Parosteal osteosarcoma of the scapula.
Parosteal osteosarcoma is a low-grade osteosarcoma, which occurs on the surface of the bone. We had experienced a parosteal osteosarcoma involving the flat bone, the scapula of a 21-year-old man. This is an extremely rare location for a parosteal osteosarcoma. Plain radiograph showed broad-based, well-defined radiodense lesion at the scapula. Computed tomogram demonstrated an intact cortex and absence of a medullary involvement. Tumor showed a lobulated, high-density lesion, indicating bone formation. Histologically, parosteal osteosarcoma is a well-differentiated osteosarcoma. The tumor is composed of a hypocellular proliferation of spindle cells, with minimal cytologic atypia. The bone is in the form of a well-formed bony trabeculae. Occasional cartilage is present in the form of a cap.
Park
Y K
YK
Department of Pathology, College of Medicine, Kyung Hee University, Seoul, Korea. damia@chollian.net
Ryu
K N
KN
D000328:Adult; D001859:Bone Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D006801:Humans; D008297:Male; D012516:Osteosarcoma / Q000000981:diagnostic imaging* / Q000473:pathology; D012540:Scapula / Q000000981:diagnostic imaging* / Q000473:pathology; D014057:Tomography, X-Ray Computed