Parotid Gland ( Case and Basic Anatomy)

ENT Clinical Meeting Presentation

1. CLINICAL MEETING 23.1.20 Department Of Otolaryngology And Head Neck Surgery Sylhet MAG Osmani Medical College Hospital

2. Presented by: Dr . Musanna Nabi Chowdhury Dr . Mahesh Acharya Dr. Asmita Paudel

3. A 31 year old male presented with swelling in the right parotid region

4. CASE Mr. Jahed Ahmed, 31 years old, Muslim, married, hailing from Golapganj, Sylhet presented with a swelling in the right side of the upper part of the neck, just below the right ear lobule for last 1 year. The size of the swelling is increasing slowly ever since. *taken with patient’s permission

5. CASE CONTINUED There is no pain over the swelling and no history suggestive of facial nerve paralysis like: any asymmetry of face, difficulty in closing the eye, chewing the food or any drooling of saliva from the angle of mouth. On query patient gives no history of weight loss. On general examination, all vitals are within the normal limit. Cervical lymph nodes are not palpable.

6. CASE CONTINUED On local examination, there is a swelling in the right parotid region of about 2cm×3cm in size , globular in shape, firm in consistency and non-tender. The surface of the swelling is smooth, margins are well defined and rounded. The swelling is free from the skin and underlying structures. The deep lobe of the parotid gland is not enlarged. There is no purulent discharge from the ductal opening in the mouth. There is no any evidence of facial nerve palsy as well.

7. PROVISIONAL DIAGNOSIS ?

8. PLEOMORPHIC ADENOMA OF RIGHT PAROTID GLAND

9. DIFFERENTIAL DIAGNOSIS Adenolymphoma of parotid gland Carcinoma of parotid gland Lipoma Fibroma Hemangioma

10. ANATOMY

11. PAROTID GLAND (Para = Around; Otic = Ear) Largest salivary gland Serous in nature   Anteriorly:  by the posterior border of the ramus of mandible. Posteriorly : by the mastoid process. Superiorly : by the external acoustic meatus and posterior part of temporomandibular joint. Medially:  by styloid process .

12. False Capsule: Formed by investing layer of the deep cervical fascia Superficial lamina(thick) Deep lamina (thin) True Capsule : Condensation of fibrous stroma CLINICAL IMPORTANCE: The parotid swellings are extremely painful because of unyielding temperament of the parotid capsule, any inflammation or pressure inside the parotid gland will cause acute pain due to stretching of the capsule. PAROTID CAPSULE

13. 1.Apex 2.Base 3.3 Surfaces: Superficial (lateral) surface 4. 3 Borders: Antero-medial surface Postero -medial surface Anterior Posterior Medial PRESENTING PARTS

14. 3 chief structures either in part or in whole traverse the gland and branch inside it. From superficial to deep these are: Facial nerve. Retromandibular vein. External carotid artery. Some members of the deep parotid  lymph nodes  and filaments of  auriculotemporal nerve  are also found inside the gland STRUCTURES TRAVERSING PAROTID GLAND

15. FACIAL NERVE (queen of the face) The 5 terminal branches of the facial nerve radiate like a goose foot via the anterior border of the gland and supply the muscles of facial expression. Such branching pattern of the facial nerve is referred to as pes anserinus .

16. PATEY’S FACIOVENOUS PLANE The parotid gland is split into large superficial and small deep parts or lobes. The plane between the superficial and deep lobes where nerves and veins are located has been designated by Patey as faciovenous plane . CLINICAL IMPORTANCE This plane helps the surgeons to eliminate the parotid tumor without damaging the facial nerve .

17. PAROTID DUCT (STENSON’S DUCT ) Parotid duct, about 5 cm long, appears from the middle of the anterior border of the gland and opens into the vestibule of the mouth opposite the crown of upper second molar tooth. The tortuous course of the duct gives a valve-like mechanism to stop the inflation of the duct system of parotid gland during excessive blowing of the mouth as in trumpet blowing

18. The probing of the parotid duct is difficult due to its tortuous course. The parotid duct and its ramifications can be demonstrated radiologically by injecting radio-opaque dye via inserted into the mouth of the duct in the vestibule of the oral cavity (parotid sialogram ). Sometimes , calculi (stones) may form in the parotid gland and parotid duct. The calculi lodged in the distal portion of the gland could be taken out by splitting up the duct from its opening in the mouth CLINICAL IMPORTANCE

19. Parasympathetic ( secretomotor ) Auriculotemporal nerve.   Sympathetic supply: Sympathetic plexus around external carotid artery Sensory Supply: Auriculotemporal nerve. Great auricular nerve (C2 and C3 ) NERVE SUPPLY

20. BLOOD SUPPLY LYMPHATIC DRAINAGE Superficial and deep parotid lymph nodes The arterial supply - external carotid and superficial temporal arteries. The venous drainage - retromandibular and external jugular veins Deep cervical lymph nodes

21. DEVELOPMENT 4 TH WEEK: The parotid glands arise from ectodermal furrow . The epithelial buds, near the primitive mouth grow posteriorly toward the otic placodes to form solid cords with rounded terminal ends 10 TH WEEK: The cords are canalized and form ducts. The rounded terminal ends of the cords form the acini of the glands . 18 TH WEEK: Secretion by the parotid glands begins. Supporting connective tissue develops from the surrounding mesenchyme.

22. DISEASES OF PAROTID GLAND

23. Congenital : 1.Aplasia : Absence of the gland, 2.Atresia:Absence of the duct , 3.Aberrancy:Ectopic gland B. Acquired : 1.Infective : Mumps, Bacterial parotitis 2.Parotid Abscess 3.Parotid tumour ( commonly, mixed parotid tumour ) 4.Neurological: Frey's syndrome 5.Sialolithiasis

24. MUMPS : . Viral disease caused by Paramyxovirus causing painful swelling of the parotid gland .Do not suppurate BACTERIAL PAROTITIS: 1.Acute 2.Chronic 3.Recurrent May suppurate to form abscess PAROTID ABSCESS: Drained By Hilton’s Method: Small horizontal incision to avoid injury of facial nerve branches INFECTIVE

25. Neurological (Frey's syndrome ) Sialolithiasis : less commonly in parotid but usually in the duct of the submandibular gland .

26. TUMOURS OF PAROTID AND OTHER SALIVARY GLANDS 1.Pleomorphic adenoma 2.Adenolymhoma(Warthin's tumour ) 3.Oncocytoma 4.Other adenomas 1.Haemangioma 2.Lymhangioma 3.Lipoma 4.Neurofibroma

27. PLEOMORPHIC ADENOMA They are called "mixed tumours " because both epithelial and mesenchymal elements are seen in histology Clinical feature • Most common benign tumour of salivary glands usually arises from superficial lobe Slight male predilection • Age 40-50 years • 85% tumor occur in parotid gland • Slow growing, mobile(except for those found in hard palate) • Painless mass

28. . Demonstrate pleomorphic patterns of various ratios of epithelial and mesenchymal elements and are enclosed in a connective tissue pseudocapsule . • The lack of true capsule, the deficiencies of the pseudocapsule , and the tumor extensions through these defects are thought to contribute to recurrences HISTOLOGY

29. WARTHIN TUMOUR : (Adenolymphoma or papillary cystadinoma lymphomatosum ) Male: female=5:1 . Commonly seen in elderly people Doughy painless mass often found in the tail of the parotid

30. Mucoepidermoid carcinoma : In minor salivary glands is more aggressive but in major salivary glands, they behave like pleomorphic adenoma. Adenoid cystic carcinoma( Cylindroma ): slowly growing but infiltrates widely into tissue planes and muscles, also invades perineural spaces and lymphatics causing pain and 7th nerve Palsy. Squamus cell carcinoma : rapidly growing that infiltrates and causes pain and ulcerates through skin

31. INVESTIGATIONS

32. Fine Needle Aspiration Cytology: Allows pre-operative assessment of nature of tumour Open biopsy is contraindicated due to Chance of injury to facial nerve Chance of parotid fistula formation Seeding of tumour cells High chance of recurrence #Indicated only if: Minor salivary gland tumour Ulcerated lesion Where FNAC suggests lymphoma In cases of diffuse enlargement

33. 2.CT/MRI : Anatomical localization Local , regional, distant invasion # MRI is better because of Excellent assessment of margin Deep extension and infiltration Bone marrow invasion Perineural spread

34. 3. USG: Distinguish intrinsic from extrinsic tumours It can be used to differentiate solid from cystic mases in the salivary glands USG guided FNAC 4.FROZEN SECTION BIOPSY: When FNAC findings/diagnosis is at odds with clinical and/or intraoperative findings When preoperative FNAC is non-diagnostic 5.Sialography : In evaluation of functional integrity of salivary gland In case of obstructions To evaluate, the ductal patterns

35. MANAGEMENT

36. TREATMENTS OPTIONS Surgery Surgery + Radiotherapy FACTORS THAT INFLUENCE TREATMENT Age Metastatic spread Facial nerve involvement Site of tumour Size, extent, grade and stage of tumour

37. SURGERY Superficial Parotidectomy : Removal of superficial lobe Total Conservative Parotidectomy : 3. Radical Parotidectomy : Removal of both lobes and facial nerve 4. Extended Radical Parotidectomy For deep lobe tumours Facial nerve preserved ‘Lazy S’ incision

38. B. Radiotherapy Primary treatment limited to unresectable tumours Post-operative indicated for: Tumour more than 4 cm Presence of positive surgical margins Facial nerve preserved despite being adherent to tumour Lymph node metastasis High grade tumour Perineural invasion Recurrent pleomorphic adenoma Spillage after surgery of pleomorphic adenoma

39. COMPLICATIONS OF PAROTID SURGERY Hematoma formation Infection Temporary facial nerve palsy and permanent facial weakness Sialocele Facial numbness Permanent numbness of ear lobe associated with greater auricular nerve transection Frey’s syndrome

40. FREY’S SYNDROME (GUSTATORY SWEATING) Commonly occurs after parotid surgery or trauma . Characterized by o Sweating o Warmth o Redness of the face as a result of salivary stimulation by the smell or taste of food There is no effective treatment, but various options are:- Injection of Botulinum Toxin A. Surgical transection of the nerve fibers (only a temporary treatment). Application of an ointment containing an anticholinergic drug such as scopolamine.