Malignant adenomyoepithelioma of the breast:Two case reports and review of the literature

BACKGROUND Malignant adenomyoepithelioma(AME)of the breast is a rare tumor in which malignancy can arise from either epithelial or myoepithelial components,or from both cell types.The incidence and prognosis of malignant AME of the breast are difficult to assess due to its rarity.Therefore,the optimal treatment for this disease is still controversial.CASE SUMMARY We present two middle-aged women(48 and 56 years old)with malignant AME of the breast.Core needle biopsy was performed before surgery.However,breast adenoma and malignant tumors were observed.The preoperative diagnosis of malignant AME of the breast is still challenging for pathologists and clinicians.Both patients underwent mastectomy and sentinel lymph node biopsy,both of which were negative,followed by adjuvant chemotherapy.CONCLUSION The follow-up duration of the two patients was two years and four months,respectively.No signs of relapse or metastasis have been observed thus far.

Diagnosis of an extremely rare case of malignant adenomyoepithelioma in pleomorphic adenoma:A case report

BACKGROUND Pleomorphic adenoma(PA)is the most common type of salivary gland tumor,and its common sites are parotid gland,sinus,nasal septum and cleft palate.PA is an uncommon benign type of tumor occurring in the breast,and there are few reports of cases in Asia.CASE SUMMARY An 84-year-old woman found a mass in the upper outer quadrant of the right breast>1 year ago.The patient underwent a right breast lumpectomy and sentinel lymph node biopsy.The pathological diagnosis was PA in the upper outer quadrant of the right breast,and the malignant component was malignant adenomyoepithelioma.The postoperative course was uneventful,and no chemotherapy was administered.At 18 mo of follow-up,the patient is alive and well,with no evidence of recurrent disease.CONCLUSION Patients with breast PA should first undergo extended excision of breast masses followed by pathological examination.If malignancy is confirmed or the surgical margin is positive,modified radical mastectomy should be performed.

Adenomyoepithelioma of the breast with malignant transformation and repeated local recurrence:A case report

BACKGROUND Adenomyoepithelioma(AME)of the breast is a rare type of benign breast tumor.Many AMEs show benign behavior,but reports of the malignant type are rare.We present the case of a patient with AME with repeated local recurrences and further malignant transformation.CASE SUMMARY A 53-year-old woman visited our hospital with a 16-mm palpable mass in the right breast.A core needle biopsy was performed.The pathological diagnosis was AME.Lumpectomy with a safety margin was performed without axillary lymph node dissection(ALND).Two years later,local recurrence developed,and the patient again underwent lumpectomy with a safety margin.The pathology showed malignant AME,and the margin was negative.Eight months later,local recurrence developed again in the same location,and a total mastectomy was performed without ALND.The pathological diagnosis was malignant AME.The patient was disease-free for three years posttreatment.CONCLUSION The treatment of AME requires caution,as it may exhibit repeated recurrences after local excision as well as malignant transformation.