Parotid neoplasms refer to abnormal growths or tumors in the parotid gland, which is the largest of the salivary glands and is located in front of the ear and extends down the neck. These neoplasms can be benign (non-cancerous) or malignant (cancerous).

Benign parotid neoplasms are typically slow-growing, painless masses that may cause facial asymmetry or difficulty in chewing or swallowing if they become large enough to compress surrounding structures. The most common type of benign parotid tumor is a pleomorphic adenoma.

Malignant parotid neoplasms, on the other hand, are more aggressive and can invade nearby tissues and spread to other parts of the body. They may present as rapidly growing masses that are firm or fixed to surrounding structures. Common types of malignant parotid tumors include mucoepidermoid carcinoma, adenoid cystic carcinoma, and squamous cell carcinoma.

The diagnosis of parotid neoplasms typically involves a thorough clinical evaluation, imaging studies such as CT or MRI scans, and fine-needle aspiration biopsy (FNAB) to determine the nature of the tumor. Treatment options depend on the type, size, and location of the neoplasm but may include surgical excision, radiation therapy, and chemotherapy.

The parotid gland is the largest of the major salivary glands. It is a bilobed, accessory digestive organ that secretes serous saliva into the mouth via the parotid duct (Stensen's duct), located near the upper second molar tooth. The parotid gland is primarily responsible for moistening and lubricating food to aid in swallowing and digestion.

Anatomically, the parotid gland is located in the preauricular region, extending from the zygomatic arch superiorly to the angle of the mandible inferiorly, and from the masseter muscle anteriorly to the sternocleidomastoid muscle posteriorly. It is enclosed within a fascial capsule and has a rich blood supply from the external carotid artery and a complex innervation pattern involving both parasympathetic and sympathetic fibers.

Parotid gland disorders can include salivary gland stones (sialolithiasis), infections, inflammatory conditions, benign or malignant tumors, and autoimmune diseases such as Sjögren's syndrome.

Parotid diseases refer to conditions that affect the parotid glands, which are the largest of the salivary glands and are located in front of each ear. These glands produce saliva that helps in digestion and keeps the mouth moist. Parotid diseases can cause swelling, pain, dry mouth, or difficulty swallowing, among other symptoms. Some common parotid diseases include:

1. Parotid gland infection (also called parotitis) - an inflammation of the parotid gland due to bacterial or viral infections.
2. Salivary gland stones (also called sialolithiasis) - calcified deposits that form in the salivary ducts and can block the flow of saliva.
3. Salivary gland tumors - abnormal growths that can be benign or malignant, and may require surgical removal.
4. Parotid gland inflammation (also called sialadenitis) - an inflammation of the parotid gland due to autoimmune disorders, radiation therapy, or dehydration.
5. Parotid gland cysts (also called ranula or mucocele) - fluid-filled sacs that form in the salivary gland or duct.

Proper diagnosis and treatment of parotid diseases require a thorough evaluation by a healthcare professional, often involving imaging studies, laboratory tests, and biopsies.

The mastoid is a term used in anatomy and refers to the bony prominence located at the base of the skull, posterior to the ear. More specifically, it's part of the temporal bone, one of the bones that forms the side and base of the skull. The mastoid process provides attachment for various muscles involved in chewing and moving the head.

In a medical context, "mastoid" can also refer to conditions or procedures related to this area. For example, mastoiditis is an infection of the mastoid process, while a mastoidectomy is a surgical procedure that involves removing part or all of the mastoid process.

Salivary glands are exocrine glands that produce saliva, which is secreted into the oral cavity to keep the mouth and throat moist, aid in digestion by initiating food breakdown, and help maintain dental health. There are three major pairs of salivary glands: the parotid glands located in the cheeks, the submandibular glands found beneath the jaw, and the sublingual glands situated under the tongue. Additionally, there are numerous minor salivary glands distributed throughout the oral cavity lining. These glands release their secretions through a system of ducts into the mouth.

An encyclopedia is a comprehensive reference work containing articles on various topics, usually arranged in alphabetical order. In the context of medicine, a medical encyclopedia is a collection of articles that provide information about a wide range of medical topics, including diseases and conditions, treatments, tests, procedures, and anatomy and physiology. Medical encyclopedias may be published in print or electronic formats and are often used as a starting point for researching medical topics. They can provide reliable and accurate information on medical subjects, making them useful resources for healthcare professionals, students, and patients alike. Some well-known examples of medical encyclopedias include the Merck Manual and the Stedman's Medical Dictionary.

Salivary ducts are the excretory tubules that transport saliva from the major and minor salivary glands to the oral cavity. The main function of these ducts is to convey the salivary secretions, which contain enzymes and lubricants, into the mouth to aid in digestion, speech, and swallowing.

There are two pairs of major salivary glands: the parotid glands and the submandibular glands. Each pair has its own set of ducts. The parotid gland's saliva is drained through the parotid duct, also known as Stensen's duct, which opens into the oral cavity opposite the upper second molar tooth. The submandibular gland's saliva is transported through the submandibular duct, or Wharton's duct, which empties into the floor of the mouth near the base of the tongue.

Minor salivary glands are scattered throughout the oral cavity and pharynx, and their secretions are drained via small ducts directly into the oral mucosa.