Review Question - QID 4893

This patient is presenting with symptoms of rotator cuff tendinopathy. There is an incidental finding of an enchondroma in the metaphysis of the right proximal humerus. The next most appropriate treatment would be physiotherapy for the rotator cuff muscle and observation of the enchondroma.

Enchondroma is one of the most common benign bone tumors. The most common location is the hand, but they are commonly found in the proximal humerus and distal femur. Males and females are equally affected. Infrequently they are symptomatic, causing soft tissue swelling and, less likely, pain at the lesion site. Pain can be a sign of pathologic fracture or malignant transformation. Treatment is largely non-operative. MRI images are not required for the diagnosis of Enchondroma. Malignant transformation is less than 1%.

Marco et al. reviewed cartilage tumors. They report that enchondroma may be associated with secondary chondrosarcoma, but distinguishing enchondroma from low-grade chondrosarcoma is difficult. They state that chondrosarcoma lesions are often larger, occur in less typical places (axial location), generally occur more proximal (epiphyseal location) and usually have more pronounced endosteal scalloping or destructive changes.

Figure A and B show radiographs of the right shoulder. There is a small enchondroma in the metaphysis of the right proximal humerus. Figure C shows a sagittal T1 MRI of the shoulder with a geographic, mildly expansile, lytic lesion. A cartilaginous matrix is seen. There are mild degenerative changes in the supraspinatus tendon, suggestive of a partial supraspinatus tendon tear, which may or may not be symptomatic. Figure D is a coronal PD FATSAT MRI of the right shoulder. Figure E is an axial PD FATSAT MRI of the right shoulder.

Incorrect Answers:
Answer 2,3,5: This lesion does not require further diagnostic work up given it's characteristic presentation.
Answer 4: The lesion does not need operative treatment.