Well-differentiated Neuroendocrine Tumor (Carcinoid) in Chronic Atrophic Gastritis

Autoimmune gastritis is typified by parietal cell loss and extensive lamina propria inflammation. ECL cell growth occurs in this setting, in both linear and nodular fashions. Here, nodular hyperplasia is reaching the threshold of forming a neuroendocrine tumor. Autoimmune gastritis is present in the background (top).