CASE PRESENTATION: We described a 43 years old male who presented with a right mastoid swelling, nine years after a right retro-sigmoid craniotomy and excision for a cerebellopontine angle meningioma. He also had multiple cranial neuropathies involving trigeminal, facial and vestibulocochlear nerves. Temporal bone CT and MRI showed features suggestive of cholesterol granuloma with extensive bony erosions. He was treated with surgical excision and drainage where bone wax residues were found intraoperatively. Histopathological analysis of the lesion confirmed the diagnosis of cholesterol granuloma. Post-operatively, the mastoid swelling resolved and his recovery was uneventful.
CONCLUSION: Our case showed that CG could manifest as a complication of bone wax usage in a neurosurgical procedure. Even though further study is needed to draw a definitive conclusion on this theory, we believe this paper will contribute to the current literature as it is the only reported case of cholesterol granuloma with bone wax as the possible causative agent. This is important so that surgeons are aware of this potential complication and use this haemostatic agent more judiciously.
METHODS: The patients were evaluated clinically and FNP was graded using the House Brackmann (HB) scale. High resolution computerized tomography (HRCT) of the temporal bone was used to evaluate temporal bone fractures. Transmastoid facial nerve decompression was performed and the facial nerve function was re-evaluated in subsequent follow ups.
RESULTS: There were five cases with immediate onset and four with delayed onset of FNP. Only three cases had pure temporal bone fractures, the others were associated with other life threatening injuries. The sensitivity and specificity of HRCT temporal bone to detect the obvious facial canal fracture line were 50% and 40% respectively. 75% of patients with immediate onset of HB grade VI FN palsy who were operated within a month recovered completely. Surgeries for the delayed onset FNP were performed at a mean of 70 days (range 51-94). All recovered to HB grade II-III from severe FNP.
CONCLUSIONS: Our study demonstrated that transmastoid FN decompression surgery was beneficial to traumatic nerve injury. Early intervention resulted in better outcomes. However, FN function could still be salvaged even in delayed FN decompression.