Small Cell Neuroendocrine Carcinoma of the Parotid Gland: An Uncommon Example of Incompletely Encapsulated Tumor Including S100 Protein-Positive Clear Cells

Abstract

Small cell carcinoma is known as a highly lethal lung cancer but is rare in the salivary glands. Along with undifferentiated carcinoma, large cell neuroendocrine carcinoma (LCNEC) and small cell neuroendocrine carcinoma (SNEC) are categorized as poorly differen-tiated carcinomas in the current 4 th edition of the World Health Organization (WHO) classification list.We herein describe an extremely uncommon example of SCNEC arising in the parotid gland, which was incompletely encapsulated and involved an inscrutable clear cell component showing immunoreactivity for S100 protein.