Abdominal Masses: Clinical Approach and Considerations

Related Subjects: |Abdominal Masses: Clinical Approach and Considerations |Abdominal Distension |Vomiting

Abdominal masses are a significant clinical finding that may arise from many underlying conditions. A systematic approach — history, examination, investigations — is essential to differentiate between benign and sinister causes. Some masses are incidental; others may signal life-threatening pathology such as an abdominal aortic aneurysm or malignancy.

📝 Patient History

• Onset & duration ⏳: Sudden vs gradual appearance.
• Associated symptoms 🤒: Pain, bowel/urinary changes, nausea, vomiting, weight loss, fatigue.
• Medical history 📚: Malignancies, previous abdominal surgery (adhesions), infections, trauma.
• Family history 👨‍👩‍👦: Genetic predispositions (e.g., polycystic kidney disease, cancers).
• Systemic symptoms 🌡️: Fever, night sweats, anorexia may suggest infection or malignancy.

👩‍⚕️ Physical Examination

• Location 📍: RUQ, LUQ, flank, pelvis, suprapubic.
• Size & shape 📏: Estimate dimensions; smooth vs irregular.
• Consistency 🪨: Hard (tumour), soft (cyst), fluid-filled, nodular.
• Mobility ↔️: Moves with respiration (e.g., liver, spleen) vs fixed (retroperitoneal/attached to bowel wall).
• Pulsatility ❤️: Expansile pulsation suggests abdominal aortic aneurysm.
• Tenderness 🤕: Guarding or rebound indicates peritonitis or infection.

⚠️ Causes of Abdominal Masses

🔬 Investigations

• Bloods 🧪: FBC, U&E, LFTs, tumour markers (AFP, CA-125, CEA depending on suspicion).
• Urinalysis 🚻: Haematuria or infection (renal/bladder causes).
• Imaging 📸: – Ultrasound → first-line, non-invasive. – CT/MRI → localisation, staging, vascular involvement.
• Endoscopy 🪞: If GI origin suspected.
• Biopsy 🔎: Essential if malignancy suspected.

🧾 Common Causes (by Organ)

• Liver: Cirrhosis, HCC, metastases, abscess.
• Spleen: Malaria, EBV, myeloproliferative disorders, lymphoma.
• Kidney: PCKD, RCC, hydronephrosis, cysts.
• Aorta: Abdominal aortic aneurysm.
• GI tract: Obstruction, Crohn’s, tumours, hernias.
• Reproductive: Ovarian cysts, fibroids, pregnancy masses.
• Bladder: Retention, transitional cell carcinoma.

💊 Management Principles

Treatment depends entirely on the underlying cause:

• 🦠 Infection: Antibiotics, drainage if abscess.
• 🎗️ Tumours: Surgery, chemo, radiotherapy depending on stage.
• 💧 Cysts: Observation if simple; aspiration or resection if symptomatic/large.
• ❤️ AAA: Endovascular repair or open surgery if ≥5.5 cm or symptomatic.
• 🚑 Obstruction: NG tube, IV fluids, surgery if complete/strangulated.
• 🟣 Ovarian masses: Gynae referral, surgery if suspicious/large.
• 💧 Bladder distension: Catheterisation, treat underlying cause (e.g., BPH).

📚 Key Teaching Pearls

• Always assess location + mobility + consistency + pulsatility.
• AAA is the most urgent to rule out — think “expansile pulsatile mass”.
• Use systematic organ-based differential to structure answers in exams.
• Management is often multidisciplinary: surgeons, oncologists, radiologists, urologists, gynaecologists.

🧠 Advanced Clinical Reasoning

Abdominal masses are best understood anatomically by asking three key questions: Is the mass intraperitoneal or retroperitoneal? Is it solid or cystic? and does it move with respiration? Organs tethered to the diaphragm (liver, spleen) descend on inspiration, whereas retroperitoneal structures (kidneys, pancreas, aorta) do not — a subtle but high-yield discriminator in OSCEs and on the ward. Always consider whether the apparent “mass” is actually distension, faecal loading, or bladder retention, particularly in older adults, those with dementia, spinal pathology, or anticholinergic drug burden.

🚨 Red Flags Requiring Urgent Action

• Expansile pulsatile mass ❤️: Assume abdominal aortic aneurysm until proven otherwise — do not repeatedly palpate.
• Rapidly enlarging painful mass 🤕: Think bleeding (ruptured AAA, splenic rupture, haemorrhagic ovarian cyst).
• Systemic features 🎗️: Weight loss, night sweats, anaemia → malignancy until proven otherwise.
• Obstructive features 💨: Absolute constipation, vomiting, severe distension → bowel obstruction.
• Sepsis signs 🌡️: Fever + mass → abscess (hepatic, psoas, intra-abdominal).

⚠️ Common Examination Pitfalls

• Splenic vs renal mass: Spleen has a notched edge, moves with respiration, cannot get above it; kidneys are ballotable.
• Bladder vs pelvic tumour: Always catheterise before imaging — a “vanishing mass” is diagnostic.
• Faecal loading: Can mimic malignancy; reassess after bowel opening.
• Obesity/ascites: Percussion and imaging are more reliable than palpation.

📋 Clinical Case Vignettes

🩺 Case 1: The Pulsatile Mass

A 72-year-old man with a heavy smoking history presents with vague back pain and collapse. Examination reveals a midline expansile pulsatile abdominal mass.

• Likely diagnosis: Abdominal aortic aneurysm (possibly leaking).
• Key reasoning: Expansile pulsation + vascular risk factors.
• Next step: Immediate CT angiography if stable; urgent vascular referral.
• Teaching pearl: Size does not correlate with rupture risk once symptomatic.

🧠 Case 2: The Left Upper Quadrant Mass

A 24-year-old student presents with fatigue and sore throat. Examination shows a LUQ mass moving with respiration.

• Likely diagnosis: Splenomegaly secondary to EBV infection.
• Key reasoning: Systemic viral symptoms + respiratory movement.
• Next step: Blood film, LFTs, EBV serology; avoid contact sports.
• Teaching pearl: Splenic rupture risk persists even after symptom resolution.

🚻 Case 3: The Suprapubic “Tumour”

An 81-year-old man with Parkinson’s disease presents with abdominal discomfort and confusion. A tense suprapubic mass is palpated.

• Likely diagnosis: Acute urinary retention.
• Key reasoning: Neurological disease + anticholinergic medications.
• Next step: Immediate catheterisation.
• Teaching pearl: Retention can cause AKI, delirium, and sepsis if missed.

🟣 Case 4: The Pelvic Mass

A 46-year-old woman reports bloating, early satiety, and increasing abdominal girth over 6 months.

• Likely diagnosis: Ovarian malignancy.
• Key reasoning: Insidious onset + pressure symptoms.
• Next step: CA-125, transvaginal ultrasound, urgent gynae referral.
• Teaching pearl: Ovarian cancer often presents late with vague GI symptoms.

🟦 Case 5: The Ballotable Flank Mass

A 65-year-old man presents with haematuria, weight loss, and left-sided flank fullness.

• Likely diagnosis: Renal cell carcinoma.
• Key reasoning: Haematuria + systemic symptoms + non-respiratory movement.
• Next step: CT urogram and urology referral.
• Teaching pearl: Classic triad is rare — haematuria alone warrants imaging.

📚 Summary Teaching Points

• Think anatomy first: location, movement, consistency.
• Always exclude AAA and urinary retention early.
• Systemic symptoms usually trump local signs.
• Re-examine after simple interventions (catheter, bowel opening).
• Imaging confirms — but clinical reasoning guides urgency.