Inflammatory Pseudotumor of the Liver with Escherichia coli in the Sputum.

Inflammatory pseudotumor is a nonmalignant lesion that mimics malignant lesions and has been reported to occur at various sites throughout the body. Though it has been reported as a reaction to infection, the true etiology of the lesion is unknown. In this report, we present the case of a patient with a liver lesion of unknown origin. Through a series of imaging studies, we were able to observe the locally aggressive nature of this lesion as it rapidly eroded into the lung. Sputum cultures showed growth of E. coli, indicating E. coli infection as a possible etiology of this lesion. Pathology was consistent with inflammatory pseudotumor.