Multicentric Primary Angiosarcoma of Bone Mimicking Metastasis on (18)F-FDG PET/CT in a Patient with a History of Sigmoid Colon Cancer: a Case Report.

Primary angiosarcoma of the bone (PAB) is a rare and fatal high-grade malignant vascular bone tumor. We report a rare case of multicentric PAB mimicking bone metastasis in a 59-year-old female patient with a history of sigmoid colon cancer. This patient complained of lower back and pelvic pain and presented with multiple osteolytic bone lesions on plain radiography and pelvic computed tomography. First, bone metastasis of sigmoid colon cancer was suspected. However, on the (18)F-fluorodeoxyglucose ((18)F-FDG) positron emission tomography/computed tomography (PET/CT) scan, the patient presented unusual multiple hypermetabolic osteolytic bone lesions involving contiguous bones of the lower half of the body. After bone biopsy, these lesions were confirmed to be multicentric PAB. To the best of our knowledge, this is the first case report of an (18)F-FDG PET/CT scan in a patient with multicentric primary bone angiosarcoma.