Malignant tumors of the minor salivary glands in northern Pakistan: a clinicopathological study.

ABSTRACT

BACKGROUND: Malignant tumors of the minor salivary glands comprise a small but significant proportion of oral cancers. We analyzed this group of tumors in our population. METHODS: The records of all cases of malignant minor salivary gland tumors diagnosed at the Armed Forces Institute of Pathology (AFIP), Rawalpindi, Pakistan, during a period of 10 years (1994-2003) are described. The institute receives biopsy material from armed forces and public and private sector hospitals in northern Pakistan as well as referrals for second opinion. RESULTS: A total of 21168 tumors were recorded at the AFIP Tumor Registry during the study period. These included 70 malignant minor salivary gland tumors. Twenty-three of these (32.8%) arose in the palate while the remaining tumors originated at other sites in the oral cavity. The commonest histological type was adenoid cystic carcinoma, constituting 30 cases (42.8%). The next most common type was mucoepidermoid carcinoma comprising 26 (37.1%) cases. The mean age of cases was 43.4 years and the male-to-female ratio was 11.4. There were 2 cases each of polymorphous low-grade adenocarcinoma and clear cell adenocarcinoma. The remaining cases included undifferentiated carcinomas, adenocarcinomas (not otherwise specified) and a few other rare tumors. CONCLUSION: Adenoid cystic carcinoma was the commonest malignant neoplasm of the minor salivary glands followed by mucoepidermoid carcinoma. The palate was the commonest location of these tumors.