Cytoplasmic vacuolation, intracytoplasmic lumina, and DPAS staining in ductal carcinoma of the breast.

A retrospective study was carried out on 30 cases of histologically proven invasive ductal carcinoma of the breast with a prior fine-needle aspiration (FNA) cytology. On evaluating the May-Grünwald-Giemsa (MGG) FNA smears, cytoplasmic vacuolation was observed in 70% cases. Positivity with periodic acid Schiff-positive, diastase-resistant (DPAS) staining was observed in 90% of cases. The chi(2) value on a McNemar test was 4.16. Thus, DPAS staining was significantly superior to MGG staining for picking up cytoplasmic vacuoles (P < 0.05). In 56.67% cases, DPAS staining showed an improvement in score as compared to MGG smears. This was highly significant (P < 0.001) on Wilcoxon matched-pairs signed-ranks test. Applying the strict criteria of thick-walled cytoplasmic vacuoles with a central darkly stained dot, none of our cases revealed true intracytoplasmic lumina. Larger studies are required to establish a role for DPAS staining in separating borderline, in situ, and invasive breast lesions, and to see if such positvity can be incorporated into the grading systems for breast carcinoma. Copyright 2003 Wiley-Liss, Inc.