Hodgkin lymphoma (HL) is a distinct hematologic malignancy originating from mature B lymphocytes within the lymphatic system. First described by Dr. Thomas Hodgkin in 1832, it represents roughly 10% of all diagnosed lymphomas.
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While a cancer diagnosis remains formidable, Hodgkin lymphoma stands as one of the major success stories of modern clinical oncology. With contemporary radiation techniques, multi-agent chemotherapy, targeted antibody-drug conjugates, and immune checkpoint inhibitors, Hodgkin lymphoma is highly curable in the vast majority of patients.
MSD Manuals
1. Pathophysiology and Unique Tumor Microenvironment
Hodgkin lymphoma is biologically unique among solid and hematologic tumors because malignant cells constitute only 1% to 5% of the total tumor mass. The vast majority of the lesion consists of a dense, reactive inflammatory infiltrate composed of non-neoplastic lymphocytes, plasma cells, eosinophils, macrophages, and fibrous tissue.
[ Transformed Mature B-Cell ]
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(Loss of B-cell Surface Markers)
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[ Reed-Sternberg (RS) Cell Formation ]
(Binucleated "Owl-Eye" Morphology)
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[ Abundant Cytokine & Chemokine Secretion ]
(IL-5, IL-6, IL-10, TGF-β, TARC)
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[ Inflammatory Microenvironment Recruitment ]
(T-cells, Eosinophils, Macrophages, Fibroblasts)
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[ Immune Evasion via PD-L1 Overexpression ]
The Reed-Sternberg Cell
The hallmark neoplastic cell in classical Hodgkin lymphoma is the Hodgkin and Reed-Sternberg (HRS) cell. Pathologically, classic RS cells are large, multinucleated or binucleated cells displaying prominent, inclusion-like nucleoli, often creating a characteristic “owl-eye” appearance under light microscopy.
Lymphoma Action
Genetically, HRS cells derive from germinal center B-cells that have lost their functional capacity to express surface immunoglobulin complexes. Rather than undergoing programmed cell death (apoptosis), these transformed cells escape immune destruction by downregulating B-cell lineage markers (such as CD20) while characteristically expressing CD30 and CD15 surface antigens.
Immune Evasion and Microenvironment Crosstalk
HRS cells survive by manipulating surrounding immune cells through secretome signaling:
- Cytokine Networks: Secrete interleukin-5 (IL-5) to attract eosinophils, IL-6 and IL-10 to promote cell growth, and transforming growth factor-beta (TGF-β) to induce tissue fibrosis.
- Immune Checkpoint Pathway: Chromosome 9p24.1 amplification in HRS cells drives constitutive overexpression of Programmed Death Ligands (PD-L1 and PD-L2). These ligands bind to PD-1 receptors on cytotoxic T-cells, effectively “disarming” the host immune response.
2. Histological Classification and Etiology
The World Health Organization (WHO) classifies Hodgkin lymphoma into two primary clinical and pathological entities:
Lymphoma Action
[ Hodgkin Lymphoma ]
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[ Classic Hodgkin Lymphoma (cHL) ~95% ] [ Nodular Lymphocyte-Predominant (NLPHL) ~5% ]
• Nodular Sclerosis • "Popcorn" cells (LP cells)
• Mixed Cellularity • CD20+, CD30-, CD15-
• Lymphocyte-Rich • Indolent, slow-growing course
• Lymphocyte-Depleted
1. Classic Hodgkin Lymphoma (cHL)
Accounts for ~95% of all cases and is divided into four distinct histological subtypes:
Lymphoma Action
- Nodular Sclerosis cHL (60–70% of cases): Most common subtype, predominantly affecting young adults. Characterized by fibrous collagen bands encircling tumor nodules containing lacunar-type RS cells. Frequently presents with mediastinal masses.
- Mixed Cellularity cHL (20–25% of cases): Rich in eosinophils and plasma cells; strongly associated with Epstein-Barr Virus (EBV) infection and more prevalent in older adults or immunocompromised individuals.
- Lymphocyte-Rich cHL (5% of cases): Abundant non-neoplastic lymphocytes surround sparse RS cells; carries a favorable prognosis.
- Lymphocyte-Depleted cHL (<1% of cases): Rare and aggressive, characterized by abundant atypical RS cells and sparse reactive lymphocytes; often associated with advanced HIV.
2. Nodular Lymphocyte-Predominant Hodgkin Lymphoma (NLPHL)
Accounts for ~5% of cases. Unlike cHL, NLPHL features neoplastic Lymphocyte-Predominant (LP) cells—often termed “popcorn cells”. LP cells express typical B-cell markers (CD20+, CD45+) but lack CD30 and CD15. NLPHL exhibits an indolent clinical course, though late recurrences can occur.
Lymphoma Action
3. Clinical Features, B Symptoms, and Staging
Hodgkin lymphoma typically follows a bimodal age distribution, peaking in young adults (ages 15–35) and again in individuals over 60 years of age.
Typical Clinical Presentation
- Painless Lymphadenopathy: Over 80% of patients present with painless, firm, rubbery swelling of lymph nodes, most commonly in the cervical (neck), supraclavicular, or axillary regions.
- Mediastinal Involvement: Large anterior mediastinal lymph node enlargement can cause dry cough, dyspnea, or Superior Vena Cava (SVC) syndrome.
- Systemic “B Symptoms”: Present in up to 40% of patients and carry major prognostic weight:
- Unexplained fever >38∘C (100.4∘F). MD Anderson
- Drenching night sweats. National Cancer Institute
- Unintentional loss of >10% body weight within 6 months. MD Anderson
- Alcohol-Induced Pain: A rare but classic symptom where involved lymph nodes become painful minutes after alcohol ingestion. MSD Manuals
| Clinical Feature | Typical Presentation | Diagnostic / Prognostic Relevance |
|---|---|---|
| Painless Adenopathy | Firm, rubbery lymph nodes (cervical/supraclavicular) | Prompts diagnostic excisional biopsy |
| B Symptoms | Fever, night sweats, >10% weight loss | Modifies staging designation (e.g., Stage IIB) |
| Pruritus | Generalized refractory itching | Common systemic paraneoplastic manifestation |
| Pel-Ebstein Fever | Cyclical high fevers over 1–2 weeks | Rare historical fever pattern in advanced cHL |
Staging: The Lugano Classification
Staging relies on FDG-PET/CT imaging to assess nodal and extranodal disease burden:
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[ Stage I ] ➔ Single lymph node region or localized single extranodal site.
[ Stage II ] ➔ Two or more node regions on the SAME side of the diaphragm.
[ Stage III ]➔ Lymph node regions on BOTH sides of the diaphragm.
[ Stage IV ] ➔ Diffuse involvement of extralymphatic organs (liver, bone marrow, lungs).
(Suffix A denotes absence of B symptoms; suffix B denotes presence of B symptoms).
4. Modern Therapeutic Paradigms
Treatment strategy depends on disease stage, risk stratification (early-stage favorable vs. unfavorable vs. advanced), and patient fitness.
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[ Confirmed Classic Hodgkin Lymphoma ]
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[ Early Favorable (Stage I–II) ] [ Early Unfavorable ] [ Advanced Stage (Stage III–IV) ]
• ABVD (2–4 cycles) • ABVD (4 cycles) • N-AVD (Nivolumab + AVD)
• Involved-Site Radiation (ISRT) • ISRT or chemotherapy alone • OR BV-AVD (Brentuximab Vedotin + AVD)
Frontline Therapy for Classic Hodgkin Lymphoma
- Early-Stage Disease (Stage I–II): Managed with abbreviated combined-modality therapy. The ABVD regimen (Doxorubicin/Adriamycin, Bleomycin, Vinblastine, Dacarbazine) combined with Involved-Site Radiation Therapy (ISRT) yields cure rates exceeding 90%. BMJ Best Practice+ 1
- Advanced-Stage Disease (Stage III–IV): Historically managed with 6 cycles of ABVD. Modern paradigms favor targeted and immunotherapeutic combinations: National Cancer Institute
- N-AVD (Nivolumab + AVD): Incorporates the PD-1 inhibitor Nivolumab with chemotherapy, achieving superior progression-free survival while omitting pulmonary-toxic Bleomycin.
- BV-AVD: Combines Brentuximab Vedotin (an antibody-drug conjugate targeting CD30) with AVD, showing high efficacy in advanced disease. National Cancer Institute
Management of Relapsed or Refractory Disease
For patients experiencing disease relapse or primary refractoriness:
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- Salvage Immunochemotherapy: Regimens incorporating PD-1 inhibitors (Pembrolizumab or Nivolumab) and Brentuximab Vedotin to achieve metabolic remission.
- Autologous Stem Cell Transplantation (ASCT): High-dose consolidation chemotherapy followed by autologous stem cell rescue remains the standard curative approach for eligible relapsed patients.
Conclusion
Hodgkin lymphoma illustrates the success of targeted cancer therapy and risk-adapted treatment protocols. By combining precise immunophenotypic diagnosis with PET-guided staging, antibody-drug conjugates, and immune checkpoint blockade, modern oncology continues to improve cure rates while minimizing long-term treatment toxicity—ensuring excellent long-term survival and quality of life for patients.