblastoma-like tumor". Cellular angiofibroma can be found at various anatomic sites such as the vulva, perineum, genital tract, and inguinal regions with approximately equal gender ratio. This tumor is usually a well-circumscribed mass showing isosignal intensity to muscle on T1-weighted images. On T2-weighted images, cellular angiofibroma may show as a mass with inhomogeneous signal intensity depending on amount of composed spindle cell, collagenous stroma, myxoid matrix, and fat tissue; however it is characterized by low signal intensity due to fibrous tissues. This highly vascular mass shows strong enhancement on post contrast images. Recommended treatment is simple local excision and no recurrence or metastasis have been reported up to date.