Although rare, there are cases in which classic Hodgkin lymphoma (CHL) and follicular lymphoma (FL) occur simultaneously at the same site. Known as composite classic Hodgkin lymphoma and follicular lymphoma (CHLFL), this condition is rare and not well understood. This article, published in the American Journal of Clinical Pathology, examined two case studies that showed a clonal relationship between CHL and FL.
Ultimately, the clonal relationship between CHL and FL components was suggested by FISH. Although the two case studies differed in many ways, they had areas of typical FL with BCL2-positive phenotype and no significant CD30/CD15 expression. Hodgkin/Reed-Sternberg (HRS) cells in both cases expressed CD30 and CD15, and HRS cells in the first case expressed BCL2.
An additional 27 CHLFL cases from the medical literature were reviewed. Of these cases, 5 of 6 tested cases had BCL2/immunoglobulin heavy chain (IgH) gene rearrangement in both FL and HRS cells.
The researchers concluded that composite CHL and FL are often clonally related. They may share a common progenitor B-cell origin and require additional genetic abnormalities to develop two distinct lymphomas. However, more robust research is needed in this area to confirm these findings .
Source: Larson, D. P., Ketterling, R. P., He, R., Shi, M., McPhail, E. D., & Yuan, J. (2021). Clonally-related composite classic Hodgkin lymphoma and follicular lymphoma. American Journal of Clinical Pathology, 156(Supplement_1), S100–S101. https://doi.org/10.1093/ajcp/aqab191.213