Isolated Leptomeningeal Carcinomatosis in Urothelial Carcinoma: A Case Report of Positive CSF Cytology With Negative Imaging.

Bladder cancer is one of the most common cancers worldwide; however, leptomeningeal carcinomatosis (LMC) is an uncommon and understudied complication. We report a male patient diagnosed with LMC while in apparent clinical remission of metastatic urothelial carcinoma of the bladder. He presented with headaches, vision changes, hearing impairment, and leg weakness. Imaging of the brain and spinal cord was negative; however, the cerebrospinal fluid was positive for malignant cells consistent with high-grade urothelial carcinoma, confirming the diagnosis of LMC. Conservative measures and whole-brain radiation were ineffective, and he died 2 months after his LMC diagnosis. Literature review identified 45 cases of LMC due to bladder cancer, and we summarize these data. It is unclear whether new and more effective systemic treatment approaches for urothelial carcinoma will also reduce the risk of LMC or provide better treatment for LMC, supporting a need for more study of this devastating complication.