A 57-year-old-man underwent resection of a right temporal GBM, followed by radiotherapy and 9 cycles of 5-day temozolomide, irinotecan, and bevacizumab. Fifteen months later the tumor recurred in the right occipital lobe and was treated with radiation and multiple rounds of chemotherapy including (etoposide/bevacizumab for 7 months, followed by imatinib / hydroxyurea / bevacizumab for 2 months, then carboplatin/bevacizumab for another 2 months). He developed progressive disease requiring further surgery. His bevacizumab was stopped 6 weeks prior to the craniotomy and tumor resection. There was no problem associated with wound healing following surgery and the sutures were removed in a delayed manner on the 14th post operative day.
About a month after surgery he developed progressively worsening headaches and noticed a serous discharge from his wound, 2 days prior to presenting in the emergency department. There was no preceding head trauma, fever, history of a urinary, or gastrointestinal infection. There were no other associated neurological symptoms. On examination he was afebrile, with meningeal signs and a fluctuant cranial wound. The remainder of his neurological examination was unremarkable. The wound was partially opened in the emergency room, following which a foul smelling purulent discharge was seen.
His routine labs revealed anemia (hemoglobin 8.3 g/dl), neutrophilic leukocyte (total white blood cells 4.03 x 109/L; 84%, with a left shift), thrombocytopenia (platelets 71,000/mm3), and normal electrolytes. A slightly elevated C-reactive protein (CRP) level (1.3 mg/dl, normal value<0.8 mg/dl) was also noted. Renal and liver function tests were normal. A computed tomography (CT) scan of his brain showed a right sided intracranial and subdural fluid collection with diffuse leptomeningeal enhancement, without any evident mass effect or midline shift [Figure 1]. Although a magnetic resonance imaging (MRI) scan would have been more sensitive and specific, we felt the CT scan provided adequate information prior to our emergent surgical intervention.
The patient underwent an emergent re-exploration of his craniotomy and a wound washout. There was immediate egress of pus under pressure with epidural, subdural, and intracavitary involvement. The right occipital ventricular horn was communicating with the surgical cavity and because of the leptomeningeal enhancement on the CT scan, along with the surgical cavity being filled with pus, a ventricular drain was placed for post operative care. The purulent material was sent for diagnostic studies and antibiotic therapy empirically started with meropenem, vancomycin, and metronidazole. Gram stain of the pus revealed gram negative rod-shaped bacteria and culture grew Salmonella group D (S. enteritidis). CSF analysis revealed clear fluid, no blood cells, low glucose (2 mg/dl), and low protein (8 mg/dl) with cultures reported negative for the growth of bacteria, and Acid Fast Bacilli (AFB) testing for tuberculosis. The first blood culture grew Salmonella enteritidis, which was sensitive to ampicillin, ceftriaxone, chloramphenicol, and trimethoprim-sulfamethoxazole. However, urine, stool, and CSF cultures were persistently negative. The chest x-ray, abdominal X-ray, and abdominal ultrasound were all unremarkable. The antibiotics were changed to ceftriaxone (2g intravenous q12 hour) on third day after blood culture sensitivity results were obtained and he was treated for with parenteral antibiotics four weeks.