Spontaneous rupture of a mycotic splenic artery pseudoaneurysm secondary to histoplasmosis: a case report

Background: A splenic artery pseudoaneurysm is a rare pathology that occurs mainly secondary to pancreatitis, abdominal trauma, peptic ulcers, pancreatic and gastric cancers, and infections. It is best diagnosed using computed tomography angiography and typically treated using endovascular embolization and, in some cases, open or laparoscopic surgery. In this report, we present a case of a ruptured mycotic splenic artery pseudoaneurysm containing Histoplasma capsulatum, which to our knowledge is the first case to report a mycotic splenic artery pseudoaneurysm of this nature.

Case presentation: We report a case of a 42-year-old white male with past medical history of Hepatitis C and IV drug abuse who presented to the Emergency Department with a 24-h history of severe diffuse abdominal pain. He was tachycardic and peritonitic on exam. Work-up demonstrated leukocytosis and lactic acidosis. Computed tomography of the abdomen and pelvis with intravenous contrast showed hemoperitoneum and active extravasation of contrast from the splenic artery into the splenic hilum, associated with a surrounding hematoma measuring 5.3 × 5.0 cm, concerning for ruptured splenic artery pseudoaneurysm. The patient was taken emergently for exploratory laparotomy, where a large intraperitoneal hematoma was evacuated. A ruptured splenic artery pseudoaneurysm was identified, isolated, and controlled, followed by completion splenectomy. Final pathology demonstrated a 3.0 × 1.3 × 0.3 cm pseudoaneurysm wall and a 14 × 9.5 × 5.5 cm spleen containing multiple necrotizing granulomata positive for the presence of Histoplasmosis species. The patient recovered appropriately and was discharged on post-operative day five.

Conclusions: This case demonstrates a successful approach to a ruptured mycotic splenic artery pseudoaneurysm resulting in a positive outcome. It is a unique case as it highlights, to our knowledge, the first report of splenic artery aneurysm secondary to Histoplasma capsulatum infection. This report helps further the understanding of the pathophysiology as well as the natural history of mycotic splenic pseudoaneurysms.