Reflection on Misdiagnosis and Mistreatment of Granulomatous Mastitis in the Accessory Axillary Breast

LI Nan; LI Dan; ZHAO Sumei; BAI Yuncui; GENG Xiaoxu

doi:10.3969/j.issn.1002-3429.2025.04.004

Abstract：Objective To analyze the causes of clinical misdiagnosis and preventive measures of granulomatous mas-titis(GM)in the accessory axillary breast.Methods The clinical data of 2 patients with GM in the accessory axillary breast who were misdiagnosed from June 2021 to June 2023 were retrospectively analyzed.Results One patient presented with left axillary mass with pain for more than 2 months.Ultrasound and breast magnetic resonance imaging(MRI)indicated malignant lesions,which was initially considered to be left accessory breast cancer(ABC),and surgical resection was performed.Dur-ing the operation,lateral mass of left accessory breast with hard quality and poorly defined boundary was found,and the post-operative pathological diagnosis was GM in the left accessory axillary breast.The misdiagnosis lasted 13 d.The postoperative follow-up was favorable for 6 months.One patient was admitted with right anterior axillary mass,redness,and pain for 1 month,was diagnosed with mastitis by color Doppler ultrasonography and received anti-infection treatment,during which the mass was enlarged with redness and swelling.GM in the right accessory axillary breast was considered by color Doppler ultra-sound in our hospital.After oral administration of traditional Chinese medicine and external application of drugs,the mass burst and yellow purulent secretions were discharged.Enhanced MRI of the breast was performed to show non-tumor enhance-ment in the lower quadrant of the right breast,indicating the possibility of inflammation.The patient was treated with breast segment plus para-mastectomy and the postoperative pathological examination revealed GM in the right accessory axillary breast.The misdiagnosis lasted 11 d.Reexamination at 3 months after operation showed that the right breast incision healed well,and no recurrence or other abnormal conditions were found.Conclusion GM in the accessory axillary breast is rare in clinical practice,and lacks specific clinical manifestations and examination measures;therefore,it is more likely to be misdi-agnosed as breast cancer,mastitis and other diseases.For breast mass,clinicians and pathologists should strengthen the un-derstanding,considering the possibility of GM and other benign diseases,in order to reduce or avoid misdiagnosis and mis-treatment.