A rare presentation of RET mutation: Early-onset medullary thyroid carcinoma with intestinal neuronal dysplasia and chronic kidney disease, A case report and literature review
Therapeutic Advances in Endocrinology and Metabolism, cilt.19, 2026 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 19
- Basım Tarihi: 2026
- Doi Numarası: 10.1177/20420188261498161
- Dergi Adı: Therapeutic Advances in Endocrinology and Metabolism
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, EMBASE, Directory of Open Access Journals, Health Research Premium Collection (ProQuest)
- Anahtar Kelimeler: Chronic kidney disease, Intestinal neuronal dysplasia, Medullary thyroid carcinoma, RET mutation
- Ankara Üniversitesi Adresli: Evet
Özet
Medullary thyroid carcinoma (MTC) is a rare pediatric tumor arising from the parafollicular C cells of the thyroid. The majority of childhood MTC cases are associated with germline mutations in the RET proto-oncogene. Although the American Thyroid Association (ATA) has classified most of these mutations according to their risk level, some rare or unclassified variants may also be identified. These variants pose significant challenges for clinicians in both diagnosis and treatment. This report presents the case of a 6-year-old girl who was admitted with growth retardation. Her medical history included intestinal neuronal dysplasia (IND), vesicoureteral reflux, and chronic kidney disease (CKD). Physical examination revealed maxillofacial anomalies. Laboratory tests demonstrated significantly elevated serum calcitonin and parathyroid hormone (PTH) levels. Thyroid ultrasonography identified bilateral nodular lesions, and a fine-needle aspiration biopsy was consistent with MTC.Genetic analysis revealed a heterozygous c.1894_1899del p. (Glu632_Leu633del) mutation in exon 11 of the RET gene. This specific mutation is not included in the ATA risk classification guidelines. The patient underwent total thyroidectomy and central-lateral lymph node dissection. Pathological evaluation confirmed MTC and revealed additional parathyroid hyperplasia. Postoperatively, calcitonin levels normalized, but PTH levels remained high due to secondary hyperparathyroidism related to CKD.This case highlights the clinical implications of an unclassified RET mutation and illustrates how rare comorbid conditions such as IND and CKD can complicate the diagnostic process. Reporting similar cases will significantly contribute to a more comprehensive understanding of the genotype-phenotype relationship and to the refinement of risk classification and management strategies for pediatric MTC.