adenoid cystic carcinoma
Meaning of adenoid cystic carcinoma: An uncommon gland cancer known for creeping along nerves and for returning many years after treatment.
Definition of adenoid cystic carcinoma
Adenoid cystic carcinoma is an uncommon cancer that begins in glands which produce secretions, most often the salivary glands of the mouth and throat. It also arises in tear glands, the windpipe, the breast and the skin. It grows slowly but tends to travel along nerves, which makes complete removal difficult and allows it to return long afterward.
Where does it start?
Any tissue with secreting glands can give rise to it, though some sites are far more common than others.
| Site | How it usually shows itself |
|---|---|
| Salivary glands | A slow-growing lump in the mouth, jaw or neck |
| Tear gland | A bulging eye or altered vision |
| Windpipe or airway | Breathlessness or a persistent cough |
| Breast | A lump, often behaving less aggressively here |
Why does it come back so late?
This carcinoma spreads by following the sheaths that wrap nerves, a pattern called perineural invasion. Tumor cells creep along these paths well beyond the lump a surgeon can see or feel, so margins that look clear may not be. That habit explains both the pain or numbness that can accompany it and the recurrences that appear a decade or more after apparently successful treatment. Long follow-up is the norm for this reason.
How is it different from other salivary gland cancers?
Most salivary tumors are benign. Among the malignant ones, mucoepidermoid carcinoma is more common and tends to declare itself sooner. Adenoid cystic carcinoma is set apart by three things: its slow pace, its attraction to nerves, and its tendency to reach the lungs rather than the surrounding lymph nodes. Under the microscope its cells form a distinctive pattern of small holes that has been likened to a slice of Swiss cheese.
Also known as
Used in a sentence
The pathology report described adenoid cystic carcinoma of the submandibular gland with perineural invasion.
Good to know
Its spread along nerve sheaths means the tumor often extends past what can be seen at surgery, and recurrence more than ten years later is well recognized.
Word origin
Where “adenoid cystic carcinoma” comes from
Adenoid combines the Greek aden, meaning gland, with eidos, meaning form; carcinoma derives from the Greek karkinos, meaning crab.