Breast Cancer Metastasis to the Thyroid Presenting as a Collision Tumor With Papillary Thyroid Microcarcinoma and Oncocytic Adenoma: A Case Report
5 affiliations
- 1Department of Internal Medicine, Universidad Nacional de Colombia, Bogota, COL
- 2Department of Hematology and Oncology, Hospital Universitario Nacional de Colombia, Bogota, COL
- 3Department of Internal Medicine, Hospital Universitario Nacional de Colombia, Bogota, COL
- 4Department of Pathology, Hospital Universitario Nacional de Colombia, Bogota, COL
- 5Department of Epidemiology, Fundación Universitaria de Ciencias de la Salud, Bogota, COL
Abstract
Thyroid metastases from breast cancer are uncommon, and their coexistence with primary thyroid neoplasms as collision tumors is even rarer, posing important diagnostic and therapeutic challenges. We report the case of a 57-year-old woman with hormone receptor-positive, HER2-negative breast cancer who developed disease recurrence 13 years after initial treatment, presenting with a cervical mass, persistent dry cough, and dysphagia. Evaluation revealed an intermediate-suspicion thyroid nodule according to the American Thyroid Association (ATA) classification, with successive fine-needle aspiration biopsies categorized as Bethesda III and IV. Right hemithyroidectomy demonstrated poorly differentiated metastatic breast carcinoma, confirmed by immunohistochemistry, coexisting within the same thyroid specimen with a 1.8-mm papillary thyroid microcarcinoma (PTMC) and a 7-mm oncocytic adenoma, constituting an exceptionally rare thyroid collision tumor. Staging studies subsequently revealed systemic metastatic disease, and treatment with ribociclib plus fulvestrant was initiated according to the phase III MONALEESA-3 regimen. This case highlights the possibility of very late recurrence of hormone receptor-positive breast cancer presenting as thyroid metastasis, illustrates the diagnostic complexity of thyroid collision tumors, and emphasizes the importance of considering metastatic disease in the differential diagnosis of thyroid nodules in patients with a history of breast cancer. Although current evidence does not support routine thyroid screening, this case raises the question of whether targeted thyroid evaluation in selected patients at high risk of late recurrence warrants further prospective investigation.
Related
- Imaging evolution of pancreatic intraductal oncocytic papillary neoplasm presenting with recurrent pancreatitis: A case report and literature review.
- Modified supraclavicular approach for hemithyroidectomy with central neck dissection in unilateral papillary thyroid microcarcinoma: a feasibility-focused retrospective cohort study
- US-Guided Fine-Needle Aspiration of Papillary Thyroid Microcarcinoma in Non-Screening Settings: Diagnostic Errors and Mitigation Strategies
- Imaging features of synchronous bilateral primary tumors of oncocytic thyroid carcinoma and papillary thyroid carcinoma: A case report
- Oncocytic Papillary Cystadenoma in the Tubarial Gland: A Case Report and Literature Review
BibTeX
@article{botia2026breast,
title = {{Breast Cancer Metastasis to the Thyroid Presenting as a Collision Tumor With Papillary Thyroid Microcarcinoma and Oncocytic Adenoma: A Case Report}},
author = {Diego G Lanza Botia and Rafael E Tejada and Julian A Tellez Villa and Jinneth Acosta and Fabian G Barrero Florez and Jennifer Parra Sanchez},
journal = {Cureus},
year = {2026},
month = sep,
doi = {10.7759/cureus.117210},
url = {https://europepmc.org/article/PMC/PMC13721624},
note = {CC BY},
}
RIS
TY - JOUR
TI - Breast Cancer Metastasis to the Thyroid Presenting as a Collision Tumor With Papillary Thyroid Microcarcinoma and Oncocytic Adenoma: A Case Report
AU - Diego G Lanza Botia
AU - Rafael E Tejada
AU - Julian A Tellez Villa
AU - Jinneth Acosta
AU - Fabian G Barrero Florez
AU - Jennifer Parra Sanchez
PY - 2026
DA - 2026/09/30
JO - Cureus
DO - 10.7759/cureus.117210
UR - https://europepmc.org/article/PMC/PMC13721624
AB - Thyroid metastases from breast cancer are uncommon, and their coexistence with primary thyroid neoplasms as collision tumors is even rarer, posing important diagnostic and therapeutic challenges. We report the case of a 57-year-old woman with hormone receptor-positive, HER2-negative breast cancer who developed disease recurrence 13 years after initial treatment, presenting with a cervical mass, persistent dry cough, and dysphagia. Evaluation revealed an intermediate-suspicion thyroid nodule according to the American Thyroid Association (ATA) classification, with successive fine-needle aspiration biopsies categorized as Bethesda III and IV. Right hemithyroidectomy demonstrated poorly differentiated metastatic breast carcinoma, confirmed by immunohistochemistry, coexisting within the same thyroid specimen with a 1.8-mm papillary thyroid microcarcinoma (PTMC) and a 7-mm oncocytic adenoma, constituting an exceptionally rare thyroid collision tumor. Staging studies subsequently revealed systemic metastatic disease, and treatment with ribociclib plus fulvestrant was initiated according to the phase III MONALEESA-3 regimen. This case highlights the possibility of very late recurrence of hormone receptor-positive breast cancer presenting as thyroid metastasis, illustrates the diagnostic complexity of thyroid collision tumors, and emphasizes the importance of considering metastatic disease in the differential diagnosis of thyroid nodules in patients with a history of breast cancer. Although current evidence does not support routine thyroid screening, this case raises the question of whether targeted thyroid evaluation in selected patients at high risk of late recurrence warrants further prospective investigation.
SN - 2168-8184
ER -