Parotid Diseases
Parotid Gland
Salivary Glands
Encyclopedias as Topic
Origin of acinar cell regeneration after atrophy of the rat parotid induced by duct obstruction. (1/72)
Acinar cell regeneration in the rat parotid gland after atrophy induced by a one week period of duct obstruction was examined using histology, immunohistochemistry and transmission electron microscopy (TEM). For immunohistochemistry, antibodies to 5-bromo-2'-deoxyuridine (BrdU), injected one hour before tissue collection, and cytokeratin were employed. When clips were removed from the duct, only ductal epithelial cells remained; all acinar cells had been deleted. Some duct cells were BrdU positive. After three days, newly-formed acini comprising immature acinar cells had appeared; many of the cells were BrdU positive and mitotic figures were readily identified. Thereafter progressive acinar cell maturation and proliferation occurred, parotid gland weight returning to control levels by 7 days. Peak BrdU labelling indices for duct and acinar cells were on days 0 and 4, respectively. By TEM, cytoplasmic organelles in epithelial cells of transitional duct-acinar structures seen at 2 days were poorly developed. Immature acinar cells seen on day 3 contained zymogen granules and had increased endoplasmic reticulum and mitochondria. By day 5, maturing acinar cells had abundant endoplasmic reticulum and zymogen granules, resembling acinar cells in control glands. These observations indicated origin of acinar cell precursors from duct cells during regeneration of the acinar cell-free atrophic gland. Subsequent expansion of the acinar cell population was dependent on maturation and proliferation of these newly-formed cells. (+info)Nontuberculous mycobacterial infection of the head and neck in immunocompetent children: CT and MR findings. (2/72)
BACKGROUND AND PURPOSE: Infections caused by nontuberculous mycobacteria (NTM) commonly manifest as cervicofacial adenitis in otherwise healthy children. The aim of this study was to characterize the imaging findings of NTM infection of the head and neck in immunocompetent children. METHODS: The medical records and imaging examinations (CT in 10, MR in two) were reviewed in 12 immunocompetent children with NTM infection of the head and neck. RESULTS: The usual presentation (n = 9) was of an enlarging, non-tender mass with violaceous skin discoloration, unresponsive to conventional antibiotics. The duration of symptoms was 6 days to 5 months. Imaging revealed asymmetric adenopathy with contiguous low-density ring-enhancing masses in all patients. There was cutaneous extension in 10 patients. Inflammatory stranding of the subcutaneous fat was minimal (n = 9) or absent (n = 2) in 11 patients. The masses involved the submandibular space (n = 3), the parotid space (n = 2), the cheek (n = 1), the anterior triangle of the neck (n = 2), the submandibular and parotid spaces (n = 2), the parotid space and neck (n = 1), and the neck and retropharyngeal space (n = 1). Surgical management included incision and drainage only (n = 2), incision and drainage with curettage (n = 2), excisional biopsy after incision and drainage (n = 1), excisional biopsy only (n = 5), superficial parotidectomy only (n = 1), and superficial parotidectomy with contralateral excisional biopsy (n = 1). All patients improved in response to surgery and long-term antimycobacterial antibiotics. CONCLUSION: NTM infection of the head and neck has a characteristic clinical presentation and imaging appearance. Recognition of this disease is important; appropriate treatment is excision and, in selected cases, antimycobacterial therapy. (+info)Parotid salivary gland dysfunction in chronic graft-versus-host disease (cGVHD): a longitudinal study in a mouse model. (3/72)
Chronic graft-versus-host disease (cGVHD) is an autoimmune-like phenomenon resulting in morbidity and mortality following allogeneic bone marrow transplantation (BMT). Major salivary gland dysfunction and hyposalivation is one of the prevalent manifestations of cGVHD. We have used the B10.D2 to Balb/C cGVHD mice model in order to assess major salivary gland function in cGVHD, evaluating sialometric, sialochemical and histopathological parameters for almost 3 months. As cGVHD is a chronic debilitating disease it is of vast importance to evaluate these parameters on a prolonged longitudinal basis. We observed significant reduction in parotid salivary flow rate and disturbance in the salivary dynamic function in cGVHD mice in comparison to the normal and syngeneic transplanted controls. On days 18, 25, 46, 56 and 88 the mean flow rates of the cGVHD group were 37.4 +/- 4.4 microl/30 min, 40.5 +/- 4.6 microl/30 min, 32.5 +/- 2.3 microl/30 min, 22.2 +/- 3.2 microl/30 min and 14.8 +/- 3.8 microl/30 min, respectively, values which were lower than those of the syngeneic transplanted controls group by 42% (P < 0.04), 32% (P < 0.03), 44% (P < 0.01), 49% (P < 0.01) and 64% (P < 0.01), respectively. These changes in flow rates were paralleled by changes in the biochemical composition of the saliva. Moreover, the reduction in flow rates correlated with the degree of salivary gland destruction observed in the pathological slides. An inverse correlation was observed between the mean parotid salivary flow rate and the degree of fibrosis observed in the histopathological evaluation of the cGVHD mice (P < 0.01). Maximal flow rate 34.8 +/- 4.6 microl/30 min was observed when no fibrosis was observed while in mice with maximal fibrosis flow rates were minimal. This may point to the pathological mechanism leading to the major salivary gland dysfunction and hyposalivation observed in cGVHD. Thus, it may broaden our knowledge and provide the scientific background for designing better therapeutic strategies for this complication. Bone Marrow Transplantation (2000). (+info)Possible malignant transformation of benign lymphoepithelial parotid lesions in human immunodeficiency virus-infected patients: report of three cases. (4/72)
Benign lymphoepithelial parotid lesions (BLL) are intraparotid pathological changes that are commonly thought to be an early manifestation of human immunodeficiency virus (HIV) infection. It is not well known whether BLL may undergo malignant transformation into B cell lymphoma and may therefore be a sort of precancerous lesion. We report 3 cases of possible malignant transformation of BLL in HIV-infected patients. (+info)Use of botulinum toxin type A in a case of persistent parotid sialocele. (5/72)
Sialocele is an uncommon complication of parotidectomy. Most cases resolve after conservative therapy consisting of repeated aspiration and pressure dressing. The condition is, however, occasionally resistant to such therapy. We report on a 52-year-old Chinese man who had a 10-year history of right parotid swelling. Following fine-needle aspiration cytology, Warthin's tumour was diagnosed, but after elective parotidectomy, a swelling developed and parotid sialocele was diagnosed. Botulinum toxin type A was given after the sialocele had persisted for almost 3 weeks after surgery, and after conservative management had been tried; the sialocele disappeared after two doses of treatment. Botulinum toxin therapy was thus an effective method of treating persistent sialocele. (+info)Earring lesions of the parotid tail. (6/72)
BACKGROUND AND PURPOSE: Masses in the parotid tail can be a source of consternation to radiologists and clinicians; inaccurate localization may lead to significant iatrogenic complication. We sought to review the pertinent anatomic localizing features of the parotid tail, relevant facial nerve anatomy, and sources of clinical and radiologic confusion. To conclude, we review imaging features that are helpful in generating a diagnosis in this location. METHODS: We retrospectively reviewed the imaging and clinical features of 111 parotid tail masses in 103 patients (56 male, 45 female, two of unknown sex; age range, 5 months-81 years). The following imaging findings were noted: size, enhancement, multiplicity of lesions, attenuation on CT scans, signal intensity on MR images, and appearance of the surrounding parotid gland. Diagnosis was confirmed by either surgical resection or biopsy findings or by specific clinical data or characteristic imaging findings. RESULTS: Seventeen types of parotid tail masses were identified. Benign lesions were: pleomorphic adenoma (n = 15), Warthin tumor (n = 14), infectious process (n = 13), venous malformation (n = 9), and Sjogren disease (n = 9), lymphatic malformations (n = 7), lipoma (n = 6), HIV lymphoepithelial lesion (n = 4), first brachial cleft cyst (n = 3), oncocytoma (n = 2), sarcoid (n = 1), and lymph node (n = 1). Malignant lesions were: Non-Hodgkin lymphoma (n = 14), metastatic disease (n = 7), mucoepidermoid carcinoma (n = 4), acinic cell carcinoma (n = 1), and undifferentiated carcinoma (n = 1). Eight patients had two diagnoses. CONCLUSION: Understanding normal parotid tail anatomy is important to radiologists, because accurate localization has implications for appropriate management of masses in this location, potentially reducing the occurrence of marginal mandibular nerve injury. (+info)An audit of parotidectomy in Singapore: a review of 31 cases. (7/72)
A series of 31 consecutive parotidectomies was evaluated. FNAC could differentiate tumour from non tumour in 72.8% of cases. For actual histology, FNAC was correct in 66.6%. Frozen section was correct in differentiating between benign, malignant and inflammatory conditions in all cases. Eighty-eight percent of frozen section histology concurred with final histology. The immediate postoperative period had 13 cases of facial nerve dysfunction, but only 3 cases had residual weakness. The branch most commonly affected was the mandibular branch (92.3%). Two patients had Frey's syndrome and one had a traumatic neuroma. FNAC and CT scans improve preoperative planning, providing histological evidence and the extent of the lesion. (+info)Alcoholic parotid sialosis: a structural and ultrastructural study. (8/72)
OBJECTIVES: The purpose of this study is to demonstrate the histopathological differences between the initial and advanced stages of Alcoholic Sialosis, a pathology that generally involves parotid hypertrophy and structurally affects, to diverse degrees, the other salivary glands. STUDY DESIGN: An analysis and comparison was carried out of the structural and ultrastructural modifications of the parotid glands from the hepatic biopsies of chronic alcoholics with clinical diagnosis of cirrhosis and from autopsies on individuals who had died from alcoholic hepatic cirrhosis. Various samples of normal gland obtained from surgical material were used as a control. RESULTS: The alterations found in the biopsies corresponded to the modifications discovered in the autopsies of alcoholics. Notable in both cases was the massive accumulation of secretory granules of different size, shape and electrodensity, which occupied the cytoplasm of the acinar cells. In both sample types the excretory ducts were enlarged and the epithelium of the striate ducts presented cells with nuclei and cytoplasm of irregular appearance and arrangement. A moderate adipose infiltration in the stroma and slight periacinal edema was also observed. The biopsies revealed, both at optical and electron microscopical levels, lipid inclusions in the acinar cells and the glandular parenchymal ducts. CONCLUSIONS: The structural and ultrastructural findings of the parotid biopsies and autopsies, clearly show that alterations are already present in the salivary glands of chronic alcoholics before the terminal phase of hepatic cirrhosis. The enlargement of the ductal system lumens could be the principal cause of glandular hypertrophy. (+info)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 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 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 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.