UMMS Affiliation

Department of Medicine

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Document Type



Endocrine System Diseases | Endocrinology, Diabetes, and Metabolism | Hormones, Hormone Substitutes, and Hormone Antagonists | Immune System Diseases | Therapeutics


The advent of immune checkpoint inhibitors has significantly improved the prognosis of patients with advanced malignancies. As we begin to understand these medications, multiple immune-related adverse effects (irAEs) have been found with these drugs, including endocrinopathies. Understanding the treatment-related adverse events of these medications is critical for clinical practice. Thyroid-related adverse effects usually occur within the first three months of treatment and rarely after eight months. It can manifest as an early onset of thyrotoxicosis, which is largely asymptomatic, followed by a rapid transition to hypothyroidism, requiring long-term levothyroxine substitution. We present a case in which our patient was found unresponsive, hypothermic, and with respiratory failure almost after completing a year of treatment with pembrolizumab. He had an initial mild elevation in thyroid-stimulating hormone (TSH) of 6.52, although with normal free thyroxine (T4) of 1.06, in his first three months of starting treatment which then rapidly progressed to a true myxedema coma. The infrequency with which this occurs makes it a diagnostic challenge.


immune checkpoint inhibitors, myxedema coma, pembrolizumab, endocrinopathies, thyroid-related adverse effects

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Copyright © 2020 Sangeetha Gummalla et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

DOI of Published Version



Gummalla S, Manjunath M, Phillips B. Myxedema Coma: A Life-Threatening Condition in Patients Using Pembrolizumab. Case Rep Endocrinol. 2020 Oct 22;2020:8855943. doi: 10.1155/2020/8855943. PMID: 33145114; PMCID: PMC7599411. Link to article on publisher's site

Journal/Book/Conference Title

Case reports in endocrinology

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Creative Commons License

Creative Commons Attribution 4.0 License
This work is licensed under a Creative Commons Attribution 4.0 License.