CLINICOPATHOLOGICAL ASPECTS OF GASTRIC NEUROENDOCRINE TUMORS

The major clinicopathologic aspects of 55 gastric neuroendocrine tumor s were analyzed. Forty-six of 55 cases were well-differentiated tumors and 9 were poorly differentiated gastric neuroendocrine carcinomas. W ell-differentiated gastric neuroendocrine tumors comprised 1 gastrinom a and 45 enterochromaffin-like (ECL)-cell tumors. ECL tumors were grou ped depending on their clinical background. Type 1, associated with ch ronic atrophic gastritis of the acidopeptic mucosa (A-GAG), included 2 8 cases with tumor growths mainly restricted to the mucosa and submuco sa, with no metastasis. Type 2, associated with hypertrophic gastropat hy, included seven cases, six of which were associated with Zollinger- Ellison syndrome (ZES) and multiple endocrine neoplasia type 1 (MEN-1) , including two cases with local metastasis. Type 3, not associated wi th any significant clinicopathologic condition (sporadic), included 10 cases, 7 of which were deeply invasive and 5 metastatic. The nine gas tric neuroendocrine carcinomas were highly aggressive metastatic tumor s. At follow-up, no tumor-related death was observed for type 1 and ty pe 2 ECL tumors. Type 3 (sporadic) ECL tumors were fatal in 3 of 10 ca ses, and 6 of 9 patients with gastric neuroendocrine carcinomas died o f their tumor disease. It is concluded that type 1 and type 2 well-dif ferentiated ECL tumors are benign or low-grade tumors, whereas type 3 well-differentiated ECL tumors and the poorly differentiated neuroendo crine carcinomas are malignant neoplasms.