Intrafollicular classical Hodgkin lymphoma mimicking nodular lymphocyte predominant Hodgkin lymphoma: a report of two cases.

We here report on two rare cases of intrafollicular classical Hodgkin lymphoma (CHL). Case 1 was a 34-year-old man who underwent left supraclavicular lymph node biopsy. Case 2 was a 28-year-old woman who underwent surgical resection of an anterior mediastinal mass. The histology and microenvironment of both specimens resembled those of nodular lymphocyte predominant Hodgkin lymphoma. Nodular architecture was observed, which comprised normal-appearing small lymphocytes and scattered lymphocyte predominant (LP)-like cells. CD23(+) follicular dendritic cell meshworks were present in the nodules, surrounded by a mantle zone containing IgD(+) B cells. The LP-like cells were ringed by CD3(+) and PD-1(+) T cells, and numerous CD20(+) B cells were present in the background. However, the immunophenotypes of the LP-like cells resembled those of Hodgkin/Reed-Sternberg cells of CHL; they were positive for CD15, CD30, and PAX5, and negative for CD20, Bcl6, Oct2, and Bob1. These histopathological findings indicate that CHL can be derived from the germinal center.