, comedo nevus (nē'vŭs kom'ē-dō-nī'kŭs, kom'ĕ-dō). Congenital or childhood linear keratinous cystic invaginations of the epidermis, with failure of development of normal pilosebaceous follicles. comedo nevus (nē'vŭs kom'ē-dō-nī'kŭs, kom'ĕ-dō). Congenital or childhood linear keratinous cystic invaginations of the epidermis, with failure of development of normal pilosebaceous follicles.