Sinonasal blue nevus: a case report and review.

Blue nevus is a type of uncommon benign pigmented lesion in the skin or the mucosa of human body which is featured by pigmented dendritic melanocytes and spindled melanocytic cells. Sinonasal blue nevus is extremely rare. We reported a sinonasal blue nevus case with the background of pituitary adenoma, type 2 diabetes mellitus, and hypertension (including endoscopic and histological pictures). Further, the existing literature about blue nevus is reviewed. This paper puts a spotlight on the potential correlation between blue nevus with the endocrine system disorder and provides support for further experimental research.