B Symptoms in Low-Grade Lymphoma
B symptoms in low-grade lymphoma include unexplained fever >38°C, drenching night sweats, and weight loss of >10% of body weight within 6 months of diagnosis. 1
Definition and Significance
B symptoms are specifically defined in the Ann Arbor staging classification system and have important prognostic implications:
- Unexplained fever >38°C - persistent fever without identifiable infection
- Drenching night sweats - severe enough to require changing clothes or bedding
- Weight loss >10% of body weight within 6 months prior to diagnosis 1
These symptoms are designated with the letter "B" in the staging classification (e.g., Stage IIB), while their absence is designated with "A" (e.g., Stage IIA).
Clinical Relevance in Low-Grade Lymphoma
B symptoms are less common in low-grade lymphomas compared to aggressive lymphomas, but their presence carries important implications:
- Indicates more advanced disease and potentially worse prognosis
- Suggests higher tumor burden
- May influence treatment decisions 1, 2
In low-grade lymphomas, particularly follicular lymphoma (FL), the presence of B symptoms is one of the criteria used to determine when to initiate treatment in otherwise asymptomatic patients. According to ESMO guidelines, therapy should be initiated upon the development of B symptoms, even in patients with otherwise indolent disease 1.
Other Associated Symptoms and Findings
While not classified as B symptoms, other constitutional symptoms may accompany low-grade lymphoma:
- Fatigue - common but nonspecific
- Pruritus (itching) - can be significant and troublesome
- Alcohol intolerance - pain in lymph nodes after alcohol consumption 1, 2
Clinical Decision Making
The presence of B symptoms in low-grade lymphoma influences management decisions:
- In asymptomatic patients with low-grade lymphoma, a watch-and-wait approach is often appropriate
- The development of B symptoms is an indication to initiate therapy 1
- According to the GELF (Groupe d'Etude des Lymphomes Folliculaires) criteria, B symptoms are considered high tumor burden criteria that warrant treatment 1
Important Considerations
- B symptoms may be absent in the majority of patients with low-grade lymphoma at initial presentation
- Their development during the course of disease often signals disease progression
- In some cases, B symptoms may herald transformation to a more aggressive lymphoma subtype 3
- Differential diagnosis should consider other causes of similar symptoms, including infections, particularly in immunocompromised patients 2
Treatment Implications
When B symptoms develop in low-grade lymphoma:
- Systemic therapy is typically indicated rather than local approaches
- Immunochemotherapy regimens (such as rituximab plus chemotherapy) are often used
- The goal is to achieve symptom control and disease remission 1
The presence of B symptoms should prompt thorough evaluation for disease extent and consideration of more aggressive treatment approaches, even in otherwise indolent-appearing low-grade lymphomas.