Inverted papilloma is a lesion of the mucosal membrane of the nasal cavity and the paranasal sinuses. It is a unique tumour which is characterized by its tendency to recur after incomplete removal, to destroy the bone and rarely transform to malignancy. It is a rare tumour which comprises approximately 0.5 - 4% of all the primary nasal tumours. Different names which are used for this papilloma include villiform cancer, fungiform papilloma, cylindrical/transitional papilloma, schneiderian papilloma, transformation of papilloma and many more. We hereby report a very unusual and challenging case which elicited a range from sinonasal papilloma, with invasion, atypia and foci of transitional cell carcinoma.