Bilateral segmental neurofibromatosis with gastric carcinoma.

Neurofibromatosis type 1 (NF1) is an autosomal-dominant disorder characterized by café-au-lait spots, neurofibromas, intertriginous freckles, and Lisch nodules in the iris. Segmental neurofibromatosis is fundamentally a mosaic variant of NF1. A 66-year-old man visited us with bilateral segmental neurofibromatosis (SN) on the torso. He had multiple neurofibromas on the back bilaterally and on the right abdomen, and partial unilateral lentiginosis on the left abdomen and left back. The patient had noticed the development of papules and nodules on the right abdomen and bilaterally on the back 6 years previously, and had been diagnosed with early gastric carcinoma 5 years previously. To our knowledge, this is only the third reported case of SN associated with internal malignant tumours.