Incidence of thyroid nodules in early stage autosomal polycystic kidney disease

BACKGROUND: Autosomal dominant polycystic kidney disease (ADPKD) is the most common hereditary kidney disease. Defect in cilia-mediated signaling activity is a crucial factor leading to cyst formation. Hence, ADPKD is regarded as a systemic disorder with multiple extrarenal complications, including cysts in other organs, for instance, the liver, pancreas, spleen, or ovaries. Interestingly, loss-of-function of primary cilia has been recently found to contribute to a malignant transformation from degenerated thyroid follicles. However, the increased incidence of thyroid nodules in ADPKD patients has not yet been fully confirmed. OBJECTIVES: To determine the incidence of thyroid lesions in patients with ADPKD in comparison to previous population studies. Moreover, we aimed to investigate if the pace of the disease progression is associated with a higher prevalence of thyroid lesions. MATERIAL AND METHODS: In 49 early-stage ADPKD patients recruited from our center, we performed ultrasonography of the thyroid glands, and laboratory evaluation of thyroids function. We compared the results with population studies. RESULTS: Twenty-three individuals had solid, cystic-solid, or cystic lesions revealed in the ultrasonography and 2 patients had a positive past medical history for thyroidectomy due to nodular goiter. In 10 patients out of the 23, only minor cysts with no clinical significance were found and 13 out of the 23 patients had solid or cystic-solid lesions, which occurred to be benign based on three years of follow-up or the biopsy of the nodule. CONCLUSIONS: We found no increased incidence of thyroid gland lesions in early ADPKD patients in comparison to previous population studies. Plausibly, mechanisms other than defective cilia signaling are involved in the risk for focal thyroid lesions formation. Moreover, the rate of progression of kidney function decline seems to be not accompanied by the higher incidence of thyroid pathology.