DUCTAL CARCINOMA IN-SITU OF THE BREAST - THE CLINICAL-SIGNIFICANCE OFHISTOLOGICAL CLASSIFICATION

One hundred and twenty-one cases of ductal carcinoma in situ, includin g 26 cases with Tla invasive carcinoma, were reviewed. Seventy-nine pa tients (65%) were treated by mastectomy and 42 (35%) had conservative surgery, Ductal carcinoma in situ was classified as well differentiate d intermediately differentiated (22%) or poorly differentiated (67%) a ccording to nuclear morphology and the presence or absence of cell pol arization, Poorly differentiated lesions were significantly larger tha n intermediately and well differentiated lesions (P=0.03 and P=0.01, r espectively) and were significantly associated with the presence of ex tensive necrosis, marked periductal inflammation and periductal fibros is (P <0.0001). Invasive carcinoma was more common in the poorly diffe rentiated group (25% compared with 18% in the intermediate group and 8 % in the well differentiated group) but this was not statistically sig nificant. The spectrum of differentiation was similar in symptomatic a nd mammographically detected ductal carcinoma in situ. Clinical follow -up was available in 90 patients (median period 45 months in patients who had undergone mastectomy and 23 months in those who had conservati ve surgery). Two incidences of recurrent local disease were recorded i n the mastectomy group: one patient had well differentiated and the ot her poorly differentiated ductal carcinoma in situ, No local recurrenc es were observed in the conservative surgery group, possibly reflectin g the shorter follow up period, All histological grades of ductal carc inoma in situ have the potential to progress to invasive carcinoma and mastectomy does not guarantee a cure.