Pleomorphic hyalinizing angiectatic tumor of the mesorectum: a rare case and review of literature.

Pleomorphic hyalinizing angiectatic tumor (PHAT) is a rare tumor of uncertain tissue origin. Although it has been classified as a benign tumor under the WHO classification, it is locally aggressive, and multiple recurrences have been reported. PHAT commonly involves the lower extremities; however, various unusual sites of origin have been reported. We present the case of a 30-year-old female with dysmenorrhea, who presented a presacral mass on imaging. The core biopsy confirmed the diagnosis of PHAT. She underwent laparotomy and excision. Histopathology confirmed the presence of a tumor comprised of aggregates of ectatic vessels with perivascular hyalinization. An immunohistochemical study showed diffuse CD34 positivity, but S100, MDM2, and smooth muscle actin negativity. After surgical procedures, the patient is disease free as at the 12-month follow-up. Only 120 cases have been published in the English literature to date. Our study is only the third case of PHAT arising from the pelvis to be reported. Though considered to be a rare condition, the diagnosis of PHAT should always be considered in the differential diagnosis of well-defined hypervascular soft tissue mass in the pelvis. The typical histopathological findings along with immunohistochemistry should clinch the diagnosis.