B - Duodenal bulb polyp and mass
D - Duodenal mass
Tissue "B" and "D" - Immunohistochemical evaluation, performed on specimen B, reveals the neoplastic large lymphoid cells to be immunoreactive for CD20, CD10, and BCL-6, without significant staining for BCL-2, MUM-1, CD30, or cyclin-D1 (BCL-1); there is patchy staining among the neoplastic cells for c-MYC, with some foci demonstrating staining of approximately 30% of the population. The Ki-67 (MIB-1) labeling index is approximately 70%. An immunostain for CD3 highlights background non-neoplastic small T lymphocytes. The neoplastic cells are negative for chromogranin and synaptophysin.
The constellation of features indicates a diffuse large B-cell lymphoma of germinal center B-cell type. The sampled biopsy material does not reveal an accompanying low-grade lymphomatous component.
Tissue "B" - Duodenal bulb polyp and mass, biopsy - Diffuse large B-cell lymphoma, not otherwise specified, germinal center B-cell type (see comment).
Tissue "D" - Duodenal mass, biopsy - Diffuse large B-cell lymphoma, not otherwise specified, germinal center B-cell type (see comment).