Original article
Clinicopathologic features of the mixed epithelial and mesenchymal type metaplastic breast carcinoma with myoepithelial differentiation in a subset of six cases

https://doi.org/10.1016/j.prp.2011.12.014Get rights and content

Abstract

Metaplastic carcinoma (MC) of the breast, consisting of epithelial and mixed epithelial–mesenchymal tumors, are extremely rare human neoplasms. They are mostly detected between the 5th and 7th decade and have an unfavorable prognosis. Therefore, it is of utmost important to find out the behavior and also the immunohistochemical (IHC) profile of these tumors. In the current study, the aim was to examine 6 cases of MC with detailed clinico-pathological variables of cancer, follow-up and IHC profile of several antigens. The following immunohistochemical markers were used: MNF116, vimentin, CD10, smooth muscle actin (SMA), estrogen/progesterone receptors and HER-2/neu. The mean age was 39.1 the mean size was 3.3 cm. 83% of the cases had spindle cell sarcoma-like areas. Two of six cases also had a chondrosarcoma-like component. The epithelial component was invasive ductal carcinoma in all. MNF116, vimentin, CD10, and SMA expressions were as follows: mesenchymal cells: 33%, 100%, 50%, 83%, epithelial cells: 100%, 50%, 33%, 0%. All were triple negative. 66.6% presented with the axillary lymph node metastases. The mean follow-up period was 51 months, 50% died of the disease. Two had distant metastases to the lung. Our series which only included mixed epithelial–mesenchymal type metaplastic carcinoma of the breast showed myoepithelial differentiation with a worse prognosis.

Introduction

Metaplastic carcinoma (MC) of the breast is rare, accounting for <1% of breast malignancies. It represents a heterogeneous group of tumors. According to the World Health Organization (WHO) classification, those tumors are divided into two parts: purely epithelial and mixed epithelial–mesenchymal tumors. The latter is referred to as carcinosarcoma (CS) if the mesenchymal component is malignant. The mesenchymal component of CSs most often exhibits chondroid, osteoid, or rhabdoid differentiation [17], [18]. MCs of the breast encompass a great variety of histopathology. Wargotz et al. suggested five variants of MC: matrix-producing carcinoma, squamous cell carcinoma, spindle cell carcinoma, CS, and MC with osteoclastic giant cells [20], [21], [22], [23], [24]. There is confusion regarding the origin of MCs. There is an increasing number of published reports supporting the evidence of a myoepithelial origin of these tumors [3], [4], [7], [12], [13].

Here, we present six cases of MC of the breast, and discuss their immunohistochemical profiles with histopathological features, as well as the follow-up results.

Section snippets

Materials and methods

Six cases of MCs were retrieved from the archives of pathology laboratory at our institution between 1998 and 2005. Patients’ age, size of the tumors, axillary nodal status, and follow-up results were recorded. Hematoxylin and eosin (H&E) slides of each case were carefully re-evaluated for histological subtypes, and the most representative slides were selected for immunohistochemistry (IHC). The selected paraffin blocks showing both epithelial and mesenchymal components which also had an

Results

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    All patients were female, and the age range was between 32 and 44 years, with a mean of 39.1 and a median of 40.5.

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    The tumor distribution at each site was equal, 50% by site.

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    The mean size of the tumors was 3.3 cm (1–8 cm) with a median of 3 cm (Case 6 had two different foci in the same quadrant).

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    Out of six cases, four presented with axillary lymph node metastases (66.6%).

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    Follow-up results: Follow-up data was available for six patients. The mean follow-up period was 51 months (3–90 months). One

Discussion

MC of the breast is a general term referring to a heterogeneous group of neoplasms characterized by an intimate admixture of adenocarcinomas with dominant areas of spindle cell, squamous, and/or mesenchymal differentiation [17]. The histogenesis of MC has been challenging for the pathologists since the early days of diagnostic surgical pathology [17], [20], [21], [22], [23], [24]. In this study, our aim was to determine the myoepithelial differentiation of those tumors in on our series.

Conclusions

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    MCs of the breast with mixed epithelial–mesenchymal subtypes can be seen in the younger age group.

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    The mean tumor size of the current series was slightly smaller than the reported series with a mean of 3 cm.

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    However, the use of epithelial/myoepithelial markers, as well as the number of cases, was limited as compared with the previous reports. Our IHC results support the idea that MCs of the breast probably arise from a cell capable of more than one differentiation. The triple negativity of all

Acknowledgment

This study was partly presented at the 21st European Congress of Pathology, Istanbul, 2007.

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    • 1

    Now at: Department of Pathology, Dr. E. Hayri Ustundag Gynecology and Obstetric Hospital, Izmir, Turkey.

    2

    Now at: Department of Pathology, Kanuni Training and Research Hospital Department of Pathology, Trabzon, Turkey.

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