Paper II
Question
Hodgkin’s lymphoma
Answer
Hodgkin lymphoma is defined by the presence of diagnostic Reed-Sternberg (RS) cells within a background of reactive, non-neoplastic inflammatory cells.
Reed-Sternberg cell: Large cell with abundant cytoplasm and a bilobed nucleus (or two separate nuclei), each lobe with a large, eosinophilic, inclusion-like nucleolus — “owl-eye” appearance. RS cells arise from germinal centre B cells and are CD15+ and CD30+, but typically CD45 and CD20 negative.
WHO Classification:
- Classical Hodgkin lymphoma (~95%):
- Nodular sclerosis — most common overall; broad bands of birefringent collagen dividing the node into nodules; “lacunar cells”; common in young adults, often mediastinal.
- Mixed cellularity — abundant classic RS cells in a mixed inflammatory background; EBV-associated; often advanced stage at presentation.
- Lymphocyte-rich — abundant reactive lymphocytes, fewer RS cells; favourable prognosis.
- Lymphocyte-depleted — rare; sparse lymphocytes, numerous RS cells; HIV-associated; poor prognosis.
- Nodular lymphocyte-predominant Hodgkin lymphoma (~5%): “Popcorn cells” (L&H variants), CD20+/CD45+, CD15/CD30 negative; indolent, tendency to relapse.
Clinical features: Painless lymphadenopathy (contiguous nodal spread pattern), B symptoms (fever, night sweats, weight loss) in advanced disease, staged via the Ann Arbor system. Generally excellent prognosis with combined chemo-/radiotherapy.