FDG PET/CT in a Case of Lynch Syndrome With Synchronous Inverted Urothelial Papilloma of the Bladder, Urothelial Carcinoma of the Ureter, and Jejunal Adenocarcinoma.

A 64-year-old man was referred because of the right ureteral obstruction. CT urography showed an intraluminal enhancing mass in the right midureter and an enhancing nodule in the bladder wall. FDG PET/CT showed increased FDG uptake of the ureteral mass and an unexpected hypermetabolic lesion in the jejunum. The patient underwent transurethral resection of the bladder tumor, right laparoscopic nephroureterectomy, and partial enterectomy. Inverted urothelial papilloma of the bladder, high-grade urothelial carcinoma of the right ureter, and jejunal adenocarcinoma were confirmed by histopathology. Genetic testing of the jejunal adenocarcinoma revealed MSH2 germline mutation, confirming the diagnosis of Lynch syndrome.