Two types of adenocarcinoma

• without salivary gland pattern
• the middle turbinate or in the ethmoid sinus
• arise from the mucosal lining
• mostly well differentiated

• salivary gland tumours
• features of an underlying pleomorphic adenoma
• predilection for the nasal septum and turbinates or ostial regions
• nasal cavity - relatively high proportion of benign tumours
• paranasal sinuses - mostly malignant (adenoid cystic carcinoma commonest)
• nearly all types can be seen

• recurrence rate depends almost entirely on the adequacy of primary excision
• simple enucleation - very high recurrence
• most recurrences in the first 18 months
• accounts for 5 to 10% of malignant mixed tumours
• only the epithelial component become malignant
• de novo malignant mixed tumours - biphasic component