Lateral radiograph in the emergency room. A radiolucent lesion in the proximal humerus with a"smoke ring" pattern of calcification suggestive of enchondroma. A 48-year-old female presented in the emergency room following a motor vehicle accident. There was no history of preexisting shoulder symptoms.
Lateral radiograph in the emergency room. A radiolucent lesion in the proximal humerus with a"smoke ring" pattern of calcification suggestive of enchondroma.
A magnified view of the same lesion. There is significant endosteal scalloping and a subtle suggestion of periosteal reaction raising the probability of malignant transformation to low grade chondrosarcoma despite the absence of symptoms.
A representative field from the edge of the lesion. The lesion impinges on the adjacent bone and appears responsible for the resorption that is radiographically evident as scalloping. At low magnification the tissue is clearly cartilaginous. The cell to matrix ration exceeds the ratio of benign processes in many areas. The nucleii of the majority of cells are hyperchromatic and double nucleii may be occasionally found.
A field from the central portion of the field. Greater magnification brings out the details of pleomorphism and hyperchromaticity that is suggestive of malignancy.
A diagnosis of stage I-A low grade intracompartmental chondrosarcoma was made and a wide intrarticular resection of the proximal humerus was done. Reconstruction was done with a composite allograft/endoprosthesis. At two years there has been no recurrence. The MSTS functional rating is "good".