What are B symptoms?

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B Symptoms in Hodgkin Lymphoma

B symptoms in Hodgkin lymphoma are defined as unexplained fever >38°C, drenching night sweats, or weight loss >10% of body weight within 6 months of diagnosis. 1

Definition and Clinical Significance

B symptoms are part of the Ann Arbor staging system for Hodgkin lymphoma (HL) and have important prognostic implications:

  • Each stage of HL is subdivided into categories A and B:

    • "A" indicates no systemic symptoms are present
    • "B" is assigned when any of the following are present:
      • Unexplained fever >38°C (>100.4°F)
      • Drenching night sweats
      • Weight loss >10% of body weight within 6 months of diagnosis 1
  • These symptoms indicate more advanced disease and are formally used in lymphoma staging 2

  • Patients with B symptoms often have more aggressive disease and poorer outcomes

Clinical Presentation and Evaluation

When evaluating a patient with suspected Hodgkin lymphoma, careful assessment for B symptoms is essential:

  • Fever: Document pattern, frequency, and maximum temperature (must be >38°C)
  • Night sweats: Must be drenching (requiring change of bedclothes/sheets)
  • Weight loss: Document amount and timeframe (must be >10% over 6 months)

Additional symptoms that may accompany B symptoms but are not part of the formal B symptom definition include:

  • Alcohol-induced pain (pain at lymphoma sites after alcohol consumption)
  • Pruritus (itching)
  • Fatigue
  • Poor performance status 1

Prognostic Implications

B symptoms significantly impact prognosis and treatment decisions:

  • Patients with both fever and weight loss have shown particularly poor outcomes with a 7-year survival and freedom from relapse of only 57% and 48%, respectively 3
  • Night sweats alone may have less prognostic impact than the other B symptoms 3
  • The presence of B symptoms is one of the unfavorable factors used to classify early-stage HL as "unfavorable" 1
  • B symptoms help stratify patients into treatment categories:
    • Early-stage favorable (stage I-II with no B symptoms or other unfavorable factors)
    • Early-stage unfavorable (stage I-II with B symptoms or other unfavorable factors)
    • Advanced-stage disease (stage III-IV) 1

Clinical Application

The presence of B symptoms guides clinical decision-making:

  • Patients with early-stage disease but with B symptoms are typically classified as having "unfavorable" disease and may require more intensive treatment
  • B symptoms must be distinguished from similar symptoms due to infection or other causes
  • Resolution of B symptoms is an important indicator of treatment response
  • In patients presenting with unexplained B symptoms, Hodgkin lymphoma should be included in the differential diagnosis, prompting appropriate workup including physical examination of all lymphoid regions 1

Important Considerations

  • B symptoms must be unexplained by infection or other causes
  • Documentation of B symptoms should be precise and quantitative when possible
  • The presence of B symptoms should trigger a thorough evaluation for extent of disease
  • B symptoms typically resolve with effective treatment of the underlying lymphoma

Understanding and properly identifying B symptoms is crucial for accurate staging, prognostication, and treatment planning in patients with Hodgkin lymphoma.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Guideline

Lymphoma Diagnosis and Management

Praxis Medical Insights: Practical Summaries of Clinical Guidelines, 2025

Research

Stage I to IIB Hodgkin's disease: the combined experience at Stanford University and the Joint Center for Radiation Therapy.

Journal of clinical oncology : official journal of the American Society of Clinical Oncology, 1987

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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