A Case of Meningeal Carcinomatosis Due to Signet-Ring Cell Carcinoma That Developed Severe Visual Impairment with Papillary Swelling

PURPOSE: To report a case of meningeal carcinomatosis by metastasis of signet-ring cell carcinoma resulting in severe visual impairment. CASE PRESENTATION: A 49-year-old man visited our hospital complaining of blurred vision in his left eye since 2 months ago. There was no particular history. Best corrected visual acuity (BCVA) was 25/20 in the right eye and 20/20 in the left eye. Papillary swelling in both eyes and disc hemorrhage in the left eye were observed. Gradually, the frequency of dizziness increased, and magnetic resonance imaging (MRI) suggested ventricular enlargement, infiltration around the optic nerve, and meningeal carcinomatosis. Increased cerebrospinal fluid pressure was found, and metastatic adenocarcinoma cells were observed by cerebrospinal fluid cytology. A gastroduodenal biopsy confirmed the diagnosis of poorly differentiated adenocarcinoma with signet-ring cells. Visual acuity at the final visit was 4/200 in both eyes. CONCLUSION: If papillary swelling is observed in both eyes, meningeal carcinomatosis should be considered as a differential diagnosis.