Peripheral neuropathy due to thiamine deficiency after inappropriate diet and total gastrectomy.

Peripheral polyneuropathy due to vitamin B1 deficiency was encountered after total gastrectomy for gastric signet cell carcinoma in a patient with a history of breast-conserving surgery for breast cancer. She had greatly reduced her intake of animal foods, believing that would be effective for the prevention of re-occurrence of cancer. Her daily intake of vitamin B1 was less than half of the usual daily requirement. Patients with malignancy tend to adopt unusual diets, and proper advice about food intake is important for such patients, especially those with gastrectomy.