Multiloculated Liver Abscess Due to Hypermucoviscous Klebsiella pneumoniae

(See page 257 for the Photo Quiz.) Diagnosis: Klebsiella pneumoniae liver abscess with sepsis and bacteremia. The primary infectious differential diagnosis of ring-enhancing liver lesions includes echinococcal, amoebic, and pyogenic liver abscess. However, Echinococcus granulosis is not endemic in the Philippines [1], and radiographic features considered pathognomonic for hydatid cysts (such as the presence of a laminar layer or of daughter cysts that contain fluid of lower density than the surrounding mother cyst fluid [2]) were absent. In this case, epidemiologic, historic, and imaging characteristics (see Figure 1) pointed toward a diagnosis of pyogenic liver abscess, while growth of bacterial colonies with features characteristic of K. pneumoniae on blood agar (see Figure 2) confirmed the diagnosis. In recent series, pyogenic liver abscess has been increasingly common in patients of Asian descent [3, 4]. A previous history of biliary disease, as in this case, is an important risk factor for pyogenic liver abscess [4]. Further, the most common radiographic finding in amoebic liver abscess (ALA) is a single, nonloculated subcapsular abscess (85% in one series); the presence of multiple abscesses argues against a diagnosis of ALA [5, 6]. Multiloculated liver abscesses are not uncommon in case series’ of K. pneumoniae liver abscess, although the more common finding is that of a single, right-sided lesion [3].