NCIt definition : A benign neoplasm arising from the outer hair sheath and infundibulum. It occurs in
the head and neck, usually on the face. It usually presents as an exophytic wart-like
lesion or a dome-shaped lesion with smooth surface. Multiple facial lesions are usually
associated with Cowden disease.;
Alternative definition : CDISC: A benign hair follicle neoplasm in the outer hair sheath and infundibulum,
characterized by central cells showing highly eosinophilic amorphous keratin.;