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Identification of Recurrent TERT Promoter Mutations in Intrathyroid Thymic Carcinomas
- Source :
- Endocrine Pathology. 31:274-282
- Publication Year :
- 2020
- Publisher :
- Springer Science and Business Media LLC, 2020.
-
Abstract
- Intrathyroid thymic carcinoma (ITTC) is a rare malignant neoplasm considered to be a eutopic thymic carcinoma (TC) arising ectopically in the thyroid. Histopathologically, ITTC resembles squamous cell carcinoma of the thymus with positive TC markers such as CD5 and c-KIT. Despite these similar histological findings, ITTC is clinically less aggressive than TC. In this study, we compared clinical, histological, and genetic characteristics of ITTCs and TCs. We collected 9 ITTCs and 8 TCs with their clinicopathological profiles. Immunohistochemistry for CD5, p63, CD117/c-KIT, Ki-67, p53, TTF-1, thyroglobulin, PAX8, EGFR, and PD-L1/CD274 plus in situ hybridization for EBER was performed. We further investigated mutation status of KIT, EGFR, BRAF, and TERT promoter using Sanger sequencing. In our study, ITTCs affected significantly younger patients than TCs. After a mean follow-up of 86 months, all patients with ITTC were alive, while two patients with TC had died. Immunohistochemistry showed ITTCs and TCs had a similar immunophenotype except for EGFR and p53. Genetic analysis did not identify KIT or BRAF mutations in any ITTCs or TCs. EGFR mutations were positive in 11% (1/9) of ITTCs and 25% (2/8) of TCs. Notably, TERT promoter C228T mutation was identified in 22% (2/9) of ITTCs but none of the TCs. There were no significant differences in age, tumor size, or sex between TERT-mutated and TERT-wild-type ITTCs. Collectively, ITTC and TC have similar histopathologic and immunophenotypic features but different clinical outcomes. Recurrent TERT promoter mutation may be a key event related to cancer progression in ITTCs and warrants further investigation.
- Subjects :
- Adult
Male
Thymoma
Endocrinology, Diabetes and Metabolism
medicine.medical_treatment
030209 endocrinology & metabolism
Thymus Gland
Choristoma
Pathology and Forensic Medicine
03 medical and health sciences
0302 clinical medicine
Endocrinology
Immunophenotyping
Gene Frequency
medicine
Humans
Thyroid Neoplasms
Promoter Regions, Genetic
Telomerase
Thymic carcinoma
Aged
biology
business.industry
CD117
fungi
Cancer
Thymus Neoplasms
General Medicine
Middle Aged
medicine.disease
Tertiary Lymphoid Structures
Case-Control Studies
030220 oncology & carcinogenesis
Mutation
Cancer research
biology.protein
Immunohistochemistry
Female
Thyroglobulin
CD5
business
PAX8
Subjects
Details
- ISSN :
- 15590097 and 10463976
- Volume :
- 31
- Database :
- OpenAIRE
- Journal :
- Endocrine Pathology
- Accession number :
- edsair.doi.dedup.....ee0a0adcc9cbd24aa0c7a49f11253919