AUTHOR=Zhang Daqi , Yang Mingyu , Zhang Xin , Wang Cheng , Li Kunlin , Wang Hongbo , Chi Hao , Sui Chengqiu , Dionigi Gianlorenzo , Sun Hui TITLE=Thirty synchronous medullary and papillary thyroid carcinomas JOURNAL=Frontiers in Endocrinology VOLUME=Volume 14 - 2023 YEAR=2023 URL=https://www.frontiersin.org/journals/endocrinology/articles/10.3389/fendo.2023.1153248 DOI=10.3389/fendo.2023.1153248 ISSN=1664-2392 ABSTRACT=Synopsis for table of contents

An exceptional number of synchronous MTC/PTC in the same thyroid gland is presented. This may be the most numerous case series reported in the literature. Synchronous PTC/MTC in the same thyroid gland were classified into 4 subtypes and the clinical and pathological aspects as well as the results are presented.

Background and objectives

The synchronous occurrence of multiple neoplastic processes in the thyroid gland is unusual. We investigated the clinicopathological features of 30 medullary thyroid carcinomas (MTC) in association with papillary (PTC).

Method

Retrospective analysis of operated patients for thyroid tumors. Synchronous PTC/MTC in the same thyroid gland were classified into 4 subtypes: (type I) True mixed MTC/PTC, MTC and PTC closely intermingled. (Type II) Collision MTC/PTC, i.e. tumors that meet at the same site, invade each other and appear as a single mass in the thyroid gland, i.e. MTC and PTC merge. (Type III) Synchronous anatomically separate tumors in the same thyroid lobe, i.e. separated from each other by non-tumorous thyroid parenchyma. (Type IV) Synchronous tumors occurring in separate anatomical lobes or in the isthmus. Clinical and pathological data were reviewed. Location: Department of thyroid surgery, China-Japan Union Hospital, Jilin University. Time frame: 14 years (June 2008-November 2022).

Results

Thirty patients were identified with an overall prevalence of 28621 (0.1%). 17 (56.7%) were male, 13 (43.3%) female, mean age 51.3 ± 11.0 years, mean BMI 23.6 ± 3.6kg/m2. Mean duration of symptoms was 11.2 ± 18.4 months. Mean calcitonin level was 133.7 ± 196.4 pg/ml. Fine needle aspiration (FNA) was offered in 21 cases: 9 (42.9%) were suspected carcinoma, 9 (42.9%) PTC, 1 (4.8%) MTC, 2 (9.4%) MTC/PTC. Pathology revealed type I 4 (13.3%), type II 2 (6.7%), type III 14 (46.7%), type IV 10 (33.3%). The mean diameter of MTC was 1.6 ± 2.0cm, 18 (60%) were micro-MTC. The mean diameter of PTC was 0.9 ± 1.9 cm, 26 (86.7%) were micro-PTC. In 16 (53.3%) micro-PTC/-MTC occurred in synchronous sequence. Four patients had a recurrence: 2 had to be re-operated due to MTC recurrence, 2 died due to distant metastases (bone, liver).

Conclusion

We report an exceptional number of MTC/PTC in the same thyroid gland. This may be the most numerous case series reported in the literature. The clinical and pathological aspects as well as the results are presented.