Adenoid cystic carcinomas (ACC) are a type of malignant tumor that arises from glandular tissues, most commonly in the salivary glands. It is a relatively rare form of cancer characterized by the growth of abnormal cells in the affected glandular tissue. The name "adenoid cystic" refers to the tumor's resemblance to both adenocarcinomas (tumors that arise from glandular cells) and cystic tumors (tumors that form sac-like structures filled with fluid).
These carcinomas predominantly occur in the major and minor salivary glands, such as the submandibular and parotid glands, but can also develop in other areas of the body, such as the breast, lacrimal glands, trachea, or vulva. ACCs tend to have a slow-growing nature and exhibit a tendency for local invasion, meaning they can infiltrate surrounding tissues and structures.
Histologically, adenoid cystic carcinomas are characterized by a unique pattern of growth, with the tumor forming ductal and glandular-like structures. It consists of three cell types: myoepithelial cells, ductal epithelial cells, and basement membrane material. ACCs have a tendency to metastasize to distant sites, typically to the lungs and bones, which can make successful treatment more challenging.
The symptoms of adenoid cystic carcinomas depend on the location of the tumor but can include pain, swelling, difficulty swallowing or speaking, and facial weakness. Treatment options generally involve surgery, radiation therapy, and sometimes chemotherapy.
In summary, adenoid cystic carcinomas are a malignant tumor that occurs predominantly in the salivary glands, exhibiting a unique histologic pattern and a propensity for local invasion and distant metastasis.
