Medium-sized congenital plantar nevus: about a case

Nevus (or mole) is a form of skin cancer that begins in melanocytes, the cells responsible for skin pigmentation. If it is present at birth, it is called congenital nevus. Before adolescence, nevi are regularly distributed throughout the body, with very few Large nevi (> 5 mm) prevailing on the trunk (due to brutal sun exposure) while those on the face and limbs, chronically exposed to moderate doses of UV radiation, are more numerous and smaller. We here report the case of a 4-year old patient with no previous medical-surgical history, presenting with a pigmented plaque on the right foot plant since birth. Clinical inspection showed a warty pigmented nonpruritic map-like plaque extending from the heel to the little and the big toe, measuring 15 x 6 cm, whose extent of plantar surface involved is estimated at 80%. Three diagnostic hypotheses were evoked: nevus (the most likely), mongolian blue spot, melanoma. A biopsy was performed; The histology confirmed a nevus. The risk of transformation of medium-sized nevus to melanoma appears very low, then physical examinations should be performed every 6 months. © Youssouf Fofana et al.