Work

Diffuse bilateral differentiated high-grade thyroid carcinoma presenting as a giant clinical neck mass with iodine-avid pulmonary metastases: a case report and focused literature review

Year: 2026

Type: article

Abstract: Differentiated high-grade thyroid carcinoma (DHGTC) is a follicular-cell-derived malignancy defined in the 2022 World Health Organization classification. It retains differentiated morphology but shows tumor necrosis and/or at least 5 mitoses per 2 mm². Longitudinal evidence on giant tumors and radioactive iodine (RAI) treatment remains limited. A 58-year-old woman presented with a 6-year enlarging neck mass, dyspnea, and dysphagia. The clinical mass measured 13 cm; computed tomography showed a thyroid-lesion cross-section of 12.4 × 7.7 cm and bilateral pulmonary nodules. Total thyroidectomy with bilateral central-node dissection and right lateral neck dissection (levels II–V) were completed in July 2024. Pathology showed bilateral DHGTC with necrosis, more than 5 mitoses per 2 mm², multifocal vascular invasion, negative margins, no extrathyroidal extension, and central (7/13) and right lateral (3/6) nodal metastases (pT3a pN1b). Two RAI courses were documented. A September 2024 scan established iodine-avid mediastinal and pulmonary metastases (cM1); March 2025 imaging showed improvement. In June 2025, thyroglobulin was 656.85 ng/mL. By September 2025, pulmonary computed tomography showed mixed changes and thyroglobulin exceeded 500 ng/mL. At last contact on 26 August 2026, the patient was alive and reported generalized and low-back pain, without imaging confirmation of new metastases. DHGTC may present after prolonged enlargement with a giant clinical neck mass, nodal spread, and iodine-avid pulmonary metastases. Early post-RAI improvement did not establish durable control. The 13-cm value describes the clinical mass, not a single pathological tumor diameter. Missing RAI activities and incompletely synchronized tests preclude definitive classification as RAI-refractory disease. Not applicable.

Source: BMC Endocrine Disorders

DOI: 10.1186/s12902-026-02559-6

Authors: Shengyu Gao, Xiaoyu Xu, Weiwei Wei

Institutions: First Affiliated Hospital of Jiamusi University, Jiamusi University

Language: English

Topic: Thyroid Cancer Diagnosis and Treatment

Subfield: Endocrinology, Diabetes and Metabolism

Field: Medicine

Domain: Health Sciences

SDG: Good health and well-being

Open Access status: gold

Estimated APC paid: $3,190