Objective To investigate the clinical and MRI features of primary non-urachal adenocarcinoma of the bladder.Methods The clinical and MRI data of 9 patients with histopathologically confirmed primary non-urachal adenocarcinoma of the bladder were analyzed retrospectively.Results Clinical symptoms of hematuria were present in 7 cases and urinary irritation symptoms in 5 cases among all patients.On MRI,1 case showed diffuse thickening of the bladder wall,8 cases showed a solitary nodular/cauliflower-like mass in the bladder with iso-hypointensity on T1WI and slight hyperintensity on T2WI,and patchy areas of hyperintensity on T2WI were seen in some patients.The apparent diffusion coefficient(ADC)ranging from 0.83× 10 3 mm2/s to 1.85× 10 3 mm2/s,mean ADC was approximately 1.23×10-3 mm2/s.Dynamic enhancement showed mild to marked enhancement,with some rim or compartmentalized enhancement,and patchy or diffusely distributed areas of no enhancement can be seen.No cystic changes and necrosis were seen in all patients,invasion of the muscularis propria and above were seen in 7 cases,lymph node metastasis was seen in 3 cases,and distant metastasis was seen in 2 cases.Conclusion Primary non-urachal adenocarcinoma of the bladder has certain clinical and MRI features.Patients often present with hematuria and urinary irritation symptoms,and some may present with blennuria.MRI shows that the lesion is solitary and more aggressive,with some hyperintensity on T2 WI,cystic changes and necrosis are rare.These features help to improve the accuracy of preoperative diagnosis to some extent,and the final diagnosis still relies on pathology.