Mantle Cell Lymphoma with Classic & Pleomorphic Features
Lessons From the Friday Unknowns
Histologic sections show lymph node in which the architecture is completely replaced by lymphoma. The neoplasm also extends into perinodal adipose tissue. The neoplasm has a predominantly diffuse pattern but there are also some vaguely nodular areas. Many blood vessels with sclerotic walls are present. In most of the neoplasm the lymphoma cells are small with highly irregular nuclear contours and mitotic figures are relatively infrequent (classic Variant). However, there are some smaller areas where the neoplastic cells have relatively more cytoplasm and show more pleomorphism. In these areas mitotic figures are more easily identified (pleomorphic variant).
Virtually all of the lymphoma cells are positive for cyclin D1 and SOX-11. The antibody specific for Ki-67 shows a proliferation rate of approximately 10–20% in the areas of classic variant but 40–50% in the areas of pleomorphic variant.
Flow cytometry immunophenotypic studies were performed on this specimen elsewhere and 89.5% of events were aberrant B cells positive for monotypic lambda, B-cell antigens and CD5, and negative for CD23 and CD200.
Link to digital slides: https://bit.ly/3FQIqKe | Case 4