"Growing fibroadenoma": Are there clinical and pathological features predicting a phyllodes tumor on surgical excision?

In cases of growth of FA on imaging, core needle biopsies (CNB) are often performed to rule out phyllodes tumor (PT). We aim to focus on "growing FAs" and to identify clinical and histopathologic features that are likely to predict a PT on excision. Thirty-four FAs with radiologic documentation of growth were included. Various clinical and pathological features such as age, body mass index (BMI), lesion size, and growth rate were recorded. On excision, 17 cases (50 %) were FAs, whereas 16 (47 %) were re-classified as benign PT despite only 19 % being suspicious for PT on CNB. PT patients were older (mean age 42.6) than those with FAs (mean age 28.2), p = 0.0002. All false negative cases demonstrated intracanalicular growth. Mitotic rate was the most significant histologic feature in PT on excision compared to others, such as lesion circumscription and stromal cellularity. Recognition and careful counting of mitotic rate, especially with intracanalicular patterns in growing FAs, can potentially prevent missing a PT on CNB. In patients with "growing FAs" who are ≥40 years of age, excision may be recommended due to the high likelihood of PT diagnosis on excision and high false negative rate on CNB.

Clinicopathologic update of calcium oxalate in breast: A 15-year retrospective review.

Mammary malignancies are radiologically detected by presence of masses, architectural distortions or microcalcifications. Unlike calcium hydroxyapatite, calcium oxalate (CaOx) deposits have been almost exclusively associated with benign mammary processes. The etiology and mechanism of mammary CaOx deposition remains poorly understood, and the original studies elucidating its histopathologic correlation are dated several decades ago. We reviewed radiopathologic findings of breast biopsies and excisions to re-examine the clinicopathologic significance of CaOx deposits and to ascertain potential radiologic characteristics for their identification. Fifty patients from 2004 to 2019 with reported "calcium oxalate" were retrospectively reviewed. CaOx was invariably detected with histopathologic changes of nonproliferative ducts/cysts (90%, 45 of 50), and less commonly, ducts/cysts with usual ductal hyperplasia (10%, 5 of 50). CaOx was missed on one biopsy with a subsequent excision showing apocrine cyst with CaOx. Despite the benign pathological findings, mammographic findings corresponding to CaOx ranged from benign to highly suspicious with 20% categorized as benign (round or punctuate), 22% as intermediate amorphous, 14% as suspicious (coarse/heterogeneous), and 18% as highly suspicious/pleomorphic, respectively. Lobular carcinoma in situ (LCIS) was present in separate fields from CaOx containing benign ducts in two cases which were radiologically characterized as "grouped heterogeneous" and "localized linear." On imaging, more than half of the cases (52.5%) had a corresponding BI-RADS score of 4 and the calcifications were associated with variable distributions and appearances. In conclusion, this is one of the largest studies of CaOx in breast with radiology and pathology correlation. The radiologic appearances of CaOx are nonspecific from benign to highly suspicious. Identification of CaOx on the biopsy is reassuring for a benign diagnosis. Incidental atypical lesions can occur that are often not directly associated with CaOx. CaOx may be overlooked on pathologic evaluation which results in unnecessary surgery. Our findings support close radiologic-pathologic correlation for clinical decision-making pertaining to breast calcifications.

Improving outcomes of screening breast MRI with practice evolution: initial clinical experience with 3T compared to 1.5T.

PURPOSE: To determine if changing from 1.5T to 3T breast magnetic resonance imaging (MRI) is associated with a change in BI-RADS categories, positive predictive value of biopsy recommendation, or cancer detection rates in high-risk screening breast MRI. MATERIALS AND METHODS: Institutional Review Board (IRB) approval was obtained for this Health Insurance Portability and Accountability Act (HIPAA)-compatible retrospective review. Prior to October 2010, breast MRI was performed at 1.5T and after October 2010 breast MRI was performed at 3T. Reports of 495 consecutive screening 3T breast MRI exams from October 2010 through October 2011 were reviewed. Comparison was made to previously collected data on 650 screening breast MRI exams at 1.5T. Data were analyzed for statistical significance using the two-sample test of proportions. RESULTS: There were 495 screening breast MRI exams. There were 419 (84.6%) BI-RADS 1/2 results, 35 (7.1%) BI-RADS 3 results, and 41 (8.3%) BI-RADS 4/5 results. BI-RADS 4/5 results increased at 3T (P=0.04). The positive predictive value for BI-RADS 4/5 was 29.3% (12/41) at 3T, compared with 17.6% at 1.5T (P<0.001). Cancer detection rate was 2.6% at 3T, compared with 0.9% at 1.5T (P=0.02). CONCLUSION: Transition to 3T breast MRI in a screening population resulted in increased BI-RADS 4/5 interpretations, positive predictive value of biopsy recommendations, and cancer detection rate.

High-risk lesions at MRI-guided breast biopsy: frequency and rate of underestimation.

OBJECTIVE: The purpose of this article is to determine the underestimation rate of high-risk lesions diagnosed at MRI-guided breast biopsy. MATERIALS AND METHODS: This was a retrospective review of 446 MRI-guided breast biopsies from January 2006 through December 2010. Data were collected on examination indication, lesion size and type, and pathology results. Biopsies were performed with a 9-gauge vacuum-assisted device. Biopsy results of atypical ductal hyperplasia (ADH), papillary lesion, radial scar, lobular neoplasia, and atypia were identified and compared with final excisional pathology results. Underestimation rates were calculated and data were compared by patient and lesion characteristics using chi-square analysis. RESULTS: Of the 446 MRI-guided biopsies, 96 (21.5%) were high-risk lesions. Forty-two of 96 lesions (44%) were masses, and 54 (56%) showed nonmass enhancement. Twenty of 96 lesions (20.8%) were ADH, nine (9.4%) were lobular neoplasia, 27 (28.1%) were papillary lesions, 20 (20.8%) were radial scar, and 20 (20.8%) were other atypias. Sixty-nine of 96 lesions (71.9%) had surgical excisional pathology results available. Sixteen of 69 (23.2%) lesions were upgraded to malignancy; 11 of the 16 (68.8%) were upgraded to ductal carcinoma in situ (DCIS) and five (31.2%) were upgraded to invasive carcinoma. The underestimation rate was 31.6% (6/19) for ADH, 5.9% (1/17) for papillary lesions, 23.1% (3/13) for radial scar, 28.6% (2/7) for lobular neoplasia, and 30.8% (4/13) for other atypias (p = 0.43). There was no statistically significant difference in underestimation rate by lesion type, size, or history of newly diagnosed breast cancer. CONCLUSION: MRI-guided breast biopsy yielded high-risk lesions in 21.5% of cases, and the underestimation rate was 23.2%. No patient or lesion characteristics correlated with underestimation rate.

In Search of Calcifications : Histologic Analysis and Diagnostic Yield of Stereotactic Core Needle Breast Biopsies.

OBJECTIVES: Stereotactic core needle biopsy (SCNB) is used in the diagnostic assessment of suspicious mammographic calcifications to rule out breast ductal carcinoma in situ (DCIS). With advances in imaging technology and increased biopsy tissue volume, the detection rate of calcifications and DCIS in SCNB is unclear. METHODS: This retrospective study included 916 consecutive SCNBs for calcifications performed on 893 patients in a 2-year period. RESULTS: We found the cancer detection rate was 27.1% (DCIS, 23.7%; invasive, 3.4%). The detection rate for calcifications was 74.8% with the standard 3 levels. Additional leveling of calcification-negative cases further increased the detection of both calcifications (to 99.4% of cases) and DCIS (to 32.9% of cases). Lobular neoplasia (LN) was diagnosed in 41 cases. Twenty-five (61.0%) cases of LN were incidental without associated calcification. Of 32 invasive carcinomas detected on SCNB, 87.5% were T1a or less, and calcifications were associated with atypical ductal hyperplasia/DCIS or LCIS. The common benign lesions associated with calcifications were fibrocystic change (32.5%), fibroadenomatous change (30.2%), and columnar cell change and hyperplasia (8.2%). CONCLUSIONS: We determined the up-to-date detection rates of calcification and DCIS in SCNB, as well as the common benign and malignant breast lesions associated with calcifications. Additional levels significantly increase the detection rate when standard levels show only stromal or scant/absent calcifications. Lobular neoplasia is often an incidental finding in SCNB for calcifications. When calcifications are present with LN, they are commonly florid, pleomorphic LCIS, or with concurrent invasive carcinoma.