Abstract: This paper reports the imaging and clinical features of a patient with an atypical parathyroid adenoma characterized by recurrent fractures,high parathyroid hormone level,negative 99Tcm-methoxyisobutylisonitrile(MIBI)SPECT imaging at initial diagnosis and positive 99Tcm-MIBI SPECT/CT tracking imaging at follow-up.By reviewing and analyzing relevant literature,this paper aims to explore the diagnostic approach when both CT and ultrasound localization diagnostic results are negative,and even when the 99Tcm-MIBI SPECT/CT imaging are still negative,in order to improve the understanding and early diagnosis of atypical parathyroid adenoma and avoid clinical missed diagnosis.