Elastofibroma of the gluteal region with a concomitant contralateral lesion: case report and review of the literature.

A 51-year-old man presented with elastofibroma (EF) of the gluteal region with a concomitant contralateral lesion. The patient presented with a slow growing mass of the proximal third of the right buttock and had swelling, discomfort in sitting, and right-hip pain during walking for 2 months. On MRI, a soft-tissue mass was noted between the gluteus maximus and the gluteus medius muscle. The mass showed similar signal intensity to the surrounding tissue on T1- and T2-weighted images and with linear hyperintense areas in its internal structure. At surgery, a soft, non-encapsulated, irregular, and rubber-like mass was found attached to the gluteus medius muscles. It was pathologically confirmed to be an EF. This unusual manifestation of an EF is discussed.