Histopathology of myoepithelial (basocellular) hyperplasias in adenosis and epitheliosis of the breast demonstrated by the reactivity of cytokeratins and S100 protein. An analysis of heterogenic cell proliferations in 90 cases of benign and malignant breast diseases

CD109, a new marker for myoepithelial cells of mammary, salivary, and lacrimal glands and prostate basal cells

The CD109 gene encodes a glycosylphosphatidylinositol (GPI)-anchored cell surface protein. Herein it is shown that CD109 is highly expressed in myoepithelial cells of mammary, salivary, and lacrimal glands; and in prostate basal cells. The anti-CD109 antibody generated by the authors was available for formalin-fixed paraffin section, and it strongly stained myoepithelial cells and basal cells but not ductal, acinar, and secretory cells in these glands. CD109 expression was negative in examined breast ductal carcinomas and prostate adenocarcinomas. These findings indicate that CD109 is a useful marker for the diagnosis of invasive breast and prostate carcinomas.

Fine-needle aspiration cytology of benign and malignant adenomyoepithelioma: report of two cases

Cytological features of a malignant spindle-cell variant and a benign tubular variant of adenomyoepithelioma were examined to improve diagnosis of this tumor. Fine-needle aspiration cytology, of both a malignant and a benign case, characterized cellular and cohesive cell clusters composed of epithelial and myoepithelial cells. The smears of the malignant case were rich in spindle-shaped myoepithelial cells, admixed with a few epithelial cells. In about a fourth of the clusters, atypical cells with enlarged hyperchromatic nuclei and prominent nucleoli comprised more than 20% of cells. The smears of the benign case were composed of tubular epithelial cells surrounding one to several layers of myoepithelial cells with clear cytoplasm. Mild atypia was occasionally noticed. A review of the literature showed that a cytological diagnosis of malignancy is not warranted, if nuclear atypia is not generally severe. Focal severe atypia is not definitively indicative of benignity or malignancy.

Malignant adenomyoepithelioma of the breast with malignant proliferation of epithelial and myoepithelial elements: a case report and review of the literature

Malignant adenomyoepithelioma of the breast is a rare lesion characterized by malignant proliferation of epithelial and myoepithelial cells that show characteristic histologic and immunohistochemical features. Eleven cases have been reported, 4 of which showed evidence of distant metastasis. The authors report a case of malignant adenomyoepithelioma in the axillary tail of a 71-year-old woman, one of the oldest patients described so far, and review the literature. Malignancy in the current case was evidenced by the presence of local invasion, high mitotic rate, and severe cytologic atypia. The tumor was associated with adenosis and lobular adenomyoepithelial hyperplasia. Malignant adenomyoepithelioma is a rare neoplasm, diagnosable by light microscopy and immunohistochemistry. To date, it has only been reported in women, who ranged in age from 26 to 76 years. Metastases have only been documented in tumors 2.0 cm in diameter or larger.

Use of keratin 35betaE12 as an adjunct in the diagnosis of mammary intraepithelial neoplasia-ductal type--benign and malignant intraductal proliferations

A variety of studies have investigated the role of low molecular weight (LMW) and high molecular weight (HMW) cytokeratin (CK) expression in the normal breast and invasive breast carcinomas. A few studies with small numbers of cases have addressed this issue in intraductal proliferations of the breast. This study investigates the expression of these CKs in a large series of ductal intraepithelial neoplasias of the breast. We examined 150 ductal carcinomas in situ (DCIS), 35 cases of intraductal hyperplasia (IDH), and 15 cases of atypical intraductal hyperplasia (AIDH). Immunohistochemistry was performed using monoclonal antibodies against CK-34betaE12 (HMW CK), CK-8, and CK-19 (LMW CK) on formalin-fixed, paraffin-embedded tissue. The intensity (0, +1, +2, +3) and percentage of positive intraductal cells (0-100%) were multiplied to obtain a score from 0 to 300. The immunoprofiles of IDH, AIDH, and DCIS were categorized into four groups showing negative or low (0-60), moderate (61-100), high (101-200), and very high (201-300) scores. All cases of IDH showed an intensely positive reaction (high to very high scores) for CK-34betaE12. In contrast, 90% of the DCIS showed a negative or only focal and weak reaction (negative or low score) for this antigen. The remaining 10% of DCIS showed a positive immunoreaction for CK-34betaE12 with moderate to high scores. All cases of florid IDH and 96% of cases of DCIS expressed CK-8 intensely with high to very high scores. Although CK-19 was strongly expressed in 97% of cases of IDH (high to very high scores), a very high score was also found in 80% of cases of DCIS that were positive for CK-19. Of the 15 AIDHs, 80% had a negative or only focal reaction (negative or low score) for CK-34betaE12 and the remaining 20% had a moderate to high score for this antigen. Although CK-8 was strongly positive in 87% of cases of AIDH (high to very high scores), only 53.5% of AIDHs showed intense positivity for CK-19. The present study clearly shows that the immunoprofile of IDH is different from DCIS as far as HMW CK is concerned. Although florid IDH is characterized by a diffuse and intense immunoreaction for HMW CK, the lack of or only weak positivity for HMW CK (CK-34betaE12) is, in most cases, a hallmark of ductal carcinoma in situ. The immunoprofile of AIDH is very similar to that of DCIS. The expression of CK-8 and CK-19 is not useful in separating the various categories of ductal intraepithelial proliferations of the breast. We recommend the use of CK-34betaE12 as an adjunct in the diagnosis of a variety of problematic intraductal proliferations of the breast.