Splenic abscess is a rare but possibly life-threatening condition that can be caused by various Gram-positive and Gram-negative bacterial pathogens. Fever, abdominal pain, nausea, vomiting, and a poor general condition in severe cases is the typical clinical presentation. Underlying immunosuppression or the presence of comorbidities such as diabetes mellitus significantly increase mortality rates. Clinical, imaging and microbiological studies are necessary to make the diagnosis.
Despite the fact that a splenic abscess is rarely encountered in clinical practice, the importance of early recognition lies in the fact that mortality rates are as high as 47% despite treatment, whereas virtually all patients die in the absence of proper therapy . Many studies have confirmed that the presence of one or more comorbidities, such as diabetes mellitus, endocarditis, pancreatitis, liver disease, and various disorders causing immunosuppression (including human immunodeficiency virus infection and hematologic malignancies) predisposes to a poorer prognosis    . A splenic abscess can be seen in patients of all ages, but middle-aged and older adults comprise the majority of cases    . In addition, some reports have established a slight predominance toward male gender    . The clinical presentation starts with a fever of unknown origin, sometimes with chills, that is accompanied by abdominal pain in the majority of cases   . Pain is usually confined to the upper left quadrant, but diffuse, as well as left chest wall pain, have been described in a significant number of cases    . Nausea and vomiting are important constituents of the clinical presentation as well  . Splenomegaly, although frequently present, is not always observed during the physical examination .
The life-threatening risk of a splenic abscess must be considered by the physician in the differential diagnosis of unexplained fever, upper left quadrant abdominal pain, and confirmed immunosuppression . For this reason, a properly obtained patient history is of critical importance. Furthermore, a detailed palpation of the abdomen can aid in identifying the underlying cause. Auscultation of the lungs is very important, as both dullness and rales may be heard in the left basilar region . The next step is a full laboratory workup where leukocytosis is a common finding   . Blood cultures or microbiological investigation of aspirated abscess material is recommended, and principal pathogens that have been identified in the literature include Gram-positive (Streptococci, Staphylococci, Enterococci) and Gram-negative (Enterobacteriaceae, Brucella, etc.) bacteria     . Imaging studies, however, are the cornerstone in solidifying the diagnosis. Abdominal ultrasonography, often chosen as the first-line study, can reveal solitary (or less commonly multiple) abscesses in the splenic parenchyma    . Pleural effusions and infiltrations of the lower lungs are additional findings on ultrasonography, but also on plain radiography, although nonspecific findings are more common on a chest X-ray  . Computed tomography (CT) is performed as a superior method to confirm an abscess in the spleen and is thus considered the gold standard of splenic abscess imaging    .