Klebsiella Pneumoniae Brain Abscess in a Patient With Chronic Lymphocytic Leukemia.

Klebsiella Pneumoniae (K. pneumoniae) is a common nosocomial pathogen. However, Klebsiella-associated meningitis and brain abscess formation are extremely rare in the United States. We present a case of a 73-year-old male who initially presented for a tonsillar abscess of unknown etiology. While awaiting an abscess biopsy, the patient underwent molar extraction for chronic periodontitis and decay. The patient subsequently developed K. pneumoniae bacteremia and meningitis. As he clinically declined, repeat imaging revealed a brain abscess with eventual hemorrhagic transformation. Notably, the patient had underlying hypogammaglobulinemia from chronic lymphocytic leukemia (CLL), which we believe contributed to the invasive disease. Given the global spread of virulent strains of Klebsiella (such as hypervirulent or hypermucoviscous K. pneumoniae), clinicians must bear this pathogen in mind while treating critically ill and immunocompromised patients.