Comparison of Intraoperative Findings and Computerised Tomographic Scan of Sinonasal Tumors with Suspected Intracranial Extension: Challenges for the Surgeon and the Radiologist.

Background: Computerised tomographic scanning is a very important radiological tool in the diagnosis of the site, size and extent of sinonasal tumours and to exclude or confirm intracranial extension. Intraoperative findings may occasionally be at variance with the radiologic findings causing radiologic and surgical challenges. Materials and Method: Cases of sinonasal tumours reported as having intracranial extension with computerized tomographic scan were compared with intraoperative findings in order to assess the accuracy of the radiologic report. Results: Twenty nine consecutive cases were reviewed whose computerised tomograhic scan was radiologically reported from various centres as sinonasal tumour with intracranial extension over a nine year period (January 2000-December 2008), Twenty-four(82.8%) were males while five(17.2%) were females. Intraoperative finding of intracranial extension was only established in 10(34.5%) patients (Smales, 5females) with an age range of 1 years to 60years and mean age of 34,1years. Nineteen (65,5%) cases did not have intracranial extension. Transfacial approach was used to resect the tumours in 24(82.8%) cases while combined transcranial and transfacial approaches were used to resect the tumour in 5(17.2%) cases, Cases of misdiagnosis of intracranial extension were most common when ethmoidal, nasopharyngeal and sphenoidal sinuses were involved. The examinations were done using conventional CT machines. Conclusion: Computerized tomographic scan is crucial in evaluating intracranial extension of sinonasal tumours. However conventional CT machines may be associated with incorrect report of intracranial extension. The combined use of 3D CT and gadolinium-enhanced MRI will be more precise in assessing intracranial extension.