Diffuse Large B-Cell Lymphoma : Pan-keratin
The main differential diagnostic considerations of gastric diffuse large B-cell lymphomas include undifferentiated gastric carcinoma, Burkitt lymphoma, and melanoma. In small gastric biopsies, these entities may appear morphologically similar. Immunohistochemical evaluation with lymphoid, epithelial, and melanocytic markers can help confirm the diagnosis. The image shows negativity for pankeratin in the tumor with a nice internal positive control.