Mucosa-associated lymphoid tissue lymphoma in the terminal ileum: A case report

Figure 2 Biopsy of terminal ileum showing. A: Hematoxylin & eosin-dense lymphocytic infiltrate composed of small cells, with a cytoplasmic halo, characteristic of cells in the marginal zone; B: Cyclin D1-Negative neoplastic infiltrate for protein expression of cyclin D1. Observe the positive control in the glandular epithelium; C: Cytokeratin cocktail AE1/AE3-negative neoplastic infiltrate for protein expression of cytokeratin. Observe the positive control in the glandular epithelium; D: BCL6-Protein label for BCL60. Note the negativity of the neoplastic infiltrate, and the positive internal controls in the germinal center of a reactional follicle.