Mantle Cell Lymphoma, Blastoid Variant
Lessons From the Friday Unknowns
Histologic sections show core needle shaped fragments of tissue involved by lymphoma. The neoplasm is mostly diffuse and composed of intermediate to large atypical lymphoid cells with slightly irregular nuclear contours and dispersed nuclear chromatin (blastoid). Mitoses are frequently seen.
Immunohistochemical studies show that the tumor cells are CD20, CD5 and cyclin D1 and are negative for CD3. Ki-67 shows a proliferation rate of 60%. TP53 is weakly positive in a subset supporting a wild type pattern.
Flow cytometry analysis shows a monoclonal, kappa light chain restricted, B cell population positive for CD19, CD20, CD22, CD5 and CD10.
In summary, the findings are those of mantle cell lymphoma blastoid variant.
Link to digital slides: https://bit.ly/3RbO7VO | Case 2