The basic and additional immunohistochemical criteria in differential diagnostics of tumors and tumor-like processes of mammary gland

Morphological diagnostics of mammary gland neoplasm is complex due to polymorphism of tumors and tumor-like processes. The purpose of our research was to reveal the basic and additional immunohistochemical markers for differential diagnostics of some diseases. We have established that the basic markers for differential diagnostics of adenosis and invasive carcinomas were MSA, α-SMA, S100, collagen IV, р63, Кі-67 and р53, additional - 34βЕ12, СК7, СК8, СК5/6, E-cadgerin. The loss of expression of myoepithelial markers, positive reaction with Кі-67, р53, Her2/neu also matters. Mutually contrary patterns of 34βЕ12 and E-cadgerin expression allow to differentiate ductal or lobular primacy of process. СК7, СК8, 34βЕ12 play a key role in differential diagnostics of carcinosarcomas and sarcomas. myoepithelial markers and basal membrane also give the additional information. At differential diagnostics of carcinoma and malignant tumors of other nature СК7, СК8, E-cadgerin, Her2/neu, ER/PgR, myoepithelial markers were the most important, being typical only for epithelial tumors. At Paget disease the reliable diagnostic criteria are absence of S100 and expression of certain classes СК (more often luminal epithelium СК7, СК8), E-cadgerin, СЕА. Clone AE1/AE3 and revealing СК7 is valuable for diagnostics of micro-metastasises.