CD5-Negative, CCND1-IGH Translocation- Negative Mantle Cell Lymphoma

Lessons From the Friday Unknowns

Histologic sections show needle–shaped fragments of lymphoma.

The neoplasm has a vaguely nodular and diffuse pattern and is composed predominantly of small lymphoid cells with slightly irregular nuclear contours.

There are many blood vessels with sclerotic walls. A few residual reactive germinal centers are present surrounded by the neoplasm.

In some areas, plasma cells are present. It is unclear if these cells are a part of the neoplastic process.

The neoplastic cells are positive for CD20, PAX–5, BCL–2, Mum 1/IRF4 (weak, subset), cyclin D1 (strong) and SOX-11 (strong) and are negative for CD3, CD5, CD10, CD23, BCL–6, TdT, C–MYC, CD138.