Co-existing pleomorphic and tubular basal cell adenomas of the parotid gland.

We report a hitherto undescribed case of co-existence of a pleomorphic adenoma and a tubular basal cell adenoma affecting the superficial lobe of the left parotid gland of a 53-year-old man. The histology of the pleomorphic adenoma is also of interest in that the prominent adipose metaplasia of its myxoid stroma yielded an appearance reminiscent of myxoid lipoma. The tubular basal cell adenoma showed gross cystic change, and its solid portion consisted of closely packed tubules lined by double layers of cuboidal cells with little intervening stroma. Unlike Warthin's tumour and membranous basal cell adenoma, both pleomorphic and tubular basal cell adenomas exhibit no propensity towards multicentricity or bilaterality. We, therefore, believe that their co-existence in the superficial lobe of the parotid gland of our patient is a mere coincidence rather than association.