DLBCL with Increased T-cells
Lessons From the Friday Unknowns
Histologic sections show needle-shaped fragments of lymph node involved by lymphoma.
The lymphoma is diffuse and composed of large atypical cells which are mostly scattered sitributed and admixed with numerous small lymphoid cells and histiocytes. Mitotic figures are seen. Large areas of tumor necrosis are present.
The lymphoma cells are positive for CD20, PAX5, CD45, IgD, EMA, CD10, BCL2 (subset), PD1 (subset), MUM1 (subset) and BCL6 and negative for CD3, CD15, CD21, CD30, ALK1, and Myc. In situ hybridization for Epstein-Barr virus-encoded small RNA (EBER) is negative. The tumor proliferation index as measured by Ki-67 is approximately ~70%.
In summary, the overall findings are those of a large B-cell lymphoma, expressing CD10 most consistent with diffuse large B cell lymphoma. Although numerous T cells and histiocytes are noted in the background, the large neoplastic cells constitute >10% of the cellularity, therefore this neoplasm does not meet the criteria of T cell rich histiocyte rich large B cell lymphoma. The expression of EMA and IgD in conjunction with the morphology suggest that this neoplasm could have evolved from a nodular lymphocyte predominant Hodgkin lymphoma.
Link to digital slides: https://bit.ly/3PDoxrB | Case 1