Structures within the parotid gland 1. External carotid artery : Gives terminal branches in the gland Maxillary artery and superficial temporal artery. 2. Retromandibular vein Formed by union of sup. Temporal and maxillary vein Joins post. Auricular vein to form the external jugular vein.
Structures within the parotid gland 3. The facial nerve Enters upper part of posteromedial border Passes forward and downward and divides into Temporal br. Temporofacial Zygomatic br. Main trunk Buccal branches Cervicofacial Marginal mandibular br. Cervial br.
Acute suppurativeparotitis Causative organisms : Staph. aureus, streptococcus viridans, pneumococci commonly. Route : usually from stensen’s duct, rarely blood born Predisposing factors : Dehydrated patients Obstructed duct
Clinical features Pain and swelling on the side of face BRAWNY edematous swelling over parotid region with all signs of inflamation Fever If pressed pus may be seen coming from the opening of stensen’s duct.
Treatment Improve general condition. Improve oral hygeine. Soft diet as chewing is painful. Antibiotics. If no response incision and drainage : Vertical incision on skin but transverse incision on the parotid fascia to safeguard facial nerve and branches
Acute parotitis Usually due to viral parotitis. Rarely in association with tuberculosis, actinomycosis and cat scratch disease. MUMPS – commonest cause Non suppurative Initially unilateral but proceeds to bilateral affection.
Recurrent subacute and chronic parotitis If on both sides, suspect Sjogren’s syndrome. Other causes : calculus, autoimmune Recurrent attacks of pain and swelling. Gland progressively replaced by fibrous tissue.
Management Investigation : sialography Treatment Control infection by antibiotics. Remove stone Dilate the duct if it is constricted Total conservative parotidectomy if all above measures fail
Neoplasms of the salivary gland 75% occur in the parotid glands. In parotid glands, 80% of tumors are benign. Of these 80% are Pleomorphic adenomas. 15% of salivary tumors occur in submandibular glands. Of these 50% are benign and 50% and malignant. In carcinomas mucoepidermoid ca> adenoid cystic ca > adenocarcinoma
10% of salivary tumors occur in sublingual and minor salivary glands 60-70% of these are malignant
Pleomorphic adenoma ‘Mixed tumor’ Commonest tumor of salivary glands. There is cartilage besides epithelial cells on histology. Sites : 90% Parotids 7% Submandibular gland 3% rest
Pathology Macro : rubbery, bosselated, on cut section, mucoid appearance with zones of cartilage. Micro : pleomorphicstroma with pseudocartilage, lymphoid, myxoid and fibrous elements besides epithelial cells.
Clinical features Age : any age but common around 40 yrs Sex : slightly more incidence in females. Painless swelling since years. Slow growth. Site : usually below the lobule of ear. Variable consistency : firm and rubbery
Malignant transformation Malignant transformation may occur in 3% to 5% Signs of malignant transformation : Long duration (10-20yrs) Becomes painful Starts growing rapidly Becomes stony hard Facial nerve involvement L. node involvement. Jaw movement restriction.
Treatment The tumor is radioresistant. Excision is the treatment of choice. For diagnosis FNAC can be done but incisional biopsy is contraindicated. Superficial parotidectomy is the treatment of choice. Submandibular gland : submandibular gland excision.
Warthin’s tumor Represents 5-15% of parotid tumors. Occurs only in parotid. Almost always in lower portion of parotid gland.
Pathology Gross : soft and frequently cystic Micro : cores of papillary processes with abundant lymphoid tissue.
Clinical features Age : middle and old age Sex : much more common in males Painless slow growing tumor over angle of jaw May be bilateral Surface is smooth
Management FNAC Hot spot in 99mTC pertechnate scan Treatment : superficial parotidectomy
Mucoepidermoid carcinoma Slow growing Invade local tissues to a limited degree Occasionally metastasise to lymph nodes, lungs or skin. Clinically they are hard, become fixed when very large.
Acinic cell tumor Almost all occur in parotid gland Composed of cells resembling acini Women > Men Rare and slow growing Tend to be soft and occasionally cystic
Adenoid Cystic Carcinoma Consists of myoepithelial and duct epithelial cells Slow growing but more invasive than the above described malignant tumors Tumor is always more extensive than the physical or radiological appearance Minor glands > submandibular > parotid
Adenocarcinomas, Epidermoid ca & Undifferentiated Ca Resemble various glandular elements seen in salivary glands Divided according to predominant cell type Demonstrate fixation to adjacent bone, pain, anesthesia of skin and paralysis of muscles
In case of parotid gland, facial nerve irritability occurs first, later gives rise to facial paralysis Limitation of jaw movements
Submandibular gland Composed of superficial part and deep part Divided by mylohyoid muscle Superficial part lies in the submandibular triangle b/w 2 bellies of digastric muscle Deep part lies abv & deep to mylohyoid in the floor of mouth
Acute suppurativesialadenitis of submandibular gland Usually secondary to obstruction of Whartons duct Organism – S. aureus common Responds well to antibiotics and improved oral hygiene Rarely, I & D is required
Recurrent subacute and chronic sialoadenitis These inflamations are always secondary to obstruction or autoimmune disease. Recurrent attacks of pain and swelling Sialography confirms the diagnosis and gives a clue about the cause Treatment is of the primary condition
Tumors of submandibular glands Tumors in this gland are uncommon Enlargement is more due to calculus Of all tumors, mixed tumor is most common Swelling is hard but not stony hard and should be differentiated from submandibular lymph node
Obstruction of a major salivary gland duct Characteristic symptom : Recurrent painful swelling of the affected gland at mealtimes. First indication may be acute/ subacute infection
Causes of obstruction Salivary calculi Strictures of the duct wall Edema or fibrosis of the papilla Pressure on the duct Invasion of the duct by malignant neoplasm
Salivary calculi Submandibular calculi are most common Easily demonstrated on plain X ray Calculi within the duct removed via floor of mouth Calculi within the gland or chronic infection excision of the gland
Sublingual and minor salivary gland diseases Mucous cyst (retention cyst) : pink, soft swellings on inner surface of lips and cheeks Cyst and associated minor gland should be excised together Tumors : usually malignant palate > upper lip > rest Treatment : wide excision and grafting
Ranula Extravasation cysts arising from a damaged sublingual duct Ranula = frog (latin) Transluscent bluish swelling in the floor of mouth with vessels running over it May flow over post margin of mylohyoid and present as a plunging ranula Rx : excision, marsupilization
Mikulicz’s disease Characterized by Enlargement of all salivary glands Enlargement of both lacrimal glands Dry mouth This occurs due to replacement of glandular tissue by lymphocytes Occurs b/w 20 and 40 yrs of age Thought to be autoimmune process
Sjogren’s syndrome All features of Mikulicz’s disease plus Dry eyes (Keratoconjuntivitissicca) Generalized arthritis
Frey’s syndrome Also called as auriculo-temporal syndrome Occurs due to damage to the autonomic innervation of the salivary gland Inappropriate regeneration of parasympathetic fibers Stimulation of sweat glands of overlying skin with stimulus of salivation
Causes : Surgery of the parotid gland Injury to parotid gland Clinical features : sweating and erythema at the site of parotid surgery by smell or taste of food.
Investigation : Starch iodine test : After painting the area with iodine Starch applied over the area becomes blue on gustatory stimulus.
Prevention Sternomastoid muscle flap Temporalisfascial flap Artificial membranes Form a barrier between skin and parotid bed to minimise inappropriate regeneration of autonomic nerve fibres.
Treatment Initially conservative management Most recover in 6 months Anti-perspirants Denervation by tympanic neurectomy Injection of botulinum toxin into the afected skin.
Parotidectomy Types : Superficial parotidectomy : superficial to facial nerve Total conservative parotidectomy : for benign diseases involving deep lobe. Facial nerve is preserved. Radical parotidectomy : For carcinomas Facial nerve, fat, facia, muscles and lymph nodes are removed. Later reconstruction using hypoglossal or greater auricular nerve.
Identificaton of facial nerve Conley’s pointer : inferior portion of cartilagnous canal. Facial nerve is 1cm deep and inferior to its tip. Upper border of posterior belly of the digastric muscle. Fascial nerve immediately superior to this. By nerve stimulator
How To Save The Facial Nerve During Parotid Salivary Gland Tumor Surgery.flv