[Primary bone tumors and "tumor-like lesions" of the shoulder. Their histopathology and imaging].

Purpose of this review is to demonstrate typical X-ray, CT and MR morphology of primary bone tumors and "tumor-like lesions" of the shoulder in correlation with histopathology. 711 primary bone tumors of the shoulder and proximal humerus were studied. 602 were localized in the humerus, 90 in the scapula and 19 in the clavicula. The most frequent benign tumors were osteochondromas (n = 143), simple bone cysts (n = 115), enchondromas (n = 75) and aneurysmal bone cysts (n = 50). Fibrous dysplasia (n = 25), chondroblastoma (n = 15), osteoid osteoma (n = 13), giant cell tumors (n = 12) and non ossifying fibroma (n = 11) were less frequent. The most frequent malignant bone tumors were osteosarcoma (n = 72), chondrosarcoma (n = 52) and Ewing's sarcoma (n = 46). Focal plasmocytoma (n = 20) and lymphoma (n = 10) were less frequent. The average age of the patients was 31.5 years. Some of these tumors were typically located in the shoulder, i.e. simple bone cysts and chondroblastoma. In summary the shoulder was a rather infrequent site of primary bone tumors, but since most of these tumors were benign, the radiologist should be aware of the differential diagnosis to guide therapy.