Epithelioid sarcoma of the right ilium mimicking sacroiliitis.

Epithelioid sarcoma represents less than 1% of soft tissue sarcomas and has a high recurrence rate and strong ability to invade the regional lymphatic pathways. Classic epithelioid sarcoma has a predilection for young men and usually affects the distal extremities, while the proximal-type is characterized by different histological features and most commonly occurs in the proximal part of the extremities, trunk and pelvis. Intraosseous tumor development is rare. We describe a 47 year old patient with sacroiliac pain mimicking sacroiliitis. A computed tomography of the pelvis showed a destructive intraosseous lesion of the upper- right iliac. Percutaneous biopsy of the lesion was obtained and histological findings were typical of classic epithelioid sarcoma. To our knowledge, this is the second case of intraosseous epithelioid sarcoma described in the medical literature.