Bilateral nevus comedonicus syndrome.

Nevus comedonicus is an uncommon skin abnormality characterized by an aggregation of dilated follicular orifices filled with keratinous material. Nevus comedonicus is occasionally complicated with other conditions including cataracts, skeletal defects, central nervous system abnormalities or other extra-cutaneous diseases (nevus comedonicus syndrome). Although most cases of nevus comedonicus occur unilaterally on the face, neck and chest, the lesions occasionally show a bilateral distribution (bilateral nevus comedonicus). We report here an unusual case of bilaterally disseminated nevus comedonicus with various systemic complications. A 62-year-old Japanese man presented with a 50-year history of numerous keratotic papules and comedo-like lesions, which gradually worsened with time. Physical examination revealed that the papules were skin-colored and 1-4 mm in diameter. Some papules had dark-black keratinous materials on their surface, giving them a comedo-like appearance. The lesions were located predominantly on the face, head, neck and trunk with symmetric distribution, following Blaschko's lines. The patient's past medical history was noteworthy; he had undergone surgical treatments for thyroid cancer, pneumothorax and schwannoma in the cauda equina. He also suffered from scoliosis, cervical spondylosis and atrial fibrillation. Histopathologic examination revealed dilated and invaginated follicular structures filled with lamellar keratin, compatible with nevus comedonicus. Our patient's case did not fit with any previously reported diseases, and we thought a diagnosis of "bilateral nevus comedonicus syndrome" was the most appropriate for our patient's condition. He was treated with topical retinoic acid and activated vitamin D3 ointment for 3 months each, but the lesions remained unchanged.