Leptomeningeal Carcinomatosis of Metastatic Primary Prostate Cancer.

Leptomeningeal carcinomatosis (LC) is an uncommon complication of cancer in which the disease metastasizes to the meninges; it is estimated that this occurs in 5% of cancer patients and is most often terminal. LC has a median survival time of approximately 15.7 weeks [Leal et al., Curr Cancer Ther Rev. 2011;7(4):319-27]. Furthermore, metastasis from the prostate is exceptionally rare with only a few cases described in medical literature. Until recently, leptomeningeal disruption was very rare and cerebral involvement was irrelevant [Bubendorf et al., Hum Pathol. 2000;31(5):578-83; Schaller et al., Br J Cancer. 2000;77(12):2386-9]. With improved imaging, diagnostic modalities, and treatment with therapies that do not cross the blood-brain barrier, the incidence of LC has been on the rise [Batool and Kasi, StatPearls, https://www.ncbi.nlm.nih.gov/books/NBK499862/]. Diagnosis previously relied on biopsy, supported by lumbar puncture findings. We submit a case demonstrating progressive and consistent evidence of LC found on imaging, justifying its acceptance as a diagnostic modality.