Lymphomas

Study guide:

Definitions:  

Lymphomas are a group of diseases caused by malignant lymphocytes that accumulate in lymph nodes and could lead to the characteristic clinical features of lymphadenopathy. In some cases, they could go into the bloodstream (leukemia) or infiltrate organs outside the lymphoid tissue.

Two main subdivisions of Lymphomas, which are Hodgkin and non-Hodgkin lymphoma. They were named after Thomas Hodgkin since he was the first to explain them. The presence of Reed-Sternberg cells, bi or multinucleated cells with eosinophilic nucleoli, under microscope is the only way to distinguish the two types.

 

Epidemiology:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Classifications of Hodgkin lymphoma:

Hodgkin lymphoma (HL) is classified into four types:

  1. Lymphocyte predominance:  Reed–Sternberg cells and B cells

  2. Nodular sclerosis

  3. Mixed cellularity: large numbers of Reed–Sternberg cells.


Lymphocyte depletion: it is associated with the worst prognosis.

 

 

 

 

 

 

Also, HL are further subdivided into stages of involvement:

 

Stage I: One lymph node involved or one extranidal place.

Stage II: Two or more lymph node involved yet on the same side of the diaphragm.

Stage III: Lymph nodes are involved in both sides of the diaphragm.

Stage IV: Disseminated type. (multiple involvement of the extranidal organs).

Risk factors: For both types.

  1. Age: the older the patient, the more is the chance that they will develop Lymphoma, yet that is not always true since there are types of Hodgkin lymphoma that affect younger ages.

  2. Gender: both genders are affected (the male gender more often).

  3. Race

  4. Positive family history.

  5. Exposure to chemicals and drugs.

  6. Certain infections: such as EBV with NHL.

  7. Exposure to radiation.

  8. Autoimmune diseases: such as rheumatoid arthritis and systemic lupus erythematosus were found to increase the risk for developing NHL.

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Classification of Non-Hodgkin lymphoma:

  1. Mature B-cell neoplasm: Which accounts for almost 85% of NHL cases.

  2. Mature T-cell and/or NKC neoplasm: Accounts for the other 15%.

 

 

Clinical features:

 

Hodgkin lymphoma:

 

  1. Painless, non-tender, asymmetrical lymphadenopathy. Cervical lymph nodes are the commonest place, but other lymph nodes can be involved.

  2. Splenomegaly and hepatomegaly are seen in some patients.

  3.  Unexplained weight loss, unexplained fever, night sweats and pruritus (B-cell or constitutional symptoms).

  4. Chest pain, shortness of breath and coughing.

  5. In case of nodular sclerosis, involvement of mediastinal is seen.

Non-Hodgkin Lymphoma:

 

  1. Painless, non-tender, asymmetrical lymphadenopathy. It can be the only symptom.

  2. B-symptoms are less common that HL.

  3. Abdominal pain with either splenomegaly or hepatomegaly (Sometimes both).

  4. Symptoms of anemia or thrombocytopenia due to the involvement of bone morrow.

 

Diagnosis:

Hodgkin lymphoma:

  1. Lymph node biopsy— To detect RS cells.

  2. Presence of inflammatory cell infiltrates.

  3. Imagining modalities such as CXR and CT scan: to detect lymph node involvement

  4. Bone marrow biopsy

  5. Laboratory findings: to look for leukocytosis, eosinophilia. Also, increased ESR levels is linked to the nature of the activity of the disease.

 

Non-Hodgkin Lymphoma:

  1. Lymph node biopsy.

  2.  Imagining modalities such as CT scan and CXR: to find out the places that are involved and see if treatment is working.

  3. Serum LDH and β 2 -microglobulin.

  4. Increased level of alkaline phosphatase can tell that bone or liver are involved.

  5. Liver laboratory tests or bilirubin level: find out if liver is involved or not.

  6.  CBC.

  7. Bone marrow biopsy.

 

Management:

 

       Hodgkin lymphoma:

 

Treatment consists mainly of chemotherapy and radiation therapy to the involved field.

 

1. Stages I, II, and IIIA can be treated with radiotherapy alone. However, some patients may benefit from chemotherapy more.

 

2. Stages IIIB and IV will need chemotherapy.

 

      Non-Hodgkin Lymphoma:

 

There is not always a standard treatment for a given type of NHL.

  1. Indolent NHL are not curable.

  2. Intermittent and high-grade NHL could sometimes be curable with aggressive treatment.

Prognosis:

Hodgkin lymphoma:

 


Over 90% of patients with early-stage HL achieve complete remission when treated with chemotherapy and radiotherapy.

Non-Hodgkin lymphoma:

 

The 5-year relative survival rate of patients with NHL is 71.4%.

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References:

  1. https://onlinelibrary.wiley.com/doi/pdf/10.3322/canjclin.55.6.368

  2. https://emedicine.medscape.com/article/203399-overview#a6

  3. https://emedicine.medscape.com/article/201886-overview#a6

  4. https://www.cancer.org/cancer/non-hodgkin-lymphoma/causes-risks-prevention/risk-factors.html

  5. Hoffbrand, A. V., & Moss, P. A. (2016). Hoffbrands essential haematology. Chichester, West Sussex: Wiley Blackwell.

  6. Agabegi, S. S., & Agabegi, E. D. (2016). Step-up to medicine. Philadelphia: Wolters Kluwer Health.

  7. Ralston, S. H., Penman, I. D., Strachan, M. W., & Hobson, R. P. (2018). Davidsons principles and practice of medicine. Edinburgh: Churchill Livingstone/Elsevier.

First author: Raed Al Zarah


Reviewed by:

Osama Wadaan

Abdulrahman Alhassan


Format Editor:  Noura Abdullah Alsubaie.