[A case of leptomeningeal carcinomatosis involving loss of eyesight after total gastrectomy for gastric cancer].

A 78-year-old woman had undergone total gastrectomy and chemotherapy for gastric cancer (pT4N3bM0 Stage IIIC, poorly differentiated adenocarcinoma). She received S-1 monotherapy 3 times weekly (S-1 at 80mg twice daily for 14 days, every 3 weeks). She underwent routine examinations, including tumor markers and computed tomography. She had no signs of recurrent disease, but she suffered from a loss of eyesight 2 years and 8 months after the operation. A choked disc was found, but she had no headaches, nausea, or unconsciousness, which indicated high intraventricular pressure. Enhanced T2-weighted magnetic resonance imaging showed high intensity around the optic nerve. We performed cerebrospinal fluid cytological analysis, which showed poorly differentiated adenocarcinoma. She was diagnosed as having leptomeningeal carcinomatosis of gastric cancer. The patient chose best supportive care and died 2 months after symptoms appearance. Histological analysis during the autopsy showed moderately to poorly differentiated adenocarcinoma. The carcinoma had also infiltrated the spinal cord, peritoneum, and adrenal glands. Histologically, the carcinoma had infiltrated the optic nerve, which caused loss of eyesight. We have not yet established effective therapies for leptomeningeal carcinomatosis, and the prognosis is poor. Leptomeningeal carcinomatosis of gastric cancer that appears by loss of eyesight is very rare. This case illustrates that the possibility of leptomeningeal carcinomatosis should be considered when we treat patients with loss of eyesight of an unknown cause after surgery.