Simultaneous large cell neuroendocrine carcinoma and adenocarcinoma of the stomach

Figure 1 Gross features of the 2 tumors of the stomach. One is an ulcerated tumor in the antrum (arrow) and the other is a polypoid tumor in the gastric body (double arrows). The ulcerated tumor is an adenocarcinoma, and the polypoid tumor is a large cell neuroendocrine carcinoma. The organ on the right is the gallbladder.

Figure 2 Microscopic features of adenocarcinoma. Well defined tubules are seen (× 200).

Figure 3 Polypoid tumor. A: The polypoid tumor consists of malignant cells with hyperchromatic nuclei arranged in a trabecular pattern (HE, × 100); B: Higher power view shows large cells, vesicular nuclei, nucleoli, mitotic figures and apoptotic bodies (HE, × 200). HE: Hematoxylin and eosin.

Figure 4 Immunohistochemical findings. Tumor cells are positive for pancytokeratin AE1/3 (A), synaptophysin (B), Ki67 (C), and PDGFRA (D) (× 100). PDGFRA: Platelet-derived growth factor-α.