Blue nevus of the hard palate.

The occurrence of a blue nevus of the hard palate in a 72-year-old man is reported. Of the 25 previously documented cases of blue nevus of the oral cavity, 19 were on the hard palate, three on the upper lip, and one each on the lower lip, buccal mucosa, and soft palate. Fourteen were in women and 11 were in men. All but five patients were younger than 50 years of age. The size of the asymptomatic, flat to somewhat elevated, blue-black lesion varied up to 5 mm except for one that was 10 mm in the greatest dimension. Most nevi were of unknown duration and were found incidentally during dental examination. The histogenesis of extracutaneous blue nevus is undetermined but derivation from melanogenic potential of Schwann or endoneurial cells or from stimulation of retained melanoblasts in the stroma developing into melanocytes and formation of blue nevus is possible.