“It’s just a fatty lump on my leg — it’s only got a bit bigger”

Most soft-tissue lumps are benign lipomas (soft, freely mobile, superficial, small and stable), but the features that distinguish a possible SOFT-TISSUE SARCOMA are large SIZE (>5 cm), DEEP location (fixed, deep to fascia, not freely mobile), FIRM/hard consistency and — most importantly — INCREASING IN SIZE; painlessness does not reassure. NICE NG12 (Suspected cancer: recognition and referral, last updated April 2026) sets an explicit threshold: consider an URGENT direct-access ultrasound (within 2 weeks) to assess for soft-tissue sarcoma in ADULTS with an unexplained lump that is increasing in size (VERY URGENT / within 48 hours in children and young people), with a suspected cancer pathway referral to a sarcoma/specialist service if the scan suggests sarcoma, or is uncertain and concern persists. The size over 5 cm and deep-to-fascia features come from the British Sarcoma Group (2024), not NG12; do not excise or biopsy an enlarging deep lump in primary care. The classic error is confidently diagnosing a lipoma from the chair and advising "watch and wait" — sarcomas frequently masquerade as lipomas and delay costs outcomes, so a deep, firm, large or enlarging lump is IMAGED first, even when it looks benign. The examinable hidden agenda is minimisation — a practical man avoiding doctors, not wanting a fuss or bad news, seeking permission to ignore it, with a partner’s concern as the reliable signal and a quiet awareness that it has grown. Characterise the lump, recognise the increasing-size trigger, arrange the urgent ultrasound (avoiding both over-reassurance and alarm), refuse to collude with the wish to be reassured, and safety-net and follow up the result.