1. KCP 764 강북삼성병원 전임의 구지혜

2. 병력 주소 : 최근 커진 좌측 뺨 종괴 (10 여 년 전 발생, 최근 크기 증가 ) 나이 / 성별 : 61 세 / 여자 촉진 상 약 3cm 의 주변에 고정되어 있는 단단 한 종괴 컴퓨터 단층촬영 소견 :  위치 : 좌측 이하선  크기 : 2.3 x1.4 x 1.0 cm  경계가 좋은 낭성 변화를 동반한 엽상모양

9. Microscopic features Low celluarity Thick mucus materials background Monolayered sheets Polygonal cells More small round cells Columnar cells with mucin

10. Differential diagnosis Mucoepidermoid carcinoma  Low grade  High grade Pleomorphic adenoma Carcinoma ex pleomorphic adenoma Mucocele Warthin tumor

11. KCP 764 Mucoepiderm oid carcinoma Low grade Mucoepidermo id carcinoma High grade Pleomorphic adenoma Age 61yr40-60 Location Parotid gland CytologyCytology Feature Columnar like appearance cell with mucin Polygonal cell Uniform round small cell Mucus cell + epidermoid cell + intermediate cell Low grde + more atypia + greater proportion of squamoid cells Epithelial cells + myoepithelial cells Matrix Myxoid background Extracelluar mucin Fibrillar myxoid or myxochondroid Atypism Rare Mild Moderate to severeMild Other Cystic change Cystic change, common (low grade) Less prominent cystic component Round to polygonal

12. Cytologic Diagnosis Bland-looking ductal cell nests and some mucin containing polygonal cells in background of thick mucus material Note) Differential diagnosis includes pleomorphic adenoma with predominant myxoid change, carcinoma ex pleomorphic adenoma and mucoepidermoid carcinoma. Excision and histologic confirmation are recommended.

18. Diagnosis Mucoepidermoid carcinoma, low grade

19. Mucoepidermoid carcinoma Definition  Malignant epithelial tumor  Varying proportion of mucus, epidermoid, intermediate, columnar, clear, and occasionally oncocytic cells General features  Most common malignant salivary gland tumor  53 % in major salivary glands (m/c parotid gland)  3 to 95 (mean age: 46)

20. Mucoepidermoid carcinoma Clinical feature  Solitary, painless masses in prearuricular and submandibular regiones  Average known duration: 1.5yr Gross finding  Circumscribed and at least partially encapsulated mass  Cut surface: firm, gray, tan-yellow, lobulated  Cystic change