Anthracosis mimicking mediastinal lymph node metastases with 18F-FCholine in high-risk prostate cancer.

A 62-year-old patient with prostate adenocarcinoma underwent PET with radiolabeled choline (18F-Fcholine) for pretreatment staging of a high-risk prostate cancer. Images showed a significant mediastinal lymph node uptake of 18F-Fcholine. Owing to the rarity of spread to supradiaphragmatic lymph nodes, a surgical removal was performed, revealing anthracosis and no malignant cells. Even if its specificity seems better than 18F-FDG, false positives have been reported and other pathologies could mimic lymph node metastases. Consequently, histology should be performed so that the appropriate treatment can be initiated.