Educational draft · awaiting clinical reviewUse Rapid for revision, not patient-care decisions. Check current national and local guidance and the BNF or BNFC before acting.
2 min synopsisUK scopeSources checked 27 Aug 2026Clinical review pending
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Haemorrhage, compartment compromise or visceral obstruction
A bleeding or ruptured tumour, rapidly expanding mass with threatened limb perfusion or nerve function, or retroperitoneal disease causing bowel, ureteric or vascular obstruction needs urgent physiological and sarcoma-specialist control.
Action: Use ABCDE care, control external bleeding without cutting through the mass, document distal neurovascular status and obtain urgent cross-sectional imaging. Involve the regional sarcoma surgical, interventional-radiology and oncology teams before drainage, embolisation, decompression or resection so emergency access does not compromise definitive margins.
Synopsis
Recognise a potentially malignant soft-tissue mass before unplanned removal, use specialist ultrasound, MRI and tract-planned core biopsy to establish subtype and grade, then coordinate wide surgery, radiotherapy, systemic treatment, rehabilitation and recurrence surveillance.
An enlarging lump is the single most important warning feature; lack of pain does not make a soft-tissue mass benign.
Deep location, size above 5 cm, fixation, recurrence and pain increase concern, but a small superficial sarcoma still occurs.
In primary care, urgent ultrasound is the practical first-line test for an unexplained enlarging lump; an uncertain or suspicious study requires direct sarcoma-pathway referral.
Key red flags
Any unexplained soft-tissue lump that is increasing in size requires prompt imaging, even when it is painless or initially small.
Neurovascular threat
Rapidly increasing pain, weakness, numbness, coolness, absent pulse or tense swelling indicates urgent compartment and vascular assessment.
Investigation priorities
01
First-line urgent ultrasoundFirst stepFirst line
Determine whether an enlarging superficial lump is cystic, fatty, solid, vascular or deep and identify features requiring referral.
02
Preferred contrast MRIPreferred
Define local tumour extent, fascial compartment, necrosis, oedema and relationship to skin, bone, joints, nerves and vessels before biopsy.
Management branches
Enlarging lumpEscalate uncertain imaging without excision
A soft-tissue mass is enlarging, deep, painful, recurrent or otherwise clinically concerning.
Document size, depth, mobility, skin and neurovascular findings and arrange urgent ultrasound when this is the appropriate first community test.
Refer any suspicious or indeterminate lesion to the regional sarcoma diagnostic service for contrast MRI before biopsy and avoid aspiration, steroid injection or shell-out excision.
Key medicines
DoxorubicinA common first-line adult regimen gives doxorubicin 75 mg/m² intravenously on day 1 every 21 days for up to six cycles, with dose and schedule adjusted to protocol, organ function, response and cumulative exposure.
Ifosfamide with mesnaUse a specialist fractionated multi-day ifosfamide regimen with equidose mesna uroprotection, intravenous hydration and protocol blood and urine monitoring; exact dose varies by histology and combination.
National guidance is shown before implementation-dependent detail. Typical adult dose examples remain subject to patient factors, contraindications and the live BNF or specialist protocol. Source check completed 27 Aug 2026; clinical approval remains outstanding.