Lymphoma

Lymphoma is a group of hematologic cancers originating from lymphocytes, a type of white blood cell. It typically refers to cancerous tumours rather than benign ones.

There are many subtypes, but the two main categories are non-Hodgkin lymphoma (NHL), which comprises 90% of cases, and Hodgkin lymphoma (HL), which accounts for the remaining 10%. Lymphomas fall under the broader category of hematopoietic and lymphoid tissue tumours.

Signs and Symptoms

Lymphoma often presents with non-specific symptoms. The primary symptom is painless lymphadenopathy, or swelling of the lymph nodes. Systemic symptoms, known as B symptoms, include fever, night sweats, and weight loss. Other symptoms may include anaemia, increased susceptibility to infections, loss of appetite, fatigue, respiratory distress, and itching.

Diagnosis

Diagnosis of lymphoma typically begins with a lymph node biopsy, where a sample of lymphoid tissue is examined under a microscope. This reveals histopathological features indicative of lymphoma. Additional tests to identify specific features of different lymphoma types include immunophenotyping, flow cytometry, and fluorescence in situ hybridisation (FISH) testing.

Classification

Lymphomas are classified based on the type of lymphocyte involved. Hodgkin lymphoma is characterised by the presence of Reed-Sternberg cells, while non-Hodgkin lymphomas vary widely in their characteristics and prognosis.

Staging

Staging determines the extent of lymphoma spread and guides treatment. The Ann Arbour staging system is commonly used, ranging from stage I (localised) to stage IV (spread to distant sites). Imaging modalities like CT and PET scans are used to stage the cancer. The presence of B symptoms also influences staging.

Treatment

Low-grade Lymphoma

Low-grade lymphomas often remain indolent for years. Watchful waiting is a common approach, with treatment initiated upon symptom development. Radiotherapy or chemotherapy can alleviate symptoms, though these lymphomas are generally incurable.

High-grade Lymphoma

High-grade lymphomas, such as Burkitt lymphoma, are more aggressive but also more responsive to treatment. Chemotherapy regimens like CHOP or R-CHOP are commonly used. Relapsed cases may involve high-dose chemotherapy and autologous stem cell transplantation.

CAR-T cell therapies, such as lisocabtagene maraleucel and axicabtagene ciloleucel, are FDA-approved for certain non-Hodgkin lymphomas.

Hodgkin Lymphoma

Hodgkin lymphoma is often treated with radiotherapy alone if localised. Advanced cases require systemic chemotherapy, with regimens like ABVD or BEACOPP. Interim PET scans can be used to gauge treatment response.

Palliative Care

Palliative care focuses on symptom management and stress relief, very important for those undergoing aggressive treatments. It is particularly important for children and individuals requiring bone marrow transplants.

Supportive Treatment

Physical exercise can be beneficial, potentially reducing fatigue and depression. However, its impact on mortality and quality of life is minimal.

Prognosis

The five-year relative survival rate depends on the stage at diagnosis. Localised lymphoma has a survival rate of 82.3%, while distant spread reduces it to 62.7%.

Epidemiology

Lymphoma is the most common hematologic malignancy in the developed world, representing 5.3% of all cancers in the United States. Immunocompromised individuals, such as those with HIV, have a higher incidence of lymphoma.

History

Thomas Hodgkin first described lymphoma in 1832. The term "lymphoma" is derived from Latin and Greek, meaning "water" and "morbid growth," respectively.

Research

Lymphoma research is divided into clinical/translational and basic research. Clinical research focuses on immediate applications, such as new treatments, while basic research aims to understand the disease process.

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Self-assessment MCQs (single best answer)

What is the primary symptom of lymphoma?

Which type of lymphoma is characterised by the presence of Reed-Sternberg cells?

What is the common staging system used for lymphoma?

Which imaging modality is commonly used to stage lymphoma?

Which of the following is a systemic symptom (B symptom) of lymphoma?

What is the treatment approach for low-grade lymphomas when symptoms are absent?

Which chemotherapy regimen is commonly used for high-grade non-Hodgkin lymphomas?

What is the survival rate for localised lymphoma?

Which category of lymphoma accounts for 90% of cases?

Who first described lymphoma in 1832?