Popcorn cell in nodular lymphocyte predominance Hodgkin lymphoma

Q. I’m working on getting all of these lymphomas straight in my head.I was wondering if you could elaborate on the differences between nodular lymphocyte predominance and the “classical” Hodgkin lymphomas. Specifically, I can’t easily differentiate between nodular lymphocyte predominance Hodgkin and lymphocyte-rich Hodgkin lymphoma.

A. You’re right – the classical lymphocyte-rich Hodgkin lymphoma seems really similar to the non-classical nodular lymphocyte predominance Hodgkin lymphoma that is set apart in its own little category.

The biggest difference between nodular lymphocyte predominance (NLP)  and lymphocyte-rich (LR) Hodgkin lymphoma is in the Reed-Sternberg cells. In NLP Hodgkin lymphoma, the Reed-Sternberg cells have an unusual, multilobed nucleus. They are actually called “popcorn cells” because they look kind of like popped kernels of corn (check out the popcorn cell in the center of the photo above). These guys express different surface markers than regular Reed-Sternberg cells. They actually “look” more like B cells from an immunophenotypic standpoint: they are positive for CD20 (a B-cell marker), and negative for CD15 and CD30 (markers that are present on typical Reed-Sternberg cells).

For a long time, people thought this particular subtype of Hodgkin lymphoma was a B-cell lymphoma. To confuse the issue even more, a small number of cases of NLP Hodgkin lymphoma actually do transform into tumors that look more like diffuse large B-cell lymphoma.

Lymphocyte rich (LR) Hodgkin lymphoma has typical Reed-Sternberg cells (and sometimes mononuclear variants) – but not popcorn cells. The Reed-Sternberg cells in this type of Hodgkin lymphoma have a typical immunophenotype (positive for CD15 and CD30, and negative for other B-cell markers, T-cell markers, and CD45).

The other major difference between the two is a clinical one. Most patients with NLP Hodgkin disease are young males (under 35 years of age) who present with cervical or axillary lymphadenopathy. In both NLP and LR Hodgkin lymphoma, though, the prognosis is good to excellent.