What are the key points to consider when examining a patient with an abdominal mass?

Key Points in Abdominal Mass Examination

When examining a patient with an abdominal mass, prioritize assessment for peritonitis and hemodynamic instability first, followed by systematic characterization of the mass through inspection, palpation, and determination of its size, location, mobility, and associated features. 1

Initial Assessment: Rule Out Life-Threatening Conditions

Immediately assess for signs of peritonitis and hemodynamic compromise:

• Check vital signs including pulse rate, blood pressure, temperature, and respiratory rate 1
• Look for tachycardia, fever, and hypotension which indicate potential perforation or sepsis 1
• Assess for peritoneal signs including guarding, rigidity, and rebound tenderness 1
• Evaluate general appearance for signs of distress, pallor, or shock 1

Systematic Physical Examination Approach

Inspection

• Observe for abdominal distension, asymmetry, or visible masses 1
• Note any skin changes, surgical scars, or dilated veins 1
• Look for signs of weight loss or cachexia 1
• Assess for jaundice or pallor suggesting anemia 1

Palpation Technique and Characteristics

Perform palpation systematically, starting away from the area of pain:

• Determine the mass location (right upper quadrant, left upper quadrant, epigastric, periumbilical, right lower quadrant, left lower quadrant, suprapubic) 1
• Assess mass size and measure dimensions when possible 1
• Evaluate consistency: soft, firm, hard, or elastic 2
• Determine mobility: does it move with respiration, is it fixed to surrounding structures 1
• Check for pulsatility which may indicate vascular origin like abdominal aortic aneurysm 3
• Assess tenderness: marked tenderness suggests inflammation, infection, or acute process 1, 2
• Define borders: well-circumscribed versus ill-defined 1

Critical Specific Examinations

Digital rectal examination is essential when appropriate:

• Provides information on lower abdominal and pelvic masses 1
• Assesses rectal masses, their position and extent 1
• Should be performed carefully, ideally after imaging if foreign body or sharp object suspected 1

Measure waist circumference when obesity is present:

• Measured halfway between last rib and iliac crest 1
• Helps distinguish true masses from adipose tissue 1

Age-Specific Considerations

In pediatric patients:

• Most common abdominal malignancies include neuroblastoma, Wilms' tumor, hepatoblastoma, lymphoma, and germ cell tumors 4
• Consider child abuse if mass related to trauma, especially in young children 1
• Distribution and presentation vary significantly by age 4

In adults:

• Consider retroperitoneal sarcomas, which often present as large masses before symptoms develop 1
• Appendiceal masses are often discovered incidentally during appendectomy 1
• Elderly patients may have self-treatment attempts for fecal impaction leading to rectal masses 1

Associated Findings to Document

Extraintestinal manifestations:

• Joint symptoms, skin changes, or eye findings suggesting inflammatory bowel disease 1
• Lymphadenopathy (supraclavicular, inguinal) suggesting malignancy 1
• Lower extremity edema or varicocele suggesting vascular involvement 1
• Subcutaneous nodules indicating metastatic disease 1

Perianal examination findings:

• External aspect of perianal area 1
• Presence of abrasions, bruising, or fissures 1
• Status of anal sphincter tone 1
• These findings must be documented for medicolegal purposes if assault suspected 1

Common Pitfalls to Avoid

Do not skip abdominal radiography in acute presentations:

• Plain films can identify bowel obstruction, perforation (pneumoperitoneum), or masses 1
• Essential before digital rectal exam if sharp foreign body suspected 1

Do not assume all pulsatile masses are aortic aneurysms:

• Normal aortic pulsation can be prominent in thin patients 3
• Ultrasound definitively distinguishes normal pulsation from true aneurysm with near 100% sensitivity and specificity 3

Do not delay imaging for hemodynamically unstable patients:

• Proceed directly to surgical intervention rather than obtaining CT if patient is unstable 1

Maintain professionalism with sensitive presentations:

• Patients with rectal foreign bodies often delay presentation due to embarrassment 1
• Up to 20% will not initially report the true chief complaint 1
• High index of suspicion and non-judgmental approach are essential 1