Utility of four-quadrant random sections in mastectomy specimens

Standard practice in surgical pathology dictates that random sections from the four quadrants of the breast be taken in mastectomy specimens. These sections are obtained in addition to sampling of any grossly visible lesions within the breast specimen. While tradition dictates the submission of these sections, we are unaware of any study supporting their efficacy. We have investigated the utility and significance of these random sections in a series of 78 mastectomy specimens. This retrospective study identified mastectomy specimens from pathology files of Magee Woman's Hospital, the University of Pittsburgh, and the University of Utah School of Medicine between 1997 and 2000. Clinical data (palpable versus nonpalpable), radiographic features (mammographic diagnosis, presence of mass density and/or calcification), and pathologic features (size, histopathologic type, etc.) were studied. The histologic sections of the cases were reviewed and the random sections were specifically studied for pathologic findings. Diagnosis and clinically significant features obtained from examining these random sections, but not demonstrable in grossly selected sections, were tabulated. A total of 78 mastectomy specimens were analyzed. Diagnoses rendered were infiltrating ductal carcinoma (23), infiltrating ductal carcinoma with ductal carcinoma in situ (DCIS) (16), DCIS (25), infiltrating lobular carcinoma (4), biopsy cavity with no residual malignancy (4), infiltrating lobular carcinoma with lobular carcinoma in situ (3), invasive ductal and lobular carcinoma (1), adenoid cystic carcinoma (1), and atypical ductal hyperplasia (1). The number of random sections ranged from 2 to 17 (mean 9). Random sections provided additional information in 21 of 78 mastectomies (27%). The multifocal/multicentric nature of the lesion was diagnosed in 20 cases: DCIS (6), lobular carcinoma in situ and invasive (2), invasive ductal carcinoma (6), invasive and in situ ductal carcinoma (5), invasive lobular carcinoma (1), invasive ductal and lobular carcinoma (1). Additional findings include lymphovascular invasion (2 cases), atypical ductal hyperplasia (1), DCIS at the operative margin (1), DCIS within less than 1 mm of an operative margin (1), and atypical lobular hyperplasia (1). In the remaining 57 cases, random sections did not provide any additional information. Histologic examination of random sections from breast quadrants yielded important information about the presence of multifocality, multicentricity, vascular invasion, and margin involvement by carcinoma in only a minority of cases, many of which had a lobular morphology.