64-year-old man presented with epigastralgia and severe weight loss in the previous 4 months. The patient underwent a gastric endoscopy, which showed a large ulceroinfiltrative lesion in the gastric antrum. A total gastrectomy was performed and was submitted to pathologic examination. The gross specimen showed a large ulceroinfiltrative lesion measuring 5.5 3 4.0 3 2.8 cm in the antrum infiltrating all layers of the gastric wall. The histologic examination showed a neoplasm composed of medium-sized to large cells with anaplastic nuclei, prominent eosinophilic to amphophilic macronucleoli, granular chromatin, and eosinophilic finely granular cytoplasm. These cells were disposed in solid nests, trabeculae, and ribbons (Figure 1). Foci of typical poorly differentiated gastric signet ring cell carcinoma were admixed with these areas (Figure 2), as well as constituting distinct neoplastic foci. Immunohistochemistry was performed using the avidin-biotin-peroxidase technique with antibodies against low-molecular-weight cytokeratin, epithelial membrane antigen, carcinoembryonic antigen, synaptophysin, chromogranin, and neuron-specific enolase. The immunostaining showed 2 distinct patterns of positivity in the solid and the signet ring areas. In the solid area, cells showed positivity for low-molecular-weight cytokeratin, epithelial membrane antigen, synaptophysin, chromogranin, and neuron-specific enolase, whereas the signet ring cell foci were immunoreactive for low-molecularweight cytokeratin, epithelial membrane antigen, and carcinoembryonic antigen. However, some signet ring cells showed distinct granular immunoreactivity for both synaptophysin and chromogranin (Figure 3). Six of the 11