❤️ Abdominal Mass — Assessment & Management

The AAA rupture recognition is a time-critical primary care emergency — the classic triad (pulsatile abdominal mass + back/flank pain + hypotension) is present in only approximately 50% of cases. The other 50% present with: isolated severe back pain (misdiagnosed as musculoskeletal), isolated flank pain (misdiagnosed as renal colic — patients may have been given diclofenac and sent home with serious consequences since diclofenac in AAA rupture reduces platelet aggregation and worsens haemorrhage), or painless syncope with incidental pulsatile mass on examination. The critical rule: any male over 65 with known or suspected AAA who presents with sudden-onset back, flank, or abdominal pain must have an AAA rupture excluded as the first priority — before considering renal colic, muscular pain, or any benign diagnosis. Do not examine forcefully — a tense, tender pulsatile epigastric mass in an unwell patient is almost certainly a ruptured AAA until proved otherwise.

The clinical distinction between splenomegaly and a left renal mass is a classic examination station that requires attention to specific signs — the three most reliable bedside differentiators: (1) the spleen cannot be felt above (you cannot get fingers between it and the ribs), whereas a left kidney can be ballot-ted bimanually and the examiner's hand can be placed above it; (2) the spleen moves medially and inferiorly with inspiration (toward the right iliac fossa in progressive enlargement), whereas the kidney moves downward with inspiration; (3) the spleen is dull to percussion anteriorly (no bowel between it and the abdominal wall), whereas the kidney is resonant anteriorly (bowel lies anterior to kidney). Additional distinguishing features: the notched medial border of an enlarged spleen (Traube's space — the area of resonance in the left lower costal area) is obliterated by a massively enlarged spleen. When clinical differentiation is uncertain: USS is definitive.

The Virchow's node (Troisier's sign) is a physical examination finding that carries significant oncological importance — a palpable hard, non-tender node in the left supraclavicular fossa (above the clavicle, just lateral to the sternocleidomastoid muscle) raises concern for metastatic malignancy — gastrointestinal, pancreatic, lung or ovarian — with intra-abdominal spread classically via the thoracic duct. The thoracic duct (which drains abdominal and thoracic lymphatics) empties into the venous circulation at the left subclavian-jugular junction, and tumour emboli can deposit at this terminal lymph node. The classic association is gastric cancer, but Virchow's node metastases also occur from: pancreatic, ovarian, colorectal, testicular, oesophageal, hepatic, and uterine carcinomas. Any palpable left supraclavicular lymph node in an adult with an abdominal mass should prompt an urgent suspected cancer pathway referral for the likely primary site — primary lymphoma of this node is possible but much less common than metastatic disease from an abdominal primary.

The Risk of Malignancy Index (RMI) is mainly used to triage an adnexal mass (particularly in postmenopausal patients), usually within the gynaecology pathway — it is not a primary-care test for every ovarian cyst — it combines three components: (1) menopausal status (M: pre-menopausal = 1; post-menopausal = 3); (2) USS features (U: none of the below = 1; any of multilocular cyst, solid areas, bilateral lesions, ascites, intraabdominal metastases = 3); and (3) CA125 level (IU/mL). The formula: RMI = M × U × CA125. Interpretation: RMI <25 = low risk (approximately 3% malignancy); RMI 25-250 = moderate risk (approximately 20%); RMI >250 = high risk (approximately 75% malignancy) — urgent gynaecology suspected cancer pathway referral (gynaecological oncology). Thresholds differ (RCOG RMI I ≥200; NICE CG122 250), so the local gynaecology pathway sets the operational cut-off. Important: RMI is not validated for premenopausal women with straightforward functional cysts — USS alone is usually sufficient for these, and most functional cysts (follicular, corpus luteum) resolve within 2-3 menstrual cycles without treatment.

The abdominal mass in primary care carries a significant malignancy probability that justifies a systematic urgent approach — a new palpable abdominal mass carries a high risk of malignancy in primary care, which is why NICE NG12 (updated April 2026) lists it as a trigger for FIT (colorectal), urgent direct-access USS (liver or gallbladder mass) or a suspected cancer pathway referral (pelvic or abdominal mass in women). Unlike many symptoms (which have a broad differential including benign conditions), a new palpable abdominal mass in an adult (especially over 40) must be considered malignant until proved otherwise, and the primary care response should be: (1) FIT and urgent imaging by site; (2) a site-specific suspected cancer pathway referral if FIT is ≥10 µg Hb/g, a woman has a pelvic or abdominal mass not obviously fibroids, or clinical or imaging features are suspicious; (3) never reassure without investigation. The practice of prescribing laxatives for a 'probable constipation mass' without arranging USS is clinically risky — a sigmoid carcinoma can present as a palpable LIF mass, and a caecal carcinoma as a RIF mass, both of which may soften and partially resolve with laxative treatment, giving false reassurance.

The appendix mass — surgical team follow-up is a safety-critical investigation that is often omitted — a caecal carcinoma can perforate and present exactly like appendix abscess (perforated caecal carcinoma forms a pericolic mass that is clinically and radiologically indistinguishable from a perforated appendix phlegmon, particularly in patients over 50). After conservative management the surgical team should arrange appropriate follow-up — typically colonoscopy or CT, timed by them and particularly in older adults — to: (1) confirm the appendix is the source and exclude an underlying caecal carcinoma; (2) assess the caecum and terminal ileum for alternative pathology. The GP's role is to confirm this follow-up has been arranged, not to schedule it.

Why the GP does not front-load investigations: a broad tumour-marker panel has poor sensitivity and specificity (CEA and CA19-9 can be normal in cancer and raised in benign disease), and a blanket GP-requested CT can delay the referral, duplicate the pathway's own straight-to-test imaging and expose the patient to unnecessary contrast and radiation. The safest GP contribution is a prompt, well-documented referral with baseline bloods, plus symptom control that does not mask obstruction — which is why generic modified-release opioids, high-dose laxatives and sedating tricyclics have no place while the diagnosis is open.

The GP's distinctive role here is generalist: honest communication, support through the diagnostic wait, nutrition and benefits signposting, and making sure nothing falls between services. Treatment-specific advice — peri-operative carbohydrate loading, neutropenic precautions, tumour-lysis prophylaxis, radiotherapy diets, tumour-marker surveillance — belongs to the specialist oncology or surgical team's protocol, and duplicating it in primary care risks contradicting it.

The GP responsibility for tracking suspected cancer referral outcomes is a clinical governance standard that is frequently under-documented — GPs who refer patients on the suspected cancer pathway retain clinical responsibility during the referral period, and NICE NG12 (updated April 2026) asks the referrer to give the person information about the referral and the safety-netting plan. This includes: (1) having a system to track that the patient received an appointment (many GP practices use recall/task systems at day 10 to confirm appointment received); (2) having a system to receive and act on the specialist outcome letter (confirm receipt in the clinical record); (3) informing patients what the outcome was and what the follow-up plan is. A patient referred on the suspected cancer pathway who fails to attend their appointment ('did not attend') requires active follow-up from the GP — a simple letter or phone call, not passively waiting. The medicolegal principle: a GP who makes a suspected cancer pathway referral and then has no further knowledge of whether the patient was seen and what was found is not fulfilling the minimum duty of care.