Canalicular adenoma is a type of growth that occurs in human

salivary glands The salivary glands in many vertebrates including mammals are exocrine glands that produce saliva through a system of Duct (anatomy), ducts. Humans have three paired major salivary glands (Parotid gland, parotid, Submandibular gland, submandibula ...

. It is a benign growth which occurs in the

epithelial Epithelium or epithelial tissue is a thin, continuous, protective layer of cells with little extracellular matrix. An example is the epidermis, the outermost layer of the skin. Epithelial ( mesothelial) tissues line the outer surfaces of man ...

cells, and is typically arranged in columns of cells that form interconnecting cords. Canalicular adenoma is a very rare

benign Malignancy () is the tendency of a medical condition to become progressively worse; the term is most familiar as a characterization of cancer. A ''malignant'' tumor contrasts with a non-cancerous benign tumor, ''benign'' tumor in that a malig ...

neoplasm; it constitutes about 1% of all salivary gland tumors and about 4% of all benign salivary gland tumors.

Presentation

Canalicular adenoma is most common in patients age 70 to 80, with females affected about four times as often as males. Most growths present in the upper lip; some also occur in the a few present in

palate The palate () is the roof of the mouth in humans and other mammals. It separates the oral cavity from the nasal cavity. A similar structure is found in crocodilians, but in most other tetrapods, the oral and nasal cavities are not truly sep ...

or buccal (cheek) tissue as a slowly enlarging mass. The growths will often arise in multiple places at the same time or develop multiple nodes, despite not being clinically invasive or

malignant Malignancy () is the tendency of a medical condition to become progressively worse; the term is most familiar as a characterization of cancer. A ''malignant'' tumor contrasts with a non-cancerous benign tumor, ''benign'' tumor in that a malig ...

Diagnosis

Canalicular adenoma growths are usually small at the time they are noticed, with an average size of about 1.6 cm. Their histologic appearance is very distinct, with a channel-like pattern between cords and ribbons; the pattern has been described as resembling a "string of pearls." The growths often contain are often small bight

squamous Epithelium or epithelial tissue is a thin, continuous, protective layer of cells with little extracellular matrix. An example is the epidermis, the outermost layer of the skin. Epithelial ( mesothelial) tissues line the outer surfaces of man ...

balls, or morules. They also typically contain a well-developed supporting tissue - a fibrous stroma - which is rich in

hyaluronic acid Hyaluronic acid (; abbreviated HA; conjugate base hyaluronate), also called hyaluronan, is an anionic, nonsulfated glycosaminoglycan distributed widely throughout connective, epithelial, and neural tissues. It is unique among glycosaminog ...

and chondroitin sulphate. In a few cases, the growths may contain small calcium deposits or microliths. Although it is seldom necessary, a

pathologist Pathology is the study of disease. The word ''pathology'' also refers to the study of disease in general, incorporating a wide range of biology research fields and medical practices. However, when used in the context of modern medical treatme ...

can confirm the existence of canalicular adenoma through

immunohistochemistry Immunohistochemistry is a form of immunostaining. It involves the process of selectively identifying antigens in cells and tissue, by exploiting the principle of Antibody, antibodies binding specifically to antigens in biological tissues. Alber ...

studies, with the cells reacting with pancytokeratin, S100 protein and SOX10, with a delicate GFAP reaction around the periphery. Although it is a benign tumor, a positive diagnosis of canalicular adenoma may be necessary to exclude the existence of other medical conditions such as a basal cell adenoma, pleomorphic adenoma,

adenoid cystic carcinoma Adenoid cystic carcinoma is a rare type of cancer that can exist in many different body sites. This tumor most often occurs in the salivary glands, but it can also be found in many anatomic sites, including the breast, lacrimal gland, human lung, ...

, and polymorphous adenocarcinoma.

Treatment

Most instances of canalicular adenoma are treated with conservative

surgery Surgery is a medical specialty that uses manual and instrumental techniques to diagnose or treat pathological conditions (e.g., trauma, disease, injury, malignancy), to alter bodily functions (e.g., malabsorption created by bariatric surgery s ...

References

{{Reflist Oral neoplasia