What causes upper left abdominal pain approximately 2 inches below the last rib?

Upper Left Abdominal Pain Below the Rib Margin: Diagnostic Approach

CT abdomen and pelvis with IV contrast is the preferred initial imaging modality for evaluating upper left abdominal pain approximately 2 inches below the last rib, as it provides comprehensive assessment of all potential causes including splenic, pancreatic, gastric, renal, and vascular pathology. 1

Immediate Clinical Assessment

The location you describe—upper left abdomen about 2 inches below the costal margin—encompasses several anatomical structures that require systematic evaluation:

Key Clinical Features to Identify

• Fever and leukocytosis: These findings indicate inflammatory or infectious processes (abscess, pancreatitis, pyelonephritis) requiring urgent imaging 1
• Postprandial timing: Pain occurring 1-3 hours after eating suggests chronic mesenteric ischemia, especially with weight loss and atherosclerotic risk factors 1
• Tenderness on palpation: A reproducible tender spot on the costal margin suggests painful rib syndrome (also called slipping rib syndrome), which accounts for 3% of general medical referrals and is often overinvestigated 2
• Rebound tenderness with distension: This combination occurs in 82.5% of patients with peritonitis and mandates immediate surgical evaluation 1

Differential Diagnosis by Organ System

Splenic Pathology

• Splenic infarction can present as isolated left upper quadrant pain without predisposing hematologic or cardiac factors 3
• Splenic injury or rupture should be considered with any trauma history 4
• Splenic pathology is readily identified on CT with IV contrast 1

Pancreatic Disease

• Acute pancreatitis of the pancreatic tail can present solely as left flank/left upper quadrant pain without typical epigastric symptoms 5
• This represents a diagnostic pitfall, as ultrasound may be falsely negative and the presentation mimics renal disease 5
• CT is superior to ultrasound for detecting pancreatic pathology in this location 1

Renal Pathology

• Nephrolithiasis or pyelonephritis must be excluded in cases of nonspecific pain, particularly if fever is present 1
• CT with IV contrast effectively evaluates for renal causes 1

Musculoskeletal Causes

• Painful rib syndrome presents with pain in the lower chest or upper abdomen, a tender spot on the costal margin, and reproduction of pain on pressing the tender spot 2
• This diagnosis requires no investigation and is made clinically by systematic firm palpation of the costal margin 2
• 70% of patients are women with mean age 48 years 2
• Critical pitfall: 43% of these patients undergo extensive unnecessary investigation, including non-curative cholecystectomy in some cases 2

Vascular Causes

• Chronic mesenteric ischemia from celiac axis or superior mesenteric artery stenosis presents with postprandial pain, weight loss, and food fear 6, 1
• Celiac artery thromboembolism causing splenic infarction is an uncommon but important consideration 3

Imaging Strategy

First-Line Imaging

CT abdomen and pelvis with IV contrast is rated 8/9 (usually appropriate) by the American College of Radiology for this presentation 1:

• Alters diagnosis in nearly half of cases 1
• Detects unexpected findings including malrotation with atypical appendicitis 1
• Provides comprehensive evaluation of splenic, pancreatic, gastric, renal, and vascular structures 1

Imaging to Avoid

• Plain radiography has very limited diagnostic value and should not be used 1
• Ultrasound has limited utility due to overlying bowel gas and rib shadowing, though it may identify splenic or renal pathology 1
• Important exception: If painful rib syndrome is clinically diagnosed by reproducible tenderness on palpation, no imaging is required 2

Management Algorithm

If Fever or Leukocytosis Present:

1. Obtain CT abdomen/pelvis with IV contrast immediately 1
2. Consider intra-abdominal abscess, pancreatitis, or pyelonephritis 1
3. Start broad-spectrum antibiotics after blood cultures if sepsis suspected 1

If Postprandial Pain with Weight Loss:

1. Consider chronic mesenteric ischemia 1
2. Obtain CT angiography to evaluate mesenteric vessels 1
3. Endovascular therapy (angioplasty with or without stenting) is preferred over surgical bypass 6

If Reproducible Tenderness on Costal Margin:

1. Diagnose painful rib syndrome clinically 2
2. Do not order imaging—this is a safe clinical diagnosis 2
3. Reassure patient; 70% will have persistent but tolerable pain at 4-year follow-up 2

If Peritoneal Signs Present:

1. Immediate surgical consultation required 1
2. NPO status, IV fluid resuscitation, nasogastric decompression 1
3. CT to identify perforation (92% positive predictive value for free air) 1

Critical Pitfalls to Avoid

• Do not dismiss pain as benign without imaging when clinical suspicion exists, as CT alters diagnosis in 49% of patients with nonlocalized abdominal pain 1
• Do not rely on ultrasound alone for pancreatic tail pathology, as it can miss acute pancreatitis presenting as isolated left-sided pain 5
• Do not over-investigate painful rib syndrome—33% of patients are re-referred despite firm diagnosis, leading to unnecessary testing 2
• Do not attribute all symptoms to constipation without excluding serious causes first 7
• In elderly patients, laboratory tests may be normal despite serious infection, requiring lower threshold for imaging 6