Bone Echinococcosis Mimicking Malignancy on FDG PET

MRI revealed a thoracic vertebrae lesion in a 40-year-old woman with back pain. She was referred to our institution; MRI demonstrated a mass from the second to the fifth thoracic vertebra and compression fractures. CT revealed a splenic mass, multiple pulmonary nodules, and low-density masses in the liver. F-18-FDG PET/CT showed increased uptake (SUVmax, 10.6) in the peripheral rim of the thoracic vertebra mass, with central parts showing lower uptake than the peripheral rim. The splenic mass exhibited increased accumulation (SUVmax, 4.8). The thoracic spine lesion was fixed; a biopsy was performed. Alveolar echinococcosis was confirmed immunologically. Alveolar echinococcosis can present with bone lesions. It must be differentiated from malignancy.