A case of pulmonary cholesterol granuloma: an (18)F-fluorodeoxyglucose positron emission tomography image

A 77-year-old woman with Sjögren's syndrome has been followed for mild interstitial pneumonia. A 2-cm pulmonary nodule was incidentally found in the left lower lobe, and positron emission tomography-computed tomography showed (18)F-fluorodeoxyglucose uptake with a maximum standardized uptake value of 8.78 in this nodule. Although this suggested a malignant disease, transbronchial biopsy of the nodule revealed that it was cholesterol granuloma. It is known that some benign inflammatory diseases show an increased uptake of (18)F-fluorodeoxyglucose, particularly granulomatous lesions like tuberculosis. To our knowledge, this is the first report of (18)F-fluorodeoxyglucose-positron emission tomography findings for cholesterol granuloma. We speculate that increased (18)F-fluorodeoxyglucose uptake with cholesterol granuloma occurs through cellular infiltration and macrophage proliferation, resulting in the activation of glycolysis-like tuberculosis.