Leptomeningeal metastasis as initial manifestation of signet ring colorectal adenocarcinoma: a case report with review of literature.

Leptomeningeal carcinomatosis (LMC) is an exceedingly rare event especially as a first manifestation of an occult primary colorectal cancer and even when there is a known history of malignancy. Sensorineural hearing loss is by itself an unusual isolated presentation of LMC with unsolved pathophysiology in this setting. In this paper, we report such a case and review the literature for similar cases, focusing on postulated mechanisms of spread. In view of the poor prognosis they carry, we highly recommend that physicians be aware of the risk of rare metastasis from colorectal adenocarcinoma in order to establish an early confirmative diagnosis.