Metastasis of Urothelial Carcinoma to the Wrist: A Case Report of an Overlooked Finding on Whole-body 99m Tc-MDP Scan.

A 65-year-old man presented with painless hematuria and a bladder mass, diagnosed as high-grade papillary urothelial carcinoma following transurethral resection. Considering negative metastasis workup, he was scheduled for radical cystectomy. During follow-up, he reported chronic wrist pain. A whole-body 99m Tc-Methylene diphosphonate (MDP) scan showed focal uptake in the wrist, misinterpreted as arthritis and overlooked as inconsequential. Three months later, x-ray imaging revealed a lytic wrist lesion, later confirmed as metastatic carcinoma through biopsy. Immunohistochemical analysis supported the diagnosis, highlighting the importance of careful interpretation of imaging findings in patients with bladder cancer.