What is the recommended primary care workup for a patient with suspected lymphoma?

Primary Care Workup for Suspected Lymphoma

In primary care, when lymphoma is suspected, immediately obtain an excisional lymph node biopsy (not fine needle aspiration), order comprehensive laboratory studies including CBC with differential, comprehensive metabolic panel, LDH, and hepatitis B/C screening, and arrange contrast-enhanced CT imaging of chest/abdomen/pelvis before referring to oncology. 1

Essential Diagnostic Steps

Tissue Diagnosis - The Critical First Step

• Excisional lymph node biopsy is the gold standard and must be performed to establish diagnosis 1, 2
• Core needle biopsy should only be used when lymph nodes are not easily accessible 1
• Never rely on fine needle aspiration (FNA) - it is inappropriate for lymphoma diagnosis and should only be used in rare emergency situations 1
• The biopsy specimen should be reviewed by a pathologist with expertise in lymphoma diagnosis 3
• Request that fresh frozen tissue be stored when possible to allow for additional molecular analyses 1

Mandatory Laboratory Studies

Complete Blood Work:

• CBC with platelets and differential 3, 1
• Comprehensive metabolic panel including renal and liver function 3, 1
• Lactate dehydrogenase (LDH) - elevated levels indicate higher tumor burden 3, 1, 2
• Uric acid, potassium, phosphates, and calcium (tumor lysis syndrome panel) 3, 1

Infectious Disease Screening:

• Hepatitis B surface antigen and core antibody testing is mandatory before any treatment, particularly if rituximab or chemotherapy is planned 3, 1
• Hepatitis C screening 3, 1
• HIV testing 3, 1

Additional Studies:

• Erythrocyte sedimentation rate (ESR) 1
• Serum protein immunofixation for certain subtypes 3
• Pregnancy testing in women of childbearing age 3

Essential Imaging Studies

Initial Imaging:

• Chest X-ray to rule out mediastinal mass - this is particularly important as mediastinal involvement is common in T-cell lymphomas 3
• Contrast-enhanced CT scan of chest, abdomen, and pelvis 3, 1

Advanced Imaging Considerations:

• PET-CT is valuable for staging and should be arranged through oncology referral 1, 2
• CT or MRI of the head with contrast if neurologic symptoms are present 3

Physical Examination - Key Red Flags

Critical Features to Document:

• Painless lymphadenopathy is the classic presentation 2
• Size and location of all palpable lymph nodes 3, 1
• Liver and spleen size 3
• B symptoms: unexplained fever, drenching night sweats, unintentional weight loss >10% in 6 months 2

Specific Examinations:

• Complete skin examination for cutaneous involvement 3
• Testicular examination in males (scrotal ultrasound if indicated) 3
• Waldeyer's ring examination (tonsils, nasopharynx) 1

Common Pitfalls to Avoid

Critical Errors:

• Do not attempt FNA as the primary diagnostic method - it lacks sufficient tissue architecture for proper subtyping 1
• Do not delay hepatitis B screening - reactivation can be fatal with immunotherapy/chemotherapy 3
• Do not skip chest imaging even if no respiratory symptoms - mediastinal masses may be asymptomatic 3

Timing Considerations:

• Arrange biopsy and initial workup promptly but do not delay referral to oncology 1, 2
• Bone marrow biopsy is typically performed by the oncologist, not in primary care 3, 1

When to Refer Immediately

Urgent Oncology Referral Indicated For:

• Any confirmed or highly suspected lymphoma diagnosis 1, 2
• Presence of B symptoms with lymphadenopathy 2
• Mediastinal mass on chest imaging 3
• Rapidly enlarging lymph nodes 2
• Neurologic symptoms suggesting CNS involvement 3

Pre-Referral Counseling

• Discuss fertility preservation options, particularly for younger patients, as chemotherapy and radiation can cause infertility 3
• Provide smoking cessation counseling if applicable 3
• Arrange psychosocial assessment or counseling resources 3