Leptomeningeal carcinomatosis in gastric cancer.

We analyzed 19 cases of cytologically confirmed leptomeningeal carcinomatosis (LMC) treated at our institution over the past 11 years. LMC was the initial manifestation of gastric cancer in 2 patients. With the exception of 1 patient, the primary gastric cancer was Borrmann type III or IV, and 88% had poorly differentiated or signet-ring cell histology. The gastric cancer was progressive or a recurrent disease in most of the patients. The distribution of extraneural metastasis suggested that Batson's venous plexus might be the predominant route to the subarachnoid space. Eighty percent of the patients had multiple neuraxis syndrome, and the combination of brain plus cranial nerve syndrome was the most common manifestation. Computed tomography (CT) findings were abnormal in a minor proportion of the patients, while magnetic resonance imaging (MRI) revealed abnormality in 67% of the patients, which could help the diagnosis. LMC complicating gastric cancer was ultimately fatal. Median survival was very short, 4 weeks. By univariate analysis, good performance status, intrathecal chemotherapy, and low CSF LDH concentration favored survival. Multivariate analysis revealed that the administration of CSF chemotherapy was the independent prognostic factor for survival.