Left Ventricular Apical Intracardiac Mass With Embolic Stroke During Aggregatibacter segnis Bacteremia Following Acute Cholangitis: A Case Report

An elderly woman with cholangiocarcinoma and a metallic biliary stent presented with fever and anorexia and was initially treated for acute cholangitis with biliary drainage and intravenous ampicillin/sulbactam. Two sets of blood cultures grew Aggregatibacter segnis (A. segnis) identified by matrix-assisted laser desorption/ionization-time-of-flight (MALDI-TOF) mass spectrometry, prompting evaluation for infective endocarditis (IE). Transthoracic echocardiography (TTE) showed no vegetation but revealed apical hypokinesis suggestive of Takotsubo cardiomyopathy. Despite antimicrobial therapy, fever persisted, and repeat TTE on hospital day 13 demonstrated a newly developed, highly mobile, irregular mass measuring 14 × 7 mm at the left ventricular apex. On hospital day 15, the patient developed aphasia and right-sided hemiparesis, and brain magnetic resonance imaging revealed extensive acute cerebral infarction involving the left hemisphere. Follow-up TTE performed immediately after the neurological event showed the complete disappearance of the apical mass, suggesting embolization. This case highlights the importance of careful echocardiographic follow-up in patients with A. segnis bacteremia, even when initial imaging is unremarkable, particularly in the presence of apical wall-motion abnormalities that may alter intracardiac flow.