Adenocarcinoma (AC) is a type of cancerous tumor that can occur in several parts of the body. It is defined as neoplasia of epithelial tissue that has glandular origin, glandular characteristics, or both. Adenocarcinomas are part of the larger grouping of carcinomas, but are also sometimes called by more precise terms omitting the word, where these exist. Thus invasive ductal carcinoma, the most common form of breast cancer, is adenocarcinoma but does not use the term in its name—however, esophageal adenocarcinoma does to distinguish it from the other common type of esophageal cancer, esophageal squamous cell carcinoma. Several of the most common forms of cancer are adenocarcinomas, and the various sorts of adenocarcinoma vary greatly in all their aspects, so that few useful generalizations can be made about them.
Epithelium or epithelial tissue is one of the four basic types of animal tissue, along with connective tissue, muscle tissue and nervous tissue. It is a thin, continuous, protective layer of compactly packed cells with a little intercellular matrix. Epithelial tissues line the outer surfaces of organs and blood vessels throughout the body, as well as the inner surfaces of cavities in many internal organs. An example is the epidermis, the outermost layer of the skin.
The parotid gland is a major salivary gland in many animals. In humans, the two parotid glands are present on either side of the mouth and in front of both ears. They are the largest of the salivary glands. Each parotid is wrapped around the mandibular ramus, and secretes serous saliva through the parotid duct into the mouth, to facilitate mastication and swallowing and to begin the digestion of starches. There are also two other types of salivary glands; they are submandibular and sublingual glands. Sometimes accessory parotid glands are found close to the main parotid glands.
An adenoma is a benign tumor of epithelial tissue with glandular origin, glandular characteristics, or both. Adenomas can grow from many glandular organs, including the adrenal glands, pituitary gland, thyroid, prostate, and others. Some adenomas grow from epithelial tissue in nonglandular areas but express glandular tissue structure. Although adenomas are benign, they should be treated as pre-cancerous. Over time adenomas may transform to become malignant, at which point they are called adenocarcinomas. Most adenomas do not transform. However, even though benign, they have the potential to cause serious health complications by compressing other structures and by producing large amounts of hormones in an unregulated, non-feedback-dependent manner. Some adenomas are too small to be seen macroscopically but can still cause clinical symptoms.
Surface epithelial-stromal tumors are a class of ovarian neoplasms that may be benign or malignant. Neoplasms in this group are thought to be derived from the ovarian surface epithelium or from ectopic endometrial or Fallopian tube (tubal) tissue. Tumors of this type are also called ovarian adenocarcinoma. This group of tumors accounts for 90% to 95% of all cases of ovarian cancer; however is mainly only found in postmenopausal women with the exception of the United States where 7% of cases occur in women under the age of 40. Serum CA-125 is often elevated but is only 50% accurate so it is not a useful tumor marker to assess the progress of treatment. 75% of women with epithelial ovarian cancer are found within the advanced-stages; however younger patients are more likely to have better prognoses than older patients.
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 gland tumor and the most common tumor of the parotid gland. It derives its name from the architectural Pleomorphism seen by light microscopy. It is also known as "Mixed tumor, salivary gland type", which refers to its dual origin from epithelial and myoepithelial elements as opposed to its pleomorphic appearance.
In anatomy and physiology, a duct is a circumscribed channel leading from an exocrine gland or organ.
Acinic cell carcinoma is a malignant tumor representing 2% of all salivary tumors. 90% of the time found in the parotid gland, 10% intraorally on buccal mucosa or palate. The disease presents as a slow growing mass, associated with pain or tenderness in 50% of the cases. Often appears pseudoencapsulated.
Ceruminous glands are specialized sudoriferous glands located subcutaneously in the external auditory canal, 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 layer of cells. They are classed as apocrine glands. The glands drain into larger ducts, which then drain into the guard hairs that reside in the external auditory canal. Here they produce cerumen, or earwax, by mixing their secretion with sebum and dead epidermal cells. Cerumen keeps the eardrum pliable, lubricates and cleans the external auditory canal, waterproofs the canal, kills bacteria, and serves as a barrier to trap foreign particles by coating the guard hairs of the ear, making them sticky.
Salivary gland tumours, also known as mucous gland adenomas or neoplasms, are tumours that form in the tissues of salivary glands. The salivary glands are classified as major or minor. The major salivary glands consist of the parotid, submandibular, and sublingual glands. The minor salivary glands consist of 800 to 1000 small mucus-secreting glands located throughout the lining of the oral cavity. Patients with these types of tumours may be asymptomatic.
Epithelial-myoepithelial carcinoma of the lung is a very rare histologic form of malignant epithelial neoplasm ("carcinoma") arising from lung tissue.
Salivary gland–like carcinomas of the lung generally refers a class of rare cancers that arise from the uncontrolled cell division (mitosis) of mutated cancer stem cells in lung tissue. They take their name partly from the appearance of their abnormal cells, whose structure and features closely resemble those of cancers that form in the major salivary glands of the head and neck. Carcinoma is a term for malignant neoplasms derived from cells of epithelial lineage, and/or that exhibit cytological or tissue architectural features characteristically found in epithelial cells.
Odontogenic cyst are a group of jaw cysts that are formed from tissues involved in odontogenesis. Odontogenic cysts are closed sacs, and have a distinct membrane derived from rests of odontogenic epithelium. It may contain air, fluids, or semi-solid material. Intra-bony cysts are most common in the jaws, because the mandible and maxilla are the only bones with epithelial components. That odontogenic epithelium is critical in normal tooth development. However, epithelial rests may be the origin for the cyst lining later. Not all oral cysts are odontogenic cyst. For example, mucous cyst of the oral mucosa and nasolabial duct cyst are not of odontogenic origin.
In addition, there are several conditions with so-called (radiographic) 'pseudocystic appearance' in jaws; ranging from anatomic variants such as Stafne static bone cyst, to the aggressive aneurysmal bone cyst.
Myoepithelioma of the head and neck, also myoepithelioma, is a salivary gland tumour of the head and neck that is usually benign. When malignant, which is exceedingly rare, they are known as malignant myoepithelioma or Myoepithelial carcinoma, and they account for 1% of the salivary tumors with poor prognosis.
Epithelial-myoepithelial carcinoma (EMCa) is a rare malignant tumour that typically arises in a salivary gland and consists of both an epithelial and myoepithelial component. They are predominantly found in the parotid gland and represent approximately 1% of salivary gland tumours.
Hyalinizing clear cell carcinoma (HCCC) is a rare malignant salivary gland tumour, with a good prognosis, that is usually found on the tongue or palate.
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 along the posterior surface; therefore, the tumor develops within a very specific location.
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 otherwise specified (NOS), ceruminous adenoid cystic carcinoma (ACC), and ceruminous mucoepidermoid carcinoma.
Sclerosing polycystic adenosis is a rare salivary gland tumor first described in 1996 by Dr. Brion Smith. The major salivary glands, specifically the parotid gland and the submandibular gland, are affected most commonly. Patients usually come to clinical attention with a mass or swelling in their salivary glands in the 5th decade of life, with females affected much more commonly than males. Nearly all of the cases reported so far have a benign behavior, although there is a single case that has had an associated malignant transformation.
Papillary carcinomas of the breast (PCB), also termed malignant papillary carcinomas of the breast, are rare forms of the breast cancers. The World Health Organization (2019) classified papillary neoplasms of the breast into 5 types: intraductal papilloma, papillary ductal carcinoma in situ (PDCIS), encapsulated papillary carcinoma (EPC), solid-papillary carcinoma (SPC), and invasive papillary carcinoma (IPC). The latter four carcinomas are considered here; intraductal papilloma is a benign neoplasm considered in its Wikipedia page. The World Health Organization regarded solid papillary carcinoma as having two subtypes: in situ and invasive SPC.
