A diagnostic dilemma of central skull base osteomyelitis mimicking neoplasia in a diabetic patient

Abstract

We present a case which illustrates the diagnostic difficulty in distinguishing between osteomyelitis of the central skull base and base of skull tumours. A woman in her early forties presented with seizures and multiple cranial nerve palsies. She also had a background of chronic otalgia and poorly controlled diabetes mellitus. The clinical diagnosis of skull base osteomyelitis (SBO) was made, but both MRI and bone scans were unable to distinguish this from a skull base malignancy on imaging criteria. Eventually biopsies were required to exclude the diagnosis of malignancy and the patient was treated for central SBO.

Figure 1

MRI scan showing bilateral and central skull base enhancement. Note that the appearances are difficult to distinguish from central skull base neoplasia, especially in the setting of cranial nerve palsies.

Figure 2

CT axial scan showing increased soft tissue in the post nasal space and central skull base region.

Figure 3

Interval MRI scan post-treatment with intravenous antibiotics showing an improvement in the central and bilateral skull base enhancement. This correlated with the patient's improvement in symptoms.