Adenoid cystic carcinoma (ACC) is a very rare malignant cancer that occurs in salivary glands. The tumor may occur in either the major (parotid) or minor salivary glands. ACC can even occur in other organs like the trachea, breast, skin, vulva and the lacrimal gland (eye gland which secretes tears). There is no way of telling what the tumor is by just looking at it and in all cases a biopsy must be performed.
ACC has no specific outward signs or symptoms and is never at the top of the differential diagnosis. It may present as a small mass which is growing slowly over the face or neck. It rarely presents with any other symptoms. Many people first discover the mass on the face while shaving or observing a bump on their eye or neck. However, when the tumor is advanced it has a tendency to invade the nearby nerves and may cause pain or a tingling sensation. Sometimes the tumor may grow large and cause paralysis of one side of the face. When carcinoma adenoid cystic occurs in the eye, it may cause a large bulge in the upper eyelid, alter vision or cause mild protrusion of the eye ball. ACC of the trachea can present with changes in voice and mild wheezing.
Unlike other malignancies, carcinoma adenoid cystic is a very slow growing tumor. The majority of individuals easily survive 5-7 years after the diagnosis of this cancer is made. However, ACC also has a tendency to recur after removal. Recent studies indicate that more than 80% of patients with adenoid cystic carcinoma are alive at 5 years but less than 40% are alive at 15 years. The reason for the longevity is that ACC rarely spreads to the lymph nodes or metastasizes to other parts of the body. However, when spread does occur, the tumor tends to migrate to the lungs and liver. Spread to the bones also occurs and is an ominous sign.
Today, one can predict the prognosis of cystic adenoid carcinoma from histology. The prognosis is poor if the tumor has invaded the nerves at surgery or the surgeon is unable to remove the entire tumor because of nearby spread.
ACC occurs in all age groups but the majority of people diagnosed with this cancer are middle aged individuals. Females tend to be more prone to this cancer and no risk factors have been identified. It is believed that some type of genetic damage may be responsible for the cancer.
Diagnosis of cystic adenoid carcinoma is only made by a biopsy and the cancer may occur in several patterns. The more solid pattern is associated with a more virulent course. Recurrence of the tumor can be followed with radiological studies like PET scans.
The standard treatment for ACC is surgery when the tumor is localized. Some centers administer radiation after surgery to decrease the chance of recurrence. So far the cancer has proven resistant to all types of chemotherapy. Currently there are several clinical trials looking at the effects of platinum based drugs on ACC. For more on the trials regarding Adenoid cystic carcinoma, visit the webpage at the national cancer institute or talk to your surgeon.