Case presentation
A 48-year-old female noticed a subcutaneous nodule. She presented with remittent fever, fatigue, weight loss, and abdominal pain. Laboratory tests showed elevated levels of lysozyme, soluble interleukin-2 receptor, and angiotensin-converting enzyme. Computed tomography (CT) revealed pulmonary reticular opacities, hepatomegaly, and massive splenomegaly. Fluorodeoxyglucose position emission tomography (FDG PET)/CT showed FDG uptake not only in the liver, spleen, and systemic lymph nodes, but also in the humerus, scapula, the 4–7th thoracic vertebrae, pelvis, and femur (Figure 1, 2). Histological samples from the skin, liver, and bone marrow biopsies exhibited noncaseating granulomas with epithelioid cells, which were diagnosed as multiorgan sarcoidosis.
Sarcoidosis is a systemic inflammatory disease of unknown etiology characterized by the formation of noncaseating granulomas in the affected organs. Although FDG PET/CT is not included in the standard workup for sarcoidosis, its usefulness in the diagnosis of this condition and its subsequent management has been proposed (1). Moreover, FDG PET/CT has been reported to be especially useful in detecting bone lesions because it is difficult to detect bone sarcoidosis involvement using conventional radiography (2). Sarcoidosis can affect any site in the body while being asymptomatic. Therefore, FDG PET/CT should be considered for the detection of affected lesions of sarcoidosis.