Variao interobservador no diagnstico histopatolgico do carcinoma ductal in situ da mama

ABSTRACT Purpose: to perform a critical evaluation of the histopathological diagnosis of ductal carcinoma in situ (DCIS) of the breast,through the analysis of interobserver variation related to diagnosis, architectural pattern, nuclear grade, and histologicalgrade. Methods: eighty-five cases with an initial diagnosis of DCIS were reviewed by the same pathologist, specialist inbreast pathology, who selected 15 cases for interobserver analysis. The analysis was carried out by five pathologists andan international expert in breast pathology, who received the same slides and a protocol for classifying the lesions asatypical ductal hyperplasia (ADH), DCIS, or ductal carcinoma in situ with microinvasion (DCIS-MIC). If the diagnosis wasDCIS, the pathologists should classify it according to the dominant architectural pattern, nuclear grade, and histologicalgrade. The results were analyzed using percent concordance and the kappa test. Results: there was a great interobserverdiagnostic variation. In one case we had all diagnoses, from ADH, DCIS to DCIS-MIC. The kappa test for the comparisonamong the five observers’ and the expert’s diagnoses showed minimum interobservers’ concordance (<0.40). RegardingDCIS classification related to the dominant architectural pattern and the histological grade, the kappa test values wereconsidered poor among the pathologists. The best results were obtained for the nuclear grading, with a kappa index up to0.80, considered as good concordance.