Case report: Real-time contrast-enhanced ultrasonography for the diagnosis of typical 'bull's eye' sign of hepatic abscess caused by Acinetobacter baumannii in a tumor patient.

The present case report details a unique case of a 51-year-old male patient who underwent a radical operation for carcinoma of the stomach and pancreaticoduodenectomy. Conventional ultrasonography examination exhibited a characteristic 'bull's eye' sign in the liver; whereas real-time contrast-enhanced ultrasonography (CEUS) demonstrated the patient was suffering from a hepatic abscess, corroborated by cytologic examination, which confirmed the presence of Acinetobacter baumannii. The hepatic localization of A. baumannii is rare in tumor patients presenting with a typical 'bull's eye' sign; and such a case could easily be misdiagnosed as hepatic metastasis. The findings presented in this case report demonstrate that real-time CEUS may offer important diagnostic elements, albeit not specific, which should, together with a positive cytologic test, confirm the diagnosis of a hepatic abscess.