Fibroblast growth factor receptor 3 (<i>FGFR3)</i> gene mutations in the germline are well-known causes of skeletal syndromes. Somatic <i>FGFR3</i> mutations have been found in malignant neoplasms and more recently in several cutaneous elements. We present a 14-year-old girl with mild hypochondroplasia who developed acanthosis nigricans. The report of a K650Q mutation in the <i>FGFR3</i> gene in a similar case prompted us to conduct a point mutation analysis. The K650Q mutation was confirmed, but in contrast to the previous case, we additionally report findings of hyperinsulinemia. In the recent literature, an increasing number of different cutaneous elements have been found to harbor mutations of <i>FGFR3</i>, suggesting that <i>FGFR3</i> plays a role in the pathogenesis of these elements. We review the present literature, describing studies in which <i>FGFR3</i> mutations have been investigated in skin lesions: primarily seborrheic keratoses and epidermal nevi, but also other benign skin tumors and a single case of a squamous cell carcinoma. In addition, an overview of the <i>FGFR3</i> point mutations in relation to each cutaneous element is given. Based on the current knowledge, it seems likely that these cutaneous lesions have a common genetic background. Our case shows that <i>FGFR3</i> mutation analysis should be considered in case of the coexistence of acanthosis nigricans and a skeletal dysplasia. Testing for hyperinsulinemia is essential, also if a gene mutation is confirmed.