Thumanoon RuangchaijatupornEric Y. ChangChristine B. ChungMahidol UniversityVA Medical CenterUniversity of California, San Diego2018-12-112019-03-142018-12-112019-03-142016-12-01Skeletal Radiology. Vol.45, No.12 (2016), 1741-174514322161036423482-s2.0-84990829842https://repository.li.mahidol.ac.th/handle/20.500.14594/40972© 2016, ISS. A 56-year-old man presented with a painless prepatellar mass of the left knee. MR images demonstrated a large, well-defined mass with heterogeneous intermediate signal intensity on T1- and proton density-weighted images. Mild, heterogeneous enhancement was noted after the intravenous administration of gadolinium. Diagnostic imaging included atypical soft-tissue infection, fibrogranulomatous reaction, gouty tophus, rheumatoid nodule and xanthoma or possibly malignancy. The histopathological examination revealed sarcoidosis involving the prepatellar bursa.Mahidol UniversityMedicineArticleSCOPUS10.1007/s00256-016-2494-4