Work

Pembrolizumab-associated primary hypothyroidism followed by central hypothyroidism: a case report

Year: 2026

Type: article

Abstract: Introduction: PD-1 inhibitors are widely used anticancer drugs and frequently trigger immune-related adverse events, with thyroid dysfunction as the most prevalent. Suspected isolated central hypothyroidism emerging during PD-1 inhibitor therapy has rarely been documented. Case presentation: A 56-year-old man received pembrolizumab for esophageal squamous cell carcinoma. Before treatment, he had pre-existing Hashimoto's thyroiditis with low TT4 and normal TSH. He developed painless thyroiditis manifesting as transient thyrotoxicosis followed by primary hypothyroidism. Shortly after hypothyroidism was pharmacologically controlled, TSH progressively declined to the lower limit of detection, accompanied by low TT4. Pituitary MRI showed pituitary gland thinning without focal structural abnormalities. Integrating the clinical course, central hypothyroidism was considered. Given altered upper gastrointestinal anatomy after esophagectomy, split-dose levothyroxine was administered, and the patient's FT4 levels remained stable. Conclusion: This rare sequential evolution of thyroid dysfunction may represent an uncommon endocrine immune-related adverse event of immune checkpoint inhibitors.

Source: Frontiers in Oncology

DOI: 10.3389/fonc.2026.1978296

Authors: Jiawei Sun, Chunnuo Wang, Zhanzhan Sun, Wei Li

Institutions: Wenzhou Medical University, Cixian People's Hospital, Ningbo Medical Center Lihuili Hospital

Language: English

Topic: Cancer Immunotherapy and Biomarkers

Subfield: Oncology

Field: Medicine

Domain: Health Sciences

SDG: Good health and well-being

Open Access status: gold

Estimated APC paid: $3,801