Mucoepidermoid carcinoma with Warthin like features- rare case report

Abstract

Mucoepidermoid carcinoma with Warthin like features is a deceptive tumour and can be potentially misdiagnosed as a Warthin tumour which is benign, Warthin tumour with mucinous and squamous metaplasia or MEC transformed from Warthin tumour. We are presenting a case of a 25-year-old woman with recurrent solitary mass in the left parotid gland. Microscopically it consists of predominantly cystic areas and focal solid infiltrative tumour with mucinous, intermediate and epidermoid cells having complex architecture in a fibrotic stroma. Extracellular mucin pools seen. Cystic areas are lined by monolayered as well as bilayer epithelium with lymphoid stroma (Warthin like morphology). Occasional mitosis noted. No necrosis and perineural invasion seen. Immunohistochemically, the tumour is positive for P63, P40, CK5/6, EMA, Mucicarmine stain, diffusely positive for CK7. We reached at the final conclusion of low grade MEC, Warthin like features. Even though the cytogenetic studies are confirmatory, we emphasize the role of histomorphology study with IHC and clinical history in identifying this rare variant of MEC with Warthin like features.