Brain abscess due to Klebsiella pneumoniae in liver-transplanted children

Introduction. Neurological complications represent a large cause of morbidity and mortality especially in short-term follow-up after liver transplantation. Brain abscesses are quite rare (0.6–1%); and the diagnosis may be difficult because imaging resembles that of central nervous system (CNS) lymphoma (Selby R et al., Arch Surg, 1997). Most reported cases are due to fungal infections, particularly Mycelia (Candida and Aspergillus) whereas bacterial infections are less common (Nocardia). We report the first case of cerebral abscess due to Klebsiella pneumoniae occurring during long-term follow-up of a liver transplanted child. Case report. S.D. underwent orthotopic liver transplantation at 10 months for biliary atresia. At age of 12.5 years, he was admitted for headache and asthenia. At this time physical examination was unremarkable. Routine laboratory tests resulted all negative. Chest X-rays, abdominal ultrasounds and fundus oculi were normal. Head X-rays showed a chronic maxillary sinusitis and treatment with amoxicillin was started. Four days later the patient was newly admitted for increasing weakness and behaviour changes (sad and melancholic). Neurological examination showed marked left lower limb hypostenia. EEG showed focal irritation of right anterior temporal–parietal region.CTrevealed a voluminous not homogeneous lesion on the right temporal-parietal lobe with multiple cystic-like areas and surrounding oedema, which caused a right ventricular dislocation, suggesting a CNS lymphoma diagnosis. Mannitol i.v. was started. Differently from CT scan, MR imaging showed a unique multilobate lesion with a heterogeneous solid–liquid content suggesting an infectious nature. This lesion caused a mass effect on the median line and on the ventricles. Microbiological studies on the purulent material obtained by stereotactic drainage revealed Klebsiella pneumoniae, sensitive only to ciprofloxacin and meronem. A treatment with these drugs was continued for 4 months. Follow-up revealed clinical symptoms resolution and imaging improvement. Conclusions. Appearance of neurological symptoms during long-term follow-up of immunosuppressed patients should alert clinicians to consider a brain abscess in differential diagnosis also in the absence of overt clinical/laboratoristic infectious signs. Our case due to Klebesiella pneumoniae demonstrates the possible pathogenetic role of bacteria other than Nocardia.