Unusual polypoidal tumours of the nasal cavity: a clinicopathological review of 18 casesA variety of nasal conditions may present as simple polypi. Clinically, these lesions, some very rare, present a diagnostic problem. Eighteen cases of unusual lesions which were thought to be simple polyps on clinical grounds are reviewed with the relevant literature. The series includes 2 olfactory neuroblastomas, a haemangiopericytoma and a basal encephalocoele. Atypical features from the history and examination are highlighted. It is emphasized that every nasal polyp must be submitted for histological examination and the pathology report consulted when the patient is reviewed. Failure to do so delays appropriate treatment.