Sclerosing Central Mucoepidermoid Carcinoma: Rare Case Series and Review

Introduction: The most frequent malignant tumour of the salivary glands is mucoepidermoid carcinoma which accounts for 30% of all malignancies of the salivary glands. There are numerous histologic variations with various levels of differentiation. Sclerosing MEC (SMEC) is a rare subtype of MEC that has the potential to be misdiagnosed as a low-grade non-SMEC malignancy or a benign reactive condition. There have been no cases of the extremely rare sclerosing variant of central or intraosseous MEC reported as of yet. Case reports: We present two cases of Sclerosing Central MEC, in which histologic analysis revealed relatively well-circumscribed, nonencapsulated tumours made up of dispersed epithelial islands of low-grade MEC and extensive central sclerosis. Similar sclerotic stroma was present in the tumor in the second case, but the epithelial component was of intermediate grade. Both cases showed abundant intracytoplasmic mucin and positive Mayer mucicarmine and PAS stains. Conclusions: Sclerosing central mucoepidermoid carcinoma was identified as the cause. Both cases underwent a complete resection of the tumor and have since been free of the disease.