Adenoid cystic carcinoma of breast: Recent advances

Lower Female Genital Tract Tumors With Adenoid Cystic Differentiation: P16 Expression and High-risk HPV Detection

Lower female genital tract tumors with adenoid cystic differentiation are rare, and data on their relationship with high-risk human papillomavirus (HPV) are limited. Here we report the clinicopathologic features from a case series. Tumors with adenoid cystic differentiation, either pure or as part of a carcinoma with mixed differentiation, arising in the lower female genital tract were evaluated by means of immunohistochemical analysis for p16 expression and in situ hybridization using 1 or more probes for high-risk HPV (a high-risk probe covering multiple types, a wide-spectrum probe, and separate type-specific probes for HPV16 and HPV18) and when possible by polymerase chain reaction for high-risk HPV. Six cervical carcinomas with adenoid cystic differentiation admixed with various combinations of at least 1 other pattern of differentiation, including adenoid basal tumor (epithelioma and/or carcinoma), squamous cell carcinoma (basaloid or keratinizing), and small cell carcinoma were identified in patients ranging in age from 50 to 86 years (mean, 73 y; median, 76 y). All of these tumors were characterized by diffuse p16 expression. High-risk HPV was detected in 5 of 6 tested cases: 4 cases by in situ hybridization (all positive for HPV-wide-spectrum and HPV16) and 1 by polymerase chain reaction (HPV45). Seven pure adenoid cystic carcinomas (6 vulvar and 1 cervical) were identified in patients ranging in age from 27 to 74 years (mean, 48 y; median, 48 y). All of these tumors were characterized by variable p16 expression ranging from very limited to more extensive but never diffuse. No high-risk HPV was detected in any of these pure tumors. Lower female genital tract carcinomas with adenoid cystic differentiation appear to comprise 2 pathogenetically distinct groups. Cervical carcinomas with mixed differentiation, including adenoid cystic, adenoid basal, squamous, and small cell components, are etiologically related to high-risk HPV and can be identified by diffuse p16 expression. Pure vulvar and cervical adenoid cystic carcinomas appear to be unrelated to high-risk HPV and are distinguished from the mixed carcinomas by nondiffuse p16 expression.

The unique luminal staining pattern of cytokeratin 5/6 in adenoid cystic carcinoma of the breast may aid in differentiating it from its mimickers

Adenoid cystic carcinoma (AdCC) of the breast is an uncommon but distinct neoplasm composed of a dual cell population polarized around true glandular (luminal) spaces and pseudolumina. The aim of this study was to clarify whether various immunohistochemical markers (CK7, EMA, CD117, p63, calponin, CD10, S100, CK5/6, CK14, vimentin, and type IV collagen) can distinguish between the two cell types in classical AdCC (n = 14) and in collagenous spherulosis (n = 5). The sensitivity and specificity of these 11 markers to distinguish luminal from abluminal cells were evaluated using a curve created by plotting the true-positive rate (sensitivity) against the false-positive rate (1 - specificity) at threshold settings of 0, 10, 50, and 70 %. The most sensitive and specific markers for luminal cells in AdCC were CK7 and EMA; those for abluminal cells were type IV collagen, p63, and vimentin. CD10 and S100 did not act as abluminal markers in AdCC. CK5/6, one of the basal/myoepithelial markers, was expressed more frequently in luminal than in abluminal cells of AdCC. Thus, CK5/6 immunostaining resulted in a reverse expression pattern, analogous to what we recently documented in clear cells in mammary adenomyoepithelioma. In conclusion, compared with myoepithelial/abluminal cells of normal breast or collagenous spherulosis, the neoplastic abluminal cells of classical AdCC are characterized by enhanced vimentin and attenuated CD10 and S100. Furthermore, the luminal cells of AdCC show a unique aberrant staining pattern for CK5/6 that may aid in the differential diagnosis.

Triple-negative Breast Carcinoma: Morphologic and Molecular Subtypes

Breast carcinoma is a heterogenous disease. Carcinomas lacking expression of estrogen, progesterone, and HER2/neu receptors by immunohistochemistry and Her2 amplification are designated as triple negative. This group of carcinomas comprises approximately 10% to 20% of all breast carcinomas and is characterized by an aggressive nature with shorter rates of disease-free and overall survival. This aggressive behavior is further compounded by the lack of available targeted therapies. Patients receive cytoxic chemotherapy regimens. Although tumors are initially sensitive to this therapy, drugs are toxic and ineffective in maintaining long-term response thereby providing limited benefit. Much effort is being spent on this group of cancers for the identification of appropriate molecular targets, an effort that is proving challenging due to the presence of marked heterogeneity, both at the morphologic and molecular levels. An understanding of the advances in this field is crucial for developing targeted therapies and tailored patient management protocols. This report summarizes the pathologic subtypes of breast cancer that are commonly of a triple-negative immunophenotype and recent molecular advances in this field.

Breast adenoid cystic carcinoma in a 19-year-old man: a case report and review of the literature

Adenoid cystic carcinoma (ACC) of the breast is very rare in males. There have been only eight previous articles published on breast ACC in males. Here, we will report on the first case of this type of tumor in the Chinese province of Hainan. The patient was a 19-year-old male, and he underwent a radical mastectomy (RM) with axillary lymph node dissection. The histopathological examination specimen revealed that surgical margins were negative; none of the 41 axillary lymph nodes excised were positive for malignancy. The patient is alive and well 67 months after radical mastectomy. In the present study, we discuss the diagnosis and treatment options for male breast ACC based on previous English publications.