Testicular cancer is the most common cancer in males aged 15–45 and is one of the most curable cancers overall — 5-year survival is 98% for localised disease and 74% even for metastatic disease (the highest of any cancer with metastases). This makes early diagnosis critically important. The GP's role is rapid referral — any painless testicular lump should trigger same-day urology referral for urgent scrotal USS rather than watchful waiting. NICE NG151 (Testicular Cancer) recommends USS within 2 weeks for suspected testicular cancer. The clinical rule is: if the lump is not clearly separate from the testicle (i.e. it arises within the testis), assume cancer until USS proves otherwise. Epididymal lumps that are clearly posterior and separate from the testicle are usually benign (epididymal cyst, spermatocele).

Cryptorchidism (undescended testis) is the most important risk factor for testicular cancer — it increases the risk 4–10-fold, and importantly, the risk persists even after orchidopexy (surgical correction). This is why all patients with a history of cryptorchidism should be educated about testicular self-examination from adolescence. Gynaecomastia as a presenting feature of testicular cancer occurs in beta-hCG secreting non-seminomatous germ cell tumours (NSGCT) — beta-hCG stimulates oestrogen production in peripheral tissues, causing breast development. A young man with new gynaecomastia + any scrotal abnormality must have urgent testicular USS.

Secondary varicocele is an important diagnostic trap — a new left-sided varicocele in a man over 40 that does not empty on lying down (non-draining varicocele) should raise suspicion for a left renal cell carcinoma compressing the left renal vein and preventing drainage of the left gonadal vein. Renal USS is indicated. A right-sided varicocele (less common anatomically) should also prompt investigation as it may indicate inferior vena cava obstruction from a tumour. All new adult hydroceles should be investigated with scrotal USS to exclude an underlying testicular tumour — a secondary hydrocele forms when a tumour irritates the tunica vaginalis and increases fluid production.

Tumour markers (AFP, beta-hCG, LDH) must be drawn before any surgical intervention (orchidectomy) — they serve as baseline values against which response to treatment and recurrence are monitored. If orchidectomy is performed without pre-operative markers, subsequent tumour marker trends cannot be interpreted. AFP is produced by yolk sac tumour elements — it is elevated in 70% of NSGCTs but never elevated in pure seminoma. An elevated AFP in a man with apparent seminoma on biopsy means the tumour contains NSGCT elements (mixed germ cell tumour) and changes the treatment approach.

Testicular torsion has a salvage rate of 97% if operated on within 6 hours of onset, 70% at 12 hours, and nearly 0% at 24 hours. Any clinician who suspects torsion must phone 999 or transfer the patient directly to A&E — there is no role for "watchful waiting" or "return if worse." The clinical rule is: if in doubt, explore. Epididymo-orchitis and torsion can be clinically indistinguishable — Doppler USS can help but should not delay surgical exploration when torsion is clinically likely. A urologist would rather perform an exploration showing epididymo-orchitis than miss a torsion.

The antibiotic choice for epididymo-orchitis depends on the patient's age and risk profile. Under 35, sexually active — chlamydia and gonorrhoea are the most likely pathogens — ceftriaxone IM covers gonorrhoea (including ESBL-producing strains) and doxycycline covers chlamydia. Over 35, not sexually active, with urinary symptoms — enteric organisms (E. coli) are more common — ofloxacin (a fluoroquinolone) covers both enteric organisms and has some chlamydia coverage. Duration of 14 days is important as shorter courses risk inadequate treatment leading to chronic epididymitis and subfertility from epididymal scarring.

The inguinal approach for orchidectomy (rather than trans-scrotal) is critically important for staging — the scrotum has different lymphatic drainage (inguinal lymph nodes) compared to the testicle (retroperitoneal paraaortic nodes). A trans-scrotal biopsy or orchidectomy redirects tumour cells into scrotal and inguinal lymphatics, changing staging and potentially requiring inguinal radiotherapy or lymphadenectomy. This is why GPs should never attempt to biopsy or aspirate a scrotal mass. Sperm banking is a fertility preservation service available on the NHS before gonadotoxic treatment — it is often not discussed adequately in the rushed perioperative setting. GPs are well-placed to proactively ask young patients with testicular cancer whether sperm banking has been discussed.

Testicular self-examination monthly from age 15 is the single most effective early detection strategy for testicular cancer — it requires no NHS resources and detects cancers at earlier, more curable stages. Despite this, public awareness campaigns have been limited. GPs should incorporate testicular self-examination education into consultations for all young men, particularly those with risk factors. The Orchid Cancer charity (orchid-cancer.org.uk) provides excellent patient leaflets that can be handed out in clinic. Proactively asking about body image concerns after orchidectomy is important — up to 40% of men experience significant distress about testicular loss, affecting relationships and self-esteem, but rarely raise it without direct enquiry.

Surveillance-based management for Stage I testicular cancer (no metastases) avoids the toxicity of adjuvant chemotherapy in 70–80% of patients who would never relapse — it is the preferred approach in most UK centres for low-risk Stage I disease. The GP's role during surveillance is to ensure the patient attends all appointments (non-attendance rates are significant in this young demographic) and to recognise symptoms of relapse (back pain, dyspnoea, abdominal lump) promptly. The 2–5% lifetime risk of contralateral testicular cancer is substantially higher than the general population risk — all testicular cancer survivors should be taught to continue monthly self-examination for life.