||The patient is a 65-year-old man who presents for an upper endoscopy because of reflux symptoms. On endoscopy, a 5 cm gastric mass was noted. The endoscopist noted that the lesion was suspicious for lymphoma. Subsequent imaging revealed lesions in the lung, liver, and spleen. The following images are from 5 cm gastric mass biopsy.
For this case, immunohistochemistry is extremely helpful. What lesions remain in the diagnosis after the following panel is performed?
Cytokeratin AE1/AE3: Negative
S-100 Protein: Positive