Adenoid Cystic Carcinoma

Definition

Definition of Adenoid Cystic Carcinoma
Adenoid cystic cancer (AdCC) is a rare type of cancer that can exist in many different body sites. It most often occurs in the areas of the head and neck, in particular the salivary glands; but has also been reported in the breast, lacrimal gland of the eye, lung, brain, bartholin gland, trachea, and the paranasal sinuses. It is sometimes referred to as adenocyst, malignant cylindroma, adenocystic, adenoidcystic, ACC, AdCC.

Symptoms

Symptoms of Adenoid Cystic Carcinoma
These depend largely on the site of origin of the tumor. Early lesions of the salivary glands present as painless masses of the mouth or face, usually growing slowly. Advanced tumors may present with pain and/or nerve paralysis, for this neoplasm has a propensity to invade peripheral nerves. Tumors of the lacrimal gland may present as proptosis and changes in vision. ACC arising in the tracheobronchial tree may present with respiratory symptoms, while tumors arising in the larynx may lead to changes in speech.

Causes

Causes of Adenoid Cystic Carcinoma
A wide age range has been reported for adenoid cystic carcinoma, including cases in the pediatric age group. Most individuals are diagnosed with the disease in the fourth through sixth decades of life. There is a slight female preponderance (female to male ratio approximately 3 to 2). No strong genetic or environmental risk factors have been identified. Damage to the DNA genome occurs in the development of ACC, as it does in all cancers studied to date. Various studies have shown chromosomal abnormalities and genetic deletions occurring in samples of ACC. There is some evidence that the p53 tumor suppressor gene is inactivated in advanced and aggressive forms of this neoplasm. Otherwise the specific molecular abnormalities that underlie this disease process are unknown.

Diagnosis

Diagnosis of Adenoid Cystic Carcinoma
The diagnosis is made by histologic analysis of a biopsy or resection specimen of a tumor mass. There are three major variant histologic growth patterns of ACC: cribriform, tubular and solid. The solid pattern is associated with a more aggressive disease course. There are no serum markers for this neoplasm. Recurrences are usually identified by radiographic imaging techniques, such as computed tomography.

Treatment

Treatment of Adenoid Cystic Carcinoma
Primary treatment for this cancer, regardless of body site, is surgical removal with clean margins. This surgery can prove challenging in the head and neck region due to this tumour's tendency spread along nerve tracts. Adjuvant or palliative radiotherapy is commonly given following surgery. In some cases surgery is not a reasonable option, however radiation used alone may provide an effective treatment. Chemotherapy is used for metastatic disease. Chemotherapy is considered on a case by case basis, as there is limited trial data on the positive effects of chemotherapy. Clinical studies are ongoing, however.

Prognosis

Prognosis of Adenoid Cystic Carcinoma
In addition, AdCC generally nests in the salivary glands but can be found in areas including the brain, the eye, AdCC of the breasts, trachea, lungs and even the paranasal sinuses. It is prone to spreading along the nerve cells or throughout the bloodstream and can often times spread to other bodily sites from its origin. Although it is not a benign disease, this type of cancer progresses in a slow pace over several years while other cases tend to be far more aggressive. Spreading throughout the lungs can create life-threatening ramifications. Despite no indication of any specific environmental or genetic factors including genetic abnormalities associated with adenoid cystic carcinoma prognosis, it is known that this type of cancer can impair DNA, which is not uncommon with the majority of cancers.

Prevention

Prevention of Adenoid Cystic Carcinoma
Consult with your doctor.