Diagnostic role of immunohistochemistry in the evaluation of breast pathology specimens.

CONTEXT: Immunohistochemistry plays a vital role in the evaluation of breast pathology specimens. OBJECTIVE: To discuss the role of myoepithelial cell markers in the evaluation of various breast lesions. Other markers, such as E-cadherin and those used to differentiate mammary carcinoma from metastatic tumors to the breast, and markers used in the differential diagnosis of Paget disease, are also discussed. DATA SOURCES: Data were obtained from review of the pertinent peer-reviewed literature. CONCLUSIONS: Myoepithelial cell markers vary in their sensitivity and specificity, and one should be aware of the potential pitfalls in interpretation. Using panels of 2 or more myoepithelial cell markers is always recommended, either singly or in cocktail forms. Although negative E-cadherin staining supports the diagnosis of lobular origin, positive staining does not rule it out. Immunohistochemistry can be helpful in differentiating Paget disease from its mimics. Although metastatic tumors to the breast are rare, a triple-negative immunophenotype and absence of an in situ component should be a "red flag" for such possibility, especially in patients with clinical history of an extramammary malignancy.

Nanoscale noncontact subsurface investigations of mechanical and optical properties of nanoporous low-k material thin film.

Revealing defects and inhomogeneities of physical and chemical properties beneath a surface or an interface with in-depth nanometric resolution plays a pivotal role for a high degree of reliability in nanomanufacturing processes and in materials science more generally. (1, 2) Nanoscale noncontact depth profiling of mechanical and optical properties of transparent sub-micrometric low-k material film exhibiting inhomogeneities is here achieved by picosecond acoustics interferometry. On the basis of the optical detection through the time-resolved Brillouin scattering of the propagation of a picosecond acoustic pulse, depth profiles of acoustical velocity and optical refractive index are measured simultaneously with spatial resolution of tens of nanometers. Furthermore, measuring the magnitude of this Brillouin signal provides an original method for depth profiling of photoelastic moduli. This development of a new opto-acoustical nanometrology paves the way for in-depth inspection and for subsurface nanoscale imaging of inorganic- and organic-based materials.