Non-Hodgkin's lymphoma and Hodgkin’s disease - basic histologic types. Target organs
What is a lymphoma? A lymphoma is simply tumour cells, usually in lymph nodes, as a localised mass that can progress into leukemia.
There are two main classes of lymphoma:
- Hodgkin's lymphomas
- Distinctive neoplastic Reed-Sternberg giant cells
- Generally affect axial lymph nodes (cervical, mediastinal, para-aortic)
- Histological types, based on cellular morphology and cell infiltration in lymph node biopsy:
- Classical
- Nodular sclerosing
- Lacunar cells (the RS cell variant of the nodular sclerosing type)
- Mixed-cellularity subtype
- Lymphocyte rich
- Lymphocyte depleted
- Nodular lymphocyte-predominant
- Symptoms include swelling of lymph nodes, fatigue, fever, sweats and weight loss
- Spread in in a stepwise fashion along lymph chains
- Two peaks of incidence, adolescence and >50 y.o.
- Non-Hodgkin's lymphoma
- Can start in almost any part of the body (unlike Hodgkin's which starts in a single node)
- Generally onset is older (over 65)
- Many subtypes but generally
- Aggressive
- Indolent (slow development)
H&E: Reed-Sternberg cell (outlined), large with two nuclei and a prominent eosinophilic nucleolus in each ('owl's eyes'); a normal lymphocyte for size.
Image: “Reed-sternberg cell” by National Cancer Institute, Public domain, via Wikimedia Commons.
Remember: the classic Reed-Sternberg cell has two mirror-image nuclei (or one bilobed nucleus), each with a large eosinophilic nucleolus, the 'owl's eyes'. It is CD15+ and CD30+. These cells are only a small minority of the tumour; most of the node is reactive lymphocytes, eosinophils, plasma cells and histiocytes.
All types of lymphoma have four clinical stages:
- Stage I - involvement of a single lymph node region
- Stage II - involvement of two or more lymph node regions on the same side of the diaphragm
- Stage III - involvement of lymph node regions on both sides of diaphragm
- Stage IV - disseminated involvement of one or more extralymphatic organs