Diffuse cutaneous mastocytosis with novel somatic KIT mutation K509I and association with tuberous sclerosis.

Diffuse cutaneous mastocytosis (DCM) is a rare but potentially fatal condition when diagnosis and targeted treatments are delayed. This case illustrates the life-threatening complications in DCM and reviews the currently available treatments. To our knowledge, this is the first report of mastocytosis with somatic K509I mutation and concomitant tuberous sclerosis.