B27.90 — Infectious Mononucleosis
Denied27M · investigation — Lymph Node Biopsy
Insurer Rationale
The presentation remains consistent with infectious mononucleosis in a young adult. Observation for four weeks is appropriate before tissue diagnosis is considered.
Clinical Contradiction
Insurer states
“Lymphadenopathy is consistent with infectious aetiology; biopsy is premature”
Clinical evidence shows
Persistent lymphadenopathy >6 weeks with B-symptoms and night sweats requires tissue diagnosis to exclude lymphoma
Patient risk
Delayed lymphoma diagnosis reduces treatment response and survival
Reasoning Chain
Fatigue, fever, lymphadenopathy, and organomegaly are shared between infectious mononucleosis and lymphoma. Persistent nodes, night sweats, and weight loss move the probability toward lymphoma. Biopsy is the discriminating investigation and delay prolongs a potentially treatable haematological malignancy.
Reasoning Chain
Findings
Persistent lymphadenopathy, Fever, Marked fatigue, Night sweats, Unintentional weight loss
Differential
Infectious Mononucleosis (initial working diagnosis) vs Lymphoma (not excluded)
Shared findings
Fatigue, Fever, Lymphadenopathy, Organomegaly
Discriminating investigation — DENIED
Lymph Node Biopsy
Provides tissue diagnosis when persistent glandular fever-like illness may actually represent lymphoma
Verdict
Denial is clinically unsafe. Watchful waiting is the wrong move once the presentation crosses from self-limited viral syndrome into B-symptom territory.
Clinical Evidence
NICE Guideline NG12 — Suspected cancer: recognition and referral
Haematological cancers
Persistent unexplained lymphadenopathy with systemic symptoms warrants urgent assessment and tissue diagnosis.
British Society for Haematology Guidance on Lymphadenopathy (2024)
Biopsy thresholds
B symptoms and persistent nodal enlargement beyond the expected viral course justify biopsy.