Solitary Osteochondroma at Unusual Sites: A Case Report and Literature Review.

Osteochondromas (OCs) are bone lesions composed of cartilaginous and medullary bone capped with hyaline cartilage. OCs result from the separation of epiphyseal growth plate cartilage, pushing through the periosteal bone cuff. They commonly appear as pedunculated or sessile masses in the metaphysis of long bones and are the most common benign bone tumors. While rare in the scapula, OCs can occur there. Symptoms may arise from fractures, osseous abnormalities, or potential malignant transformation, especially in the presence of hereditary multiple exostoses (HME). The estimated rate of malignant transformation in solitary lesions is 1%, whereas in hereditary multiple OCs, it can reach up to 3-5%. We report a case of a 10-year-old female who presented with a gradually progressive swelling on the back of her right scapula. This progressive growth has been observed over the course of the past two years accompanied by mild pain. The pain was intermittent and did not affect her daily activities. On examination, a hard, tender, non-mobile swelling of approximately 2 × 2 cm was found over the right scapula. The patient had a normal range of motion in the shoulder and scapulothoracic regions. In conclusion, since solitary scapular OCs are extremely rare, they are quite common when associated with HME. This study aimed to increase awareness of the unusual site of OCs. Furthermore, we have included a full account of the surgical therapy we administered to this patient in order to assist future surgeons who may come across similar conditions.