Mantle Cell Lymphoma Involving Tonsillar Tissue
Lessons From the Friday Unknowns
Histologic sections of the tonsils show enlarged tonsils with extensive replacement by lymphoma. The neoplasm has a nodular and diffuse pattern in the tonsils with a minor mantle zone component.
The neoplastic cells are generally small with slightly irregular nuclear contours. Large cells are rare. Sclerotic blood vessels and epithelioid histiocytes are scattered throughout the neoplasm.
Flow cytometry immunophenotypic studies showed an aberrant B-cell population positive for monotypic kappa, CD5, CD19, CD20, CD22 and CD45.
Immunohistochemical studies show that the lymphoma cells are positive for CD5 (weak and variable), CD20, BCL–2, cyclin D1 and SOX11, and are negative for CD3, CD10 and CD23. The antibody specific for CD23 shows…