The cytopathology of ductal carcinoma in situ of the breast. A detailed analysis of fine needle aspiration cytology of 58 cases compared with 101 invasive ductal carcinomas

The existence of cytological findings that discriminate ductal carcinoma in situ (DCIS) of the breast from invasive ductal carcinoma (IDC) has not been unanimously accepted and the role of fine needle aspiration cytology (FNAC) remains controversial, We report the cytological findings of a large series of FNAC from histologically proven DCIS compared with those of ductal carcinomas having a different extent of the invasive component. The association of high cohesiveness of atypical cells and absence of tubular aggregates showed good sensitivity (SE) and specificity (SP) for the diagnosis of DCIS vs IDC. The simultaneous presence of necrotic background, atypical cells with abundant eosinophilic cytoplasm and a low percentage of single malignant cells resulted in low sensitivity but high specificity and positive predictive value (PPV) for differential cytological diagnosis of DCIS vs IDC.