RET and columnar cell hyperplasia of the breast: Clinical investigation in our patients revealed that only one (II-5) had bilateral MTC at the age of 70, one (III-10) had bilateral CCH at age 44, and two (III-8 and III-3) had bilateral multiple nodules in both thyroid lobes at ages 46 and 48, which may be caused by the RET p.V292M/R67H/R982C mutation.