Nodular gastritis is a Helicobacter pylori-related gastritis with endoscopically proven gooseflesh skin-like nodularity in the gastric antrum. Although an association between nodular gastritis and gastric malignancies has been suggested, there is neither a treatment strategy nor a treatment guideline for this condition because of its relative rarity. We have recently experienced two cases of diffuse-type nodular gastritis invading both the antrum and corpus of the stomach with atypical findings that required specific treatments in two young females. The first patient was diagnosed with a suspicious low grade gastric mucosa associated lymphoid tissue (MALT) lymphoma lesion on a diffuse-type nodular gastritis, and was cured by H. pylori eradication. The second patient was diagnosed with a signet cell type gastric cancer on a diffuse-type nodular gastritis, and was cured by surgical resection. When considering the nature and significance of these gastric lesions, a link between nodular gastritis and gastric malignancy should be considered, especially in young women who have diffuse-type nodular gastritis involving both the antrum and corpus of the stomach.