Superficial spreading type of early gastric cancer coexisting with multiple hyperplastic polyps.

We encountered a rare case that involved the superficial spreading type of early gastric cancer coexisting with multiple hyperplastic polyps. An 81-year-old Japanese woman with a history of Helicobacter pylori infection was diagnosed with gastric cancer (cT1bN0M0), which presented as a wide, nodular, aggregated protrusion that was associated with multiple pedunculated and sessile polyps. Distal gastrectomy was performed, and the resected specimen involved an 8 cm × 4 cm nodular aggregated protruding lesion and 15 polyps that were 2-20 mm in size. Histopathological examination revealed that the nodular aggregated protruding lesion was a mucosal adenocarcinoma and that the multiple polyps were hyperplastic. The coexistence of multiple hyperplastic polyps and mucosal adenocarcinoma with nodular aggregated protrusions suggested that the mucosal adenocarcinoma had developed from a fusion of multifocal hyperplastic lesions. This may have occurred via a hyperplasia-carcinoma sequence related to the Helicobacter pylori infection. The superficial spreading type of early gastric cancer has a potential developed from a fusion of multifocal hyperplastic polyps.