Open Access

CASE REPORT

Cardiac Metastasis from Poorly Differentiated Thyroid Carcinoma: A Rare Case Report and Review of the Literature

Xin Qian, Xian Deng, Rongjia Zhang, Xu Li, Dehui Qiao, Xiaodong Chen, Hui Yang^*

Department of Thyroid Surgery, The Affiliated Hospital of Southwest Medical University, Luzhou, China

* Corresponding Author: Hui Yang. Email:

Oncology Research 2026, 34(8), 29 https://doi.org/10.32604/or.2026.079674

Received 26 January 2026; Accepted 30 April 2026; Issue published 16 July 2026

Abstract

Background: Poorly differentiated thyroid carcinoma (PDTC) is a rare, aggressive malignancy. Cardiac metastasis from PDTC is exceedingly uncommon. We report early cardiac metastasis occurring shortly after radical thyroidectomy to highlight atypical distant spread and management challenges. Case Description: A 62-year-old woman presented four months after thyroidectomy with progressive exertional dyspnoea, fatigue, productive cough, facial oedema, lip cyanosis, and dizziness. Postoperative pathology showed poorly differentiated thyroid carcinoma of the right lobe and isthmus (pT2N1bM0) with capsular and recurrent laryngeal nerve invasion. Transthoracic echocardiography revealed a right atrial mass that enlarged to 5.3 × 4.0 cm and extended toward the tricuspid orifice; imaging also demonstrated continuous tumor thrombus involving the right internal jugular vein, brachiocephalic vein, and superior vena cava. Cytology from internal jugular vein puncture showed malignant cells, supporting metastatic intraluminal tumor thrombus with intracardiac extension. After surgery, levothyroxine was initiated as thyroid hormone replacement and for gradual thyroid-stimulating hormone (TSH) suppression as tolerated. During cardiology admission, the patient received antimicrobial therapy, anticoagulation, thrombolysis, and cardiac workload reduction, with symptomatic improvement. She was discharged against medical advice before definitive oncologic treatment could be initiated and was subsequently lost to follow-up. Conclusions: In aggressive thyroid cancers such as PDTC, clinicians should remain vigilant for atypical distant metastases—including intracardiac extension via venous tumor thrombus—soon after surgery. Early multimodality imaging and coordinated multidisciplinary care are essential for individualized management.

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Supplementary Material

Supplementary Material File

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