This case presents a young female presenting with only cystic lung disease and kidney tumors, identified as having a never before identified heterozygous mutation in the folliculin (<i>FLCN</i>) gene which is the likely cause of her syndrome.<h4>Case presentation</h4>A 34-year-old female was found to have bilateral renal masses, 2.4 cm on the right and 7.6 cm on the left, as well as multiple, small cysts in the lungs. This evidence concerns the gene FLCN and kidney neoplasm.