Abstract
INTRODUCTION: Advanced adrenocortical carcinoma has a poor prognosis and is treated with chemotherapy that includes mitotane with etoposide, doxorubicin, and cisplatin as first-line therapy. However, second-line therapy has not been determined yet. Pembrolizumab has been approved for high microsatellite instability for which standard treatments have failed. CASE PRESENTATION: Here, we present a patient with advanced adrenocortical carcinoma treated with complete surgical resection. 21 months later, he had local and metastatic recurrences. After four cycles of first-line therapy, we switched to pembrolizumab because microsatellite instability-high was detected in his tumor. He has received mitotane and pembrolizumab for 15 months, and this has exerted a radiographical response without severe adverse events. CONCLUSION: We presented a patient with microsatellite instability-high advanced adrenocortical carcinoma treated with pembrolizumab and mitotane.