Sclerosing polycystic adenosis is a recently described, extremely rare, reactive, sclerosing, inflammatory process somewhat similar to fibrocystic changes and adenosis tumor of the breast. To date, there have been 22 cases described in the literature. Because of the infrequency of this lesion, we describe our combined experience with 16 cases, 1 of which has been previously reported. Thirteen tumors arose in the parotid gland, two involved the submandibular gland, and one arose in the buccal mucosa. There were 9 men and 7 women. Patients ranged in age from 9 to 75 years. Fourteen patients presented with a primary mass. Two were incidental findings in patients with a mixed tumor and an oncocytoma. Tumors ranged in size from 0.3 to 6 cm in greatest dimension. They are typically well circumscribed and are composed of densely sclerotic lobules with prominent cystic change. Hyperplasia of ductal and acinar elements and areas of apocrine-like metaplasia are frequent. Foci with mild ductal epithelial atypia were frequent with >50% of cases demonstrating at least focal areas of duct epithelial hyperplasia with atypia. Follow-up ranged from 1.5 to 40 years. One tumor recurred twice; no patient has developed metastases or died of disease.