Parotid tumors

General surgery ppt - PG

1. Parotid tumors Dr . bharath rajh Junior resident Dept of plastic surgery

2. Parotid gland – anatomy

3. The parotid glands are a pair of mainly serous salivary glands Located inferior and anterior to the external acoustic meatus, between the ramus of mandible and sternocleidomastoid muscle. The gland is roughly wedge-shaped

4. Gland is divided into two lobes Superficial lobe – 80% Deep lobe – 20 %

5. Also called as Stenson’s duct It emerges from the anterior border of the gland, superficial to the masseter muscle, then it pierces the buccinator muscle & opens into the oral cavity on the inner surface of the cheek, usually opposite to the maxillary second molar. Parotid duct

6. Investing layer of deep fascia forms the capsule Splits into Superficial lamina Deep lamina Parotid capsule

7. Structures passing through parotid gland Artery: External carotid enters in the posteromedial surface Maxillary artery Superficial temporal artery Posterior auricular artery

8. Parasympathetic fibres :- Secretomotor Preganglionic fibres arise from the inferior salivatory nucleus Pass through glossopharyngeal nerve Relay in otic ganglion Postganglionic fibres reach the gland through auriculotemporal nerve Sympathetic fibres :- Vasomotor Sensory nerves :- Auriculotemporal nerve Nerve supply

9. Benign Pleomorphic adenoma Warthin’s tumor Malignant Mucoepidermoid carcinoma Adenoid cystic carcinoma Acinic cell carcinoma Adenocarcinoma Squamous cell carcinoma Parotid neoplasia

10. It is also known as “Mixed salivary tumor” It is the most common benign tumor of salivary glands – 80 % Characterized by neoplastic proliferation of parenchymatous glandular cells along with myoepithelial components Pleomorphic adenoma

11. Distribution: Parotid gland: 84%  Submandibular gland: 8% M inor salivary glands: 6.5% W idely distributed including the nasal cavity, pharynx, larynx, trachea S ublingual glands: 0.5%

12. Swelling Painless Raised ear lobule Curtain sign positive Clinical features

13. Common in females (3:1) Common in 4 th and 5 th decade of life Smooth , firm lobulated mobile swelling with positive curtain sign Ear lobule lifted Obliteration of retro mandibular groove Deep lobe tumour passes through Patey’s stylomandibular tunnel pushing tonsil, pharynx, uvula Along with dysphagia

14. 1.5% in 5 yrs. ; 9.5% in 15 yrs. Recent increase in size Pain Nodularity Involvement of skin, LN , Facial nerve , masseter Restriction of jaw movements Features of malignant change Capsular distension Obstruction of saliva Nerve infiltration Tumour necrosis

15. Gross: Cartilages Cystic spaces Solid tissues Pathology

16. They contain both epithelial and myoepithelial ( mesenchymal ) tissues Even though it is capsulated, tumor may come out as pseudopods beyond the original extend of the tumor Histology

17. Fine needle aspiration Core needle aspiration USG CT scan MRI scan Diagnosis

18. USG – Hypoechoic with lobulated and distinct borders

19. CT scan – Smoothly margined or lobulated homogeneous small spherical mass Small regions of calcification When the tumour is small, the enhancement tends to be prominent

20. MRI : W ell-circumscribed and homogeneous T1:  U sually of low intensity T2 : U sually of very high intensity (especially myxoid type ) T1 C+ ( Gd ):  U sually demonstrates homogeneous enhancement

21. Surgical excision of the tumour Superficial( Patey's operation) parotidectomy Total parotidectomy Treatment Complications: Recurrence of 5 to 50% Facial nerve injury

22. It is also called Adenolymphoma or Papillary cystadenolymphomatosum It is a benign tumour occurs only in parotid, usually in the superficial lobe, lower pole. Second most common Warthin’s tumour

23. 10 – 15 % bilateral Usually occurs in 6 th decade More common in males 4:1 Associations: Cigarette smoking Irradiation

24. Slow growing, non tender, smooth, soft, cystic, fluctuant swelling. Often multi-centric and are usually small (1-4 cm ). Typically heterogeneous appearance on all modalities, often with cystic components Morphology

25. Ultrasound : A well defined, ovoid, hyper echoic mass. In some cases anechoic internal cystic areas may be present. They are often hyper vascular CT scan: C an be often well defined , bilateral tumor   Classic appearance is a cystic lesion posteriorly within the parotid with a focal tumour nodule C ystic changes appear as intralesional lower attenuation N o calcification Investigations

26. Adenolymphoma produces a “Hot spot“ in Technetium 99 -pertechnetate scan Diagnostic – due to high mitochondrial content

27. Surgical excision is curative Rate of recurrence is almost nil No malignant change Treatment

28. Commonest type of malignant salivary tumor in adults Commonest malignant tumor of parotid in childhood Common in middle age (35-65 years of age) Female predilection Mucoepidermoid tumor

29. Parotid is the most common site of tumor 2nd common is palate minor salivary gland Radiation – etiological factor t(11;19)(q21;p13)  chromosome translocation resulting in a MECT1-MAML2 fusion gene

30. Presents as painless, slow-growing mass that is firm or hard . Grossly – Un encapsulated mass with cystic spaces Facial nerve involvement in late stages

31. The tumours are composed of a mixture of: Mucus secreting cells ( muco -  ) Squamous cells ( - epidermoid ) Lymphoid infiltrate often also present Histology

32. L ow grade: Well-differentiated cells with little cellular atypia High proportion of mucous cells P rominent cyst formation I ntermediate grade: intermediate features H igh grade: P oorly differentiated with cellular pleomorphism H igh proportion of squamous cells S olid with few if any cysts Grade of tumor

33. USG :- well-circumscribed hypo echoic lesion, with a partial or completely cystic appearance CT scan :- Low-grade tumors appear as well-circumscribed masses, usually with cystic components. Calcification may be present High-grade tumors are poorly defined margins, infiltrate locally and appear solid.

34. Low grade – wide local excision or superficial parotidectomy without any adjuvant radiotherapy High grade requires complete or radical parotidectomy , often with sacrifice of the facial nerve, neck dissection (as nodal metastases are common) and adjuvant radiotherapy Treatment

35. It is also called as cylindromatous carcinoma Low grade tumor Wide distribution and mainly occur in relation to the airways, salivary glands, lacrimal glands and breast Tendency for perineural extension is high Adenoid cystic carcinoma

36. Common in females 3:1 Occurs in 5 th & 6 th decade of life Slow growing tumor but highly malignant High affinity for perineural transmission [Anterograde and retrograde] Maxillary and mandibular branch of trigeminal nerve Facial nerve Reaches Gasserian trigeminal ganglion, pterygopalantine ganglion & cavernous sinus

37. Microscopy:- Cribriform – Swiss cheese pattern Tubular Solid It involves periosteum and bony medulla

38. Radical parotidectomy with adjucvant radiotherapy Fast neutron therapy Chemotherapy Treatment

39. Recurrence is common 5 years survival rate is 89 % 15 years survival rate is 40 % Positive margin, perineural spread, solid type carry poor prognosis

40. Indications: Chronic parotitis Salivary calculi Parotid abscess Parotid tumors T1,T2,T3 – Total conservative parotidectomy T4 – Radical parotidectomy Parotidectomy

41. Types: Superficial parotidectomy Total conservative parotidectomy Radical parotidectomy Suprafacial parotidectomy

42. Facial nerve is 1cm deep and below the tip of inferior portion of cartilaginous canal – conley’s point By nerve stimulator It is inferomedial to the tragal point Deep to digastric muscle Nerve is just lateral to styloid process Tracing branch from distal to proximal (Hamilton bailey technique) Identification of facial nerve

43. Preoperative weakness / paralysis of nerve Intraoperative evidence of gross invasion Tumors transgressing through facial nerve from superficial to deep lobe Nerve stump is checked for frozen section for negative margins, if positive, mastoidectomy & nerve dissection is required Indication for nerve sacrifice

44. Facial nerve injury Hemorrhage Salivary fistula Infection – flap necrosis is common Frey’s syndrome Sialocele Injury to greater auricular nerve Complications of parotidectomy

45. Thank you…