Local extension staging of sinonasal tumours: retrospective comparison between CT/MRI assessment and pathological findings.

OBJECTIVES: To assess the reliability of clinical staging with CT and MRI in sinonasal cancers.

METHODS: We conducted a retrospective review of patients who underwent surgery for a sinonasal cancer. The 7th edition of the TNM classification was used to establish tumour staging. Standardised preoperative CT/MRI staging was compared with the pathological staging based on specimens obtained during surgery from each subsite within and around the tumour.

RESULTS: We analysed data from 68 patients between January 2010 and December 2014. A comparison of cT and pT stages was established for 49 naso-ethmoidal and 16 maxillary tumours. Clinical staging for naso-ethmoidal cT1 and maxillary cT2 was consistent with pathological results. Clinical staging for naso-ethmoidal cT2, cT3 and cT4b was overstated in comparison with pT findings. The positive predictive value of imaging was <65% for the lamina papyracea, the cribriform plate, the dura, and the frontal and sphenoid sinuses. Sensitivity was over 75% for each anatomical site except for the cribriform plate (73.3%) and the sphenoid sinus (57.2%).

CONCLUSION: Systematic pathologic analysis of the anatomical areas around the sinonasal cancer has to be applied in further studies to improve our therapeutic management. CT/MRI mapping cannot replace accurate assessment of tumour extension during surgery.