Adenoid Cystic Carcinoma

Li Liu, MD
Last Modified: November 1, 2001

Dear OncoLink "Ask the Experts,"
I have recently been diagnosed with adenoid cystic carcinoma (cylindroma) minor salivary gland tumor but am unable to find any information. Can you help?

Li Liu, MD, OncoLink Editorial Assistant, responds:

Thank you for your interest and question.

Malignant tumors in minor salivary glands are relatively rare. The histologic varieties include adenoid cystic carcinoma, mucoepidermoid carcinoma, adenocarcinoma, malignant mixed, acinic cell, and oncocytic carcinomas. Adenoid cystic carcinoma is the most common histologic subtype, comprising approximately two thirds of the malignant tumors in minor salivary glands.

Due to the low incidence and relatively modest experience, there is no consensus on the exact role of surgery with postoperative radiotherapy or radiotherapy alone. The most comprehensive series were reported by Dr. Parsons from University of Florida (International Journal of Radiation Oncology, Biology, and Physics, 35:443-454, 1996). According to their experience, adenoid cystic carcinoma has the worst prognosis. This is probably due to its insidious growth pattern, tendency to develop late recurrences, and a high rate of distant metastases. The recurrences and/or metastases can occur more than 10 years after diagnosis of the primary tumor.

The treatment options are dependent upon the site and stage of the tumor. Dr. Parsons recommended combined surgery and radiotherapy for most of the cases, but there are situations where surgery alone or radiotherapy alone may be used. The role of combining chemotherapy with radiotherapy has not been defined at this point.

You should discuss your case with your oncologists.