Smoking predisposes to parotid adenolymphoma.

Of 574 patients with previously untreated, unremarkable parotid lumps, 194 proved to have pleomorphic adenomas and 73 adenolymphomas. ABO blood group details were available in 59 and 85 per cent of patients respectively. Smoking details were available in 84 per cent of a randomly chosen 46 per cent subgroup of patients with pleomorphic adenomas and in 86 per cent of all those with adenolymphomas. The incidences of smoking and of the ABO blood groups in these two diagnoses were compared with standard sources. There was no evidence that either histological diagnosis of parotid tumours was linked to an abnormal pattern of ABO blood groups. However, there was a much greater incidence of smoking among the adenolymphoma than in the pleomorphic adenoma group: only one of 63 patients with adenolymphoma as opposed to 31 of 75 with pleomorphic adenoma had never smoked, while the mean number of cigarettes smoked by each patient with an adenolymphoma was estimated to be 300,000 as opposed to 80,000 for those with pleomorphic adenoma.