BACKGROUND: Skull base osteomyelitis (SBO) typically evolves as a complication of external otitis in diabetic patients and involves the temporal bone. Central SBO (CSBO) mainly involves the sphenoid or occipital bones without coexisting external otitis. We characterized a group of patients with CSBO. The endoscopic nasopharyngeal and clival biopsy technique is described. METHODS: Medical records of patients diagnosed as having SBO were retrospectively analyzed (from 2001 to 2006). Patients' symptoms and signs, laboratory findings, imaging characteristics, endoscopic clival and periclival histopathology results, treatment, and outcome were retrieved. RESULTS: Of 20 patients with SBO, 6 patients without external otitis were studied (age range, 54-76 years; 5 men; mean follow-up, 21 months). All patients suffered from unilateral headache, three of six patients had serous otitis media (SOM), three of six patients had cranial nerve (CN) palsies, and five of six patients had elevated acute-phase reactants. Computed tomography (CT) findings were clival cortical bone erosion and adjacent soft tissue swelling. Magnetic resonance (MR) findings were texture changes and enhancement of the involved bones and soft tissues. Biopsy specimens revealed chronic inflammation. All six patients were treated with antibiotics for 3-6 months. Headache disappeared in five of six patients, SOM resolved in two of three patients, and CN palsies partially recovered in two of three patients. Imaging findings improved in five of six patients. CONCLUSION: CSBO may mimic malignancy and represents a diagnostic challenge. Typical clinical picture and imaging findings together with a positive response to ciprofloxacin may suffice to establish the diagnosis and obviate the need for biopsies. When in doubt, nasopharyngeal and clival biopsies are performed to rule out malignancy.
BACKGROUND: Skull base osteomyelitis (SBO) typically evolves as a complication of external otitis in diabeticpatients and involves the temporal bone. Central SBO (CSBO) mainly involves the sphenoid or occipital bones without coexisting external otitis. We characterized a group of patients with CSBO. The endoscopic nasopharyngeal and clival biopsy technique is described. METHODS: Medical records of patients diagnosed as having SBO were retrospectively analyzed (from 2001 to 2006). Patients' symptoms and signs, laboratory findings, imaging characteristics, endoscopic clival and periclival histopathology results, treatment, and outcome were retrieved. RESULTS: Of 20 patients with SBO, 6 patients without external otitis were studied (age range, 54-76 years; 5 men; mean follow-up, 21 months). All patients suffered from unilateral headache, three of six patients had serous otitis media (SOM), three of six patients had cranial nerve (CN) palsies, and five of six patients had elevated acute-phase reactants. Computed tomography (CT) findings were clival cortical bone erosion and adjacent soft tissue swelling. Magnetic resonance (MR) findings were texture changes and enhancement of the involved bones and soft tissues. Biopsy specimens revealed chronic inflammation. All six patients were treated with antibiotics for 3-6 months. Headache disappeared in five of six patients, SOM resolved in two of three patients, and CN palsies partially recovered in two of three patients. Imaging findings improved in five of six patients. CONCLUSION: CSBO may mimic malignancy and represents a diagnostic challenge. Typical clinical picture and imaging findings together with a positive response to ciprofloxacin may suffice to establish the diagnosis and obviate the need for biopsies. When in doubt, nasopharyngeal and clival biopsies are performed to rule out malignancy.