Ductal carcinoma in situ of the breast: correlation of architectural, cytological, IHC findings and recurrence analysis

Objective: This study evaluated the histopathological features of ductal carcinoma in situ (DCIS), including cytological grade, architectural pattern and immunohistochemistry (IHC) in pure DCIS and DCIS associated with invasive carcinoma of no special type (ICNST). Methods: We evaluated a series of 232 cases of pure DCIS and DCIS associated with ICNST from a total of 399 breast carcinomas from a population consisting by women diagnosed with breast cancer and submitted to breast surgery from 2011 to 2015. Results: DCIS presented a mixed architectural pattern in most cases (56%); the solid subtype was the most common morphology (30%). High-grade DCIS was identified in 84/221 cases (38%), and comedonecrosis was present in 106/221 cases (48%). High-grade was more common in the solid subtype (61/155 cases, 39%, p < 0.001). Tumor size was greater in the presence of comedonecrosis than in the absence (mean 27 vs 20 mm, p = 0.009). Estrogen receptor (ER) was positive in 81% of cases with a cribriform pattern (p = 0.013). Greater locoregional recurrence was found in the comedonecrosis (15%) and micropapillary (19%) subtypes in DCIS associated with ICNST. Conclusion: We observed a greater relationship of ER with the low nuclear grade, while Ki-67 was related to the high-grade. DCIS presented a higher nuclear grade compared to ICNST. The less common pure pattern was the micropapillary, and the most common, the solid. Comedonecrosis was more frequent in the solid pattern. Our results showed that high-grade was more common in the solid and comedo subtype, and low-grade was more frequent in the cribriform.