[233] Correlation between MRI Findings and Gross and Microscopic Pathology in Total Mastectomy Cases: A Review of 109 Cases

Kevin G Neill, Jingxuan Liu, Bernstein Cliff, Brian O'Hea, Meenakshi Singh, Carmen Tornos. Stony Brook University Hospital, Stony Brook, NY

Background: Bilateral breast MRI's are often done to evaluate the extent of disease preoperatively in patients recently diagnosed with invasive carcinoma or DCIS. Based on the MRI findings, total mastectomy may be recommended if there is multifocal/multicentric disease, or if the main lesion is large compared to the breast size.
Design: We reviewed 109 cases of total mastectomies performed at our institution, in which MRI's were completed and available before the surgery. We compared the number of biopsy proven malignant lesions and highly suspicious lesions found on MRI, including size, location and MRI diagnosis, with the findings on gross and microscopic examination of the same areas. A copy of the MRI report was available in all cases at the time of grossing to establish correlation between MRI and gross findings. Samples were taken from all areas of concern on MRI to correlate with histologic diagnosis. Patients treated with neoadjuvant chemotherapy were excluded.
Results: In 9 cases the size of the carcinoma was overestimated by the MRI by more than 1 cm (Table). In two cases the size of the carcinoma was underestimated by the MRI by more than 1 cm (1.2 cm to 2.5 cm invasive ductal carcinoma, and 2.4 cm to 3.9 cm IDC). In 3 cases the MRI did not detect any carcinoma, only biopsy site changes, but there was invasive carcinoma (one case had 0.9 cm invasive lobular carcinoma, one case had 2 foci of IDC 1.7 cm and 0.3 cm, and one case had 3 foci of IDC 1 cm, 0.7 cm, and 0.15 cm).

Cases of Breast Carcinoma Overestimated by MRI
218cmInv + DCIS12.6cm DCIS + 0.2cm IDC 
323.5cm, 2.9cmInvasive both13.1cmIDC
416cm DCIS + 3.7cm inv 13.5cmIDC
5Multifocal7cm areaInv lobular21.3cm + 0.8cmILC + LCIS
613.7cmInvasive11.6cmILC + LCIS
724.8cm + 1cmBoth invasive12.8cmIDC+ florid Bx site

Conclusions: MRI is an accurate method of detecting and measuring foci of invasive carcinoma and ductal carcinoma in situ. In this series “major discrepancies” as defined above were detected in 14 cases (12.8%). Six cases can be attributed to florid biopsy site changes, or florid LCIS in areas of adenosis. In 8 cases a definite explanation could not be found.
Category: Breast

Monday, March 4, 2013 1:00 PM

Poster Session II # 33, Monday Afternoon


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