Patients with tuberous sclerosis develop benign cutaneous tumors that are typically multiple in number and location. These tumors include facial angiofibromas, forehead plaques, shagreen patches, periungual fibromas, and gingival fibromas. The tumors are permanent, slow growing, and often disfiguring. The purpose of this study is to elucidate the molecular basis for these tumors. Specifically, we plan to identify the genetically altered cells in these hamartomatous lesions, and to quantify factors (e.g. cytokines) produced by these cells which induce the growth of these tumors. To accomplish this, we plan to obtain samples of these cutaneous tumors, to test tumor DNA for loss of heterozygosity, and to measure RNA and protein expression levels.