Melioidosis: Spectrum of Radiological Manifestations

Abstract

Melioidosis, a bacterial infection caused by Burkholderia pseudomallei is expanding in its endemicity around the world. Melioidosis most commonly infects adults with an underlying predisposing condition, mainly diabetes mellitus. Primary skin and soft tissue involvement is more common in younger patients. Almost every organ can be affected, but the most commonly affected organ is the lung followed by the spleen. Melioidosis has a wide range of radiological manifestations making it a mimicker. Diagnosis requires a high index of clinical suspicion in patients with septicemia or a fever of unknown origin living in or with a travel history to endemic areas. We present a pictorial review of the radiological manifestations of melioidosis, which is a useful knowledge for radiologists to help arrive at an early diagnosis. In this pictorial review, we present the radiological manifestations chosen from 139 patients with culture proven melioidosis. Illustrated examples are chosen from our clinical experience of the past 15 years at the National University Hospital in Singapore.

Keywords: Abscess; Burkholderia infections; melioidosis.

Figure 1

Acute pulmonary melioidosis. Chest X-ray at initial presentation (a) Left upper lobe infiltrate (arrow). Two days later there is interval increase with larger infiltrate. (b) Follow-up X-ray. (c) A week later shows complete opacification of the left hemithorax denoting complete involvement of the left lung.

Figure 2

(a) Acute septicemic pneumonic melioidosis. Left upper lobe consolidation. (b) Acute nonsepticemic pneumonia in a 50-year-old patient showing left lower opacity.

Figure 3

Pulmonary cavities. The melioidosis cavities have predilection for upper lobes and are usually thin-walled and rarely contain air-fluid levels.

Figure 4

Splenic abscesses. Multiple hypodensities in spleen in two different patients with melioidosis. Note that spleen is mildly to moderately enlarged.

Figure 5

Splenic abscess with perisplenic extension (blue arrow) along the gastrosplenic ligament (yellow arrow).

Figure 6

Hepatosplenic melioidosis. Computed tomography scan showing multiple discrete liver abscesses (arrow heads) in the liver and extensive splenic involvement (blue arrow).