Case Presentation: An 83 year old male with hypertension, chronic urinary retention, recurrent urinary tract infections, and a 2.9 cm bladder stone presented with three weeks of progressive suprapubic pain. He was afebrile (97.9°F), hemodynamically stable (BP 130/95 mmHg, HR 99), and had mild suprapubic tenderness to palpation on exam. Initial studies showed leukocytosis (white blood cell count [WBC] 18.7 × 10⁹/L), acute kidney injury (creatinine 1.5 mg/dL; baseline 1.0), and sterile pyuria on urinalysis. Computed tomography (CT) of the abdomen and pelvis with contrast demonstrated a right internal iliac artery pseudoaneurysm with an adjacent 4.0 × 6.9 cm fluid collection. Blood cultures grew pan-susceptible Escherichia coli and Salmonella enterica. His bacteremia was treated with ceftriaxone, and he underwent coil embolization with stent graft placement for the pseudoaneurysm.Following treatment, his pain unexpectedly progressed, becoming increasingly localized and intense in the right lower pelvis and inguinal region. Despite persistently negative repeat blood cultures on ceftriaxone, his WBC rose to 21.4 × 10⁹/L. These findings prompted repeat contrast-enhanced CT which revealed enlargement of the perivascular collection to 5.1 × 7.6 cm. Interventional radiology performed percutaneous drainage, and the aspirate grew non-typhoidal Salmonella enterica, suggesting a peri-pseudoaneurysmal abscess as the likely source of his progressive leukocytosis. His symptoms improved with drainage and continued ceftriaxone (two inpatient weeks, ≥6 weeks total planned), with plans for long-term levofloxacin suppressive therapy given the presence of vascular hardware.
Discussion: Although non-typhoidal Salmonella enterica is classically associated with gastrointestinal illness, it also demonstrates a well-documented yet frequently under-recognized capacity to hematogenously seed vascular structures. This process can result in arterial inflammation, progressive compromise, and formation of mycotic aneurysms or pseudoaneurysms – where “mycotic” denotes infection-mediated arterial destruction. Failure to detect these vascular complications may lead to persistent bacteremia, aneurysmal expansion, and life-threatening rupture. Notably, Salmonella enterica is the second most common cause of mycotic aneurysms following Staphylococcus aureus.This case highlights a key principle in hospital medicine: clinical deterioration despite appropriate antimicrobial therapy and microbiologic clearance should raise concern for a persistent anatomic source. For hospitalists, carefully trending physical examination findings – such as evolving pelvic or inguinal tenderness – and integrating these with laboratory and imaging changes is critical for early detection of deep-seated infection. In this patient, rising leukocytosis, evolving pelvic pain, and interval enlargement of a perivascular collection signaled a concealed vascular infection. Early recognition enabled timely drainage and minimized the risk of pseudoaneurysm rupture.
Conclusions: This case underscores that rising inflammation and evolving exam findings despite appropriate antibiotics and an apparently controlled source should immediately raise suspicion for an atypical nidus such as perivascular infection. Rapid, multidisciplinary action among hospital medicine, interventional radiology, and infectious disease is critical to secure true source control, prevent progression, and avert catastrophic rupture.
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