Adenoid Cystic Carcinoma of the Palate

A histological re-classification of 383 tumours primary in the palate showed an adenoid cystic carcinoma in 37 cases. The relative incidence of this type of tumour is considerably higher in the palate than in the submandibular and parotid glands. A distinct difference is present between the prognosis in tumours at these three sites. Thus, the prognosis is best when the adenoid cystic carcinoma is located to the palate, and worst when it is located to the submandibular gland. The 37 adenoid cystic carcinomas of the palate were divided into two histologically characteristic types of differentiation: one with predominance of the cribriform component, and one with predominance of the solid component. A long-term clinical follow-up study disclosed a much better prognosis in tumours with predominance of the cribriform component, as compared to the extremely poor prognosis in tumours with predominance of the solid component. It is pointed out that a histological grading of adenoid cystic carcinoma into high-grade and low-grade malignant types is justified, and is of clinical significance.