Sarcoidosis With Multiple Bone Lesions Mimicking Advanced Lung Cancer With Multiple Bone Metastases

Bone lesions in sarcoidosis are more common than previously known. A 59-year-old female with a history of sarcoidosis was referred due to suspected lung cancer. 18F-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) revealed numerous bone lesions in addition to abnormal uptake by pulmonary nodules and mediastinal lymph nodes, which mimicked metastatic advanced lung cancer. Biopsy of bone lesions detected epithelioid cell granuloma consistent with bone sarcoidosis. Moreover, prednisolone treatment was tried to exclude malignant disease. One month after prednisolone administration, bone lesions and other abnormal uptake disappeared on PET/CT. Bone sarcoidosis is often asymptomatic and is discovered incidentally as multiple lesions that may require differentiation from malignant disease. Biopsy of bone lesions and administration of corticosteroids may be useful for accurate diagnosis.