Origin of the Term "B Symptoms"
The term "B symptoms" originates from the Ann Arbor staging classification system for Hodgkin lymphoma, where the letter "B" designates the presence of specific constitutional symptoms, distinguishing these patients from those with "A" designation who lack such symptoms. 1
Historical Context and Nomenclature
The "B" designation is simply an alphabetical modifier within the Ann Arbor staging system that was developed to classify patients based on symptom status. 1 The system uses:
- "A" suffix: No systemic symptoms present 1
- "B" suffix: Presence of at least one of the three cardinal constitutional symptoms 1
This binary classification (A versus B) was incorporated into the staging nomenclature to capture prognostic information, as the presence of these symptoms indicated more aggressive disease behavior and worse outcomes. 2, 3
The Three Cardinal B Symptoms
The "B" designation specifically requires at least one of the following: 1, 3
- Unexplained weight loss >10% of baseline body weight during the 6 months prior to staging 1, 3
- Recurrent unexplained fever >38°C 1, 3
- Recurrent drenching night sweats 1, 3
Clinical Significance of the Designation
The B suffix fundamentally alters risk stratification and treatment intensity. 2, 3 Patients with early-stage disease (Stage I-II) are reclassified from "early favorable" to "early unfavorable" when B symptoms are present, which directly impacts treatment decisions regarding chemotherapy duration and radiation therapy. 2, 3, 4
Modern Application
Current guidelines from the Lugano classification (2014) specify that A/B suffixes should only be included for Hodgkin lymphoma staging, not for non-Hodgkin lymphoma, emphasizing the historical and prognostic specificity of this nomenclature to HL. 1, 2
Important Clinical Caveat
In immunocompromised patients, particularly those with HIV, B symptoms must be distinguished from infectious etiologies, as opportunistic infections can mimic lymphoma presentation. 3 An infectious disease workup should be performed when B symptoms are present in these populations to avoid misattribution. 3