B Symptoms in Lymphoma
B symptoms in lymphoma are a specific triad of constitutional symptoms consisting of unexplained fever >38°C (>101°F), drenching night sweats requiring changing of clothes or bedding, and unexplained weight loss of >10% of body weight within 6 months of diagnosis. 1, 2
Clinical Definition and Components
The three B symptoms are precisely defined:
- Fever: Unexplained temperature >38°C (>101°F) 1, 2
- Night sweats: Drenching sweats severe enough to require changing clothes or bedding 2
- Weight loss: Unexplained loss of >10% of body weight within the 6 months preceding diagnosis 1, 2
Clinical Significance
B symptoms serve as critical indicators for treatment initiation and prognostic stratification in lymphoma management. 1
Treatment Implications
In follicular lymphoma specifically, B symptoms are one of the key criteria that mandate treatment initiation:
- Therapy should be initiated when B symptoms develop, even in otherwise asymptomatic patients with advanced disease 1
- Other indications for treatment include hematopoietic impairment, bulky disease, vital organ compression, ascites, pleural effusion, or rapid lymphoma progression 1
- In the absence of B symptoms and other concerning features, watch-and-wait remains the standard approach for asymptomatic advanced follicular lymphoma 1
Prognostic Value
B symptoms indicate more advanced or aggressive disease:
- Presence of B symptoms correlates with unfavorable prognosis across lymphoma subtypes 3
- In Hodgkin lymphoma, B symptoms are more common and are incorporated into the Ann Arbor staging system, where "B" designation indicates presence of these symptoms and "A" indicates their absence 1, 2
- Patients with B symptoms frequently present with advanced disease and elevated serum LDH levels 4
Staging Classification
The Ann Arbor staging system formally incorporates B symptoms:
- Each stage (I-IV) is subdivided into "A" (absence of B symptoms) or "B" (presence of B symptoms) 1, 2
- This classification directly influences treatment decisions and prognostic assessment 1, 2
Clinical Pitfalls
Constitutional symptoms are uncommon in indolent follicular lymphoma in the absence of transformation to diffuse large B-cell lymphoma. 5 Therefore, when B symptoms appear in a patient with known indolent lymphoma, strongly consider:
- Histologic transformation to aggressive lymphoma (requires repeat biopsy) 1
- Disease progression requiring treatment initiation 1
Hodgkin lymphoma more commonly presents with B symptoms compared to non-Hodgkin lymphoma, particularly in young adults and older adults (bimodal age distribution) 2