Jessica W.T. Leung

Magnetic Resonance Imaging Captures the Biology of Ductal Carcinoma In Situ

PURPOSE Magnetic resonance imaging (MRI) is an important tool for characterizing invasive breast cancer but has proven to be more challenging in the setting of ductal carcinoma in situ (DCIS). We investigated whether MRI features of DCIS reflect differences in biology and pathology. PATIENTS AND METHODS Forty five of 100 patients with biopsy-proven DCIS who underwent MRI and had sufficient tissue to be characterized by pathologic (nuclear grade, presence of comedo necrosis, size, and density of disease) and immunohistochemical (IHC) findings (proliferation, Ki67; angiogenesis, CD34; and inflammation, CD68). Pathology and MRI features (enhancement patterns, distribution, size, and density) were analyzed using pairwise and canonical correlations. RESULTS Histopathologic and IHC variables correlated with MRI features (r = 0.73). The correlation was largely due to size, density (by either MRI or pathology), and inflammation (P < .05). Most small focal masses were estrogen receptor-positive. MRI enhancement patterns that were clumped were more likely than heterogeneous patterns to be high-grade lesions. Homogenous lesions were large, high grade, and rich in macrophages. Presence of comedo necrosis and size could be distinguished on MRI (P < .05). MRI was most likely to over-represent the size of less dense, diffuse DCIS lesions. CONCLUSION The heterogeneous presentation of DCIS on MRI reflects underlying histopathologic differences.

The California Breast Density Information Group: A Collaborative Response to the Issues of Breast Density, Breast Cancer Risk, and Breast Density Notification Legislation

In anticipation of breast density notification legislation in the state of California, which would require notification of women with heterogeneously and extremely dense breast tissue, a working group of breast imagers and breast cancer risk specialists was formed to provide a common response framework. The California Breast Density Information Group identified key elements and implications of the law, researching scientific evidence needed to develop a robust response. In particular, issues of risk associated with dense breast tissue, masking of cancers by dense tissue on mammograms, and the efficacy, benefits, and harms of supplementary screening tests were studied and consensus reached. National guidelines and peer-reviewed published literature were used to recommend that women with dense breast tissue at screening mammography follow supplemental screening guidelines based on breast cancer risk assessment. The goal of developing educational materials for referring clinicians and patients was reached with the construction of an easily accessible Web site that contains information about breast density, breast cancer risk assessment, and supplementary imaging. This multi-institutional, multidisciplinary approach may be useful for organizations to frame responses as similar legislation is passed across the United States. Online supplemental material is available for this article.

Developing Asymmetry Identified on Mammography: Correlation with Imaging Outcome and Pathologic Findings

OBJECTIVE Developing asymmetry on mammography is a focal asymmetric deposit that has appeared or increased in size or conspicuity since a previous examination. We examined the frequency, imaging outcome, and pathologic significance of developing asymmetry. MATERIALS AND METHODS This study was performed in a retrospective cohort manner. We searched for all cases of developing asymmetry consecutively entered in our mammography database from April 1985 to April 2005. We examined radiology records to determine whether sonography and MRI were used as adjunctive diagnostic tools and examined pathology records to determine tissue diagnosis. RESULTS Developing asymmetry was present in 292 (0.16%) of 180,801 consecutive screening examinations and 32 (0.11%) of 27,330 consecutive diagnostic examinations. After exclusion for absent data, the study consisted of 281 screening and 30 diagnostic cases. In the 281 cases of screening-detected developing asymmetry, biopsy was recommended and was performed in 84 (29.9%) of the cases. Thirty-six cases of cancer were identified, resulting in a positive predictive value of 12.8%, obtained by division of the number of cases of cancers by the number of examinations with abnormal mammographic findings (PPV1), and a PPV2 of 42.9%, obtained by division of the number of cases of cancer by the number of mammographic examinations in which findings led to a recommendation for biopsy. Biopsy was recommended and performed in 26 (86.7%) of the 30 cases of diagnostic mammography. Eight cases of cancer were identified, resulting in a PPV1 of 26.7% and a PPV2 of 30.8%. Of the 44 cancers detected at screening and diagnostic mammography, 21 had available sonographic data. Five (23.8%) of these 21 cases of cancer had no correlate at sonographic examination. MRI was performed in only two cases, both with benign diagnoses. CONCLUSION Developing asymmetry is an uncommon finding. When this sign is identified on screening and diagnostic mammography, the likelihood of malignancy is sufficiently high to justify recall and biopsy. Normal sonographic findings do not exclude malignancy in the case of developing asymmetry.

Utility of Second-Look Ultrasound in the Evaluation of MRI-Detected Breast Lesions

i o u p a r D s t s In addition to mammography and breast ultrasound, magnetic resonance imaging (MRI) of the breast offers an important tool in the detection and diagnosis of breast cancer. A survey conducted by the Society of Breast Imaging (SBI) in 2008 showed that breast MRI was offered by approximately 75% of the respondents.1 The American Cancer Society isued a consensus statement in 2007 endorsing the use of MRI n breast cancer screening of high-risk patients,2 as did the American College of Radiology (ACR) and the SBI in 2010.3 The ACR has also published practice guidelines for breast MRI in both the screening and the diagnostic settings.4 Because of the increasing use of breast MRI in clinical practice, the ACR initiated its accreditation program for breast MRI in May 2010.5 Requirements for this accreditation program include specific standards in equipment and personnel (including physicians, technologists, and medical physicists or MRI scientists), as well as a clinically appropriate reporting and auditing system, similar to the requirements for mammography6 and breast ultrasound accreditation.7 One requirement unique to breast MRI accreditation is he mandate for the ability to correlate MRI studies with ammograms and ultrasounds and to perform MRI-guided iopsies (or have a direct referral program in place so that the atient may be referred to another center for MRI-guided iopsy in an expedient fashion without the need to repeat the RI examination). MRI is based on different physical principles than mamography or ultrasound and allows for the identification of mall and subtle cancers.7,8 A subset of breast cancers will be isualized using magnetic resonance only and not with any ther imaging modalities (such as mammography or ultraound) or be detected at physical examination.7-12 A recent report showed that screening MRI downgraded disease and increased patient survival from breast cancer.12 However, the reported specificity of MRI is relatively low, ranging from

Performance Parameters for Screening and Diagnostic Mammography in a Community Practice: Are There Differences Between Specialists and General Radiologists?

OBJECTIVE The purpose of this study was to compare the performance of general radiologists in interpretation of mammograms with that of breast imaging specialists in a high-volume community hospital-based private practice. MATERIALS AND METHODS A retrospective observational study was conducted with data prospectively collected over a 5-year period in a community hospital-based practice in which 106,405 screening and 52,149 diagnostic mammograms were performed. The performance of three radiologists specializing in breast imaging was compared with that of six general radiologists. The following data were extracted and analyzed: recall rate, biopsy recommendation rate, and cancer detection rate. Statistical analysis was performed with a chi-square test and two-tailed calculation of p values. RESULTS The recall rates of the specialists and generalists were nearly the same at 6.5% and 6.7%, respectively. The biopsy recommendation rate at recall from screening examinations was nearly the same for generalists and specialists (1.2% and 1.1%, respectively; p = 0.4504). This rate also was similar for diagnostic examinations (8.5% for generalists; 8.4% for specialists; p = 0.4086). The cancer detection rate in the screening setting was slightly higher for specialists than for generalists: 2.5 and 2.0 cancers per 1,000 cases, respectively (p = 0.0614). The cancer detection rate in the diagnostic setting was 24.2% higher among specialists (20.0 cancers per 1,000 cases) compared with generalists (16.1 cancers per 1,000 cases) (p = 0.0177). CONCLUSION The only statistically significant difference between generalists and specialists was in cancer detection rate among patients undergoing diagnostic mammography. No statistically significant difference was identified between the two groups in terms of recall rate, biopsy recommendation rate, or percentage of favorable-prognosis cases of cancer detected. There was a trend toward greater cancer detection by specialists in the screening setting.

Benefit of Semiannual Ipsilateral Mammographic Surveillance Following Breast Conservation Therapy

PURPOSE To compare cancer recurrence outcomes on the basis of compliant semiannual versus noncompliant annual ipsilateral mammographic surveillance following breast conservation therapy (BCT). MATERIALS AND METHODS A HIPAA-compliant retrospective review was performed of post-BCT examinations from 1997 through 2008 by using a deidentified database. The Committee on Human Research did not require institutional review board approval for this study, which was considered quality assurance. Groups were classified according to compliance with institutional post-BCT protocol, which recommends semiannual mammographic examinations of the ipsilateral breast for 5 years. A compliant semiannual examination was defined as an examination with an interval of 0-9 months, although no examination had intervals less than 3 months. A noncompliant annual examination was defined as an examination with an interval of 9-18 months. Cancer recurrence outcomes were compared on the basis of the last examination interval leading to diagnosis. RESULTS Initially, a total of 10 750 post-BCT examinations among 2329 asymptomatic patients were identified. Excluding initial mammographic follow-up, there were 8234 examinations. Of these, 7169 examinations were semiannual with 94 recurrences detected and 1065 examinations were annual with 15 recurrences detected. There were no differences in demographic risk factors or biopsy rates. Recurrences identified at semiannual intervals were significantly less advanced than those identified at annual intervals (stage I vs stage II, P = .04; stage 0 + stage I vs stage II, P = .03). Nonsignificant findings associated with semiannual versus annual intervals included smaller tumor size (mean, 11.7 vs 15.3 mm; P = .15) and node negativity (98% vs 91%, P = .28). CONCLUSION Results suggest that a semiannual interval is preferable for ipsilateral mammographic surveillance, allowing detection of a significantly higher proportion of cancer recurrences at an earlier stage than noncompliant annual surveillance.

Rapidly Enlarging Tumoral Pseudoangiomatous Stromal Hyperplasia in a 15-Year-Old Patient Distinguishing Sonographic and Magnetic Resonance Imaging Findings and Correlation With Histologic Findings

Pseudoangiomatous stromal hyperplasia (PASH) is an uncommon benign lesion of the breast, with a relatively limited number of cases documented in the English literature. 1 Breast tissue affected by PASH is characterized by dense myofibroblastic proliferation of mammary stroma, associated with interanastomosing capillarylike spaces. 2,3 Pseudoangiomatous stromal hyperplasia may present in a wide clinicopathologic spectrum, ranging from focal minor incidental microscopic changes to clinically symptomatic and mammographically evident breast masses. 4,5 Most reported cases of PASH have been small to moderate-sized lesions. There have been few radiologic descriptions of large tumoral PASH. 5-7 We report a case of a 15-year-old patient with bilateral PASH presenting with rapid and massive asymmetric enlargement of the breasts. We describe its sonographic findings with correlative magnetic resonance imaging (MRI) and histopathologic features and highlight an unusual imaging feature not previously described.

Utility of Targeted Sonography in the Evaluation of Focal Breast Pain

Objective. To determine the utility of targeted sonography in the evaluation of patients with focal breast pain. Methods. From January 1995 through December 1999, 110 targeted sonographic examinations were performed in 99 patients for evaluation of focal breast pain in the absence of an associated palpable mass. The sonographic, mammographic, and clinical findings were reviewed. The hospital pathology database was searched to identify any interval cancers and false‐negative interpretations. Results. No cancer was identified in any of the 110 examinations. Eighty‐five (77.3%) of the examinations had negative findings. Cysts were identified in 15 cases (13.6%), and 3 solid masses (2.7%) were identified. Two of these 3 solid masses had biopsies and were shown to be benign, whereas the third mass was followed for 29 months without change. Most patients were premenopausal, had no family or personal history of breast cancer, and were not taking exogenous hormones. Eighty‐five patients (77%) were referred by primary care physicians. Conclusions. In patients with focal breast pain without an associated palpable mass, sonography may be more useful for patient reassurance than for cancer detection.

Lymphoepithelioma-like carcinoma of the lung: radiologic features of an uncommon primary pulmonary neoplasm.

OBJECTIVE The purpose of this study was to review the chest radiographic, CT, and MRI appearances of primary pulmonary lymphoepithelioma-like carcinoma (LELC). CONCLUSION Primary pulmonary LELC is histopathologically identical to nasopharyngeal carcinoma. The radiographic, CT, and MRI features of primary pulmonary LELC are nonspecific, often resembling those of bronchogenic carcinoma. Primary pulmonary LELC usually presents as a poorly circumscribed, enhancing, peripheral solitary pulmonary nodule on CT; necrosis may be present and is considered a poor prognostic sign. MRI shows isointense to low-intensity signal on T1-weighted images and mildly increased signal on T2-weighted images; enhancement of abnormal tissue is typical. Most patients present with early-stage disease. Primary pulmonary LELC should be suspected in selected patients and requires differentiation from bronchogenic carcinoma and metastatic nasopharyngeal carcinoma.

New modalities in breast imaging: digital mammography, positron emission tomography, and sestamibi scintimammography

Digital mammography, PET, and sestamibi scintimammography are three new modalities in breast imaging. DM has advantages over film-screen mammography in image storage, retrieval, and processing and may lower the recall rate. Computer-aided detection may increase the sensitivity of mammographic screening without a substantial reduction in specificity. Whereas PET and sestambi scintimammography are not useful in breast cancer screening, PET may play a role in detecting nodal metastases and monitoring treatment response, and sestamibi scintimammography in selected cases may serve as an adjunct to conventional imaging. The cost-effectiveness of these new modalities remains to be evaluated, but all have the potential to significantly advance the diagnosis and management of women with breast cancer.