Mucoepidermoid carcinoma

oral pathology

1. Mucoepidermoid Carcinoma

2. Introduction

3. The structure of the salivary glands

4. The normal salivary gland “Parotid’’ serous acini & straited duct lymph node facial nerve

5. The normal salivary gland sublingual submandibualr minor

6. General clinical features of salivary gland tumors Bengin salivary glad tuomar   Malignant salivery galnd tumor On set Slow -growing Sometimes fast growing consistency Soft or Rubbery Hard Incidence of type 85% of parotid tumors 45%of minor s.g Covering epithelium Don’t ulcerate May ulcerate and invade bone mobility Not fixed to underlying structuress Fixed to the underlying structures Involvement of nerve No involvement of nerve May cause cranial nerve paralysis

7. Mucoepidermoid Carcinoma

8. What is Mucoepidermoid Carcinoma of Salivary Gland?  A Mucoepidermoid Carcinoma (MEC) is a type of malignant glandular epithelial tumor affecting either the major or minor salivary glands . It contains both epidermoid cells type and mucous secreting cells in varying proportions. It is observed in a wide age category of children and adults  MEC constitutes the most common primary tumor affecting the salivary glands. It accounts for about 5% of all salivary gland tumors arise in the parotid gland. However their realitve incidence is higher in minor salivary gland for about 10-15% of tumors

9. Site Extraoral :- parotid gland(most common site) Intraoral :- the palate being the site of predilection of minor salivary gland followed by lower lip, floor of the mouth ,tongue and retromolar area respectively) Palate > buccal mucosa> tongue> & retromolar area - intraorally I ntraosseous :- Man>max : 3times Gender both genders are affected, a slight female predominance is noted Age Generally, the mean age for these carcinomas is 47 years, however, there exists a broad age range, and is one of the few salivary gland malignancies occurring in childhood Etiology The cause of formation of this salivary gland malignancy is generally unknown, but may be due to genetic factors. No definitive risk factors are observed, though salivary gland cancers are known to be influenced by factors such as exposure to radiation sources

10. clinical feature :- slowly enlarging painless mass which simulate the pleomorphic adenoma but never exceed 5 cm in diameter It is not completely encapsulated and often contain cyctic cavities which may be filled with mucoid material It is fluctuant swelling and red or blue in color may be mistaken as mucocele . Low Grade Tumor :-

11. Blue-pigmented mass of the posterior lateral hard palate. Mucoepidermoid carcinoma. Mass of the tongue

12. High Grade Tumor :- clinical feature :- grows rapidly and cause pain particulary in late stage In the parotid gland facial palsy involvement indicate poor prognosis Trismus , Drainage of ear, dysphagia, numbness of adjacent areas & ulceration (minor salivary gland) typical feature include fixation ulceration, and involvement of Metastasize regional lymph nodes Distant metastases to lung, bone, brain & sub-cutaneous tissues are also common

13. MORPHOLOGIC FEATURES :- Grossly, the tumour is usually circumscribed but not encapsulated . It varies in size from 1 to 5 cm .

14. Histopathological features :  Characterized by: variety of cell types and often in cystic Patterns  Composed of- a)mucous secreting cells b) epidermoid cells c)intermediate cells  Grades : a) low grade b ) intermediate grade c ) high grade

15.  Histopathological Grades are based on-  Amount of cyst formation  Degree of cytoplasmic atypia Relative number of mucous , epidermoid & intermediate cells. The three types of cell – together forms cystic space or solid masses or cords

16. Microscopic features :- The name is a contraction of epidermiod and mucus - secreating cell a close association bettwen mucus and epidermoid Mucoepidermoid carcinoma. At higher power the finely granular mucous cells are seen to the right with the underlying epidermoid cells to the left.

17. It is believed to arise from salivary duct system Normal duct- lining epithelium neoplastic transformation

18. Fluctuant because of cyst formation:- mucin filled cystic spaces

19. Low grade tumor ( well differentiated tumors tumor) show large number of mucous secreting cells Numerous cystic spaces Small number of intermediate and epidermoid cells with few cellular atypia

20. . Low grade: cystic spaces and mucous tumor cells

21. Low-grade mucoepidermoid carcinoma: with a prominent cystic component.

22. Intermediate grade – Solid area of all the three cell –Cyst formation but lesser than low grade –Intermediate cell predominate

23. Intermediate grade mucoepidermoid carcinoma with mostly solid features and few mucous cells.

24. high Grade tumor Solid nests or cords Mitotic activity Prominent nuclear pleomorphism Cystic component is very less Glandular component rare, necrosis & perineural invasion may be present

25. High grade : few tumor ducts and mucous cells

26. lowspace low grade. Note intracystic space Intermediate grade Hyperchromatic nuclei & Several microcystic spaces High grade Focal necrosis

27. • Intraosseous mucoepidermoid carcinoma it may develop rarely in the jaw. Origin of salivary gland tissue maxillary mucoepidermoid carcinoma may arise from the gland of the sinus lining Mandbibular lesion from odontogenic epithelium especially that lined dentigerous cyst or from ectopic entrapped • Man>max: 3times  Histologically low-grade cancers  Radiographically seen as uniocular or multiocular lesions. Variant of tumor

28. Treatment • Conservative excision – preservation of facial nerve – low & intermediate grade of parotid. • Complete – submandibular gland • Radical neck dissection – evidences of cervical node metastasis & T3 lesion • Postoperative radiotherapy & Chemotherapy – may be used for high grade malignancy. • Low grade lesion – 92 %, 5 yr cure rate • Intermediate and high grade – 49 %, 5 year cure rate

29. Thank you