Objectives: to investigate the clinical and histology of giant congenital melanocytic nevus at National Hospital of Dermato-Venereology and 5aint Paul Hospital from Jan, 2006 to Oct, 2010. Material and Method: a cross-sectional study based on data of 30 patients hospitalized at the twd hospital. Results: Giant congenital melanocytic nevus is common in women accounting for 66.67 percent. The characteristic clinial features of that disease are: well-defme, dark color and rough surface with a lot of black hair. There are 13 percent of them had more than 100 satellite lesion
23 percent lesions located on the malignance area and 20 percent of cases had abnormal progressive. All of the case are dermal melanocytic nevus and all of them positive to 5100 and HMB-45. Conclusion: Giant congenital melanocytic nevus is more common in women than in men. Clinical: Giant congenital me!anocytic nevus is a dark area of skin with clear border, rough surface, and lots of thick dark hair. Paraclinical: Giant congenital melanocytic nevus located in dermis, immunohistochemistry is positive for 5100 and HMB-45.