Evolution Of Microwave Ablated Breast Fibroadenoma In A Nonviable Transplantation Model

Background:Breast fibroadenoma is the most common benign tumor in the female breast.Microwave ablation(MWA)is a promising minimally invasive local therapy and has been used effectively in the treatment of tumors in liver and uterus myoma.Since MWA ablate the lesion in situ without tissues removed,it appears to be mandatory to confirm that MWA ereates an area of coagulation necrotic debris can be progressively eliminated over time.Purpose:Given that nonviable transplantation couldn’t cause rejection,we evaluate the evolution of microwave ablated breast fibroadenomas in a nonviable transplantation model.Methods:Eight breast fibroadenoma samples were ablated completely by MWA and implanted in the right hind limb of eight rabbits to simulate the in vivo environment.The clinical outcomes of resolved mass were evaluated via physical examination,ultrasound follow-up and histopathological examination.Besides,two ablated samples were chosen randomly to verify being completely inactivated by 2,3,5-triphenyltetrazolium chloride(TTC)staining.Results:Confirmed by TTC staining,the ablated samples were inactivated completely.No local side effect and death related to the implantation were observed.Both physical examination and ultrasound follow-up provided information about the progressive absorption of ablated fibroadenomas.The mean volume pretreatment of fibroadenoma samples was 641.1±60.6 mm3,and the mean ultrasound volume in week 1 was 494.5±188 mm3.Then,fibroadenoma samples became nonpalpable with an average duration of 11.6±1.5 weeks.Debris was undetectable under ultrasound with a mean time of 14.0±3.1 weeks.Histopathological examination revealed an area of coagulation necrosis created by MWA and progressively eliminated from the body over time.Conclusions:Since fibroadenomas treated by MWA can be resorbed smoothly over time without either colliquation or residual mass,MWA of breast fibroadenoma may have a promising cosmetic benefit.Ultrasound can be used effectively in monitoring the evolution of microwave ablated fibroadenoma.