What is the differential diagnosis for a 33-year-old male presenting with splenic infarct?

Differential Diagnosis of Splenic Infarcts in a 33-Year-Old Male

In a 33-year-old male with splenic infarction, the most likely etiologies are hematologic disorders (particularly sickle cell disease/trait), thromboembolic conditions (especially infective endocarditis and intracardiac thrombus), and less commonly infectious causes like parvovirus B19 or Epstein-Barr virus.

Primary Diagnostic Categories

Hematologic Disorders (Most Common Overall)

• Sickle cell disease or sickle cell trait is a leading cause, particularly in young adults 1, 2
  • Sickle cell trait can manifest as acute splenic syndrome, especially with hypoxic triggers (high altitude, strenuous exercise) 2
  • May present with massive non-segmental infarction and splenic venous thrombosis 2
• Hereditary spherocytosis can cause splenic infarction, particularly when combined with prothrombotic conditions 3
• Hematologic malignancies (leukemia, lymphoma) account for a significant proportion of cases 4, 5
  • Chronic myeloid leukemia (CML) and other myeloproliferative disorders can cause splenic infarction 6

Thromboembolic Conditions

• Infective endocarditis occurs in 40% of left-sided endocarditis cases, though only 5% progress to splenic abscess 1, 7, 8
  • Viridans streptococci and S. aureus each account for 40% of cases 7
  • Must evaluate with echocardiography (transthoracic and transesophageal) 1
• Intracardiac thrombus (atrial fibrillation, dilated cardiomyopathy, recent myocardial infarction) 5
• Splenic vein thrombosis accounts for <10% of cases, follows Virchow's triad 8
  • Can be visualized on contrast-enhanced thin-slice CT 2

Infectious Causes

• Parvovirus B19 infection can cause splenic infarction through transient antiphospholipid antibody syndrome or direct thrombotic mechanisms 9
  • May occur even without elevated antiphospholipid antibodies 9
• Epstein-Barr virus (infectious mononucleosis) causes splenomegaly and can lead to infarction 8, 3
  • Particularly relevant in adolescents and young adults 3

Vascular and Anatomic Causes

• Vasculitis affecting splenic vessels 8
• Mesenteric dissection or mycotic aneurysm 8
• Anatomic abnormalities of splenic vasculature 8
• Emboli from superior mesenteric artery (>20% of SMA emboli have concurrent splenic/renal emboli) 8

Iatrogenic and Acquired Causes

• Oral contraceptive use causing acquired thrombophilia 8
• Post-angioembolization (intentional or unintentional during therapeutic procedures) 8
• Inflammatory bowel disease with associated thrombotic complications 8
• Trauma with vascular injury 8

Key Clinical Distinctions

Age-Specific Considerations

• In this 33-year-old male, hematologic disorders and thromboembolic conditions are most likely 4, 5
• Bacterial endocarditis is less common in the modern era than historically taught (only 3 of 26 cases in one series) 5
• Unexplained splenic infarction frequently uncovers a previously undiagnosed underlying disease in 81% of cases 5

Presentation Patterns

• Only 50% complain of localized left-sided abdominal pain 5
• 31% have no signs or symptoms localized to the splenic area 5
• Fever is present in 36% overall, but more common (70%) with embolic conditions 4, 5
• Single infarcts are more likely associated with fever (63% vs. 20%) and leukocytosis 5
• Elevated lactate dehydrogenase occurs in 71% of cases 5

Diagnostic Workup Algorithm

Immediate Imaging

• CT scan with IV contrast is the gold standard (90-95% sensitivity/specificity) showing peripheral wedge-shaped low-density areas 6, 7
• Add Doppler ultrasound to evaluate splenic vascularization and detect venous thrombosis 6, 2

Laboratory Evaluation

• Complete blood count with peripheral smear (evaluate for sickle cells, spherocytes, malignant cells) 1
• Hemoglobin electrophoresis if sickle cell disease/trait suspected 2
• Lactate dehydrogenase (elevated in 71%) 5
• Blood cultures (multiple sets) to rule out endocarditis 1, 7
• Parvovirus B19 IgM and IgG serology 9
• EBV viral capsid antigen IgM if infectious mononucleosis suspected 3
• Antiphospholipid antibodies (anticardiolipin, lupus anticoagulant, anti-β2-glycoprotein I) 9
• Protein C, protein S, antithrombin III levels if thrombophilia suspected 3

Cardiac Evaluation

• Transthoracic echocardiography initially, followed by transesophageal echocardiography if endocarditis or intracardiac thrombus suspected 1, 5

Critical Pitfall to Avoid

Do not rely on clinical splenomegaly as a diagnostic indicator—it is present in only 30% of cases 6, 7. The diagnosis depends on imaging and identification of the underlying cause through systematic laboratory and cardiac evaluation.