A new progression pattern, hyperprogressive disease (HPD), has been recently acknowledged in cancer patients accepted immune checkpoint inhibitors (ICIs). We report a unique case of cervical small cell carcinoma which showed primary resistance to pembrolizumab and was with a rapid radiological progression after the initiate of ICIs treatment. However, the detection results of multiple predictive biomarkers suggested that the patient was eligible for ICIs treatment. The whole exome sequencing showed that AKT1 E17K mutation was high (26.316%) in tumor tissue, and dynamic monitoring of circulating tumor DNA indicated that AKT1 E17K mutation rate was increasing successively and highly consistent with tumor growth in peripheral blood. Therefore, the correlation between AKT1 E17K mutation and HPD, and the role of AKT1 E17K mutation in identifying patients who might not benefit from ICIs treatment need to be further studied.