Epithelial cells in SLNs may result from transport of displaced cells, usually originating in intraductal papillomas. Positive immunohistochemical results in SLNs should be interpreted with extreme caution to avoid automatically concluding that such cells represent metastasis. Sentinel lymph nodes in breast carcinoma can be falsely positive.

Background Upgrade rates of high-risk breast lesions after screening mammography were examined. Study design The Breast Cancer Surveillance Consortium registry was used to identify all BI-RADS 4 assessments followed by needle biopsies with high-risk lesions. Follow-up was performed for all women. Results High-risk lesions were found in 957 needle biopsies, with excision documented in 53%. Most (N=685) were atypical ductal hyperplasia (ADH), 173 were lobular neoplasia, and 99 were papillary lesions. Upgrade to cancer varied with type of lesion (18% in ADH, 10% in lobular neoplasia and 2% in papillary). In premenopausal women with ADH, upgrade was associated with family history. Cancers associated with ADH were mostly (82%) ductal carcinoma in situ, those associated with lobular neoplasia were mostly (56%) invasive. During further 2 years of follow-up, cancer was documented in 1% of women with follow-up surgery and in 3% with no surgery. Conclusion Despite low rates of surgery, low rates of cancer were documented during follow-up. Benign papillary lesions diagnosed on BI-RADS 4 mammograms among asymptomatic women do not justify surgical excision.

BACKGROUND: Although it has been accepted that intraductal papillomas with atypia or malignancy diagnosed on core needle biopsy require surgical excision, the management of pure intraductal papillomas has been controversial. Because some series reported a small but definite incidence of atypia or malignancy, whereas others claimed that radiologic follow‐up was adequate, this study evaluated results of excision of all pure intraductal papillomas diagnosed on core needle biopsy at this institution. METHODS: By using computerized pathology files from January of 2000 to December of 2004, 200 cases of intraductal papillomas on core needle biopsy were identified. Information regarding excision was available in 104 cases. All specimens were reviewed to confirm both the diagnoses as well as the presence of biopsy site changes in excision specimens, and the findings were correlated with radiologic data. RESULTS: The age of the patients ranged from 25 to 82 years (mean, 55.5). The diagnoses on excision were as follows: intraductal papillomas = 71 cases (68.3%), no residual intraductal papillomas = 16 (15.3%), atypical duct hyperplasia = 8 (7.7%), ductal carcinoma in situ = 6 (5.8%), and invasive carcinoma = 3 (2.9%). In cases with atypia or malignancy, these findings were adjacent to but not in the biopsy site. In cases with atypical duct hyperplasia or ductal carcinoma in situ, a spectrum of histologic changes ranging from florid to atypical duct hyperplasia (14 cases), to ductal carcinoma in situ (6 cases) were present, all involving intraductal papillomas. CONCLUSIONS: The upstage rate of pure intraductal papillomas on core needle biopsy to atypia or malignancy on excision was 16.4%. Because of sampling error and the close proximity of atypia or malignancy to the intraductal papillomas (suggesting precancerous potential), excision was recommended of these lesions diagnosed on core needle biopsy. Close radiologic‐pathologic correlation was important in the evaluation of these lesions. Cancer 2009. © 2009 American Cancer Society.

BACKGROUND. Lobular neoplasia (LN), encompassing atypical lobular hyperplasia (ALH) and lobular carcinoma in situ (LCIS), is often an incidental finding on core needle biopsies (CNBs) performed in instances of radiologic densities and/or calcifications. Because LN is generally considered a risk factor for breast carcinoma, the utility of subsequent excision is controversial. METHODS. The authors' database yielded 98 cases of LCIS and/or ALH. Cases containing LN accompanied by a second lesion mandating excision (eg, radial scar, atypical ductal hyperplasia [ADH]) and those failing to meet strict diagnostic criteria for LN (eg, atypical cells, mitoses, single‐cell necrosis) were excluded. Radiographic calcifications were correlated with their histologic counterparts in terms of size, number, and pattern. RESULTS. Ninety‐one biopsies were performed for calcifications and 7 were performed for mass lesions. The ages of the patients ranged from 35 to 82 years. Fifty‐three patients were followed radiologically without excision, 42 of whom had available clinicoradiologic information. The 45 patients who underwent excision were without disease at follow‐up periods ranging from 1 to 8 years. Of these 45 patients, 42 (93%) had biopsy results demonstrating only LN. The remaining 3 patients had biopsies with the following findings: ADH in 1 biopsy, residual LCIS and a separate minute focus of infiltrating lobular carcinoma (clearly an incidental finding) in the second biopsy, and ductal carcinoma in situ admixed with LCIS in the third biopsy (a retrospective examination performed by 2 blinded breast pathologists revealed foci of atypical cells and mitoses). CONCLUSIONS. Excision of LN is unnecessary provided that: 1) careful radiographic‐pathologic correlation is performed; and 2) strict histologic criteria are adhered to when making the diagnosis. Close radiologic and clinical follow‐up is adequate. Cancer 2008. © 2008 American Cancer Society.