Mass-forming ductal carcinoma in situ: An ultrasonographic and histopathologic correlation study.

Ultrasound (US) guided core needle biopsy (CNB) for mass lesions resulting in a diagnosis of ductal carcinoma in situ (DCIS) is often considered radiologically discordant and generates surgical planning difficulty. One hundred cases of US-guided CNB for mass lesions diagnosed as DCIS were collected from 2013 to 2021. Histological features were reviewed and correlated with radiology and surgical excision findings. Thirty (30%) were high-grade (HG), and seventy (70%) were low- to intermediate-grade. Seventy-one (71%) cases had a histological correlate of a mass-forming lesion, including 26 (26%) were associated with benign mass-forming lesions (category 1) such as papilloma, complex sclerosing lesion/radial scar, fibroadenoma, sclerosing adenosis, and ruptured cyst; 23 (23%) were HG with solid pattern, comedo necrosis, and stromal desmoplasia (category 2); and 22 (22%) had predominantly papillary architecture (category 3). Twenty-nine (29%) were discordant with no histologic correlate of a mass lesion (category 4). Follow-up excisions were available in 79 cases. Invasive carcinoma was identified in 14 cases (18%), of which 8 were from the radiologically discordant category (35%), 3 (17%) associated with HG DCIS with desmoplasia, 2 (10%) associated with benign mass lesion and 1(5%) was predominantly papillary architecture. US-guided CNB for mass-forming lesions with a DCIS diagnosis on CNB can be grouped into four categories. Radiology-pathology correlation is essential. This categorization emphasized rad-path correlation and had a clear difference in upgrade rate on follow-up excision. Rad-path discordant biopsy cases were more likely to be associated with a missed invasive carcinoma (p < 0.05).