Hodgkin lymphoma

Hodgkin disease (HD) is a type of lymphoma and accounts for approximately 1% of all cancers. HD spreads contiguously and predictably along lymphatic pathways and is curable in 85 to 95% of cases, depending on its stage and sub-type.

Epidemiology

There is a bimodal distribution in the age of affected patients, with peaks in young adults (15 - 34) and older patients ( > 55).

Clinical presentation

Typical presention is with painless lymphadenopathy. Systemic symptoms (B symptoms) such as night sweats and weight loss may be present.

A uncommon presentation described in Hodgkin disease is pain in involved organs following alcohol consumption.

Pathology

The disease is characterised by the presence of Reed-Sternberg cells (considered to be a type of B cell). These cells however only occupy a very small proportion ( < 5%) of the overall cell population of the affected lymph node. Contiguous spread is another feature.

Sub types

There are five recognised histological sub types

Classical

Positive for CD 15 / CD 30 and negative for CD 20 / CD 45 / EMA

• nodular sclerosing : ≈ 70%
• mixed cellularity : ≈ 25 %
• lymphocyte rich : 5 %
• lymphocyte depleted : < 5 % : 

Non classical

Positive for CD 19, 20, 22, 79a / EMA and negative for CD 15 / CD 30

• nodular lymphocyte predominant (nodular paragranuloma) : 

For classification of lymphomas see WHO classsification of neoplasms of lymphoid tissues. 

Nodal disease

Hodgkin's disease is usually almost entirely confined to the lymph nodes. 

Extra nodal disease 

Extra nodal HD although uncommon may be found in any organ system, either as a primary manifestation or as dissemination of systemic disease. This distinction is important, as disseminated disease carries a poorer prognosis. Extranodal disease may occur via invasion of adjacent tissue or via haematogenous spread.

Organ specific involvement

• pulmonary : see pulmonary manifestations of Hodgkin's lymphoma
• cardiac : see cardiac manifestations of Hodgkin's lymphoma
• musculoskeletal : see musculosketal manifestations of Hodgkin's lymphoma
• abdominal : see abdominal manifestations of Hodgkin's lymphoma 
• central nervous system : see CNS manifestations of Hodgkin's lymphoma

Staging

In contrast to other types of lymphoma, Hodgkin disease is usually characterised by a systematic nodal spread pattern making accurate staging important. 

See : staging of Hodgkin's  lymphoma

Treatment and prognosis

Prognosis depends on stage as well as several other factors such as age, serological markers (ESR), presence of B symptoms, histological tumour sub type etc. 

• nodular lymphocyte predominant : best prognosis
• lymphocyte depleted : worse prognosis

Treatment is dependant on the stage of disease:

• stage IIA and below : localised radiotherapy 
• stage IIB and above : chemotherapy + / - radiotherapy to sites of large tumour bulk