Non-Hodgkin lymphomas

On this page

NHL Classification - The Lymphoma Lineup

  • Primary Division: B-cell neoplasms (85%) vs. T-cell/NK-cell neoplasms (15%).
  • Clinical Behavior:
    • Indolent (Slow): Waxing & waning course. E.g., Follicular, Marginal Zone, SLL.
    • Aggressive (Fast): Rapidly fatal without treatment. E.g., DLBCL, Burkitt, Mantle Cell.

DLBCL Histopathology: Large Atypical Lymphocytes

SLL vs. CLL: Small Lymphocytic Lymphoma (SLL) and Chronic Lymphocytic Leukemia (CLL) are the same disease. The diagnosis is CLL if peripheral blood absolute lymphocyte count is >5,000/μL; otherwise, it's SLL.

Indolent B-Cell NHL - The Slowpokes

  • Follicular Lymphoma: Most common indolent type.
    • Genetic hallmark: t(14;18) translocation → BCL2 overexpression (inhibits apoptosis).
    • Presents with waxing and waning, painless peripheral lymphadenopathy.
    • Histology: Nodule-like pattern of packed follicles.
    • Risk of transformation to aggressive DLBCL.
  • Marginal Zone Lymphoma: Linked to chronic inflammation (e.g., H. pylori → MALT lymphoma).
  • Small Lymphocytic Lymphoma (SLL): Tissue version of CLL; defined by <5,000 circulating monoclonal B-cells/µL.

Follicular Lymphoma Histology and Immunohistochemistry

⭐ The t(14;18) translocation juxtaposes the BCL2 gene with the immunoglobulin heavy chain (IgH) enhancer, driving overexpression and preventing apoptosis in follicular lymphoma cells.

Aggressive B-Cell NHL - The Fast & Furious

  • Diffuse Large B-Cell Lymphoma (DLBCL): Most common NHL, often a rapidly enlarging mass. Can arise de novo or from indolent lymphoma transformation. Treat with R-CHOP.
  • Burkitt Lymphoma: Extremely aggressive, linked to EBV.
    • Genetics: t(8;14) translocation of the c-myc gene.
    • Histology: Classic "starry sky" pattern.
  • Mantle Cell Lymphoma: Aggressive course, poor prognosis.
    • Genetics: t(11;14) causes Cyclin D1 overexpression, driving the G1/S phase.

⭐ The "starry sky" in Burkitt's is formed by tingible body macrophages (stars) engulfing apoptotic tumor cells amidst a sheet of dark, uniform lymphoid cells (sky).

T-Cell Lymphomas - Cutaneous Creeps

  • Mycosis Fungoides (MF): Most common cutaneous T-cell lymphoma (CTCL).
    • Indolent course; progresses from patch → plaque → tumor stage.
    • Histology: Pautrier's microabscesses-intraepidermal nests of neoplastic CD4+ T-cells with cerebriform nuclei. Pautrier's microabscess in Mycosis Fungoides
  • Sézary Syndrome: A leukemic, aggressive variant of CTCL.

    ⭐ Presents with a classic triad: generalized erythroderma (the "red man"), diffuse lymphadenopathy, and circulating malignant Sézary cells.

  • Adult T-cell Leukemia/Lymphoma (ATLL):
    • Caused by HTLV-1; common in Japan, Caribbean.
    • Features: lytic bone lesions (→ hypercalcemia), skin lesions, hepatosplenomegaly.
    • Characteristic "flower cells" on blood smear.

Diagnosis & Staging - The NHL Workup

  • Biopsy: Excisional biopsy is the gold standard for diagnosis, providing tissue architecture crucial for subtyping. Avoids sampling error of FNA.
  • Labs: ↑LDH correlates with tumor burden and is a key prognostic factor in the IPI score.
  • Staging: Ann Arbor system (I-IV) determines disease extent. Stage is the most important prognostic factor.

⭐ PET/CT is now standard for staging aggressive lymphomas like DLBCL, assessing treatment response, and detecting relapse.

  • More common than Hodgkin, NHL presents with widespread, non-contiguous lymphadenopathy and extranodal disease.
  • Burkitt Lymphoma: t(8;14) (c-myc), "starry-sky" histology, EBV association.
  • Diffuse Large B-cell Lymphoma (DLBCL): Most common NHL in adults, very aggressive.
  • Follicular Lymphoma: t(14;18) (BCL-2 overexpression), indolent course, can transform to DLBCL.
  • Mantle Cell Lymphoma: t(11;14) (Cyclin D1), aggressive with a poor prognosis.
  • Marginal Zone Lymphoma: Arises from chronic inflammation (e.g., H. pylori gastritis).

Practice Questions: Non-Hodgkin lymphomas

Test your understanding with these related questions

A 69-year-old Caucasian man presents for a routine health maintenance examination. He feels well. He has no significant past medical history. He takes aspirin for the occasional headaches that he has had for over several years. He exercises every day and does not smoke. His father was diagnosed with a hematologic malignancy at 79 years old. The patient’s vital signs are within normal limits. Physical examination shows no abnormalities. The laboratory test results are as follows: Hemoglobin 14.5 g/dL Leukocyte count 62,000/mm3 Platelet count 350,000/mm3 A peripheral blood smear is obtained (shown on the image). Which of the following best explains these findings?

Image for question 1
1 of 5

Flashcards: Non-Hodgkin lymphomas

1/8

The aggregates of neoplastic cells in the epidermis seen with mycosis fungoides are called _____

TAP TO REVEAL ANSWER

The aggregates of neoplastic cells in the epidermis seen with mycosis fungoides are called _____

Pautrier microabscesses

browseSpaceflip

Enjoying this lesson?

Get full access to all lessons, practice questions, and more.

Start For Free