Pseudoangiomatous Stromal Hyperplasia: Radiologic-Pathologic Correlation.

Pseudoangiomatous stromal hyperplasia (PASH) is a benign mesenchymal proliferative lesion of the breast. PASH is postulated to be hormonally induced and predominantly occurs in premenopausal women and postmenopausal women on menopausal hormone therapy. Clinical presentation varies from screen-detected lesions to palpable masses. Imaging findings of PASH are nonspecific. The most common mammographic findings are an oval or round circumscribed non-calcified mass or developing asymmetry. On US, PASH is often seen as an oval hypoechoic mass that may be circumscribed and can have an echogenic rim, or, when manifest as mammographic asymmetry, US may show a corresponding non-mass focal area of echogenic tissue. Limited studies have investigated the MRI appearance, with PASH most often manifesting as non-mass enhancement, or, less often, as an oval or irregular mass with persistent kinetics. Histopathologically, PASH can be mistaken for a fibroadenoma or phyllodes tumor and has features overlapping low-grade angiosarcoma. Assessment of radiologic-pathologic concordance is particularly important as PASH is often an incidental finding, adjacent to the targeted lesion at histopathology. Surgical excision or repeat core-needle biopsy is necessary for discordant suspicious cases. After a benign, concordant diagnosis of PASH, the patient may resume routine screening.

A Deep Learning Approach to Re-create Raw Full-Field Digital Mammograms for Breast Density and Texture Analysis.

PURPOSE: To develop a computational approach to re-create rarely stored for-processing (raw) digital mammograms from routinely stored for-presentation (processed) mammograms. MATERIALS AND METHODS: In this retrospective study, pairs of raw and processed mammograms collected in 884 women (mean age, 57 years ± 10 [standard deviation]; 3713 mammograms) from October 5, 2017, to August 1, 2018, were examined. Mammograms were split 3088 for training and 625 for testing. A deep learning approach based on a U-Net convolutional network and kernel regression was developed to estimate the raw images. The estimated raw images were compared with the originals by four image error and similarity metrics, breast density calculations, and 29 widely used texture features. RESULTS: In the testing dataset, the estimated raw images had small normalized mean absolute error (0.022 ± 0.015), scaled mean absolute error (0.134 ± 0.078) and mean absolute percentage error (0.115 ± 0.059), and a high structural similarity index (0.986 ± 0.007) for the breast portion compared with the original raw images. The estimated and original raw images had a strong correlation in breast density percentage (Pearson r = 0.946) and a strong agreement in breast density grade (Cohen κ = 0.875). The estimated images had satisfactory correlations with the originals in 23 texture features (Pearson r ≥ 0.503 or Spearman ρ ≥ 0.705) and were well complemented by processed images for the other six features. CONCLUSION: This deep learning approach performed well in re-creating raw mammograms with strong agreement in four image evaluation metrics, breast density, and the majority of 29 widely used texture features.Keywords: Mammography, Breast, Supervised Learning, Convolutional Neural Network (CNN), Deep learning algorithms, Machine Learning AlgorithmsSee also the commentary by Chan in this issue.Supplemental material is available for this article.©RSNA, 2021.

Time to development and imaging features of new calcifications in the treated breast after breast-conserving therapy.

OBJECTIVE: The purpose of our study was to analyze the time to development, malignancy rate, location, and mammographic features of new calcifications in the treated breast after breast-conserving therapy (BCT). MATERIALS AND METHODS: In this HIPAA-complaint, IRB-approved retrospective study, we reviewed the records of patients treated with BCT at our institution with breast-conserving surgery performed between January 1, 2009 and December 31, 2010. A total of 735 breasts in 732 women were included in our study cohort. Factors analyzed included rate of development of new calcifications, malignancy rate of new calcifications, the time between completion of radiation therapy and development of new calcifications, imaging features of new calcifications, and location of the new calcifications in relation to the primary malignancy. RESULTS: During follow-up, new calcifications developed in 155 of the 735 treated breasts (21.1%) and 155 of the 732 women (21.2%). After excluding two cases that were lost to follow-up, the malignancy rate of new calcifications was 5.2% (8/153; 95% CI: 2.3% to 10.0%). The median time to development of the benign calcifications was 27 months (range, 2 to 91 months) and of the malignant calcifications was 41 months (range, 11 to 57 months). Of the 20 (13.1%) cases of new calcifications categorized as BI-RADS 3 (probably benign), all were benign on follow-up (19 cases) or on biopsy (1 case). Of the 51 BI-RADS 4 (suspicious) cases, 8 (16%) were biopsy-proven malignant. The malignancy rate was the highest in fine pleomorphic 100% (1/1), followed by amorphous 17%, (5/29), coarse heterogeneous 8% (2/26) and typically benign 0 (0/97) calcifications (p < 0.0001). The malignancy rate was 1.5% (2/137) for new calcifications within the lumpectomy site vs. 37.5% (6/16) for new calcifications outside the lumpectomy site (p < 0.0001) and was 3.4% (5/147) for new calcifications at or within the same quadrant as the lumpectomy site vs. 50.0% (3/6) for new calcifications in a different quadrant from the lumpectomy site (p=0.002). CONCLUSION: Most new calcifications that developed in the treated breast after BCT were benign. Evaluation of morphology and distribution of those calcifications is imperative. New calcifications in the treated breast outside the lumpectomy site are more likely to be malignant and should be viewed with greater suspicion. Benign calcifications developed earlier than malignant calcifications, but the time courses overlapped.

Concerns about the economics of mammography and how radiologists can respond.

Rapidly increasing U.S. healthcare spending has been a hot topic over the past few decades. Imaging studies, including screening mammography, are possible targets for cost savings. Radiologists need to be more proactive and take charge by actively participating in the cost reduction conversation, improving the quality of care, providing patients with accurate cost estimates and educating patients along with clinicians on the value we have provided and can provide in the future.

Malignancy rates of stereotactic biopsies of two or more distinct sites of suspicious calcifications in women without known breast cancer.

OBJECTIVE: To determine the malignancy rate in women without a concurrent breast cancer diagnosis at presentation who underwent stereotactic biopsies of distinct sites of suspicious calcifications. METHODS: This retrospective study included 280 women without a concurrent breast cancer diagnosis who underwent 587 stereotactic biopsies of two or more distinct sites of suspicious calcifications in one or both breasts at our institution from 2010 to 2015. RESULTS: The overall malignancy rate was 27.9% (78/280, 95% CI, 22.7%-33.5%) at the patient level and 18.7% (110/587, 95% CI, 15.7%-22.1%) at the lesion level. Eighteen had invasive cancers (mean [range] diameter, 0.5 cm [0.1-1.7]; six grade I, ten grade II, two grade III), one of whom had multifocal and another bilateral malignancy. Sixty had ductal carcinoma in situ. Of the 171 with all calcifications of the same morphology, 139 (81.3%) had all calcifications in the same pathology category (benign, high-risk, or malignant). CONCLUSION: The malignancy rate is substantial in women who undergo stereotactic biopsies of two or more distinct calcification sites. Given the nearly 20% rate of dissimilar histopathology between calcification sites with similar morphology, if only one site is biopsied and results in a malignant pathology, biopsy of the additional calcifications is warranted. Even if the pathology result of the one site biopsy is benign, biopsy of additional sites may perhaps still be necessary.

Impact of Second-Opinion Interpretation of Breast Imaging Studies in Patients Not Currently Diagnosed With Breast Cancer.

PURPOSE: To study the impact of second-opinion interpretation of breast imaging studies submitted from outside facilities to a tertiary cancer center. MATERIALS AND METHODS: A retrospective database review was conducted of second-opinion interpretations rendered at our institution from January 1, 2010, to June 30, 2014, on studies from patients who did not have a concurrent breast cancer diagnosis. A total of 2,253 patients were included. RESULTS: In 800 of 2,253 patients (35.5%), the BI-RADS categories assigned at our institution and at outside facilities were discordant. Of 973 patients assigned BI-RADS category 4 or 5 at outside facilities, 278 (28.6%) were assigned BI-RADS category 1 to 3 (no biopsy necessary) at our institution. Of 923 patients assigned BI-RADS category 1 to 3 at outside facilities, 191 (20.7%) were assigned BI-RADS category 4 or 5 at our institution, and 189 of these had biopsies, which revealed 23 cancers, 15 high-risk lesions, and 151 benign lesions. One high-risk lesion at core biopsy was upgraded to invasive ductal carcinoma and ductal carcinoma in situ (DCIS) on excision, resulting in 24 cancers. Of these, 18 reflected true additional breast cancers detected as a result of second-opinion interpretation: 12 invasive carcinomas and 6 cases of DCIS. These results translate into a 9.4% (18/191) positive predictive value for the number of cancers diagnosed among all biopsies recommended and a 9.5% (18/189) positive predictive value for the number of cancers diagnosed among all biopsies recommended and actually performed. CONCLUSIONS: These findings demonstrate the positive clinical impact of second-opinion interpretation at a tertiary cancer center of outside-facility breast imaging studies in patients without a breast cancer diagnosis.

Upgrade Rate and Imaging Features of Atypical Apocrine Lesions.

The purpose of our work was to identify imaging features of atypical apocrine lesions and determine the rate of upgrade to ductal carcinoma in situ (DCIS) or invasive carcinoma at excision after such a diagnosis on percutaneous breast biopsy. From January 1, 2006, through October 8, 2013, a total of 33,157 breast core biopsies were performed at University of Pittsburgh Medical Center. Of those, 58 (0.2%) showed atypical apocrine lesions. For 24, atypical apocrine adenosis (AAA) or atypical apocrine metaplasia (AAM) was the only risk lesion, with no known ipsilateral malignancy, and the results of excision were available. The median patient age was 58 years (range 43-88). Among 24 atypical apocrine lesions (20 AAA and 4 AAM), four (16.7%; 95% confidence interval: 4.7, 37.4) were upgraded at excision: one invasive ductal carcinoma (grade 2, 0.2 cm, estrogen receptor positive, progesterone receptor positive, HER2/Neu negative) and three DCIS (two grade 3, one grade 2). All four upgraded lesions were AAA (20%; 4/20). Twelve AAA were seen as an irregular (n = 9) or circumscribed (n = 3) mass on ultrasound; three masses had calcifications. Six of 20 (30%) AAA were seen on biopsy of calcifications only and calcifications were within two AAA lesions at histopathology. One AAA (1/20, 5%) was asymmetry only, and one (1/20, 5%) a persistently enhancing MR focus. All four malignancies were masses on ultrasound (three irregular, one circumscribed), and three malignancies had calcifications (two coarse heterogeneous, one amorphous). While concordant with an irregular or circumscribed mass on imaging, with or without amorphous or coarse heterogeneous calcifications, AAA merits excision with a 20% upgrade rate to malignancy. Further study of AAM is warranted.

Histogram analysis for characterization of indeterminate adrenal nodules on noncontrast CT.

OBJECTIVE: To determine the effectiveness of the CT histogram method to characterize indeterminate adrenal nodules above 10 Hounsfield units (HU) on noncontrast CT. MATERIALS AND METHODS: Retrospective review of clinical CT data from January 2005 through 2008 identified 194 indeterminate adrenal nodules (>10 HU on noncontrast CT) in 175 patients. 20 nodules in 18 patients were excluded due to large standard deviation (SD > 30) of HU values. Of the remaining 174 nodules, 131 were classified as benign lipid-poor nodules based on size stability for ≥1 year (104), in- and opposed-phase MRI (17), adrenal washout CT (3), or biopsy (7). 43 were classified as malignant by size increase over a short time (30), avid FDG uptake on PET/CT (15), or biopsy (5). Histogram analysis was performed by drawing a circular region of interest on all adrenal nodules. Mean attenuation, total number of pixels, number of negative pixels, and percentage of negative pixels were recorded for each nodule. RESULTS: At the threshold value of >10% negative pixels, 59/131 benign nodules were correctly characterized, but 1/43 malignant nodules was falsely characterized as benign (sensitivity 45%, specificity 98%, positive predictive value 98%). With a slightly higher threshold value of >15% negative pixels, there were no false benign judgments. 36 nodules had more than 15% negative pixels, all of which were benign (sensitivity 27%, specificity 100%, positive predictive value 100%). In the subgroup of benign nodules measuring 11-20 HU, 80% and 54% were identified with threshold values of >10% and >15% negative pixels, respectively. CONCLUSION: The CT histogram method with a threshold value of >10% negative pixels can identify many benign adrenal nodules with attenuation values >10 HU on unenhanced CT with extremely high specificity. A threshold of >15% negative pixels can achieve 100% specificity. This method is highly robust provided very "noisy" CT examinations (SD > 30) are eliminated.

The unfulfilled/DHR51 gene of Drosophila melanogaster modulates wing expansion and fertility.

This is the first functional analysis in Drosophila of unfulfilled (unf; DHR51), the NR2E3 nuclear receptor superfamily ortholog of C. elegans fax-1 and human PNR. Both fax-1 and PNR mutations disrupt developmental events in a limited number of neurons, resulting in behavioral or sensory deficits. An analysis of two independent unf alleles revealed that unf mutants are characterized by one of two phenotypes. A proportion of the mutants eclosed but failed to expand their wings and were poorly coordinated. The remainder completed wing expansion but displayed severely compromised fertility. Consistent with the restricted neural expression of fax-1 and PNR, unf expression was detected in situ only in mushroom body neurons and a small number of other cells of the central nervous system (CNS). These data support the hypothesis that the wing expansion failure and the compromised fertility of unf mutants are the result of underlying neural defects.