Lymphomas are blood cancers that develop in lymphocytes, a type of white blood cell that helps fight infections. Lymphocytes travel through the lymphatic system, including lymph nodes and vessels, and are also found in the bloodstream, bone marrow, and organs such as the spleen.

HL often affects young, otherwise healthy people and may not cause symptoms right away. Swollen, painless lymph nodes, especially in the neck, are a typical early sign.

HL occurs when certain immune cells called B cells experience clonal transformation and multiply abnormally, creating RS cells. These cancerous cells crowd out normal white blood cells, weakening the immune system's ability to fight infections. RS cells typically form masses in the lymph nodes but can also accumulate in other parts of the body with lymphoid tissue.

When HL is suspected, your doctor will conduct a physical exam to check for swollen lymph nodes. To confirm the diagnosis, a biopsy is needed. The most thorough method is an excisional biopsy, where part of a lymph node is removed through a small incision. For surface lymph nodes, a core needle biopsy guided by ultrasound or computed tomography (CT) may be used. Deeper lymph nodes in the abdomen or chest may require surgery to obtain a tissue sample. Doctors examine the sample for Reed-Sternberg cells and use immunophenotyping, a lab test that detects specific proteins to determine the lymphoma type.

To diagnose NHL and distinguish it from other conditions causing swollen lymph nodes, doctors perform biopsies of enlarged lymph nodes. These may be excisional biopsies, core needle biopsies, or surgical procedures to obtain tissue samples. Immunophenotyping studies, using techniques like immunohistochemistry or flow cytometry with special dyes to detect cancer cell types, help identify the cell origin in NHL and determine its specific subtype. Cytogenetic analysis examines chromosomal abnormalities in cells, helping confirm the diagnosis and identify the NHL type.

Indolent lymphomas have a long survival period, respond quickly to treatments, and experience varying remission periods, but current therapies do not offer a cure.

Aggressive lymphomas progress rapidly without treatment and have high cure rates with standard chemotherapy, but result in short survival periods if not treated.