Lenvatinib-induced multiorgan adverse events in Hurthle cell thyroid cancer: A case report

BACKGROUND: The management of metastatic progressive radioiodine-resistant differentiated thyroid cancer remains challenging for clinicians. The availability of tyrosine kinase inhibitors (TKIs), sorafenib and lenvatinib, within the last decade has expanded treatment options; however, these lead to significant adverse effects, which may curtail their use. CASE SUMMARY: We report the case of a 47-year-old female with Hurthle cell thyroid cancer who underwent total thyroidectomy followed by radioiodine ablation. During follow-up, she developed noniodine-avid renal and pulmonary metastases. With respect to her pre-existing diabetes, hypertension, and polycystic kidney disease, the tumor board decided against performing renal metastasectomy because of the risk of future renal decline requiring dialysis. Metastases were treated using sorafenib, which provided stability followed by progression within a year. We switched to lenvatinib, which led to disease regression. However, the patient experienced severe adverse effects, including cardiomyopathy, bicytopenia, renal impairment, and the rarely reported nephrotic syndrome. Renal metastasis is a rare manifes-tation of Hurthle cell thyroid cancer with only two reported cases in literature. We report the experience of our first case of renal metastasis and its treatment with TKIs. This case serves as a reminder of the adverse drug reactions associated with TKI use. CONCLUSION: We advocate close monitoring of patients’ hematological and renal profiles as well as their cardiac status using an echocardiogram.