Malignant myoepithelioma of the humerus with a satellite lesion: a case report and literature review

We report an extremely rare case of malignant myoepithelioma presenting as a cortical osseous lesion on the humeral shaft with a satellite lesion. A 21-year-old man presented with persistent pain of the right upper arm after local trauma that had occurred 2 months earlier. Radiological examination revealed an expansile osseous tumour based on the cortex of the humeral shaft as well as a satellite lesion. En bloc resection was performed. Microscopic examination with immunohistochemical staining was used to establish a diagnosis of malignant myoepithelioma. Osseous malignant myoepithelioma occurring in long tubular bones rather than in bony structures with salivary tissue is extremely rare. Here, we demonstrate radiological and pathological features of a malignant myoepithelioma that developed in the cortex of the humeral shaft and review previously reported cases.