N61 — Breast Abscess / Mastitis
Denied47F · investigation — Core Needle Biopsy
Insurer Rationale
Inflammatory features suggest mastitis. Biopsy should be deferred until completion of antibiotic therapy and interval reassessment.
Clinical Contradiction
Insurer states
“Clinical presentation is consistent with mastitis; antibiotics and follow-up recommended”
Clinical evidence shows
Non-lactating breast mass with skin changes requires core needle biopsy to exclude inflammatory breast cancer
Patient risk
Inflammatory breast cancer mimics mastitis but has 40% 5-year survival if diagnosis is delayed
Reasoning Chain
Breast lump and tenderness are shared between mastitis and breast cancer. Persistence after antibiotics, absence of lactation, and nodal features all shift concern toward malignancy. Biopsy is the graph discriminator and delaying it risks stage migration behind an inflammatory explanation.
Reasoning Chain
Findings
Breast lump, Breast pain, Low-grade fever, Persistent mass after antibiotics, Axillary fullness
Differential
Breast Abscess / Mastitis (initial treatment path) vs Breast Cancer (not excluded)
Shared findings
Breast lump, Breast tenderness/pain
Discriminating investigation — DENIED
Core Needle Biopsy
Separates unresolved inflammatory change from underlying malignancy when antibiotics have already failed
Verdict
Denial is clinically unsafe. Another antibiotic interval does not answer the cancer question in a non-lactating patient with a persistent lump.
Clinical Evidence
NICE Guideline NG12 — Suspected cancer: recognition and referral
Breast cancer
Persistent breast lump in a patient over 30 warrants urgent imaging and tissue assessment rather than repeated empirical treatment.
Association of Breast Surgery Guidance (2024)
Inflammatory presentations
Failure of an apparent mastitis presentation to settle promptly should trigger triple assessment including biopsy.