Elisabeth P. Frost

Factors That Impact the Duration of MRI-Guided Core Needle Biopsy

OBJECTIVE The purpose of our study was to determine which patient-related, target lesion-related, or procedure-related variables impact the duration of MRI-guided core needle breast biopsy. MATERIALS AND METHODS Between July 11, 2006, and September 26, 2007, data were collected for 75 single-target MRI-guided 9-gauge vacuum-assisted core needle biopsy procedures using a grid-guidance technique and performed at a single institution. The following variables were studied: MRI suite occupation time, number of operators, patient age and breast size, target morphology and location, approach to target, equipment used, number of image acquisitions and times the patient was moved in and out of the closed magnet, and occurrence of complications. Statistical analysis was performed using the Students t test, analysis of variance, and Pearsons correlation, with p values < 0.05 considered significant. RESULTS The mean duration was 57.9 minutes (SD, 17.2 minutes; range, 30-109 minutes). None of the patient- or target-related variables significantly impacted the duration, although lesions located in the anterior third of the breast showed a trend to prolong the procedure (p = 0.059). The time to complete a procedure was reduced when the operating radiologist was assisted by a breast imaging fellow-in-training (p = 0.01). Increasing numbers of image acquisitions and times the patient was moved in and out of the magnet significantly lengthened the procedure duration (p = 0.0001 for both). No major complications occurred. Biopsies yielded 16% (12/75) malignant and 84% (63/75) benign diagnoses. CONCLUSION Variables that minimized procedure duration were number of image acquisitions, number of patient insertions or removals from the magnet, and assistance of a breast imaging fellow-in-training. No patient-related or target-related variables impacted procedure time.

Difficulties and Errors in Diagnosis of Breast Neoplasms

Many perceptual and interpretive factors influence the radiologic detection and assessment of breast neoplasms. Diagnostic problems can be divided into errors of detection and errors of assessment and management. Detection issues may relate to inherent features of the tumor or surrounding tissue, technical problems, or human error. Even when lesions are successfully detected, errors in assessment or management recommendations can cause diagnostic delays. Improper breast imaging-reporting and data system (BI-RADS) usage or failure to integrate mammographic, ultrasonography (US), and magnetic resonance imaging (MRI) findings with clinical findings, all lead to interpretive errors. This article reviews factors affecting the detection and diagnosis of breast cancer, to improve radiologic interpretation, benefit patients by earlier cancer detection, and lessen medicolegal exposure from a missed or delayed cancer diagnosis. Mammography is the primary imaging modality for population-based breast cancer screening, and it is also the usual initial examination performed for diagnostic evaluation of clinical or screen-detected breast abnormalities in women aged 40 years and older. Mammography is supplemented by breast US and/or breast MRI in some cases. This article will, therefore, focus on mammography in reviewing difficulties and errors in cancer diagnosis, with supplemental discussion of breast US and breast MRI.

Interpreting One-View Mammographic Findings: Minimizing Callbacks While Maximizing Cancer Detection

Overlap of breast tissue is a frequent consequence of the necessary positioning and compression of the three-dimensional breast to obtain two-dimensional mammograms. The mammary glands contain fewer anatomically fixed landmarks than solid organs do; thus, variability in positioning can have an even greater effect on mammography than it has on other imaging examinations. Most often, areas of overlapping fibroglandular tissue, also known as summation shadows, are seen on only one of the two standard mammographic views. While striving to detect breast cancer as early as possible, radiologists must learn to visually compensate for apparent abnormalities in the breast that are produced by such tissue overlap. Mammographic interpretation in this setting is made even more challenging by the fact that the only manifestation of breast cancer might be a subtle change on a single mammographic view. Breast cancer might be obscured on one of the two standard views because of the density of surrounding breast tissue, mammographic technique, lesion size or location within the breast, histopathologic characteristics of the tumor, or lack of effect by the tumor on the appearance of surrounding tissues. To heighten awareness of the factors that can lead to either unnecessary recalls or failure to identify breast cancer, cases are reviewed in which false-positive findings and breast cancers were visible on only one mammographic view. Strategies for interpreting screening mammograms and determining which findings merit diagnostic evaluation are outlined so as to help minimize false-positive findings and aid in cancer detection.

Imaging and Histopathologic Features of BI-RADS 3 Lesions Upgraded during Imaging Surveillance.

To evaluate imaging and histopathologic differences between screen‐detected benign and malignant upgraded lesions initially assessed as BI‐RADS 3 at diagnostic evaluation. An IRB approved retrospective review of the mammography data base from January 1, 2004 to December 31, 2008 identified 1,188 (1.07%) of 110,776 screening examinations assessed as BI‐RADS 3 following diagnostic evaluation at our academic center (staffed by breast specialists) or our outpatient center (staffed by general radiologists), 1,017 with at least 24 months follow‐up or biopsy. Sixty (5.9%) BI‐RADS 3 lesions were upgraded to BI‐RADS 4 or 5 during imaging surveillance (study population). Prospective reports, patient demographics, and clinical outcomes were abstracted from the longitudinal medical record. Mean patient age was 54.1 years (range 35–85). Lesions consisted of 7 masses, 12 focal asymmetries and 41 calcifications. Fifteen (25%) of 60 lesions upgraded from initial BI‐RADS 3 assessment were malignant (1.47% of total; 15/1,017 BI‐RADS 3 studies). Malignancy rates by upgraded lesion type showed no significant difference: Thirty‐three (73.3%) of 45 benign upgraded lesions were calcifications compared to 8 (53.3%) of 15 malignant upgraded lesions (p = 0.202). Twelve (26.7%) of 45 benign upgraded lesions were masses or focal asymmetries, compared to 7 (46.7%) of 15 upgraded malignant lesions (p = 0.202). Six (85.7%) of 7 malignant upgraded masses/focal asymmetries had no US correlate at initial BI‐RADS 3 assessment compared to 7 (58.3%) of 12 benign upgraded masses/focal asymmetries (p = 0.33). Breast‐imaging specialists interpreted 21 studies, 3 (14.3%) malignant; general radiologists interpreted 39 studies, 12 (30.8%) malignant (p = 0.218). There was no significant difference in malignancy rate among different types of upgraded mammographic lesions, nor depending on subspecialty interpretation versus nonsubspecialist interpretation. Although calcifications made up a majority of upgraded lesions, most were benign, suggesting that decreased surveillance of calcifications may be appropriate.

Interobserver variability in upgraded and non-upgraded BI-RADS 3 lesions

AIM To evaluate interobserver variability in the assessment of Breast Imaging-Reporting and Data System (BI-RADS) 3 mammographic lesions, and to determine if the initial evaluation of upgraded BI-RADS 3 lesions was appropriate. MATERIALS AND METHODS Retrospective review of the mammography database (1/1/2004-12/31/2008) identified 1,188 screen-detected BI-RADS 3 lesions, 60 (5.1%) were upgraded to BI-RADS 4/5 during surveillance (cases). Cases were matched to 60 non-upgraded BI-RADS 3 lesions (controls) by lesion type, laterality, and year. Available studies were assessed separately by two radiologists blinded to outcomes. RESULTS Eighty-two studies were available (43 cases, eight malignancies, and 39 controls). Reader 1 assessed 18/82 (22%) as BI-RADS 0, 13 cases, five controls; 35/82 (42.7%) as BI-RADS 2, 11 cases, 24 controls; 7/82 (8.5%) BI-RADS 3, four cases, three controls; 22/82 BI-RADS 4, 15 cases, seven controls. Reader 2 assessed 8/82 (9.8%) as BI-RADS 0, four cases, four controls; 27 (32.9%) BI-RADS 2, 11 cases, 16 controls; 33 (40.2%) BI-RADS 3, 19 cases, 14 controls; 14 (17%) BI-RADS 4, nine cases, five controls. For cancers, reader 1 assessed two BI-RADS 0, one BI-RADS 2, one BI-RADS 3, and four BI-RADS 4; reader 2 assessed two BI-RADS 2, four BI-RADS 3, and two BI-RADS 4. Reasons for BI-RADS 0 assessment included incomplete mammographic views, lack of ultrasound, and failure to include the lesion on follow-up imaging. Reasons for BI-RADS 4 assessment included suspicious morphology or instability. CONCLUSION There is much interobserver variability in the assessment of BI-RADS 3 lesions. Many BI-RADS 3 lesions were judged as incompletely evaluated on blinded review.

Optimizing success and avoiding mishaps in the most difficult image guided breast biopsies

Breast cancer is an increasing challenge in developed and limited resource areas of the world. Early detection of breast cancer offers the best chance for optimal care and best outcomes. A critical step in early detection is to obtain efficient and accurate tissue diagnoses. Although image-guided core needle breast biopsies are usually straightforward for experienced breast imagers, there are some not uncommon scenarios that present particular challenges. In this review article we will discuss these difficult situations and offer our tried and true methods to ensure safe and successful biopsies, while using stereotactic, ultrasound, and MRI guidance.

Distinguishing papillary endothelial hyperplasia and angiosarcoma on core needle biopsy of the breast: The importance of clinical and radiologic correlation

Papillary endothelial hyperplasia (PEH) is a rare non‐neoplastic exuberant organizing hematoma that can closely mimic angiosarcoma due to a resemblance to malignant anastomosing blood vessels. It could be particularly difficult to distinguish PEH from angiosarcoma in breast core needle biopsies. We identified all cases of these lesions diagnosed on core needle biopsy in order to identify clinical, radiologic, and pathologic features that could prove helpful to arrive at the correct diagnosis. Four cases of PEH and 4 cases of angiosarcoma were identified. The mean age at diagnosis was 62 for PEH and 33 for primary angiosarcoma. All cases of PEH formed small masses with circumscribed or lobulated margins by imaging (mean size 0.9 cm). In 3 cases, the masses were difficult or impossible to identify after the biopsy. Angiosarcomas presented as larger masses with ill‐defined margins (mean size 2.8 cm) that were unchanged in size after biopsy. PEH was surrounded by adipose tissue, whereas angiosarcoma invaded into fibrous stroma and involved lobules. The pseudopapillary structures of PEH were composed mainly of collagen, and thus, additional histologic stains for fibrin were not helpful for diagnosis. The 4 patients with PEH received no further treatment and are alive and disease‐free at 2‐11 years of follow‐up. In contrast, the patients with angiosarcoma underwent mastectomy and chemotherapy or radiation therapy. Two of the patients with angiosarcoma died 3 years after diagnosis and the other 2 patients are alive without disease at 5 and 6 years. Therefore, distinguishing PEH and angiosarcoma is essential for appropriate management. This is the first series to compare these lesions on core needle biopsy and the first to note important clinical, imaging, and histologic differences that aid in making a diagnosis of PEH with confidence on breast core needle biopsy.

Avoiding Pitfalls, Maximizing Success at Image-guided Breast Interventions: A Pictorial Review

Imaging and image-guided interventions have become increasingly important in the workup and treatment of breast lesions in the past 2 decades. Radiologists should be aware of potential pitfalls during the workup, the procedure itself, and in the postprocedure follow-up. In this pictorial review, we illustrate challenges related to technique and interpretation related to breast interventions, and suggest ways to maximize success.

Reply: Letter to the Editor

To the editor: We thank Dr. Syed Ali for commenting on our article and appreciate the opportunity to clarify some of the issues raised. Firstly, the pathology recorded for each of the lesions in Tables 1 and 2 reflect the final histologic diagnosis, whether the lesion was surgically excised (malignant/ADH/discordant on core biopsy) or benign and concordant following core biopsy with no surgical treatment performed. We agree that ADH is a high-risk lesion that must be excised upon diagnosis by core biopsy. We included our ADH cases in the “benign upgrade” category because these lesions were not upgraded on surgical excision. At our institution, our standard of practice is to perform stereotactic core biopsy with a 9-gauge vacuum-assisted needle for calcifications and for noncalcified lesions such as architectural distortion and focal asymmetries which are best characterized mammographically. Masses clearly seen on ultrasound undergo a core-needle biopsy under ultrasound guidance with a 14-gauge spring-loaded needle. We find that sampling masses with a 14-gauge needle provides adequate sampling and do not think that routinely using a vacuum-assist needle for such lesions would affect our results. Lastly, regarding the descriptors for the lesions, these were the characteristics given by the prospective radiologist at the initial BI-RADS 3 assessment. As the prospective reader believed that the lesions in question were probably benign, it is appropriate that no suspicious descriptors were used even for the malignant upgrades.