Peritoneal recurrence of gastric cancer with mucin phenotype 12 years after curative resection: report of a case.

We report a case of peritoneal recurrence of gastric cancer in a 58-year-old man, 12 years after curative surgery. Urinary wall thickness was seen on follow-up computed tomography and magnetic resonance imaging scans. We performed total nephroureterectomy and cystectomy for urinary tract cancers, but histological examination of the resected specimen revealed poorly differentiated adenocarcinoma with severe fibrosis, resembling the gastric cancer resected 12 years earlier. Immunohistological examination revealed human gastric mucin (45M1) and intestinal mucin (MUC2) phenotype in both the original gastric cancers and the urinary tract cancers. Thus, we concluded that the second cancer was a peritoneal recurrence of gastric cancer with gastric and intestinal mucin phenotypes. Although peritoneal recurrence so many years after curative gastrectomy is rare, careful long-term follow-up should be done for all patients undergoing surgery for gastric cancer with mucin phenotype.