Vnitr Lek 2021, 67(3):175-179 | DOI: 10.36290/vnl.2021.040

Pembrolizumab-induced hypothyreosis and subcutaneous bleeding

Pavel Polák^{1, 3, 4}, Jana Špeldová², Monika Bratová², Jiřina Zavřelová^{1, 3}, Miroslav Penka¹

¹ Oddělení klinické hematologie, Fakultní nemocnice Brno

² Klinika nemocí plicních a tuberkulózy, Fakultní nemocnice Brno

³ Katedra laboratorních metod, Lékařská fakulta Masarykovy univerzity Brno

⁴ Interní hematologická a onkologická klinika, Fakultní nemocnice Brno

Pembrolizumab belongs to so called immune checkpoint inhibitors. Frequent adverse event of this therapy is hypothyroidism. The authors present a case report of patient treated with pembrolizumab for non-small cell lung carcinoma, in whom severe hypothyroidism followed quite rapidly after transient phase of subclinical hyperthyroidism - at this time point new and spontaneous onset of large subcutaneous hematomas was observed. Acquired von Willebrand syndrome, acquired hemophilia A, dysfibrinogenemia, activation of fibrinolysis and thrombocytopathy were all actively ruled out in hematological differential diagnosis. Concomittantly, laboratory markers of secondary autoimmune disease and myositis were excluded. Despite continuous pembrolizumab treatment, there were no other bleeding complications seen after intensification of endocrine substitution therapy with thyroid hormones. Causal relationship between subcutaneous hematomas and severe drug-induced hypothyroidism is established per exclusionem.

Keywords: hematomas, hypothyroidism, pembrolizumab.

Published: May 26, 2021  Show citation