Ceruminous glands are specialized
sudoriferous glands
Sweat glands, also known as sudoriferous or sudoriparous glands, , are small tubular structures of the skin that produce sweat. Sweat glands are a type of exocrine gland, which are glands that produce and secrete substances onto an epithelial sur ...
(sweat glands) located
subcutaneously
The subcutaneous tissue (), also called the hypodermis, hypoderm (), subcutis, superficial fascia, is the lowermost layer of the integumentary system in vertebrates. The types of cells found in the layer are fibroblasts, adipose cells, and macro ...
in the
external auditory canal
The ear canal (external acoustic meatus, external auditory meatus, EAM) is a pathway running from the outer ear to the middle ear. The adult human ear canal extends from the pinna to the eardrum and is about in length and in diameter.
Stru ...
, in the outer 1/3. Ceruminous glands are simple, coiled, tubular glands made up of an inner secretory layer of cells and an outer
myoepithelial
Myoepithelial cells (sometimes referred to as myoepithelium) are cells usually found in glandular epithelium as a thin layer above the basement membrane but generally beneath the luminal cells. These may be positive for alpha smooth muscle actin a ...
layer of cells.
They are classed as
apocrine
Apocrine () glands are a type of exocrine gland, which are themselves a type of gland, i.e. a group of cells specialized for the release of secretions. Exocrine glands secrete by one of three means: holocrine, merocrine and apocrine. In apocri ...
glands. The glands drain into larger ducts, which then drain into the guard hairs that reside in the
external auditory canal
The ear canal (external acoustic meatus, external auditory meatus, EAM) is a pathway running from the outer ear to the middle ear. The adult human ear canal extends from the pinna to the eardrum and is about in length and in diameter.
Stru ...
.
Here they produce
cerumen
Earwax, also known by the medical term cerumen, is a brown, orange, red, yellowish or gray waxy substance secreted in the ear canal of humans and other mammals. It protects the skin of the human ear canal, assists in cleaning and lubrication, ...
, or earwax, by mixing their secretion with
sebum
A sebaceous gland is a microscopic exocrine gland in the skin that opens into a hair follicle to secrete an oily or waxy matter, called sebum, which lubricates the hair and skin of mammals. In humans, sebaceous glands occur in the greatest nu ...
and dead
epidermal
The epidermis is the outermost of the three layers that comprise the skin, the inner layers being the dermis and hypodermis. The epidermis layer provides a barrier to infection from environmental pathogens and regulates the amount of water relea ...
cells.
Cerumen
Earwax, also known by the medical term cerumen, is a brown, orange, red, yellowish or gray waxy substance secreted in the ear canal of humans and other mammals. It protects the skin of the human ear canal, assists in cleaning and lubrication, ...
keeps the eardrum pliable, lubricates and cleans the
external auditory canal
The ear canal (external acoustic meatus, external auditory meatus, EAM) is a pathway running from the outer ear to the middle ear. The adult human ear canal extends from the pinna to the eardrum and is about in length and in diameter.
Stru ...
, waterproofs the canal, kills bacteria, and serves as a barrier to trap foreign particles (dust, fungal spores, etc.) by coating the guard hairs of the ear, making them sticky.
These glands are capable of developing both
benign
Malignancy () is the tendency of a medical condition to become progressively worse.
Malignancy is most familiar as a characterization of cancer. A ''malignant'' tumor contrasts with a non-cancerous ''benign'' tumor in that a malignancy is not s ...
and
malignant
Malignancy () is the tendency of a medical condition to become progressively worse.
Malignancy is most familiar as a characterization of cancer. A ''malignant'' tumor contrasts with a non-cancerous ''benign'' tumor in that a malignancy is not s ...
tumors. The
benign
Malignancy () is the tendency of a medical condition to become progressively worse.
Malignancy is most familiar as a characterization of cancer. A ''malignant'' tumor contrasts with a non-cancerous ''benign'' tumor in that a malignancy is not s ...
tumors include
ceruminous adenoma
A ceruminous adenoma is a benign glandular neoplasm which arises from the ceruminous glands located within the external auditory canal. These glands are found within the outer one third to one half of the external auditory canal, more common alon ...
,
ceruminous pleomorphic adenoma
Pleomorphic adenoma is a common benign salivary gland neoplasm characterised by neoplastic proliferation of epithelial (ductal) cells along with myoepithelial components, having a malignant potentiality. It is the most common type of salivary glan ...
, and
ceruminous syringocystadenoma papilliferum
Syringocystadenoma papilliferum is a benign apocrine tumor.James, William; Berger, Timothy; Elston, Dirk (2005). ''Andrews' Diseases of the Skin: Clinical Dermatology''. (10th ed.). Saunders. .
It can arise with nevus sebaceus. Additional images ...
. The malignant tumors include
ceruminous adenocarcinoma
Ceruminous adenocarcinoma is a malignant neoplasm derived from ceruminous glands of the external auditory canal. This tumor is rare, with several names used in the past. Synonyms have included cylindroma, ceruminoma, ceruminous adenocarcinoma, not ...
,
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, lung, brain ...
, and
mucoepidermoid carcinoma
Mucoepidermoid carcinoma (MEC) is the most common type of minor salivary gland malignancy in adults. Mucoepidermoid carcinoma can also be found in other organs, such as bronchi, lacrimal sac, and thyroid gland.
Mucicarmine staining is one stain us ...
.
See also
*
References
External links
Anatomy Atlases - Ceruminous Gland
Glands
Ear
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