Leptomeningeal Carcinomatosis as the Initial Manifestation of Metastatic Disease diagnosed in Postmortem Examination: A Case Series.

Leptomeningeal carcinomatosis (LMC) refers to the infiltration of malignant cells in the pia-arachnoids. LMC is undiagnosed until autopsy in about 20% of cases. A nonspecific neurologic symptomatology makes diagnosis challenging; especially in the scenario of unknown malignancy. Diagnosis is made by the identification of malignant cells in CSF; though studies have shown that serial examination may be required for acceptable accuracy. We report 3 cases with distinct neurological presentations, negative cerebrospinal fluid (CSF) examinations and neurological imaging. A 52 year old woman with history of breast cancer on remission, a 2 year old male with left ear rhabdomyosarcoma status post resection, and a 59 year old woman with communicating hydrocephalus of unknown etiology. LMC was diagnosed at autopsy and confirmed by immunohistochemistry. LMC is a complication requiring a high level of clinical suspicion. Postmortem examination is an invaluable tool to confirm LMC as part of the multidisciplinary approach aiming towards the improvement of clinical diagnosis.