Metaplastic carcinomas of the breast (MCBs) are unusual neoplasms characterized by an admixture of glandular epithelial components, which frequently exhibit features of squamous differentiation, and mesenchymal malignant components. Regardless of the presence of myoepithelial features in MCB, no consensus concerning their putative histogenesis has yet been achieved. Recently, novel putative myo...

In mouse parotid glands, we found expression of skeletal muscle actin (actin-α1) protein and mRNA. We isolated myoepithelial cells from the mouse parotid glands and investigated their actin-α1 expression because smooth muscle actin (actin-α2) has been used as a marker for myoepithelial cells. We used actin-α1 expression to identify pathological changes in diabetic non-obese diabetic (NOD; NOD/S...

We immunohistochemically compared benign myoepithelial tumors (adenomyoepitheliomas [AMEs]) and metaplastic matrix-producing (MMP-CA) and spindle cell (MSC-CA) carcinomas of the breast to identify helpful diagnostic markers. Normal myoepithelial cells (MECs) consistently expressed cytokeratin, alpha-smooth muscle actin (SMA), myosin, S-100, CD10, and maspin. They were variably positive for vime...

Adenomyoepithelioma of the breast is an uncommon tumor characterized by the presence of both epithelial and myoepithelial cells; its first full description was published in 1970 by Hamperl. A 45-year-old woman presented a left breast lump that had been palpable for 4 weeks. There was no family history of breast cancer. Neither axillary nor supraclavicular lymph nodes were palpable. Craniocaudal...

Myoepithelial cells of the mammary gland are considered to be a key to distinguishing benign from malignant disease in fine-needle aspiration (FNA) cytology. However, identification of these cells with Papanicolaou staining is not easy. The identification of myoepithelial cells was investigated using p63 antibodies to carry out immunostaining of FNA specimens that had been used at the time of P...

Certain genetic events that occur at various stages of carcinogenesis can result in phenotypic changes. In breast carcinoma, these changes may occur either in situ, at the primary invasive site, or at a distant metastatic site. This report presents a case of dedifferentiation-like progression of breast carcinoma showing transition from luminal-type carcinoma to triple-negative carcinoma (i.e. n...

RATIONALE Epithelial-myoepithelial carcinoma (EMC) is regarded as a rare low-grade malignant tumor of the salivary gland, accounting for 0.4% to 1% of all salivary gland tumors. However, epithelial-myoepithelial carcinoma with high-grade transformation (EMC with HGT) is extremely rare, therefore it is easily to be inappropriately diagnosed and treated. Herein, we report an unusual case of EMC w...

BACKGROUND Histological examinations of MMTV-Wnt1 tumors reveal drastic differences in the tumor vasculature when compared to MMTV-Her2 tumors. However, these differences have not been formally described, nor have any angiogenic factors been implicated to be involved in the Wnt1 tumors. METHODOLOGY/PRINCIPAL FINDINGS Here, we show that MMTV-Wnt1 tumors were more vascularized than MMTV-Her2 tu...

AIMS One of the limitations of fine needle aspiration biopsy (FNAB) of the breast is in distinguishing invasive carcinoma (IDC) from ductal carcinoma in situ (DCIS). It has been proposed that the presence of myoepithelial cells overlying epithelial malignant cell clusters suggests DCIS. However, the recognition of myoepithelial cells in aspirates may be difficult. The aim of this study was to i...