Reasoning GP · Algorithm · 1-page summary
Breast lump and breast symptoms
For: adults (women and men) with a breast lump, nipple or skin change, axillary lump or breast pain in primary care. Not for: breast pain alone with a normal examination (use the mastalgia algorithm); nipple eczema or galactorrhoea (nipple problems algorithm).
Core rule: the referral is decided by age and examination findings, not by how benign a lump feels. If an NG12 criterion is met, refer first — do not arrange imaging first.
0Stop — call 999 now — rare in breast presentations
- Breast infection with septic shock — hypotension, confusion, mottled skin → 999
- Known breast cancer + back pain with leg weakness, sensory level or sphincter change (spinal cord compression) → 999 / immediate MSCC pathway
1Triage by age and finding — NICE NG12 (updated April 2026)
| Finding | Action |
|---|---|
| Lump, 30 and over | Unexplained, with or without pain (women and men) → Suspected cancer referral |
| One nipple, 50 and over | Discharge, retraction or other change of concern → Suspected cancer referral |
| Skin change | Suggestive of cancer, any age → consider Suspected cancer referral |
| Axilla, 30 and over | Unexplained lump → consider Suspected cancer referral |
| Lump, under 30 | Consider non-urgent breast clinic; sooner if hard, fixed, enlarging or strong family history |
2Screen
- Hot, tender breast with fever, rigors, spreading cellulitis or fluctuant mass → Same-day (abscess, sepsis)
- "Mastitis" not breastfeeding, or not settling after one course → breast clinic; suspicious skin or lump → suspected cancer referral (inflammatory cancer)
- Male: hard, eccentric or fixed lump, nipple or skin change → Suspected cancer referral
- Known cancer + bone pain, confusion or thirst → Same-day acute oncology
3Assess — chaperone offered and documented
☐ Inspect sitting, arms down then raised ☐ Palpate both breasts, axillary tail, behind the nipple ☐ Axillary and supraclavicular nodes ☐ Describe lump: site, size in cm, mobility, tethering ☐ Family history (CG164), HRT, pregnancy ☐ Men: testes, liver, drugs
Do not: request mammography or ultrasound before referral, do fine-needle aspiration, or squeeze the nipple repeatedly.
4Classify — examination cannot exclude cancer
- Fibroadenoma — under 30, smooth, very mobile → non-urgent clinic.
- Cyst — 35 to menopause, smooth, may appear suddenly → over 30 still suspected cancer referral.
- Nodularity — diffuse, bilateral, cyclical; no discrete lump → reassure, re-examine.
- Mastitis — lactational or periductal (smokers) → treat; review at 48 hours.
- Gynaecomastia — rubbery disc under the areola → bloods, testes, drug review.
- Uncertain — any doubt in a discrete lump → refer on the NG12 age criteria.
5Treat today — doses: NICE/SPC, BNF, local formulary
- NG12 met: refer today; explain, check contact details for the next 2 weeks.
- Lactational mastitis: keep feeding or expressing, analgesia; if indicated flucloxacillin 500 mg four times daily for 10–14 days.
- Periductal mastitis: antibiotic per local pathway (consider co-amoxiclav) + stop smoking.
- Pain, normal exam: supportive bra, paracetamol or topical NSAID (mastalgia algorithm).
6Refer routinely
- Under 30 with a lump; nipple discharge under 50 per local pathway; persistent focal pain → breast clinic.
- Family history at moderate or high risk (CG164) → family history service or genetics.
- Gynaecomastia with abnormal bloods → endocrinology; raised hCG/AFP or testicular lump → urgent urology.
7Never reassure by
- A smooth, mobile or tender lump in a patient aged 30 and over.
- A recent normal screening mammogram.
- A normal scan arranged from primary care.
- Calling a male breast lump gynaecomastia without examining.
- Repeated antibiotics for a breast that will not settle.
- A previous benign result for a new change.
8Safety-net — say it, then document it
999 “Call 999 if your breast is hot and painful and you have a high fever, shivering, confusion or feel faint.” Same day “Contact us the same day if redness spreads quickly, you feel unwell with a breast infection, or you are worse after 48 hours of antibiotics.”
Referred: contact the practice if no appointment within a week; diagnosis or cancer ruled out within 28 days. Return with any new lump, dimpling, nipple turning in or one-sided bloodstained discharge.
✓Safe to manage in primary care only if — all five, documented
No NG12 criterion met; no block 0–2 feature
Both breasts, axillae and nodes examined; chaperone offered
Age, family history, pregnancy and medicines recorded
Diagnosis named; review booked
Safety-net given; screening and breast awareness discussed
Summary of the full Reasoning GP breast lump and breast symptoms algorithm, which holds the detail, examination and evidence. Sources: NICE NG12 (updated April 2026); NICE CKS; NICE CG164; Association of Breast Surgery; NHS Breast Screening Programme. Clinical reference — follow local breast pathways and check doses in the current SPC/BNF.