Non-hodgkin lymphoma - causes, symptoms, diagnosis, treatment, pathology

Summary

Non-Hodgkin lymphoma (NHL) is a cancer originating from lymphocytes, either B or T cells, and is distinct from Hodgkin lymphoma due to the absence of Reed-Sternberg cells. It can develop in lymph nodes or extranodally, affecting various body tissues. NHL encompasses a range of subtypes, including aggressive diffuse large B-cell lymphoma and indolent follicular lymphoma, often characterized by specific chromosomal translocations. Symptoms may include painless lymph node swelling and systemic effects like fever and weight loss. Diagnosis typically involves imaging and biopsy, with treatments ranging from chemotherapy and radiation to monoclonal antibody therapy like Rituximab for CD20-positive B-cells.

Takeaways

• 🔬 Non-Hodgkin lymphoma (NHL) is a type of blood cancer that originates from lymphocytes, specifically B-cells and T-cells, which are part of the body's immune system.
• 🌟 The term 'non-Hodgkin' signifies the absence of Reed-Sternberg cells, which are characteristic of Hodgkin lymphoma.
• 🩸 B-cell development starts in the bone marrow and matures into naive B-cells that circulate in the blood and reside in lymph nodes, while T-cell development occurs in the thymus.
• 🔍 Lymph nodes, which are scattered throughout the body, are secondary lymphoid organs where B-cells and T-cells interact and are involved in immune responses.
• 🔬 Lymphoma cells can spread to various parts of the body, affecting organs like the gastrointestinal tract, bone marrow, and spinal cord, leading to diverse symptoms.
• 🧬 Genetic mutations, such as chromosomal translocations, play a significant role in the development of non-Hodgkin lymphomas, affecting genes like BCL2, MYC, and BCL1.
• 🏥 There are several types of B-cell lymphomas, including diffuse large B-cell lymphoma (aggressive), follicular lymphoma (indolent), Burkitt lymphoma (highly aggressive), and others.
• 🌐 Extranodal lymphomas occur outside of lymph nodes and can affect various tissues and organs, leading to specific symptoms related to the site of involvement.
• 💊 Treatment for non-Hodgkin lymphoma typically involves chemotherapy and radiation therapy, and may include monoclonal antibodies like Rituximab for CD20-positive B-cells.
• 🔎 Diagnosis of NHL often starts with imaging studies, followed by a lymph node biopsy to confirm the presence of lymphoma cells and to determine the subtype of lymphoma.

Q & A

What is non-Hodgkin lymphoma (NHL)?

Non-Hodgkin lymphoma (NHL) is a type of blood cancer that originates from lymphocytes, specifically B-cells and T-cells. It is called 'non-Hodgkin' because it lacks the Reed-Sternberg cells that are characteristic of Hodgkin lymphoma.

Where do B-cells mature from precursor cells in the human body?

B-cell development begins in the bone marrow, where young precursor B-cells mature into naive B-cells before circulating in the blood and settling in lymph nodes.

What is the function of plasma cells in the immune system?

Plasma cells, which differentiate from B-cells, release antibodies or immunoglobulins that bind to pathogens like viruses and bacteria to help destroy or remove them.

What is the significance of CD markers on immune cells?

CD markers, or cluster of differentiation markers, are surface proteins that function like ID cards on immune cells, helping to identify and classify different types of cells, such as B-cells and T-cells.

How does a B cell become activated?

A B cell is activated when it encounters an antigen that binds perfectly to its surface immunoglobulin, leading to the production of antibodies and the formation of germinal centers in the lymph nodes.

What are the two main categories of lymphomas?

The two main categories of lymphomas are Hodgkin lymphomas, characterized by Reed-Sternberg cells, and non-Hodgkin lymphomas, which lack Reed-Sternberg cells and can involve extranodal sites.

What is the role of genetic mutations in the development of non-Hodgkin lymphoma?

In non-Hodgkin lymphoma, genetic mutations in lymphocytes, either B cells or T cells, prevent the cells from undergoing apoptosis, leading to uncontrolled cell division and the formation of neoplastic cells.

What are the differences between nodal and extranodal lymphomas?

Nodal lymphomas develop in lymph nodes, while extranodal lymphomas occur in other tissues or organs, such as the stomach or skin. Extranodal lymphomas can spread to various parts of the body and cause different symptoms depending on the location.

What are the most common types of B cell lymphomas?

The most common types of B cell lymphomas include diffuse large B cell lymphoma, follicular lymphoma, Burkitt lymphoma, mantle cell lymphoma, marginal zone lymphoma, and lymphoplasmacytic lymphoma.

How does Rituximab, a monoclonal antibody, contribute to the treatment of non-Hodgkin lymphoma?

Rituximab is used in the treatment of non-Hodgkin lymphoma with CD20-positive B-cells. It binds to CD20, inducing complement-mediated lysis, direct cytotoxicity, and apoptosis, effectively targeting and destroying the cancer cells.

What are the symptoms associated with non-Hodgkin lymphoma?

Symptoms of non-Hodgkin lymphoma include painless lymphadenopathy, fever, night sweats, weight loss, and depending on the location of the lymphoma, bowel obstruction, fatigue, easy bruising, recurrent infections, weakness, and loss of sensation.