Mantle Cell Lymphoma, Classic Variant
Lessons From the Friday Unknowns
Histologic sections show lymph node in which the architecture is effaced by lymphoma. The lymphoma has a vaguely nodular and diffuse pattern and is composed of small lymphoid cells with irregular nuclear contours and scant cytoplasm. No areas of necrosis are noted.
The lymphoma cells are positive for CD5, CD20, CD43, BCL-2, cyclin D1 and SOX11, and are negative for CD3, CD10, CD23, CD138, p53 (wild type pattern) and BCL-6. The antibody specific for CD23 highlights disrupted follicular dendritic meshworks. CD138 highlights rare plasma cells that appear polytypic for kappa and lambda light chains as assessed by in situ hybridization.The proliferation index as assessed by Ki-67 is variable approximately 20–25%.
Flow cytometry immunophenotyping identified an atypical CD5 positive B-cell population.
TP53 mutation analysis did not detect any mutations.
In summary, the morphologic and immunophenotypic findings support the diagnosis of mantle cell lymphoma, classic variant.
Link to digital slides: https://bit.ly/3zapEtj ~ Case 1