Seeding of tumour cells following breast biopsy: a literature review

This literature review examines evidence relating to needle biopsy of the breast and the potential for later tumour cell migration into adjacent tissues.


Introduction
Our screening programme has been fully digital since April 2009 and utilises a combination of computed radiography (CR) (Fuji Profect) and three direct digital mammography (DDM) mammographic systems (Fuji Amulet, GE DS and GE Essential). This study compares the performance of our CR and DDM systems against fi lm screen (FS) mammography in a real-life screening environment. Methods Southern Derbyshire screening episodes between April 2007 and April 2010 were interrogated on NBSS using a Crystal report. Recall and cancer detection rates were collected according to mammography type. Data were analysed for signifi cance using the chi-squared test. Results A total of 66,989 screening episodes were recorded, 22,039 FS (recall rate 3.23%, cancer detection 8.08/1,000), 30,739 CR (recall rate 2.73%, cancer detection 7.87/1,000) and 14,157 DDM (recall rate 3.87%, cancer detection 9.89/1,000). Recall rates compared with FS were statistically signifi cantly diff erent for CR (P = 0.0007) and DDM (P = 0.0016). Cancer detection rates compared with FS mammography were not signifi cantly diff erent for either CR (P = 0.833) or DDM (P = 0.081), although there was a signifi cant diff erence found between CR and DDM (P = 0.035). Conclusions DDM in our programme has detected an increased number of cancers but at an increased recall rate. CR has detected a similar number of cancers as FS mammography at a lower recall rate and the study supports the use of CR in our programme. As an interim measure in changing to a fully DDM service it has allowed us to spread costs whilst adopting a single digital workfl ow, which is effi cient and safe for our clients.
Introduction As a part of a retrospective study of computer-aided detection in breast cancer screening, we recorded the percentage of the breast density on a visual analogue scale on 4,866 routine screening mammograms taken in 1996 as part of the North East of Scotland Breast Screening Service. In these women, 284 breast cancers were diagnosed from the time of the original mammograms up until February 2010. Methods The main goal was to evaluate breast density as a breast cancer risk factor by detection mode, histology and time since the original mammogram. The association of density with risk of breast cancer was assessed using logistic regression giving odds ratios per 10% increase in density, and by comparison of continuous mean densities between particular groups of cancers and those who did not develop breast cancer. Results After adjusting for age, breast density was signifi cantly associated with cancer in the fi rst 6 years after the original mammogram (OR per 10% density = 1.08, 95% CI = 1.01 to 1.15, P = 0.03), but not with cancer more than 6 years after the mammogram (OR = 1.01, 95% CI = 0.93 to 1.10, P = 0.8).
There was a statistically signifi cant association between histological type of tumour and breast density (P = 0.02). The mean densities for no cancer, invasive ductal carcinoma, DCIS and invasive lobular carcinoma were 32% (SD 23%), 33% (21%), 35% (26%) and 44% (24%), respectively. The eff ect of density on risk varied signifi cantly by detection mode (P = 0.02), with highest densities being observed in interval cancers arising more than 1 year after the mammogram (55% compared with 32% in those with no cancer). Conclusions Breast density as measured by visual analogue assessment is strongly associated with late interval cancers and with lobular carcinoma. Its predictive value for risk, however, declines with time since its measurement.
Introduction Flat epithelial atypia (FEA) is seen with increasing frequency following biopsy of calcifi cation detected through screening. FEA is often associated with more signifi cant lesions including atypical ductal hyperplasia and ductal carcinoma in situ (DCIS). It is postulated that FEA may even represent the earliest morphological manifestation of DCIS and a precursor to invasive carcinoma. However, the signifi cance of pure FEA still remains unclear. We aim to review the radiological and pathological features of FEA and evaluate the signifi cance of FEA on needle core biopsy. Methods We performed a retrospective analysis of all needle core biopsies containing FEA in the pathology database from April 2008 to April 2010. For each case the following data were recorded: mammographic features, method of further sampling (mammotome or diagnostic surgical biopsy) and histology from needle core biopsy, mammotome biopsy and surgical biopsy. Results There were 35 needle core biopsies that contained pure FEA, of which 89% (31/35) were associated with mammographic calcifi cation. Following initial core biopsy, 21 patients had further sampling with mammotome biopsy, 13 patients underwent diagnostic surgical biopsy and one patient was not suitable for further intervention. There was an upgrade to DCIS in 18% (6/34) and invasive carcinoma in 3% (1/34). Conclusions Pure FEA on core biopsy is upgraded to carcinoma in 21% (7/34) of cases on further sampling and it is vital that we do not underestimate the biological signifi cance of FEA. Increasing the awareness of FEA is crucial to ensure consistent and appropriate patient management.
Purpose To assess the diagnostic performance of computer-aided detection (CAD) for full-fi eld digital mammography (FFDM) correlated with breast density assessed by an automated breast density measurement system (Hologic, Quantra) in breast cancers and age-matched healthy controls. Materials and methods Two hundred breast cancers imaged with FFDM and 200 age-matched healthy controls were evaluated retrospectively using CAD. A CAD mark was scored true-positive if it correctly indicated a malignant lesion. All other CAD marks were considered false. CAD sensitivity and specifi city were calculated and correlated with mammographic breast density (%). Results CAD correctly identifi ed 157 of the 200 cancers, a sensitivity of 79%. Sensitivity was suggestively but nonsignifi cantly lower with increased density (P = 0.09). In those cancer cases with density at or below the median of 20%, sensitivity was 82%, compared with 75% in those with density above the median. The presence of one or more false CAD prompts was suggestively but not signifi cantly more likely in controls than cases (87% vs. 80%, P = 0.06). The number of false prompts was signifi cantly higher in controls (average 3.6 vs. 2.6, P <0.001). False prompts were signifi cantly less likely with higher density (P = 0.008). False prompts were present in 86% of cases and controls with density at or below the median, and in 81% of those with density above the median. Conclusions Increased breast density is signifi cantly associated with higher specifi city of CAD, and there is suggestive evidence that it is also associated with lower sensitivity.

Introduction
There is debate about the role and optimal organisation of follow-up following treatment for primary breast cancer. We estimated using the best available evidence whether early detection by surveillance of ipsilateral breast tumour recurrence (IBTR) and metachronous contralateral breast cancer (MCBC) was cost-eff ective. Methods An economic model compared alternative surveillance strategies involving mammographic surveillance and/or clinical follow-up performed at diff ering surveillance intervals. The model structure was based upon discussions with the clinical experts involved in the study, a survey of UK breast surgeons and radiologists, and the literature. Data to populate the model came from a series of systematic reviews and an analysis of the West Midlands Cancer Intelligence Unit Breast Cancer Registry. Results of the model were presented as incremental cost per QALYs -a measure of relative effi ciency. Results The surveillance strategy most likely to be cost-eff ective was mammographic surveillance alone provided every 12 to 24 months. This result held for women who had previously received either breast-conserving surgery or mastectomy. Results were sensitive to primary tumour characteristics (size, Introduction Women over 70 have poorer breast cancer survival than younger women, and this may be due to late stage at presentation [1]. Promoting early presentation with symptoms in older women attending for their fi nal round of breast screening may reduce stage at diagnosis costeff ectively, and is unlikely to lead to overdiagnosis. We tested the effi cacy of the 10-minute radiographer-delivered Promoting Early Presentation (PEP) Intervention to promote early presentation by increasing breast cancer awareness in the NHS Breast Screening Programme. Methods We randomised 867 women attending their fi nal round of screening to receive the PEP Intervention or usual care, measuring breast cancer awareness at baseline and 1 year. We systematically reviewed the evidence of eff ectiveness of interventions to promote cancer awareness and early presentation. Results At 1 year, the intervention increased the proportion breast cancer aware compared with usual care (24% vs. 4%; odds ratio = 15.2, 95% CI = 4.8 to 47.8). The systematic review found one randomised trial of a one-to-one intervention that showed a much smaller eff ect on breast cancer awareness.

Conclusions
The PEP Intervention is more eff ective than any other intervention to promote breast cancer awareness. It will now be off ered to all women attending for a fi nal mammogram in three NHS breast screening services, to assess costs and feasibility and to measure its eff ect on breast cancer awareness in routine clinical practice. If implemented across the whole Programme, the PEP Intervention has the potential to reduce avoidable deaths from delayed symptomatic presentation in older women. Introduction Velindre Cancer Centre (VCC), Cardiff provides radiotherapy and oncology services to the population of 1.5 million across southeast Wales. Historically at Velindre, breast cancer patients are followed up for at least 10 years, with annual mammography underpinning the service. The optimal length for continued annual surveillance has been debated and reduction to 5 years follow-up suggested. Therefore, a retrospective audit of breast cancers diagnosed on follow-up mammograms was undertaken to support the proposed reduced length of mammographic follow-up. Methods Using the RIS and HIS electronic databases, follow-up mammograms over a 3-year period from 1 June 2006 to 31 May 2009 were collected and their report codes checked. All mammogram reports are coded using the Breast Imaging Reporting and Data System (BI-RADS). All mammograms coded 3 and above were identifi ed. Subsequent radiological and histological reports were reviewed to identify confi rmed malignancies.

Results
In this 3-year period, there were 6,294 follow-up mammogram examinations at VCC. Ninety-seven reports were coded 3 or above (1.5%). Fifty-six new malignancies were confi rmed. Of these, 44 (79%) occurred more than 5 years from original diagnosis.

Conclusions
The results do not support reducing the length of follow-up to 5 years. Further analysis of original pathology will be undertaken to attempt to risk-stratify patients and thus allow tailored follow-up regimes to be developed. Introduction ShearWave™ elastography (SWE) provides a quantitative measure ment of tissue stiff ness with high spatial resolution and may improve characterization of breast masses. The goal of this study was to evaluate the reproducibility of SWE and the impact of adding SWE features to the BI-RADS classifi cation of breast masses from the fi rst 1,000 cases in a prospective multicenter trial.

An investigation of workstation image manipulation usage when examining FFDM images
Methods SWE studies were performed on a prototype of the Aixplorer system (Supersonic Imagine, Aix-en-Provence, France). A subset of 192 breast lesions (42.71% malignant) was analyzed. Reproducibility of SWE images and measurements was assessed; logistic regression analysis was performed to predict the pathology fi ndings. SWE features were added to the ultrasound BI-RADS to generate models that were challenged by comparing the areas under the ROC curves (Az), and the sensitivity and specifi city scores.

Results
In the preliminary analysis, intra-operator reproducibility of SWE size (R ≥0.93) and mean elasticity (R = 0.88) measurements were in near-perfect agreement. Using the best three-variable model (BIRADS + elasticity shape + maximum elasticity), the Az increased from 0.77 to 0.93 and specifi city increased from 61.8% to 87.3%, although sensitivity decreased from 92.7% to 87.8%. Adding more variables did not eff ect further improvements.
Conclusions In this ongoing study, SWE provided reproducible information (elasticity values and SWE mapping) that improved the characterization of breast lesions. These features are directly linked to the characteristics of SWE: local quantifi cation and millimeter resolution. Further evaluation of the study is in progress.

P11
To Conclusions Macrolane™ injection is associated with long-term complications and creates diagnostic challenges on breast imaging that are only beginning to emerge in the breast clinics and that may warrant triple assessment.

P12
Texture analysis applied to full-fi eld digital mammography: ability to discriminate between invasive ductal and invasive lobular breast cancerpreliminary results M Mayerhoefer 1 , N Perry 2 , S Milner 2 , K Mokbel 2 , S Duff y 3 , K Pinker Introduction Image degradation due to motion artefact in breast MRI represents a diagnostic challenge. Tumours are often detected manually by a radiologist or with computer-aided detection (CAD) systems, which utilise areas of enhancement that meet a predefi ned threshold. The aim of this study was to test a new threshold-independent CAD algorithm and to correlate its fi ndings to the conventional manual analysis.
Methods CAD was tested on retrospectively acquired MRIs of 14 patients with pathologically proven carcinomas. CAD results were obtained in a fully automated manner and the expert was blinded to the CAD fi ndings. Noise artefacts were eliminated with the patient motion reduction algorithm and suspicious tissues were delineated using a novel all-timepoint-based, threshold-independent parametric map approach. The algorithm evaluates the shape of the curve as a whole and uses the noise integral to the image to discriminate malignant from benign tissues. Results All CAD-identifi ed tumours and generated kinetic curves were comparable with those of the manual analysis. In particular, tumour conspicuity was enhanced in two cases where image degradation by motion artefacts made data interpretation challenging to conventional analysis. See Figure 1.
Conclusions CAD results were favourably viewed by experts and 100% correlated to conventional manual tumour detection. In particular, CAD appears to increase tumour conspicuity in cases with motion artefacts. Prospective analysis is required to test this model further. Change to patient management, radiation dose and estimated costs were also collected from the trust patient and imaging information systems and multidisciplinary notes, to assess overall value. Results One-third of patients underwent signifi cant change in medical or surgical management based on hybrid imaging. Overall, >90% of patients surveyed reported higher satisfaction following a 'one-stop' visit. Cost and total radiation dose of combined imaging were more favourable than for single visits.

Educational abstract
Conclusions Whilst hybrid SPECT/CT in breast imaging remains in its infancy, its potential to add value for the clinician and patient is clear. The positive advantages for patient management and convenience/cost suggested in our pilot study suggest it is likely to infl uence future breast cancer management protocols. We identifi ed cases with a 14-gauge core biopsy diagnosis of benign papilloma. Patients with atypia or malignancy on core biopsy were excluded. The imaging features and number of core samples were documented. All patients subsequently underwent lesion excision.
Results Seventy-eight patients had a diagnosis of a benign papilloma on core biopsy. Subsequent excision was with vacuum-assisted biopsy in 48 and surgery in 30. Twenty-eight patients with microcalcifi cation had a stereotactic-guided biopsy. Fifty patients with a mass had ultrasound-guided biopsy. Atypical ductal hyperplasia was found in three out of 28 (11%) who had microcalcifi cation (mean number of 10 cores) and one out of 50 (2%) with a mass (mean number of three cores). Seventy-four (95%) patients had a benign papilloma only.

Conclusions
The NPV for atypia and malignancy of 14-gauge core biopsy of papillomas is 95% in this series. Underestimation of disease is more common in lesions presenting with microcalcifi cation. The current practice of wider sampling of all papillary lesions diagnosed on 14-gauge core biopsy should continue.

Educational abstract
Educational abstract not submitted for online publication.  Following MDT discussion, 60/191 B3 lesions were subjected to a second biopsy (25.5%) and one lesion a third biopsy. These yielded a malignant diagnosis in 11 (18.3%) cases. Lesions successfully upgraded to malignancy included three microcalcifi cation (MCC), three masses, three masses with MCC and one cyst with solid elements. Cancers diagnosed on second biopsies were one invasive ductal, one invasive papillary carcinoma and nine ductal carcinoma in situ (DCIS). All second biopsies were performed using a vacuum device with the initial biopsy method being 14G core biopsy in eight cases and vacuum-assisted in three cases. Second biopsies were therefore equally useful in upgrading MCC and masses and especially useful for DCIS. Conclusions Second-time image-guided biopsies can successfully yield a defi nitive malignant diagnosis in B3 lesions (18.3%) and thus enable therapeutic rather than diagnostic surgery to be undertaken. Second biopsies are equally useful in the management of MCC, masses and masses with MCC.

Educational abstract
Educational abstract not submitted for online publication. Introduction Studies have shown that the combination of MRI and mammography is the most eff ective screening method for women at high risk of carcinoma, resulting in a recommendation from the National Institute for Health and Clinical Excellence (NICE) for annual surveillance MRI. The purpose of this study is to determine the eff ectiveness of screening MRI in this group. Methods A retrospective review was performed of all the patients from our family history clinic who were referred for breast MRI screening in accordance with the NICE guidelines. The study period was from July 2008 to July 2010. The recall rate, biopsy rate and outcome were recorded and analysed. Results A total of 233 scans were performed in 173 patients over the 2-year period. Of these, 38 (16.3%) were recalled for a second-look ultrasound scan (US). Fourteen of these underwent biopsy (6%). US-guided core biopsy in 12 patients confi rmed six cases of invasive ductal carcinoma and six cases of benign pathology. Two cases were referred for MR-guided biopsy, where one case was shown to be DCIS and the other was shown to be fi brocystic change. Overall, there were seven cases (3% of scans or 4% of patients) of malignancy that were all mammographically occult. Nine of the cases (3.9%) had early repeat MRI scans that were unremarkable. Recall for assessment and cancer detection rates were comparable with published data.
Conclusions This study has shown that MRI is an eff ective screening tool in the surveillance of women at high risk of breast carcinoma.

Results
The following indications were found -staging scans in patients with locoregional disease: 22%; equivocal radiology: 17%; specifi c concern of recurrent disease: 17%; diagnostic/therapeutic confl ict with second primary: 15%; staging of locally advanced disease: 11%; response to endocrine or chemotherapy: 9%; stability/speed of progression of metastatic disease: 8%. On reviewing clinical records/follow-up, the results of [ 18 F]FDG PET/ CT in many circumstances gave information about metastatic disease in locoregional recurrence, resolved issues surrounding equivocal radiology and ensured that patients with second operable cancers were not subjected to major surgery only to succumb to their breast metastasis.
Conclusions [ 18 F]FDG PET/CT can give valuable information in patients with breast cancer, particularly in scenarios with equivocal fi ndings on other imaging and regarding disease progression. The technique often contributed to management decisions in complex cases. Conclusions Based upon questionnaire fi ndings and literature review, guidelines have been now been drawn up in our unit. There is great variation evident in UK gynaecomastia imaging practice. National discussion and agreement on evidence-based guidelines could help rationalize use of precious NHS resources and reduce imaging of this benign condition.
Introduction Suspicious microcalcifi cation is investigated by vacuumassisted core biopsy. Many patients, in whom malignancy is diagnosed, go on to have breast-conserving surgery where positive resection margins require re-operation. The aim of this study was to determine whether there is an increased risk of positive margins when malignancy is identifi ed in cores without microcalcifi cation. Methods In this institute, core biopsy samples are separated into those containing calcifi cation and those not. Sixty-eight consecutive patients undergoing breast-conserving surgery were selected. From the histology report, the presence of malignancy in each group of cores was recorded. The adequacy of margins following the local excision and the need for reoperation was then analysed. Results Sixty-eight patients were included in the study. The mean age at diagnosis was 56.7 (range 40 to 77). All 68 patients had malignancy in the cores containing calcifi cation. Twenty-three (34%) patients had malignancy in these cores alone and nine (39%) of these patients required further surgery. Forty-fi ve patients had malignancy in both of the sets of cores, 24 (53%) required further surgery for inadequate margins. Although there is a diff erence between the re-operation rate, this is not statistically signifi cant (P = 0.3124, Fisher's exact test).
Conclusions Malignancy is commonly diagnosed in cores that do not contain microcalcifi cation. Although there appears to be a higher rate of inadequate margins in this group (53% vs. 39%), in this study the diff erence was not statistically signifi cant. Following the fi ndings of this initial study, we are now increasing the sample size of the group.
Introduction During the changeover from analogue to digital screening in the UK, reassurance is needed to confi rm that the outcomes with digital are equal to or better than analogue screening. Results The results show no diff erence in the rates of screen-detected cancer in prevalent or incident groups between analogue and digital, and rates were stable with time. Similar proportions of invasive and non-invasive cancers were detected in both groups and tumour size was not signifi cantly diff erent.

Methods
No signifi cant increase in cancer detection in younger compared with older women was seen in the digital group, and digital did not diagnose a higher proportion of lobular cancers. No diff erence in interval cancer rates between the two methods of screening was seen. On radiological subclassifi cation of interval cancers into normal/benign, uncertain and suspicious, signifi cantly fewer interval cancers were classifi ed as uncertain in the digital than the analogue screening group. See Table 1.
Conclusions These results are reassuring that digital diagnoses similar cancers to analogue screening, and suggest that digital may allow more defi nitive interval cancer classifi cation. Introduction All UK screening personnel are invited to take part annually in the PERFORMS self-assessment scheme where they make several judgements about series of challenging recent screening cases. As part of this process they assess the density of each case. Density is a factor known to be associated with a greater risk of developing breast cancer and thus accurate density judgements may well presage the facility to proff er improved follow-up for individual women. The present study examines the degree of variability amongst fi lm reader estimates of breast density on a large number of cases. Methods Data were examined from the most recent 2 years of the PERFORMS scheme where breast density estimates were made for each case examined using a three-point rating scale of fatty, mixed density, and dense. These data comprised information from 444 individuals (mainly consultant radiologists, advanced practitioners and breast physicians) who had all examined the same 240 diffi cult cases.

Results
The inter-rater reliability, corrected for chance agreements, was assessed using kappa. Overall, the degree of agreement across cases on breast density category was signifi cantly greater than no agreement (P <0.0001). However, only a moderate degree of inter-rater reliability was Conclusions The low agreement rates between participants for density ratings were surprising. That there were diff erences between the occupational groupings may refl ect breast screening experience.

Introduction
The prevalent round recall rate is higher than the incident recall rate. Implementation of age extension will lead to two prevalent rounds and with this increased clinical and fi nancial pressure on screening units. Any processes that help reduce the recall rate will be of benefi t to screening units. Introduction Imaging alone cannot reliably distinguish benign/malignant breast disease or assess the extent of cancer. This study assesses the feasibility of using additional information obtained at US (BHS) to aid diagnosis and preoperative assessment. Methods 3D US scans at 8 MHz, 12 MHz, 15 MHz were obtained of breast tissue in normal volunteers in two planes and with/without harmonics. Five volumes of sagittal scans at 8 MHz from three individuals were used to identify normal characteristics and defi ne the baseline. The 3D volume was divided into voxels (0.1 x 2 x 1.5 mm) and raw data from each voxel were analysed by applying linear and nonlinear classifi ers to assess 29 statistical characteristics (BHS). The training dataset contained 300,000 voxels. After training, the classifi er's output showed 3% error on both normal and abnormal tissue. The algorithm was tested on 32 further volumes representing 6,000,000 voxels of normal and abnormal tissue from 20 individuals. Abnormal tissue included various biopsy-proven lesions: malignancy (six), papilloma (one), hamartoma (one), fi broadenoma (two), cyst (two), fi brosis (one). Subclassifi ers were developed to distinguish between cancer and benign voxels.
Results In 17 normal testing volumes, 3% of isolated voxels were classifi ed as abnormal. In 15 abnormal testing volumes, the subclassifi ers diff erentiated between malignant and benign tissue. BHS in benign tissue showed <1% abnormal voxels in cyst, hamartoma, papilloma and benign fi brosis. The fi broadenomas diff ered showing <5% and <24% abnormal voxels. Abnormal voxels in cancers increased with the volume of cancer at pathology. Conclusions Histoscanning reliably discriminated normal from abnormal tissue and could distinguish between benign and malignant lesions.
Introduction Studies estimate that 10 to 32% of breast cancers are overlooked in mammograms. One of the important causes of interval breast cancer is fatigue and loss of concentration. The likelihood of fatigue increases with the duration of a reporting session and errors are more likely to occur towards the end of the session. The purpose of this talk is to address the lack of awareness of the issues that drive reporting performance. Methods A retrospective study was carried out on interval breast cancers from a 2-year period. This identifi ed 90 histopathologically proven interval breast cancers. Each interval cancer mammogram was reviewed by two blinded consultant radiologists and placed into one of three categories on retrospective radiological review: Category 1: normal; Category 2: uncertain; Category 3: suspicious. Each case was then analysed further to correlate the interval categories with their position on the mammography roller viewer.

Results
Of the 90 interval breast cancers, 59 (66%) were Category 1, 14 (16%) were Category 2 and 17 (18%) were Category 3. Statistical analyses with one-way ANOVA test revealed the presence of clinical signifi cance between Category 3 cases and their position in the roller viewer (P <0.021).
Conclusions Fatigue is identifi ed as an important factor responsible for missing breast cancer. Aside from making changes in double-reporting techniques, human performance factors such as nutrition, rest, behaviour prior to reporting and environment have to be considered. A national programme has to be implemented to facilitate a plan to raise awareness of these factors in the NHS culture. This study was based on the hypothesis that recall of benign solitary masses might be a major contributor to this as no prior imaging is available. Methods Prospectively collected data from Breast Test Wales (South East Wales) identifi ed all prevalent screens in a 3-year cycle recalled for a benign mass lesion confi rmed by core biopsy. All women attended a subsequent screen and remained free of cancer. Mammograms were retrospectively reviewed and the lesions were re-evaluated by applying criteria typical of a benign mass. Results A total of 2,322 women following a prevalent screen were recalled; 2,069 were returned to routine recall without biopsy (cysts are included in this group), 186 were diagnosed with cancer and 105 had a benign biopsy where mammography had been considered benign or probably benign. The benign to malignant biopsy ratio was 1:1.8. A total 46.6% (n = 49) lesions on retrospective review of mammography showed typical benign characteristics. Dense breast composition and overlying glandular tissue were noted to correlate with higher rates of retrospectively indicated recall.

Educational abstract
Conclusions Stricter adherence to applying classifi cation of benign solitary lesions could reduce the recall rate and decrease the psychological distress for these women without adversely compromising the cancer detection rate. The impact on the overall recall rate would be small but would signifi cantly improve the benign to malignant biopsy ratio. The issue of breast density and overlying tissue may be resolved with the advent of digital applications such as tomosynthesis.