S-Space College of Medicine/School of Medicine (의과대학/대학원) Radiology (영상의학전공) Journal Papers (저널논문_영상의학전공)
Fibroblastic Type Osteosarcoma of the Ulna: a Case Report of a Tumor in a Rare Location with Atypical Imaging Findings
- Joo, Ijin; Choi, Jung-Ah; Chung, Jin-Haeng; Oh, Joo Han; Kang, Heung Sik; Hong, Sung Hwan
- Issue Date
- KOREAN RADIOLOGICAL SOC
- KOREAN JOURNAL OF RADIOLOGY; Vol.10 1; 85-88
- The ulna is a rare site of origin for osteosarcoma, and purely osteolytic osteosarcomas are uncommonly noted on conventional radiographs. We present a patient with a lytic lesion of the distal ulna for which imaging findings suggested an aneurysmal bone cyst. The lesion was histologically confirmed to be a fibroblastic osteosarcoma.
Osteosarcoma is the second most common primary malignant bone tumor,
accounting for approximately 15% of all primary bone tumors confirmed
at biopsy (1). Osteosarcomas most frequently affect long bones, particularly
around the knee, and rarely the ulna (1, 2). On radiographs, osteosarcomas classically
appear as aggressive destructive lesions with a mixed osteolytic and sclerotic
pattern, associated periosteal reaction, and soft-tissue mass. The purely osteolytic form
of osteosarcoma occurs in about 10% of all cases (3). The differential diagnosis of lytic
and expansive bone lesions includes solitary bone cysts, aneurysmal bone cysts, giant
cell tumors, enchondromas, and telangiectatic osteosarcomas (4).
We present a case of fibroblastic osteosarcoma, with an accompanying pathologic
fracture, which arose from the distal ulna and was initially suspected to be an aneurysmal
bone cyst based on its features on conventional radiographs and magnetic
resonance (MR) images.