Cholesterol Granuloma of the Thyroid Mimicking Malignancy

Cholesterol granuloma (CG) is a rare benign disease that radiologically resembles malignancy in solid organs. CG, which occurs commonly in the middle ear, is found in many organs, such as the paranasal sinuses, breast, pancreas, gallbladder, kidney, orbit, testis, peritoneum, parotid gland, liver, spleen, and jaw.1 Only 3 cases of CG of the thyroid have been reported. In 2 of those cases, abnormal lipid metabolism caused CGs involving multiple organs, and the patients were diagnosed with Erdheim-Chester disease.2,3 In the other case, there was no abnormal lipid metabolism or involvement of multiple organs except the thyroid.4 The current case demonstrated that CG could be misdiagnosed as a malignancy on preoperative imaging studies