The diagnosis of splenic abscess is often overlooked because of its rarity and misleading clinical features, as well as the presence of predisposing conditions that obscure its clinical presentation. Hence, it is not surprising that splenic abscess is often diagnosed during postmortem examinations (0.2% to 0.7% incidence in various autopsy series), even in the era of antibiotics. Contributing factors to an apparent increase in the incidence of splenic abscess include advances in radiologic imaging, comfort with nonoperative management of blunt splenic trauma, and a greater number of patients who have cancer or are immunocompromised.

INCIDENCE AND PREDISPOSING FACTORS

Splenic abscesses occur more commonly in males (55% to 60% in several series), with the average age ranging from 25 to 54 years. Nelken et al. describe a bimodal distribution: patients younger than 40 years of age; generally immunosuppressed or drug addicts, who usually present with a multilocular abscess; and patients older than 70 years of age who are suffering from diabetes and/or a nonendocarditic septic focus and develop a unilocular abscess.

The primary predisposing causes of splenic abscess include metastatic hematogenous infection, contiguous disease processes extending to the spleen, splenic trauma, hematologic disorders (collagen-vascular diseases, hemoglobinopathies, malignancy), and immunodeficiency states (acquired, congenital). The incidence of these predisposing causes or risk factors is shown in Table 55.1.