Question
Hodgkin’s lymphoma
Answer
Hodgkin lymphoma is a lymphoid neoplasm 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 nuclei), each lobe containing a large, eosinophilic, inclusion-like nucleolus — the classic “owl-eye” appearance. RS cells are derived from germinal centre B cells and are typically CD15+ and CD30+, but CD45 and (usually) CD20 negative.
WHO Classification:
- Classical Hodgkin lymphoma (~95%):
- Nodular sclerosis — most common overall; broad bands of birefringent collagen dividing the node into nodules; characteristic “lacunar cells”; common in young adults, often mediastinal.
- Mixed cellularity — abundant classic RS cells in a mixed background (lymphocytes, eosinophils, plasma cells, histiocytes); EBV-associated; often more advanced stage at presentation.
- Lymphocyte-rich — abundant reactive lymphocytes, few RS cells; favourable prognosis.
- Lymphocyte-depleted — rare; sparse lymphocytes, numerous RS cells; associated with HIV; poor prognosis.
- Nodular lymphocyte-predominant Hodgkin lymphoma (~5%): “Popcorn cells” (L&H variants), CD20+/CD45+ but CD15/CD30 negative; indolent course, tendency to relapse.
Clinical features: Painless lymphadenopathy (commonly cervical, contiguous nodal spread pattern), B symptoms (fever, night sweats, weight loss) in advanced disease, staged by the Ann Arbor system. Prognosis is generally excellent with modern combined chemo-/radiotherapy.