Reasoning GP · Algorithm · 1-page summary
Scrotal lumps and swelling
For: adults and adolescents (men, trans women and non-binary people with male reproductive organs) with a new scrotal lump or swelling. Not for: scrotal pain without a lump (use Scrotal pain). Children: local paediatric acute-scrotum pathway.
Core rule: if the lump is not clearly separate from the testis, arrange urgent ultrasound and referral to exclude cancer — both at once. Transillumination, pain and normal tumour markers exclude nothing.
0Stop — emergency transfer now — before any scan
- Possible torsion: sudden or severe unilateral pain, high-riding or horizontal testis, nausea or vomiting, marked tenderness → Immediate ED / urology; 999 if severely unwell, uncontrolled pain, collapse or no safe urgent transfer.
- Painful irreducible groin or scrotal swelling (obstructed or strangulated hernia); trauma with suspected rupture or expanding haematoma → Emergency hospital
- Fournier's gangrene: severe pain with systemic toxicity, skin discolouration, bullae, crepitus or rapidly spreading perineal or scrotal oedema → Emergency hospital; 999 if septic.
- While arranging: do not delay for ultrasound. A present cremasteric reflex does not exclude torsion. Urgency is greatest within 6 hours, but salvage may still be possible later.
1Triage by the lump — feel it against the testis
| Finding | Route |
|---|---|
| Sudden pain | Torsion until excluded → block 0 |
| Solid, in testis | Suspected cancer pathway; USS alongside, never instead |
| Testis changed | Painless enlargement or change in shape or texture → consider Suspected cancer pathway (NG12) |
| Persistent | Unexplained or persistent symptoms or swelling → consider Urgent direct-access USS (NG12 direct access; urgency per local pathway) |
| Separate | Clearly separate, transilluminates → likely benign; USS if any doubt |
2Screen — one row is enough
- Rapid growth over days or weeks → Same-day urology. Pain or tenderness does not exclude cancer.
- Lump + back pain, weight loss or gynaecomastia → Suspected cancer pathway; do not wait for markers.
- New adult hydrocele with testis impalpable, or suspicious USS → Suspected cancer pathway
- Testicular mass + generalised lymphadenopathy (lymphoma, older men) → Urgent haematology / urology
- Varicocele sudden, right-sided, large, non-reducible or not emptying supine → investigate for renal or retroperitoneal cause.
3Assess — only once block 0 is excluded
☐ Consent and chaperone; standing and supine ☐ Both testes, epididymides, cords: inside or outside the testis, get above it, cough impulse, transillumination ☐ Abdomen, liver, gynaecomastia, groins, nodes ☐ Risk: undescended testis (even after orchidopexy), previous or family testicular cancer, Klinefelter's
Not in primary care: aspiration or biopsy; staging CT or routine CXR; AFP, β-hCG or LDH that delay referral (only if the local pathway supports them).
4Classify — only if blocks 0–2 are negative
- Epididymal cyst / spermatocele — smooth, posterior, clearly separate, transilluminates → reassure; USS if uncertain.
- Hydrocele — surrounds and obscures the testis, transilluminates → USS if testis impalpable, new, atypical, painful or with a mass.
- Varicocele — "bag of worms" above the testis, worse standing, usually left; USS confirms.
- Epididymo-orchitis — tender swollen epididymis ± fever; cause from sexual and urinary risk, not age alone.
- Inguinal hernia — cannot get above it, cough impulse → surgical referral.
- Uncertain — testis not felt separately or swelling unexplained → Urgent USS; refer if solid.
5Treat today — doses: NICE/SPC, BNF, local formulary
- Epididymo-orchitis, STI likely: ceftriaxone 1 g IM once + doxycycline 100 mg BD 10–14 days once swelling and tenderness are objective; first-pass urine NAAT first where feasible, HIV and syphilis tests.
- Enteric or urinary likely: MSU + STI screen; local guidance; fluoroquinolone only if alternatives are inappropriate (MHRA).
- Benign lump confirmed on USS: reassure; testicular awareness.
- Suspected cancer: refer and scan together; check sperm banking has been discussed.
6Refer routinely
- Urology: symptomatic cyst or spermatocele; varicocele painful, progressive, with atrophy or fertility concerns; symptomatic adult hydrocele.
- Sexual health: STI-related epididymo-orchitis, partner notification. Uropathogen, recurrent or obstructive → urology.
- No routine surveillance USS for high-risk men unless urology advises.
7Never reassure by
- Transillumination — fluid can hide a tumour.
- Pain, tenderness or a dull ache.
- Normal tumour markers.
- A hydrocele you cannot feel the testis through.
- "Infection" not improving at 48–72 h — a tumour can mimic it.
- A present cremasteric reflex or a normal scan when torsion is suspected.
8Safety-net — say it, then document it
999 “Sudden severe testicular pain, vomiting, rapid swelling, fever, skin colour change, worsening pain or being unable to pass urine — go to hospital now; call 999 if very unwell.” Same day: “The lump growing fast, new fever or weight loss while you wait, a new lump in the other testis, or infection not better by 72 hours — contact us today.” Rapid enlargement after referral → phone urology the same day.
Follow-up: confirm the USS is booked and the referral received; no appointment in 2 weeks → patient phones the hospital. Epididymo-orchitis review at 48–72 h, then about 2 weeks if it persists.
✓Safe to leave primary care only if — all five, documented
No block 0–2 row applies
Both testes examined; lump clearly separate or USS-confirmed
Torsion considered; NAAT / MSU sent if treating
Any doubt: referral and USS booked together, date recorded
Safety-net and testicular awareness given
Summary of the full Reasoning GP scrotal lumps and swelling algorithm, which holds the detail, examination, tumour markers, cancer survivorship and evidence. Sources: NICE NG12 (updated April 2026); BASHH epididymo-orchitis (2020); GIRFT/BAUS testicular torsion pathway (2026); EAU testicular cancer (2026); local antimicrobial guidelines; MHRA (January 2024). Clinical reference — follow local urology pathways and check doses: NICE/SPC, BNF.