Pathology of lung and gastric tumors. ( A) Poorly-differentiated papillary adenocarcinoma from segment 10 of the right lung composed of papillary tufts containing fibrovascular cores. Large, atypical cells with enlarged hyperchromatic nuclei were observed (hematoxylin and eosin, original magnification × 200). ( B) Tubular adenocarcinoma from the stomach with poorly-cohesive lesions containing signet-ring cells. Discohesive and highly atypical tumor cells with signet-ring cells (arrows) of intracytoplasmic mucin or eosinophilic cytoplasm can be observed (hematoxylin and eosin, original magnification × 200).