PEComa in the rectum: A case report and review of the literature on epithelioid angiomyolipoma.

Introduction And Importance: Perivascular epithelioid cell tumor (PEComa), especially angiomyolipoma (AML) is a rare mesenchymal tumor in wide array of anatomic locations such as the kidney, lung, uterus, and gastrointestinal tract. AML is commonly found in the kidneys and classified as a classic AML or epithelioid AML. We report a case of epithelioid AML diagnosed in the rectum, treated by robot assisted low anterior resection.

Presentation Of Case: A 45-year-old woman was referred to our hospital because when an intramural rectal mass was detected on a colonoscopic examination performed during a regular health checkup. Colonoscopic examination revealed an intramural mass, 2 cm in diameter, bulging in the rectal wall, 6 cm from the anal verge. Based on abdominal and pelvic computed tomography images and magnetic resonance imaging findings, the patient was suspected of having gastrointestinal stromal tumor of the rectum. The patient was treated by robot assisted low anterior resection under the diagnosis of GIST. The patient improved without any postoperative complication and was diagnosed as epithelioid AML, a type of PEComa.

Discussion: AML diagnosed in gastrointestinal tract is very rare and among them, epithelioid AML has possibility of malignancy. However, confirmed diagnosis before surgical resection is difficult because PEComa shows nonspecific imaging characteristics. Treatment of choice of epithelioid angiomyolipoma is surgical resection.

Conclusion: Because epithelioid AML has the potential for malignancy, clinicians must be aware of the knowledge of the characteristics and natural history of epithelioid AML.