Anatomy 3 major salivary glands: ◦ The parotid glands ◦ The submandibular glands ◦ The sublingual glands Many minor salivary glands in mucosa of cheeks, lips, palate.
Parotid gland Largest salivary gland Lies b/w sternomastoid and mandible below the EAM Coverings : ◦ True capsule ◦ False capsule – a layer from the deep cervical fascia
Lobes of parotid gland Parotid divided into superficial and deep lobes by the facial nerve Fasciovenous plane of Patey
Structures within the parotid gland1. External carotid artery :2. Retromandibular vein3.Facial nerve.
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.
Parotid duct Stensen’s duct 5cm in length Comes out through anterior surface of glands. Peirces buccinator and opens in buccal mucosa opposite crown of second upper molar tooth.
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
Submandibular duct (Wharton’s duct) About 5 cm long Runs fwd from the deep part of the gland to enter floor of the mouth Opens on a papilla beside the frenulum of the tongue
Structures in relation to submandibular gland The Lingual nerve The Facial artery
Neoplasms of the salivary gland Salivary gland neoplasms forms 1% of all head and neck tumours. 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 It is a ‘Mixed tumor’ Commonest tumor of salivary glands. Histologically it is charcterized by complex intermingling of epithelial component and mesenchymal areas. Sites : 90% Parotids 7% Submandibular gland 3% restOrigin:According to the multicellar theory,these tumours orginate from intercalated duct cells and myoepithelial cells of the salivary glands.
Pathology Macro : rubbery, on cut section, mucoid appearance with zones of cartilage. Micro : pleomorphic stroma 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.
ADENOLYMPHOMA (Warthin’stumor): Adenolymphoma was first reported by Albrecht and Arzt in the year 1910. It is primarily occuring in the parotid 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 Treatment : superficial parotidectomy with care taken to preserive the facial nerve.
ONCOCYTOMA(OXYPHILICADENOMA):>Primarily occur in parotid and are composed ofclusters of large eosinophilic granularcells(oncocytes).>It was first reported by DUPLAY in 1875 andaccording to the multicellular theory of salivarygland neoplasms,oncocytomas orginate from thestriated duct cells.
Clinical features:age:they usually occur among olderindividuals,in their 8th decade of life.SEX:Female predilectionSITE:Superficial lobe of the parotid is the mostfavoured location.Clinically the tumor often produces slowenlarging,painless,uninodular or sometimesmultinodular, movable swealling anterior to theear or over the ramus of the mandible.
HISTOPATHOLOGY:The tumors are cellular,containing round eosinophiliccells with a granular cytoplasm.The nuclei are small and have indentations.The granular appearance of these cells is the result ofthe number of mitochondria present in the cytoplasm.
MONOMORPHIC ADENOMA: It is characterized by proliferation of a single epithelial cell type that has a distinctive architectural patter. It does not exhibit the wide cellular diversities,which are normally encountered in pleomorphic adenomas. Basal cell adenoma is the most common type.
CLINICAL FEATURES: Basal cell adenomas: Age; commonly in 6th decade of life Sex:female Site:commonly involves parotid(70%) and 20% lession are seen in oral cavity and intraoral lession commonly arises from the upper lip and buccal mucosa. It is slow enlarging,firm,encapsulated,movabile lesions and usually measure less than 3cm .
Canalicular adenoma: Age:in 7th decade of life Sex:female Site:Minor salivary glands of the upper lip are the most common site. Major gland rare. Clinically appear as small,painless,movable encapsulated lesions being covered by a smooth intact epithelium.
HISTOPATHOLOGY:Tumors contain epithelial parenchyma,which issharply denacreted from the scant stroma by athick prominet basement appearance.The epithelial cells have a palisading appearnce atthe periphery of the tumour parenchyma.
TREATMENT:Surgical excision with a margin of normal tissue forthese benign and nonaggressive tumors.
MUCOEPIDERMOID TUMOR:It is an unusual type of malignant salivary gland neoplasm withvarying degree of aggressiveness.According to the multicellulartheory ,the mucoepidermiod tumors arises from the excretoryduct cells of the salivary gland.Tumor are graded into low,intermediate and high grade tumordepending upon their cells type.It is made of two types of cells they are-Mucous cells-Epidermoid cellsLow grade tumor have a higher proportion of mucous cellsthen epidermoid cells.High grade tumor have high epidermoid cells.Low grade tumors are smal,encapsulated,non-aggressive.High grade tumors are infiltrative,non-capsulated.largermases,solid,greyish white in appearance.
HISTOLOGICAL: >Low grade tumors contain sheets of mucoid cells separated by bands of epidermoid cells.Mucouc cells are clear and plump with small nuclei.Epidermoid components resemble squamous cell carcinoma. >High grade mucoepidermoid carcinoma are composed nearly entirely of nests of malignant epidermoid cells.Few mucous cells or none at all present.
CLINICAL FEATURES: Age:30 to 40 year Sex:Female predilection Site:The tumor frequently involve the parotid and minor salivary glands of the palate,lips,buccal mucosa,tongue, and retromolar areas etc….
TREATMENT: Surgical excision and radiotherapy
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
HISTHOPATHOLOGY:Tumor consists of either serous or mucous acinar cells ofthe salivary gland.Malignant cells are larger round or polyhedral in shapeand have granular basophilic cytoplasm and darkeccentrically placed nuclei.Cells are often arranged in acinus-like cluster and theyoften resemble the serious acinar cells of the salivarygland.Cell cytoplasm may be vacuolated or sometimes entirelyclearTumor cells may abe arranged in sheets or solid or cysticor even papillary cystic patters wuthin a lymphoid stroma.
TREATMENT: By wide local excision or superficial parotidectomy.
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
HISTOPATHOLOGY:Tumor consist of basaloid epithelial elements thatform cylindric structures.
TREATMENT: Surgical excision of the tumor along with the part of the neural tissue involved is important.
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
CARCINOMA EX-PLEOMORPHIC ADENOMA:This refers to an epithelial caercinoma arising frompleomorphic adenoma.This tumor consist of malignant epithelial componentonly with no mesenchymal element.It is rare.
CLINICAL FEATURE: Sudden rapid increase in size of a slow- growing or stable mass.Facial nerve involvement is another important feature. The gross tumor appears firm ,non- encapsulated ,nodular with areas o0f central necrosis and heamorrhage.
SQUAMOUS CELL CARCINAMO: Primary squamous cell carcinoma is rae in salivary glands. High grade mucoepidermoid carcinoma should be ruled out which may appaear similar to squamous cell carcinoma. Also SCC of skin or upper respiratiry tract with metastasis to salivary glads should be ruled out It has a tendency for local and reginol spread.
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 Temporalis fascial 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 :1. Superficial parotidectomy : superficial to facial nerve2. Total conservative parotidectomy : for benign diseases involving deep lobe. Facial nerve is preserved.3. 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