Primary Intraosseous Adenoid Cystic Carcinoma of the Jaw: Clinical and Histopathologic Analysis

Abstract

Adenoid cystic carcinoma (ACC), formerly known as cylindroma, is a malignant epithelial neoplasm typically derived from the salivary glands. Of all salivary gland tumors, the incidence of malignant salivary gland tumor has been 15 to 32% in the parotid glands, 70 to 90% in the sublingual glands, and about 50% in the minor salivary glands. Intraosseous ACC of the jaw has rarely been reported and is poorly understood. The aim of the present study was to analyze this tumor clinically and histopathologically to improve the diagnosis, management, and treatment. We collected the records of 16 patients with intraosseous ACC from 1998 to 2013, who had been treated at our hospital, including clinical data and follow-up information. We then analyzed the patients' clinical features, diagnosis, treatment, and prognosis. The average age of the 16 patients was 56.8 years, and the male/female ratio was 0.8. The primary manifestations of the tumor were obviously different. Tumor excision was performed and followed by radiotherapy or chemotherapy, or both. The average follow-up period was 57.2 months, and the average follow-up period for patients who were alive and tumor free was 52.3 months. The survival rate was 68.8% after treatment. All these results were generally in agreement with those from previous reports. The differential diagnosis of intraosseous ACC from other common tumors of jaws should be determined by the clinical, radiographic, and histopathologic subtypes. For treatment, surgery is the first choice for patients, and radiotherapy or chemotherapy might improve the prognosis in the postoperative period. In addition, the histopathologic subtypes and biologic processes of ACC are related to patient prognosis.