The development of
adenocarcinoma or
carcinoid tumors in
atrophic gastritis is widely documented. We report the simultaneous occurrence of gastric
adenocarcinoma and
carcinoid (composite
tumor) in
atrophic gastritis, a finding reported only twice before in the literature. This 52-yr-old man with rectal
bleeding, epigastric
pain, and
iron deficiency anemia was noted to have multiple polypoid masses on upper endoscopy. Biopsy revealed features of both
adenocarcinoma and
carcinoid tumor in a background of
atrophic gastritis, leading to a total
gastrectomy,
lymph node dissection, and liver biopsy. The
gastrectomy specimen was characterized by a 6 cm pedunculated
polyp and multiple sessile nodular masses between 0.4 and 2.5 cm in the background of a granular mucosa. On microscopic examination, the large polypoid mass corresponded to a well-differentiated
adenocarcinoma, intestinal type, infiltrating the wall. The smaller nodules were composed of
carcinoid tumors, restricted to the mucosa, or infiltrating the gastric wall.
Carcinoid tumor was also seen in the large polypoid mass closely intermingled with
adenocarcinoma. The
carcinoid tumor metastasized to the liver. Lymph nodes showed both
adenocarcinoma and
carcinoid tumor. The gastric mucosa was characterized by
atrophic gastritis with intestinal
metaplasia, neuroendocrine
hyperplasia, and microcarcinoids. The
adenocarcinoma stained strongly for CK7, CK 20, MIB-1, and focally for
chromogranin and
synaptophysin. The
carcinoid tumor was negative for CK7, CK 20 and MIB-1, and was positive for
chromogranin and
synaptophysin. Overexpression of p53 was noted only in the
adenocarcinoma. Electron microscopy revealed neurosecretory granules in the
carcinoid characteristic of a
neuroendocrine tumor. Composite
tumor can occur in the setting of
atrophic gastritis. The findings in this patient reinforce the concept that the epithelial and neuroendocrine cells of the gastrointestinal tract both result from multidirectional differentiation of a primitive cell.