<prompt> Mucoepidermoid carcinoma arises form -MyotheliumEpitheliumAcinusMucin secreting and epidermal cells  <response>: Mucoepidermoid carcinomas are composed of variable mixtures of squamous cells, mucus-secreting cells, and intermediate cells.The low-grade mucoepidermoid carcinoma is composed of largely mucin-secreting cells, whereas in high-grade tumors, the epidermoid cells predominate.- SchwartzThey are the most common malignant tumors of the salivary glands.TreatmentThe primary tt of all salivary malignancy is surgical excision:for parotid malignancies-Superficial parotidectomy with preservation of CN VII.Total parotidectomy with nerve preservation if deep lobe is involved.for other salivary gland -Enbloc removal of the involved glandNeck dissection for lymph nodes is doneclinically palpable nodesfor high grade malignanciesRadiation therapy is used postoperatively for specific indicationshigh grade histologypresence of extraglandular diseaseperineural invasiondirect invasion of regional structureregional metastasis 