Solitary mastocytoma on the palm.

We report a solitary mastocytoma with a recurrent tense bulla on the palm of a 4-month-old male infant. Histologically there were numerous mast cells infiltrating the dermis. The bulla subsided without treatment in 2 weeks, remaining an oval reddish patch. The present case shows that solitary mastocytoma can occur on the palm, but to our knowledge, this site is unusual.