Giant fibroepithelial polyp of the thigh and retroperitoneal fibromatosis in a young woman: a rare case

We present a case of 20-year-old woman who presented with a large pedunculated skin covered mass lesion arising from the left thigh, measuring 40 × 25 cm, with no history of pain or skin ulceration and a feeling of a lump with dragging pain in the left side of the abdomen for about 7 years. Subsequently, ultrasound, contrast-enhanced computed tomography, and magnetic resonance imaging of abdomen and left thigh region were carried out. The lesion was broad-based toward the left upper thigh with a central core of interspersed fat supplied by branches of the superficial and deep femoral arteries. Another lesion was seen in the left retroperitoneum anterior to the psoas muscle in a left paravertebral location encasing the left common iliac vessels extending into the left pelvic cavity and inguinal region inferiorly. The lesion showed dense post-acoustic shadowing on ultrasound, mild enhancement on contrast-enhanced computed tomography, and appeared hypointense on T1- and T2-weighted images. A left thigh lesion was excised, whereas incisional biopsy was done for the left retroperitoneal lesion. The diagnosis of a giant fibroepithelial polyp arising from the left thigh and left retroperitoneal fibromatosis was made. This is the first report of such a giant fibroepithelial polyp arising from the thigh with associated retroperitoneal fibromatosis.