https://doi.org/10.1177/0748806820977369 The American Journal of Cosmetic Surgery 1–9 © The Author(s) 2020 Article reuse guidelines: sagepub.com/journals-permissions DOI: 10.1177/0748806820977369 journals.sagepub.com/home/acs Original Article: Clinical Science Introduction The resultant problems that congenital melanocytic nevi (CMN) cause exceed the cosmetic appearance and malignant transformations. Congenital melanocytic nevus has direct and indirect effects on symptoms of depression and social anxiety in patients due to their loss of confidence and self-esteem. 1 Cryocarboxy surgery is the use of carbon diox- ide (CO 2 ) gas as a cryogenic agent in the treatment of CMN. The first reported medical application of controlled freez- ing for the destruction of tissues was described by Arnott (1883), an English physician who used a technique that reduced tissue temperature to approximately -20°C. Between 1819 and 1879, he published extensively on the use of cold therapy in medical treatment. 2 Solid CO 2 was used by Arnott (1851) as an effective method of cold therapy. 2 Pusey (1865) used solid CO 2 in the form of CO 2 snow to treat patients. 3 Campbell of Columbia University (USA) was the first to use liquefied gas in medicine. In 1899, he reported the successful use of liquefied air for the treatment of some dermatologic lesions, such as lupus erythematosus, chancroid, nevi, warts, carbuncles, and epitheliomas. 4 However, because of its high combustibility, liquid oxygen has been forbidden for use as a cryogenic agent. 5 Because liquid nitrogen has a boiling temperature of -196°C, it has been used as a cryogenic agent. In 1950, Arlington started using liquid nitrogen in the United States by applying it with a saturated cotton swab. By 1969, Setrag and his clinical work had become one of the important refer- ences in the field of cold therapy. The term “cryosurgery” was also coined by him. 6 The work of physician Cooper and engineer Arnold is considered to be the cornerstone in the development of the modern era of cryosurgery. They invented a cryosurgical probe on which later types of probes were modeled. 7 Facial CMN is a pigmented lesion composed of nevus cells present at birth or immediately after birth. It is found in approximately 1% of neonates. 8 Congenital melanocytic nevi are classified according to their diameter. Lesions less than 1.5 cm in diameter are considered small-sized. Lesions from 1.5 to 20 cm are considered medium-sized. Lesions 977369ACS XX X 10.1177/0748806820977369The American Journal of Cosmetic SurgeryElmelegy research-article 2020 1 Tanta University, Tanta, Egypt Corresponding Author: Nader Gomaa Elmelegy, Professor, Plastic & Reconstructive Surgery, Head of Department, Tanta University, Tanta 3111, Egypt. Email: naderelmelegy@gmail.com Cryocarboxy Surgery for the Treatment of Congenital Melanocytic Nevi of the Face, a New Addition of Simple Treatment for a Troublesome Problem Nader Gomaa Elmelegy, MD 1 Abstract Congenital melanocytic nevi of the face cause substantial psychological and cosmetic problems in affected patients. The treatment of giant congenital nevi has been a long-standing challenge, but currently, various treatment options, such as cryotherapy, chemical peeling, electrical cautery, laser therapy, and surgery, have been tried for the treatment of congenital melanocytic nevi. In this article, we present our experience and the outcomes of the use of controlled carbon dioxide gas as a cryogen in the treatment of congenital melanocytic nevi. This study included 42 patients with varying sizes of congenital melanocytic nevi seen from January 2014 to April 2019. Cryocarboxy surgery was performed in all cases. The average evaluation score of our patients was excellent in 28 (66.6%) cases, good in 9 (21.4%) cases, satisfactory in 5 (12%) cases, and we had no poor results. Cryocarboxy surgery is a good addition to the armamentarium for the treatment of congenital melanocytic nevi. Carbon dioxide is a cheap, non-explosive, and readily available gas. Keywords congenital melanocytic nevus, giant nevus, cryosurgery, cryocarboxy, hyperpigmentation