A rare presentation of soft tissue chondroma: A case report

INTRODUCTION: Extraskeletal chondroma (ESC) is a benign, slow-growing cartilaginous tumor arising from tenosynovial sheaths. The aim of this article is to report and discuss a case of ESC affecting upper thigh. CASE REPORT: A 41-year-old male presented with a swelling in the medial aspect of the left thigh. On clinical examination, there was a 10 × 15 cm non-tender, hard, ill-defined mass in the medial aspect of the left upper thigh. Ultrasound showed a large well defined thick wall mass, located inside gracillis or adductor muscles. Magnetic resonance imaging showed a large well defined mass involving the adductor compartment of the upper thigh. The patient underwent wide local excision under spinal anesthesia. The histopathological examination of the specimen revealed binucleated chondrocytes with dots of calcification confirming ESC. DISCUSSION: There are many theories trying to explain the origin of ESC, as some authors think that it originates from the pluripotent cells of the tenosynovium, while others state that it may be derived from metaplasia of the tendon sheath. In this case, the lesion was completely surrounded by muscle fibers away from the nearby tendons. CONCLUSION: Extraskeletal chondroma is a rare benign lesion, although mostly affect the upper extremities, it can be found anywhere in the body, histopathological examination of the specimen is the diagnostic method of choice.