[Expression of E-cadherine as a differential diagnostic fest for lobular infiltrative breast cancers].

An immunomorphological study of 30 breast carcinomas was conducted. In accordance with the histological characteristics they had been previously diagnosed as lobular infiltrative carcinomas (LIC). We have studied E-cadherin cell-cell adhesion molecules and also epithelial markers and basement membranes. We have analyzed the cryostate and paraffin sections of in situ structures, invasion components and metastases. E-cadherin staining was negative, positive or mixed. The E-cadherin negative group consisted of 17 carcinomas of classic LIC accompanied with dyshesive invasion. The E-cadherin positive group consisted of 6 carcinomas. According to our results this diagnosis was changed to ductal infiltrative carcinoma. The E-cadherin mixed group consisted of 7 special type carcinomas with double lobular-ductal differentiation, which had in situ structures of negative or positive cells. In these cases in situ structures consisting of both E-cadherin negative and positive parts were also observed. It is shown that E-cadherin expression can be used in doubtful cases in order to differentiate between the lobular and ductal forms of breast carcinoma.