Median canaliform dystrophy of Heller: a report of three cases

Median canaliform nail dystrophy of Heller (MCND), also known as dystrophia unguis mediana canaliformis, solenonychia, and nevus striatus unguis, is an uncommon nail disorder characterized by a paramedian or midline ridge or groove or canal formation in the nail plate of one or both the thumbnails. It rarely involves the other fingernails or toenails. Most of the cases of MCND are idiopathic. However, it may also be secondary to traumatic injury to the base of the nail, subungual skin tumors such as glomus or myxoid tumor, and the use of drugs like oral isotretinoin. Although it is believed to be an acquired condition, few familial cases have also been reported. Here we report three cases of MCND involving fingernails and toenails.