Diagnostic Workup for Night Sweats, Fatigue, and Weight Loss

Initial Assessment

The National Comprehensive Cancer Network recommends screening for fatigue severity using a numeric rating scale (0-10) or categorization as none, mild, moderate, or severe, with patients having fatigue scores of 4-10 warranting a more focused evaluation 1, 2
Documenting the presence of B symptoms (fever, drenching night sweats, unexplained weight loss >10% of total body weight over 6 months) is crucial, as per the Annals of Oncology 3
Assessing for other associated symptoms such as cough, dyspnea, pruritus, alcohol-induced pain, and lymphadenopathy is also important, according to the Annals of Oncology and the National Comprehensive Cancer Network 3, 4

A complete blood count with differential should be performed to evaluate for cytopenias, leukocytosis, or abnormal cells, as recommended by Blood and the National Comprehensive Cancer Network 5, 4
Erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) should be assessed to evaluate for inflammation, according to the Annals of Oncology 3
Blood chemistry, including liver enzymes, alkaline phosphatase, lactate dehydrogenase, and albumin, should be evaluated, as per the Annals of Oncology and the National Comprehensive Cancer Network 3, 6
Thyroid-stimulating hormone (TSH) should be tested to rule out hyperthyroidism, as recommended by Praxis Medical Insights 2
HIV testing and tuberculosis screening (IGRA or TST) should be considered, according to the Annals of Oncology and the Journal for ImmunoTherapy of Cancer 3, 7

A chest X-ray should be performed as initial screening for pulmonary pathology, as recommended by the Annals of Oncology 3
A contrast-enhanced CT scan of neck, chest, and abdomen should be considered to evaluate for lymphadenopathy, organomegaly, or masses, according to the Annals of Oncology and the National Comprehensive Cancer Network 3, 4
A PET/CT scan should be considered if lymphoma is suspected, as it has high sensitivity for bone marrow involvement and can guide biopsy, as per the Annals of Oncology 3

A bone marrow biopsy should be considered if blood counts are abnormal or if lymphoma/leukemia is suspected, as recommended by Blood and the National Comprehensive Cancer Network 5, 6
An excisional or incisional lymph node biopsy should be performed if lymphadenopathy is present, with fresh tissue sent for pathology, flow cytometry, and cytogenetics, according to the National Comprehensive Cancer Network 4
Treatable contributing factors to fatigue, including pain, emotional distress, and sleep disturbances, should be evaluated, as recommended by the National Comprehensive Cancer Network and Praxis Medical Insights 1, 2

The Annals of Oncology and the National Comprehensive Cancer Network recommend looking for painless regional or diffuse lymphadenopathy, hepatosplenomegaly, or extranodal involvement 3, 4
Assessing for oncologic emergencies such as superior vena cava syndrome, respiratory compromise, or spinal cord compression is crucial, according to the National Comprehensive Cancer Network 4
An excisional lymph node biopsy with immunophenotyping and cytogenetics should be considered for definitive diagnosis, as recommended by the National Comprehensive Cancer Network 4

The National Comprehensive Cancer Network recommends evaluating for constitutional symptoms, including >10% weight loss in 6 months, night sweats, and unexplained fever (>37.5°C) 6
Increasing splenomegaly and leukoerythroblastic peripheral blood picture should be looked for, according to the National Comprehensive Cancer Network 6
A bone marrow biopsy with fibrosis grading and molecular testing should be considered, as recommended by the National Comprehensive Cancer Network 6

The Journal for ImmunoTherapy of Cancer recommends performing either tuberculin skin test (TST) or interferon-gamma release assay (IGRA) for patients with risk factors 7
If positive, active TB should be ruled out with clinical history, physical examination, chest radiograph, and respiratory sampling, according to the Journal for ImmunoTherapy of Cancer 7
Submitting three sputum specimens for acid-fast bacilli smear, mycobacterial culture, and nucleic acid amplification testing should be considered if active TB is suspected, as recommended by the Journal for ImmunoTherapy of Cancer 7

In high TB prevalence settings or high-risk patients, obtaining a chest x-ray is recommended even before TB test results return, particularly if fever or hemoptysis is present, as suggested by the American Thoracic Society 8

If lymphadenopathy >1.5 cm is present on examination or imaging, proceeding directly to excisional or incisional lymph node biopsy is recommended, rather than fine-needle aspiration, as stated by the American Society of Hematology 9

The Centers for Disease Control and Prevention (CDC) recommends that tuberculosis (TB) screening be performed as the first diagnostic step in any patient with a month‑long history of night sweats and chills, irrespective of traditional risk factors, because TB frequently presents with fever, chills, and night sweats. Strong recommendation. 10
When TB screening (either tuberculin skin test or interferon‑γ release assay) is positive or when the chest X‑ray is abnormal, the CDC advises collecting three sputum specimens on separate days for acid‑fast bacilli smear, mycobacterial culture, and nucleic acid amplification testing to confirm or exclude active TB. Strong recommendation. 11

The American College of Chest Physicians (ACCP) recommends that a chest X‑ray be ordered simultaneously with TB testing for patients with ≥1 month of night sweats and chills, without waiting for TB test results, to promptly identify pulmonary pathology. Moderate recommendation. 12