Dideases of parotid lecture 2021 (1).pptx

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1. PAROTID GLAND Dr Urooj Ahmed Abbasi Senior registrar General surgery

2. OBJECTIVES TO KNOW; Surgical Anatomy Inflammatory disorders Obstructive disorders Tumors of parotid gland Parotidectomy & its complications

3. INTRODUCTION Major salivary gland a. Parotid gland b. Submandibular gland c. Sublingual gland 2. Minor salivary gland 450 minor salivary gland distributed throughout the mucosa of the upper aerodigestive tract.

4. INTRODUCTION

5. SURGICAL ANATOMY PAROTID GLAND: Superficial part: 80% Deep part: 20% Structures passing through parotid gland: Facial nerve. Retromandibular vein. Terminal branch of external carotid artery.

6. SURGICAL ANATOMY Fascial vein Fascial artery Hypoglossal nerve Lingual nerve Marginal mandibular branch of fascial nerve Sub mandibular gland:

7. INFLAMMATORY DISORDERS Viral Infections Bacterial infections Most common cause of acute painful parotid swelling. Predominantly affects children. Airborne infection. Prodromal period: 1-2 days Diagnosis: clinical Duration: 5-10 days Treatment: symptomatic (paracetamol + adequate fluid intake). Complications: orchitis, oophoritis, pancreatitis, sensorineural deafness. Ascending infection via the parotid duct, usually associated with a salivary calculus. Organism: staph. aureus & streptococcus viridans . More common in adult & older age group. Examination: Painful swelling, often localises to lower pole, pus exuding from the duct. Treatment: IV antibiotics, aspiration/drainage.

8. INFLAMMATORY DISORDERS Recurrent parotitis of childhood HIV associated sialadenitis Unknown aetiology . Clinical presentation: Rapid swelling, worsen by chewing & eating + systemic upset. Symptoms usually last for 3-7 days followed by quiescent period of weeks to months. More common between 3 & 6 years of age. Diagnosis: sialography, which shows a characteristic “snow storm” appearance. treatment: regular endoscopic washouts + long courses of antibiotics. Clinical presentation is similar to classical Sjogren syndrome in adults. Ct scan: swiss cheese appearance due to multiple cystic lesion. Treatment: swelling regresses with institution of anti viral therapy.

9. OBSTRUCTIVE DISEASES Sialolithiasis: 20% of stones are formed in parotid gland. Usually Radiolucent & rarely visible on plain radiograph. Treatment: 1. upto 4mm; retrieved via dormie basket 2. upto 8mm; lithotripsy 3.over 8mm; endoscopic assisted surgery. Stricture: 20% of obstructive parotitis is due to stricture. Meal-time syndrome: starting at breakfast & saliva can not seep past so swelling persist. Treatment: dilatation & endoscopic washout with steroid solution

10. TUMOURS Comprise 2% of the head & neck. More common in adults. 85% of salivary gland tumor occur in the parotid. 10 – 15% in the minor salivary gland. 5 – 10% in the submandibular gland. 80% of the parotid tumor are benign. 50% of the submandibular gland tumor are malignant. 75% of the minor salivary gland are malignant

11. TUMOURS Parotid is the most common site for salivary gland tumor. Usually in the superficial lobe. Painless swelling. 80-90% of tumours of paotid gland are benign. Most common is pleomorphic adenoma

12. CLASSIFICATION OF TUMORS Malignant epithelial Benign epithelial Soft tissue tumor Hematolymphoid tumor Acinic cell carcinoma Mucoepidermoid carcinoma Adenoid cystic carcinoma Epithelial-myoepithelial carcinoma Oncocytic carcinoma Cyst adenocarcinoma Pleomorphic adenoma Warthins tumor Oncocytoma Cystadenoma Myoepithelioma lymphadenoma haemangioma Hodgkin lymphoma Diffuse large B cell lymphoma Extra nodal marginal zone lymphoma WHO histological classification of salivary gland tumors

13. CONT.. Pleomorphic adenoma Most common 4 th to 5 th decade of life. Unilateral, more common in females Capsulated, may come out as pseudopods Involve both lobes, Dumb bell tumour . Swelling single, painless, smooth, firm, lobulated & mobile. Obliteration of retromandibular groove. Ear lobule lifted Facial nerve not involved. Long term pleomorphic adenoma may turn into carcinoma Warthins tumor 2 nd most common Also known as adenolymphoma. Bilateral, more common in white(10%) males(4:1) Strongly associated with smoking(40%) Slow growing cystic , soft, smooth , fluctuant, nontender, lower poles. Involves superficial lobe Multicentric . Never turns into malignancy.

14. CONT.. Malignant neoplasms: Mucoepidermoid carcinoma – 40% Commonest malignant tumor , mostly in parotid gland. Clinically it is Slow growing, hard & nodular with involvement of skin and LN. Facial nerve involvement is not common until it is high grade. Adenoid cystic carcinoma – 10% Adenoid cystic carcinoma are unique among the salivary gland tumors due to its indolent and protracted clinical course. Characterized by preneural spread including skip lesions. Acinic cell carcinoma – 10 – 15 % of Malignant mixed tumor - 7% Polymorphous low grade adenocarcinoma – 10% Adeno carcinoma – 10% Squamous cell carcinoma – 4%

15. RISK FACTORS Radiation exposure Older age Male gender Family history Smoking and alcohol use Diet (low in vegetables and high in animal fat) Industrial compounds

16. RELEVANT INVESTIGATION Ct scan: Temporal bone or mandibular destruction is best identified by CT. MRI: MRI permits more detailed evaluation of soft tissue infiltration, perineural invasion, and intracranial extension FNAC. Core needle biopsy: more specific and sensitive than FNAC. “Open needle/Incisional biopsy is contraindicated”

17. SURVIVAL RATE Stage 5-year Relative  Survival Rate I 91% II 75% III 65% IV 39%

18. TREATMENT SURGICAL RX: complete surgical resection is the corner stone of treatment. RADIOTHERAPY. CHEMOTHERAPY.

19. SURGICAL TREATMENT OF PAROTID TUMOR Superficial parotidectomy: removal of entire superficial lobe with dissection along the branches of FN. For benign tumors involving both lobes like pleomorphic adenoma Total parotidectomy: removal of whole gland with preservation of facial nerve. For high grade malignant tumors without gross involvement of fascial nerve Radical parotidectomy: In high grade malignant tumor with stage 4 disease. Removal of whole gland, rami of mandible and fascial nerve .

20. SURGICAL TREATMENT How to identify fascial nerve per operatively??? 1. Tragal cartilage (pointer of conley ) – The facial nerve is 1 cm. inferior and 1 cm. medial to the pointer.

21. SURGICAL TREATMENT How to identify fascial nerve per operatively??? 2. Tympanomastoid fissure – FN is 4 mm inferior to the tympanomastoid fissure as it exit from the stylo mastoid foramen.

22. SURGICAL TREATMENT How to identify fascial nerve per operatively??? 3.Posterior belly of digastric muscle - The facial nerve is superior to the upper border of the belly of the digastric muscle.

23. SURGICAL TREATMENT Frey’s syndrome: 10%. Fascial nerve injury: temporary injury- 27-43%, permanent 4-22% Numbness in the ear. Salivary fistula & sialocele : long term complication in 5% of patients. Flap necrosis. First bite syndrome: very rare, treated with simple analgesics. Xerostomia. COMPLICATIONS

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