Alvarez M, Luna M, Suarez E, Rincon O, Guzman I, Mancera P. Thyroid collision tumor and Graves’ disease: A case report and review of literature. World J Clin Cases 2026; 14(5): 117016 [DOI: 10.12998/wjcc.v14.i5.117016]
Corresponding Author of This Article
Mauricio Alvarez, Department of Endocrinology, Hospital Militar Central, Tv. 3C No. 49-02, Bogota 110221, Distrito Capital de Bogotá, Colombia. mauricioalvarez613@gmail.com
Research Domain of This Article
Endocrinology & Metabolism
Article-Type of This Article
Case Report
Open-Access Policy of This Article
This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Feb 16, 2026 (publication date) through Feb 10, 2026
Times Cited of This Article
Times Cited (0)
Journal Information of This Article
Publication Name
World Journal of Clinical Cases
ISSN
2307-8960
Publisher of This Article
Baishideng Publishing Group Inc, 7041 Koll Center Parkway, Suite 160, Pleasanton, CA 94566, USA
Share the Article
Alvarez M, Luna M, Suarez E, Rincon O, Guzman I, Mancera P. Thyroid collision tumor and Graves’ disease: A case report and review of literature. World J Clin Cases 2026; 14(5): 117016 [DOI: 10.12998/wjcc.v14.i5.117016]
World J Clin Cases. Feb 16, 2026; 14(5): 117016 Published online Feb 16, 2026. doi: 10.12998/wjcc.v14.i5.117016
Thyroid collision tumor and Graves’ disease: A case report and review of literature
Mauricio Alvarez, Maria Luna, Elkin Suarez, Oswaldo Rincon, Isaac Guzman, Pedro Mancera
Mauricio Alvarez, Oswaldo Rincon, Isaac Guzman, Department of Endocrinology, Hospital Militar Central, Bogota 110221, Distrito Capital de Bogotá, Colombia
Maria Luna, Pedro Mancera, Department of Endocrinology, Universidad Militar Nueva Granada, Bogota 110221, Colombia
Elkin Suarez, Internal Medicine Program, Universidad Militar Nueva Granada, Bogota 250001, Bogotá, Colombia
Author contributions: Luna M conceived the study and wrote the paper; Suarez E, Rincon O, Guzman I, and Mancera P contributed to the writing of the paper; Alvarez M conceived the study and wrote the paper.
Informed consent statement: Written informed consent was obtained from the patient using the hospital’s official institutional format, authorizing the publication of this case report and any accompanying images.
Conflict-of-interest statement: The authors declare that there are no conflicts of interest regarding the publication of this article.
CARE Checklist (2016) statement: The authors have read the CARE Checklist (2016), and the manuscript was prepared and revised according to the CARE Checklist (2016).
Open Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: https://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Mauricio Alvarez, Department of Endocrinology, Hospital Militar Central, Tv. 3C No. 49-02, Bogota 110221, Distrito Capital de Bogotá, Colombia. mauricioalvarez613@gmail.com
Received: November 26, 2025 Revised: December 20, 2025 Accepted: January 16, 2026 Published online: February 16, 2026 Processing time: 76 Days and 0.7 Hours
Abstract
BACKGROUND
Collision tumors of the thyroid are rare entities, defined by the coexistence of two histologically distinct tumors within the same organ, separated by intervening normal tissue. Graves’ disease (GD) is a well-known risk factor for papillary thyroid cancer but has not been associated with thyroid collision tumor or medullary thyroid cancer (MTC).
CASE SUMMARY
A 37-year-old female presented with palpitations, weight loss, and tremors. Thyroid function tests showed suppressed thyrotropin and slightly elevated free thyroxine. A thyroid ultrasound was performed with a report of a nodule in the right thyroid lobe. Thyroid scintigraphy revealed a goiter with increased radiotracer uptake. Ultrasound-guided fine needle biopsy suggested an MTC, Bethesda VI. Immunohistochemistry was positive for synaptophysin and negative for thyroglobulin. Calcitonin levels were elevated. Total thyroidectomy with central lymph node dissection was performed. Pathological exam revealed a medullary carcinoma in the right thyroid lobe and a 3-mm papillary microcarcinoma in the left lobe. Lymph nodes showed reactive hyperplasia without evidence of tumor involvement. The final diagnosis was synchronous medullary thyroid carcinoma and papillary thyroid microcarcinoma, staged as T1N0M0. Sequencing of the rearranged during transfection (RET) oncogene revealed no pathogenic variants, and multiple endocrine neoplasia was ruled out.
CONCLUSION
Collision tumors are rare entities but thyroid collision tumors in GD are even more infrequent despite the known association between GD and differentiated thyroid cancer. The mechanisms by which this clinical entity occurs are unclear. Because it is a rare pathology, there are currently no guidelines for its treatment. Treatment must be guided separately or based on the more aggressive neoplasm.
Core Tip: Collision tumors of the thyroid are rare entities, characterized by the presence of two histologically distinct tumors within the same organ, separated by normal intervening tissue. Graves’ disease is a well-established risk factor for papillary thyroid cancer but has not been associated with thyroid collision tumors or medullary thyroid carcinoma. In this review, we evaluate the available evidence on thyroid collision tumors.
