Microscopic description:

Lesion showed glandular differentiation and mucocytes line the ducts

Luminal mucin is seen

Nests of epidermoid cells are present

Background stroma shows sclerosis

Discussion:

Mucoepidermoid carcinoma (MEC) is the most common salivary gland tumor in all age groups

Majority of the lesions are seen in major salivary glands

MEC maybe low, intermediate or high grade depending upon the presence of necrosis, mitotic index, growth pattern, perineural invasion and degree of pleomorphism. Low grade lesions show cystic growth pattern and high glandular differentiation while high grade lesions show solid growth pattern.

Up to 80% of lesions have chromosomal translocation t(11;19)(q21:p13) leading to the fusion of MECT1 and MAML2 gene

Low grade MEC with MECT1 and MAML2 gene fusion have good prognosis. Overall 10 year survival is 53%.

References:

Young A, Okuyemi OT. Malignant Salivary Gland Tumors. In: StatPearls. Treasure Island (FL): StatPearls Publishing; October 9, 2021.

Namboodiripad PC. A review: Immunological markers for malignant salivary gland tumors. J Oral Biol Craniofac Res. 2014;4(2):127-134. doi:10.1016/j.jobcr.2014.05.003

Seethala RR, Barnes EL. Common Malignant Salivary Gland Epithelial Tumors. Surg Pathol Clin. 2011;4(4):1177-1215. doi:10.1016/j.path.2011.07.005

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