Klebsiella liver phlegmon mimicking a solid liver tumour

This case examines the sonographic and clinical challenge of diagnosing a Klebsiella pnumoniae pyogenic liver abscess with systemic metastatic infection.

The patient in this case study is an 81-year-old man who presented with intermittent rigors. Following radiological and clinical assessments, a Klebsiella pnumoniae pyogenic liver abscess, with evidence of systemic metastatic infection, was diagnosed. Sonographic features of the liver abscess were atypical for a cystic lesion and instead appeared as a solid mass, raising the possibility of malignancy. Treatment of intravenous ceftriaxone infusions resulted in full resolution of the liver lesion.

The discussion criticises the terminology when describing hepatic lesions, which result from a Klebsiella pnumoniae infection. The term hepatic phlegmon is appropriate when a liver lesion caused by bacterial infection demonstrates a solid appearance on radiologic imaging. The term hepatic abscess is appropriate in cases where liver lesions caused by bacterial infection demonstrate a fluid filled core on radiologic imaging. Differentiation of these terms is important when treating the underlying lesion as a phlegmon, in contrast to an abscess, cannot be drained because it contains no pus. The variable sonographic appearances of Klebsiella pnumoniae pyogenic abscesses were also examined. Despite reported sonographic appearances in the literature, none are sufficient to distinguish a pyogenic liver abscess from malignancy without further investigation.

Ultrasound operators should be aware of the variable sonographic appearances of a Klebsiella pnumoniae liver abscess and how these features, combined with non-homogenous terminology, can obfuscate the correct diagnosis.