Myoepithelial Carcinoma: A Rare Neoplasm of the Breast

A case of adenomyoepithelioma with myoepithelial carcinoma of the breast

Adenomyoepithelioma with myoepithelial carcinoma of the breast is rare and diagnosed with histology and immunohistochemistry. We present a case of malignant transformation over 10 years, with ultrasonographic findings, highlighting the importance of an early excisional biopsy. Conservative surgery and radiation therapy were performed. There was no recurrence for 2 years.

Malignant myoepithelioma of the breast: A case report and review of the literature

Malignant myoepithelioma of the breast is an extremely rare tumor composed entirely or almost entirely of malignant spindle cells with myoepithelial differentiation. Only a limited number of case reports have been descibed to date; therefore the biological behavior and treatment outcomes of this rare tumor have not been clearly determined. Herein, we present a case of a 74-year-old woman who was admitted with inflammatory-like cancer of the breast, presenting with invasion of the chest wall and axillary lymph node metastasis at the time of diagnosis. The histological examination revealed a tumor composed of epithelioid and spindle cells with moderate to marked nuclear atypia, with foci of hemorrhage and necrosis. The tumor cells were immunoreactive for vimentin, p63, p53, CD10, cytokeratin (CK)8/18, CKAE1-3 and S-100. Finally, a diagnosis of myoepithelial carcinoma of the breast was established. Neoadjuvant chemotherapy was first administered and proved to be ineffective. Due to locoregional progression that was associated with the development of an abscess and subsequent excessive bleeding, a palliative mastectomy was performed. Postoperatively, one more cycle of systemic chemotherapy was administered. However, the patient experienced an early relapse to the chest wall and succumbed to septic shock due to persistent local infection. The aggressiveness and chemoresistance of the tumor in this case was consistent with the existing bibliography.

Atypical breasts cancers

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Myoepithelial carcinomas comprise exclusively of tumour cells with myoepithelial differentiation and can be managed through surgical excision with radiotherapy.

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Mucinous carcinomas are difficult to diagnose but important to distinguish as survival rate between the types can vary.

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Invasive apocrine carcinomas are difficult to diagnose due to the variable presentation and lack of diagnostic criteria.

Introduction

Method

Conclusion

Malignant myoepithelioma of the breast: a case report and review of literature

In this article, we described a malignant myoepithelioma of the breast (MMB) in a 69-year-old woman. Breast cancer derived from myoepithelial cells is very rare, usually benign. The diagnosis of MMB based on histological and immunohistochemical finding. In this case, the author diagnosed the tumor as MMB, because tumor tissues were immunopositive for 34βE12, P63, SMA, S-100, CD10, E-Cad and Ki-67, and immunnegative for CK5/6, desmin, ER, PR and C-erbB-2, because tumor tissue showed invasive growth and local hemorrhage or necrosis, suggesting malignant, and also because there was a transition between the tumor cells and hyperplastic myoepithelium of non-tumorous ducts. The patient's postoperative recovery is smooth and regular following of patient is essential.

Myoepithelial carcinoma of the breast treated with surgery and chemotherapy

Myoepithelial carcinoma (malignant myoepithelioma) of the breast is a rare tumor, for which only a limited number of reports have been published. Most of the reports emphasized diagnosis and pathology but not biological behavior and treatment. We report a 61-year-old patient with breast myoepithelial carcinoma who developed locoregional and distant metastases and received many chemotherapy regimens. She presented with an elastic hard mass of the left breast. Breast conserving surgery was performed as part of both diagnosis and treatment. From the results of histological and immunohistochemical examinations, this case was considered to be a myoepithelial carcinoma. Fifteen months after the completion of adjuvant radiotherapy, distant metastasis of the left parasternal lymph node metastasis developed. She was treated by further excision and received a total of four regimens of chemotherapy including a combination of doxorubicin and cyclophosphamide. She received chemotherapy for 20 months after the diagnosis of metastasis.

Myoepithelial carcinoma of the breast

Breast carcinoma is the commonest cancer among females in a majority of the Indian cities. The advances in the research and management have improved the breast cancer survival significantly in the past three decades globally. Adenocarcinoma is the commonest histological variant which arises from the ductal epithelia. The myoepithelial cells (ME) are the normal components of the breast parenchyma, which separate the ductal epithelia from the basement membrane and the stroma. The pure ME cell carcinoma is extremely rare and only 38 cases have been reported so far in the indexed literature. This may owe to the difficulties in the identification, and the non availability of established diagnostic criteria. We herein describe the clinical, radiological and the pathological characteristics of a case of myoepithelial carcinoma, to supplement the available literature. The possible impact of these cells in clinical practice was also reviewed. Identification and the further research on the genesis of these tumours, and the pathways by which the ME cells regulate the milieu interior of the breast epithelia, may unravel new molecular targets to prevent or treat both epithelial and myoepithelial cancers at early stages.