How should I evaluate and manage left upper quadrant fullness in a 33-year-old man?

Evaluation and Management of Left Upper Quadrant Fullness in a 33-Year-Old Male

Order CT abdomen and pelvis with IV contrast immediately as your primary diagnostic test, as this modality provides comprehensive evaluation of splenic, pancreatic, gastric, and vascular pathology with near-complete diagnostic accuracy. 1, 2, 3

Initial Assessment and Red Flag Identification

Before imaging, rapidly assess for life-threatening vascular catastrophes that require emergent intervention:

• Check hemodynamic stability (blood pressure, heart rate) and examine for pulsatile abdominal mass, which suggests splenic artery aneurysm rupture or aortic dissection requiring immediate CT angiography and surgical consultation 2
• Assess bilateral extremity pulses for differential findings that indicate aortic dissection 2
• Ask about syncope or sudden-onset severe pain, which occurs in >10% of aortic dissections 2
• Obtain 12-lead ECG within 5 minutes to exclude cardiac causes of referred pain 2

Immediate Laboratory Workup

Draw blood immediately for the following comprehensive panel while arranging imaging:

• Complete blood count (CBC) to assess for leukocytosis indicating infection, inflammation, or splenic pathology 1
• Comprehensive metabolic panel including liver enzymes (ALT, AST, alkaline phosphatase, bilirubin) to evaluate hepatobiliary disease 1, 2
• Amylase and lipase to rule out pancreatitis, a common cause of left upper quadrant pain 1, 2
• Lactate level to assess for mesenteric ischemia or severe infection 1, 2
• Coagulation studies (PT/INR, PTT) if splenic rupture or hematoma is suspected 1

Critical interpretation points: Amylase >4× normal or lipase >2× upper limit confirms acute pancreatitis 2; elevated lactate suggests mesenteric ischemia requiring urgent vascular imaging 2; leukocytosis with left shift indicates infection or inflammation such as splenic abscess 1, 2

Primary Imaging Strategy

CT abdomen and pelvis with IV contrast is the definitive first-line imaging study for left upper quadrant fullness in this age group 1, 2, 3:

• Diagnostic accuracy approaches 98% for identifying splenic, pancreatic, gastric, and vascular pathology 2
• Detects complications including abscess, hemorrhage, perforation, and vascular rupture 2
• Identifies alternative diagnoses in approximately 50% of cases with nonlocalized abdominal symptoms 2
• Guides treatment decisions by determining disease severity and need for intervention 2

Why Ultrasound is Inadequate

Do not rely on ultrasound as your primary imaging modality for left upper quadrant fullness 4:

• The spleen provides a much more limited sonographic window than the liver due to its smaller size 4
• Overlying bowel gas and rib shadowing significantly limit visualization 2
• Posterior intercostal approach is required but remains technically challenging 4

Differential Diagnosis to Consider

The sensation of "fullness" in the left upper quadrant in a 33-year-old male most commonly represents:

• Splenomegaly from infectious, hematologic, or infiltrative causes 3
• Splenic pathology including infarction, abscess, or subcapsular hematoma 1, 3
• Pancreatic disease including pancreatitis or pancreatic mass 1, 3
• Gastric distension or mass 3
• Splenic flexure pathology including colitis or mass 3
• Renal pathology affecting the left kidney 1, 3

When to Escalate to Emergency Surgery

Obtain immediate surgical consultation if CT reveals 2:

• Free intraperitoneal air indicating perforation
• Vascular rupture or dissection
• Splenic rupture or large hematoma with hemodynamic instability
• Evidence of bowel ischemia or necrosis

Common Pitfalls to Avoid

• Do not order plain radiography as initial imaging—it has very limited diagnostic value for left upper quadrant pathology 2
• Do not dismiss normal laboratory values as excluding serious pathology; imaging is still necessary based on clinical presentation 1
• Do not delay CT imaging in favor of ultrasound in adult males with left upper quadrant fullness, as ultrasound has significant limitations in this anatomic region 4, 2
• Do not overlook atypical presentations of common diseases—even appendicitis can present with left upper quadrant pain in cases of intestinal malrotation 5

Follow-Up Based on CT Findings

If CT is negative but symptoms persist beyond 2-3 days, consider repeat imaging or alternative diagnoses including functional disorders 2