Culture-negative cryptogenic splenic abscess in an immunocompetent host with recurrent misdiagnosis as pleural effusion: a case report with a review of the literature.

Splenic abscess is a rare yet potentially life-threatening condition, often challenging to diagnose due to nonspecific clinical presentations. This case report describes a 52-year-old immunocompetent male who initially presented with fever and left-sided abdominal pain, and had been previously hospitalized and treated for pneumonia and left pleural effusion-a misattribution that delayed the definitive diagnosis-with transient clinical improvement only to return 2 weeks later with recurrent symptoms. Initial laboratory findings revealed leukocytosis, raised C-Reactive Protein (CRP) and elevated procalcitonin, while computed tomography (CT) imaging confirmed a splenic abscess. The patient underwent a combination of broad-spectrum antibiotic therapy and surgical intervention. Pus culture yielded no bacterial growth. Post-treatment, the patient's condition markedly improved, with resolution of symptoms and successful hospital discharge. In immunocompetent patients with no identifiable predisposing condition, splenic abscess may hide behind the facade of recurrent pleural effusion-and culture negativity, far from a diagnostic dead end, should accelerate the decision for surgical intervention rather than delay it.