Follicular thyroid cancer in a patient with Pendred syndrome.

We present the clinical and molecular studies of a family with Pendred syndrome, in which one affected individual developed follicular thyroid cancer. Two siblings with classic Pendred syndrome triad were operated on because of enormous multinodular goiter. Histopathology showed a follicular thyroid cancer in the male and a multinodular goiter in the female. PDS gene analysis revealed G-to-A transition in the splice donor site of intron 8 (IVS8+1G>A/c.1001+1G>A). Careful surveillance is needed in all cases of thyroid nodules in patients with Pendred syndrome, due to the high risk of malignancy.