Usefulness of three-phase bone scintigraphy and SPECT/CT for the diagnosis of bone lesions of systemic sarcoidosis

We report a three-phase bone scintigraphy for the diagnosis of a peripheral bone lesion caused by systemic sarcoidosis. A 32-year-old man with suspected osteomyelitis of the right forefinger underwent three-phase bone scintigraphy with Tc-99m hydroxymethylene diphosphonate (HMDP) and single-photon emission computed tomography/computed tomography (SPECT/CT). The lesion was rich in blood flow according to flow study and blood pool study on bone scintigraphy, and was associated with an osteolytic change on SPECT/CT imaging performed 3 hours after injection of a radioisotope (RI). Whole-body bone scintigraphy indicated multiple high levels of abnormal RI accumulation. The findings of the three-phase bone scintigraphy and SPECT/CT suggested the presence of systemic sarcoidosis; however, a subsequent (18)F-fluorodeoxyglucose positron emission tomography/CT (FDG-PET/CT) could not exclude the possibility of multiple metastases from testicular tumors. Therefore, testicular enucleation was performed, and the pathological examination confirmed the presence of sarcoidosis.