Imaging of breast cancer-beyond the basics.

Imaging of breast cancer is the backbone of breast cancer screening, diagnosis, preoperative/treatment assessment and follow-up. The main modalities are mammography, ultrasound and magnetic resonance imaging, each with its own advantages and disadvantages. New emerging technologies have also enabled each modality to improve on their weaknesses. Imaging-guided biopsies have allowed for accurate diagnosis of breast cancer, with low complication rates. The purpose of this article is to review the common modalities for breast cancer imaging in current practice with emphasis on the strengths and potential weaknesses, discuss the selection of the best imaging modality for the specific clinical question or patient population, and explore new technologies / future directions of breast cancer imaging.

Incidental Gonadal Vein Thrombosis Diagnosed Using Computed Tomography Imaging: A Single-Center, Retrospective, Cohort Study.

Objectives Gonadal vein thrombosis is an uncommon but serious condition that can be fatal if it goes unnoticed. Up to 80% of cases occur in patients after delivery, hysterectomy, or lymphadenectomy for gynecological neoplasms. The objective of this study was to determine the incidence of gonadal vein thrombosis using computed tomography (CT) imaging at our center and to describe associated risk factors. Methods A retrospective, single-center, observational study was conducted at King Abdulaziz Medical City in Jeddah, Saudi Arabia. Data were collected for all patients diagnosed with incidental gonadal-vein-thrombosis using contrast-enhanced computed tomography imaging of the abdomen and pelvis between January 2005 and December 2017. We included all patients with incidental findings of gonadal vein thrombosis and excluded those with incomplete data. Results In total, 58/68,268 (0.08%) patients were included. Fifty-seven patients were females, and only one was male. The mean age (years) of the patients was 50.0±15.0 (range 4-87). Thirty-four patients (59%) had right gonadal vein thrombosis, 20 (34%) had thrombosis on the left side, and four (7%) had bilateral thrombosis. Nineteen patients (33%) had undergone pelvic surgery previously. Forty-four patients (76%) had a malignancy at the time of diagnosis. Forty-two patients (72%) were treated with anticoagulants after the diagnosis. Conclusion Gonadal vein thrombosis is a rare clinical entity with vague clinical presentation. The incidence in the oncology population is similar to the reported incidence in the obstetric population. Initiation of anticoagulation therapy is important to treat this condition and limit complications.

Is there any added value to substitute the 2D digital MLO projection for a MLO tomosynthesis projection and its synthetic view when a 2D standard digital mammography is used in a one-stop-shop immediate reading mammography screening?

OBJECTIVES: Breast cancer screening consists of batch interpretation of two-view (cranio-caudal CC- and medio-lateral oblique MLO) digital mammography (DM) per breast. The DM-MLO view was substituted by an MLO-digital breast tomosynthesis (DBT) and its synthetic (2D-synthetic mammography (SM)-MLO) view. The performance of this hybrid protocol was evaluated in a one-stop-shop screening visit, providing immediate reading and additional work up. METHODS: Retrospective, observational review, comparing the cancer detection rate (CDR), breast US rates, and biopsy rates in 13,048 women screened with DM from June 2015 to November 2016 and 8639 women screened with SM-DBT/DM from January 2017 to July 2018. Chi-square tests or Fisher's exact tests were used to compare proportions between the two screening imaging methods. RESULTS: SM + DBT/DM significantly increased the overall CDR (10.8‰) versus DM (7.5‰) (p = 0.0120) with more invasive lobular carcinoma (14% versus 4%) (p = 0.0357) detected and overall more invasive cancers among women with breast density type B (p = 0.0411) and those aged between 60 and 70 (p = 0.0306). This was achieved at the expense of additional sonographic examinations performed (33.5% in DBT group versus 26.7% in DM group) (p < 0.0001), more BI-RADS category III assigned (1.8% in SM-DBT/DM group versus 1.5% in DM group) (p = 0.0443) and more biopsy rates (3.0 % in SM-DBT/DM group versus 1.7% in DM group) (p < 0.0001). CONCLUSIONS: Hybrid mammographic protocol replacing 2D-MLO by DBT-MLO and SM-MLO views in a one-stop-shop screening visit improved CDR, at the expense of more sonographic examinations, biopsies, and BI-RADS III lesions. Breast US alone detected 9.2% of all breast cancers in this cohort. KEY POINTS: • Hybrid protocol including MLO (DBT + SM) with 2D DM CC may improve CDR compared to standard 4 views 2D DM in a screening program providing immediate interpretation. • Adding screening breast US, when perceived necessary, in the same visit of a screening mammography, increases cancer detection rate of 9.2%. • Based on our results, hybrid protocol including DBT + SM in MLO plane and DM in CC plane could be safely implemented as a transition towards DBT and SM alone, without any compromise in the cancer detection ability. Our results may vary according to the properties of machines from different vendors.

Unusual Male Breast Lesions.

Most of male breast masses are benign with gynecomastia being the most common entity encountered. Primary male breast cancer accounts for less than 1% of the total number of breast cancer. Male breast can be affected by a variety of conditions affecting the female breast with less frequency due to the lack of hormonal influence and consequent glandular sub-development. Imaging features of male breast masses are quite similar to the female breast. Therefore, using the knowledge of the female breast and applying it may help in the diagnosis and management of male breast abnormalities. In this article, we aim to review a variety of unusual male breast masses. We discuss the demographics of male breast tumors, describe the diagnostic algorithm for evaluating male breast masses, and review the imaging features of rare breast masses and mimickers of male breast cancer.

Breast MRI Does Not Help Differentiating Radial Scar With and Without Associated Atypia or Malignancy.

PURPOSE: To review breast magnetic resonance imaging (MRI) features of radial scar (RS) with and without associated atypia/malignancy. METHODS: Twenty-eight (mean age 56.8) patients diagnosed with 30 biopsy-proven RS (n = 25, ultrasound-guided 14-gauge, n = 5, stereotactically guided 9-gauge) subsequently underwent breast MRI followed by surgery. Magnetic resonance imaging protocol included axial T1, axial fat sat T2, and postgadolinium in axial and sagittal planes. Two radiologists reviewed the mammographic and MRI findings in consensus according to the Breast Imaging Reporting and Data System lexicon. RESULTS: Of the 30 RSs excised surgically, 14 (14/30, 47.7%) were not associated with atypia/malignancy while atypia/malignancy was found in 16 (16/30, 53.3%) RSs. Three (3/30, 10%) RS lesions did not enhance on dynamic MR. Mean lesion size on MRI was 1.4 cm (range, 0.5-5 cm). Seventeen (17/30, 56.7%) lesions presented as nonmass enhancement and 9 (9/30, 30%) as masses. Nonmass lesions showed focal distribution (13/17, 76.5%) and heterogeneous enhancement (15/17, 88.2%). Masses showed irregular shape and margins (6/9, 67%) and heterogeneous enhancement (8/9, 89%). Multivariate analysis did not show any significant difference in MRI presentation between RS only and RS associated with atypia/malignancy. CONCLUSION: Breast MRI does not help differentiate between RS with or without associated atypia/malignancy.

Case 285: Primary Breast Lymphoma.

History A 25-year-old woman was referred to our breast clinic for assessment of a palpable mass in her left breast that developed quickly in 2 weeks. She denied any associated fever, chills, redness, or pain. She had no relevant medical or surgical history; no evidence of recent pregnancy, abortion, or breastfeeding; and no family history of breast cancer. Clinical examination enabled confirmation of a firm mass occupying the retroareolar region and the outer quadrant of the left breast with no skin retraction, edema, or erythema. There was no evidence of enlarged axillary lymph nodes. US of the left breast, bilateral breast MRI, and fluorine 18 (18F) fluorodeoxyglucose (FDG) PET/CT were performed.

Outcomes of Multidetector Computed Tomography Pulmonary Angiography in Pregnant and Postpartum Women With Suspected Pulmonary Embolism.

PURPOSE: Verify whether there is a difference in likelihood of developing pulmonary embolism (PE) between pregnant women, nonpregnant women of reproductive age, and postpartum (up to 6 weeks) women, by comparing their outcomes on computed tomography pulmonary angiography (CTPA) done for suspicion of PE. MATERIALS AND METHODS: Retrospective cohort study of 1463 CTPA done for suspicion of PE in females of reproductive age (18-40 years), nonpregnant, pregnant (antepartum), and postpartum, from 2 tertiary-care academic hospitals between October 2006 and September 2015. Primary outcome was diagnosis of PE on imaging. Additional assessment was made of technical adequacy of the studies and method of delivery for the postpartum cohort (vaginal vs caesarean birth). Twenty-nine technically nondiagnostic studies were excluded. The effect of any potential variable on PE status was tested using univariate logistic regression. Subgroup analysis was performed after excluding patients with independent risk factors for PE. RESULTS: The rate of CTPA positive for PE was less among pregnant patients compared to early postpartum and nonpregnant women of similar age, 2.9% vs 11.5% and 10.3%, respectively. Pregnancy was associated with statistically significant decreased odds ratio of developing a PE on CTPA, 0.23 (0.09-0.89), P value = .004. After excluding patients with additional independent risk factors for PE, there was no statistically significant odds ratio association between presence of PE on CTPA and pregnancy 0.41 (0.13-1.34), P value = .14. CONCLUSION: Rate of CTPA positive for PE in pregnant women was lower than in nonpregnant and early postpartum women. Pregnancy was statistically significantly less likely to be associated with positive PE on a CTPA study. The common perception that pregnancy (antepartum state) is associated with an increased risk of PE may require a thorough critical reappraisal.

Case 285.

History A 25-year-old woman was referred to our breast clinic for assessment of a palpable mass in her left breast that developed quickly in 2 weeks. She denied any associated fever, chills, redness, or pain. She had no relevant medical or surgical history; no evidence of recent pregnancy, abortion, or breastfeeding; and no family history of breast cancer. Clinical examination enabled confirmation of a firm mass occupying the retroareolar region and the outer quadrant of the left breast with no skin retraction, edema, or erythema. There was no evidence of enlarged axillary lymph nodes. US of the left breast (Fig 1), bilateral breast MRI (Fig 2), and fluorine 18 fluorodeoxyglucose PET/CT (Fig 3) were performed.

Utilization of breast MRI and breast MRI-guided biopsy in clinical practice: results of a survey in Québec and France.

BACKGROUND: To investigate the practice regarding breast MRI exams and breast MRI-guided biopsies in two countries with different health care systems, France and Québec. A 12-item questionnaire was distributed online among radiologists from France and Québec, attempting to determine: demographic characteristics and breast MRI diagnostic and MRI-guided practices (indications, workload, availability, and waiting time assessment). RESULTS: One hundred and seventy radiologists (France, 132 respondents (28.5%); Quebec, 38 respondents (35.2%)) participated in the survey, most of them based in non-academic centers. Thirty-eight percent of Quebec and 2.3% of French radiologists did not perform breast MRI in their daily practice. Nearly 50% of French and Quebec respondents interpreted 1-10 breast MRI exams per week. Decision-making factors of preoperative MRI were similar in both countries (pathology, age, and breast density), with a heavier emphasis placed on the surgeon's opinion in Quebec (47.8% versus 21.8% (p = 0.009)). Quebec demonstrated a higher waiting time than France (1-2 weeks in 40% versus less than 1 week in 40%). MRI-guided breast biopsies (less than 5 MRI-guided biopsies per week) were being performed by a minority of the respondents (36% in France and 43% in Québec). CONCLUSION: Most of radiologists performing breast MRIs work in non-academic institutions in both countries. Waiting time is higher in Quebec, but most of preoperative breast MRIs are performed within 3 weeks in both countries. The surgeon plays an important role in recommending preoperative MRI in Quebec. MRI-guided breast biopsies are not widely available in both countries.

Venous malformation of the pectoral muscle depicted on mammogram.

Venous malformation of the pectoral muscle diagnosed on a mammogram of a 41-year-old patient presenting with clinical suspicion of a gynecomastia.

Value of Shear Wave Elastography for the Differentiation of Benign and Malignant Microcalcifications of the Breast.

OBJECTIVE. The objective of our study was to evaluate whether shear wave elastography (SWE) can differentiate benign from malignant microcalcifications of the breast when detected on ultrasound (US). SUBJECTS AND METHODS. Between February 9, and June 23, 2016, 74 patients with mammographically detected suspicious microcalcifications underwent breast US. When microcalcifications were identified on US, stiffness was assessed using SWE. Biopsy was subsequently performed under US guidance using a 10-gauge vacuum-assisted needle. Qualitative and quantitative elastography results were compared between benign and malignant calcifications as well as between pure ductal carcinoma in situ and lesions with invasive components using the Mann-Whitney U test. ROC curves were created to assess the performance of SWE in detecting malignancy and invasive components. RESULTS. Twenty-nine groups of microcalcifications in 29 patients were identified on US. At pathology, 16 groups were benign and 13 were malignant. Stiffness of malignant calcifications was significantly higher than that of the benign ones (p = 0.0004). The AUC, sensitivity, specificity, negative predictive value, positive predictive value, and accuracy of SWE for the diagnosis of malignancy were 0.89, 69%, 100%, 80%, 100%, and 86%, respectively, and for detection of an invasive component were 0.93, 75%, 100%, 75%, 100%, and 85%. CONCLUSION. SWE has the potential to differentiate benign from malignant micro-calcifications of the breast when detected on US with high specificity.

Can strain elastography improve the characterization of breast lesions identified during second-look MRI-directed sonographic examination?

PURPOSE: To evaluate strain elastography as a complementary tool for characterization of lesions identified during second-look MRI-directed sonographic examination. METHODS: We reviewed 83 breast lesions evaluated with MRI, secondlook ultrasound (US) and strain elastography in 75 consecutive patients (median age, 56 years). US-guided biopsies were performed in all cases. RESULTS: After histopathological examination, 44 lesions were benign, 38 were malignant and 1 was high-risk. At MRI, the mean size of the lesions was 12 mm. Forty lesions (48.2%) appeared as masses, 30 (36.1%) as "non-masses" and 13 (15.7%) as "foci." At second-look US examination, 56 (67.5%) appeared as masses (mean size, 7 mm) and 27 (32.5%) as non-masses (mean size, 14 mm). At strain elastography, among the 39 malignant/high risk lesions, 5 (12.8%) had a score of 4 or 5, whereas 16 (41%) had a score of 1 and 2 (false negative). Among the 44 benign lesions, 36 (82%) had a score of 1 or 2, whereas none had a score of 5. Sensitivity and specificity of strain elastography in the diagnosis of breast cancer were 58% and 81%, respectively. CONCLUSION: The addition of strain elastography offers no benefit in the characterization of lesions identified on second-look US after breast MRI.(E1, 3).

Imaging features of pure and mixed forms of mucinous breast carcinoma with histopathological correlation.

METHODS:: A cross-sectional study identified cases of mucinous breast carcinoma from pathology records (2004-2012). Two radiologists classified imaging features by consensus and two pathologists classified cases into pure or mixed subtypes. Bi-variable analyses were performed using relevant statistical tests. RESULTS:: We identified 80 lesions in 77 female patients (median age 65 years, range 29-88): 58 lesions on mammograhy, 72 on ultrasound, and 25 on MRI. Statistically significant findings (p < 0.05) are as follows. On mammography, tumour margins tended to be indistinct (12, 48%) and spiculated (11, 44%) for pure and mixed lesions, respectively. Pure mucinous masses were less microcalcified (23, 77%) and mixed masses equally so. On ultrasound, pure tumours tended towards an irregular or oval shape (44, 42%) with mixed tumours having an irregular shape (78%). More pure tumours (53%) had posterior acoustic enhancement than mixed lesions (33%), and all pure tumours lacked posterior acoustic shadowing. Pure lesions had a heterogeneous echo pattern more than mixed tumours (78% vs 39%). On MRI, pure tumours tended towards a persistent kinetic curve (42%) whereas mixed tumours predominantly had a washout pattern (75%). Most pure tumours were T2 hyperintense (83%) whereas mixed lesions were T2 isointense or hyperintense (61%, 23%), respectively. CONCLUSION:: An analysis of imaging features can help to infer underlying histology of pure and mixed forms of mucinous breast carcinoma. ADVANCES IN KNOWLEDGE:: Pure mucinous carcinomas present less suspicious imaging features than mixed mucinous carcinomas and could be mistaken for non malignant lesions. An imaging analysis of mucinous breast carcinoma can help infer their underlying histology.

Sonoelastography of retroareolar carcinomas.

PURPOSE: To review the sonographic and elastographic features of retroareolar carcinomas. MATERIALS: Institutional review board approval was obtained. Among 967 sonographically guided biopsies (2013-2014) (14-gauge cores), 53 yielded the diagnosis of retroareolar carcinoma (located less than 2cm from the nipple on mammograms). Out of these 53 lesions, 30 were assessed additionally with strain elastography prior to the biopsy in addition to conventional sonographic analysis. Imaging features were analyzed in consensus by two radiologists. Elasticity score was evaluated by the score defined by Itoh (Tsukuba score). Descriptive analysis was performed. RESULTS: A total of 30 lesions were included (30 patients; mean age, 66.03 (±12.88)). The mean size of the lesions at diagnosis was 23.97mm (±13.64). Sonographically, most of lesions appeared as hypoechoic masses (96.5%, 28/29) displaying an irregular shape (75.9%, 22/29), non parallel orientation (58.6%, 17/29), non circumscribed margins (86.2%, 25/29), posterior attenuation (93.3%, 28/29). Among the 30 lesions, 3.3% (1/30) of lesions appeared as an attenuation and distortion without discrete mass. Most of the lesions were categorized as BI-RADS category 5 (76.7%, 23/30). Approximately half of lesions (53.3%, 16/30) appeared as firm and larger than 2D mode with strain elastography according to the Tsukuba score. CONCLUSION: Retroareolar carcinoma displayed malignant features at US and elastographic examination. In our study population, the addition of elastography to breast US in this location did not improve diagnostic accuracy.

Evaluating the Impact of Breast Density on Preoperative MRI in Invasive Lobular Carcinoma.

BACKGROUND: The focus of this study was to assess the accuracy of breast MRI in predicting pathologic tumor size in invasive lobular carcinoma (ILC) and to evaluate the incidence and factors associated with the detection of additional MRI lesions in ILC patients. STUDY DESIGN: We retrospectively reviewed data from patients with stage I to III ILC diagnosed between 2010 and 2016 at our institution. Univariable and multivariable logistic regression were used to determine factors associated with detection of additional suspicious lesions on MRI. RESULTS: The cohort included 99 women with ILC who underwent preoperative MRI, with a median age of 61 years (range 35 to 80 years). The sensitivity of MRI for detecting invasive lobular carcinoma was 99%, higher than that of mammography (68%) and ultrasound (92%). Mammography and ultrasound had a tendency to underestimate ILC, and MRI estimates of final tumor size were concordant in the majority (58.6%) of cases, with a median discordance of -2 mm. Magnetic resonance imaging detected additional ipsilateral malignancy in 23.2%, occult contralateral disease in 3.0%, and altered surgical management in 29.3% of ILC cases. In multivariable analyses, factors significantly associated with additional suspicious findings on MRI included higher breast density (odds ratio 3.19; 95% CI 1.01 to 10.0) and lymph node-positive disease (odds ratio 4.02; 95% CI 0.96 to 16.9). CONCLUSIONS: Preoperative MRI is a useful adjunct to conventional breast imaging in ILC, particularly in women with dense breast tissue.