Atypical Presentation of a Splenic Abscess Secondary to Splenic Artery Thrombosis With Isolated Confusion: A Case Report.

Splenic abscess is a rare but life-threatening condition whose diagnosis is frequently delayed because of its nonspecific presentation. Development of a splenic abscess following splenic infarction secondary to splenic artery thrombosis is exceptional, particularly when revealing an underlying myeloproliferative neoplasm. An 85-year-old woman presented to the emergency department after three weeks of intermittent confusion without fever, abdominal pain, or gastrointestinal symptoms. While neurological investigations were unrevealing, thoracoabdominal computed tomography unexpectedly demonstrated a large splenic abscess associated with splenic artery thrombosis and bilateral pulmonary emboli. Laboratory tests showed marked systemic inflammation and severe thrombocytosis. Ultrasound-guided percutaneous drainage isolated Escherichia coli, and treatment with intravenous antibiotics and therapeutic anticoagulation was initiated. The patient's course was complicated by septic shock requiring intensive care admission but ultimately evolved favorably with prolonged antimicrobial therapy and continuous percutaneous drainage, avoiding splenectomy. Additional investigations identified deep vein thrombosis and confirmed JAK2 V617F-positive essential thrombocythemia as the cause of a systemic prothrombotic state leading to multiple arterial and venous thrombotic events. This case illustrates how splenic abscess may present solely as delirium in older adults, without localizing abdominal symptoms. Emergency physicians should consider occult intra-abdominal infection in elderly patients presenting with unexplained delirium and inflammatory syndrome. When unusual arterial and venous thromboses coexist, an underlying myeloproliferative disorder should be actively investigated. In selected patients, image-guided percutaneous drainage combined with prolonged antibiotic therapy may provide an effective spleen-preserving alternative to splenectomy.