Objective: To evaluate and discuss the indications for breast magnetic resonance imaging in an oncology reference center. Materials and Methods: Retrospective study approved by the Committee for Ethics in Research of the institution and developed through a review of patients’ records and clinical reports. All the breast magnetic resonance studies performed in the period from July 2008 to July 2009 (n = 529) were included. Results: Mean patients’ age was 49 years, ranging from 17 to 86 years. Family history of breast and/or ovarian cancer was present in 162 patients (30.6%). Most common indications for breast magnetic resonance imaging included inconclusive mammographic/sonographic findings (48.8%), evaluation of tumor recurrence/surgical scar after breast surgery (15.1%), disease staging/surgical planning (11.7%) and screening in high-risk patients (8.5%). Conclusion: In spite of inconclusive findings at conventional imaging studies being the most common indication for breast magnetic resonance imaging, there is no evidence in the literature supporting such a conduct. Because of its high sensitivity and high rate of false positive results, magnetic resonance imaging should be appropriately indicated in order to avoid unnecessary procedures. Once such method is appropriately indicated, it may contribute in the decision making process, constituting an essential tool in the assessment of breast lesions.

Keywords: Magnetic resonance imaging; Breast neoplasms; Early detection of cancer.

Primary ovarian carcinoma rarely metastasizes to the breast, and few cases are described in the literature. The authors report the case of a patient with ovarian carcinoma that developed breast metastasis eight years after the initial diagnosis, and present a literature review on this subject, emphasizing imaging findings.

Keywords: Ovarian carcinoma; Breast metastasis; Imaging findings.

OBJECTIVE: To correlate the results of ¹⁸F-fluoro-2-deoxy-D-glucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT) performed with a specific protocol for assessment of breasts with histological/immunohistochemical findings in breast carcinoma patients. MATERIALS AND METHODS: Cross-sectional study with prospective data collection, where patients with biopsy-confirmed breast carcinomas were studied. The patients underwent PET/CT examination in prone position, with a specific protocol for assessment of breasts. PET/CT findings were compared with histological and immunohistochemical data. RESULTS: The authors identified 59 malignant breast lesions in 50 patients. The maximum diameter of the lesions ranged from 6 to 80 mm (mean: 32.2 mm). Invasive ductal carcinoma was the most common histological type (n = 47; 79.7%). At PET/CT, 53 (89.8%) of the lesions demonstrated anomalous concentrations of ¹⁸F-FDG, with maximum SUV ranging from 0.8 to 23.1 (mean: 5.5). A statistically significant association was observed between higher values of maximum SUV and histological type, histological grade, molecular subtype, tumor diameter, mitotic index and Ki-67 expression. CONCLUSION: PET/CT performed with specific protocol for assessment of breasts has demonstrated good sensitivity and was associated with relevant histological/immunohistochemical factors related to aggressiveness and prognosis of breast carcinomas.

Keywords: Breast cancer; PET/CT; Histology.

Hyperechoic lesions are not a frequent finding at breasts ultrasonography, and most of times are associated with benign pathologies that do not require further evaluation. However, some neoplasms such as invasive breast carcinomas and metastases may present with hyperechogenicity. Thus, the knowledge about differential diagnoses and identification of signs of lesion aggressiveness are of great relevance to avoid unnecessary procedures or underdiagnosis, and to support the correct clinical/surgical approach. On the basis of such concepts, the present essay describes and illustrates the main features of hyperechoic lesions at breast ultrasonography in different cases, with anatomopathological correlation.

Keywords: Hyperechoic breast lesions; Ultrasonography; Breast neoplasms; Differential diagnosis.

OBJECTIVE: To assess the role of magnetic resonance imaging (MRI) in the planning of breast cancer treatment strategies. MATERIALS AND METHODS: The study included 160 women diagnosed with breast cancer, who underwent breast MRI for preoperative staging. Using Pearson's correlation coefficient (r), we compared the size of the primary tumor, as determined by MRI, by conventional imaging (mammography and ultrasound), and in the pathological examination (gold standard). The identification of lesions not identified in previous examinations was also evaluated, as was its influence on treatment planning. RESULTS: The mean age of the patients was 52.2 years (range, 30–81 years), and the most common histological type was invasive ductal carcinoma (in 60.6% of the patients). In terms of the tumor size determined, MRI correlated better with the pathological examination than did mammography (r = 0.872 vs. 0.710) or ultrasound (r = 0.836 vs. 0.704). MRI identified additional lesions in 53 patients (33.1%), including malignant lesions in 20 (12.5%), which led to change in the therapeutic planning in 23 patients (14.4%). CONCLUSION: Breast MRI proved to be more accurate than conventional imaging in determining the dimensions of the main tumor and was able to identify lesions not identified by other methods evaluated, which altered the therapeutic planning in a significant proportion of cases.

Keywords: Breast neoplasms; Neoplasm staging; Magnetic resonance imaging.

OBJECTIVE: To assess the role of diffusion-weighted imaging (DWI) in the evaluation of breast lesions classified as suspicious on magnetic resonance imaging (MRI), correlating the findings with the results of the histological analysis. MATERIALS AND METHODS: This was a retrospective, descriptive study based on a review of the medical records of 215 patients who were submitted to MRI with DWI before undergoing biopsy at a cancer center. Apparent diffusion coefficient (ADC) values were calculated for each lesion, and the result of the histological analysis was considered the gold standard. RESULTS: The mean age was 49 years. We identified 252 lesions, 161 (63.9%) of which were found to be malignant in the histological analysis. The mean ADC value was higher for the benign lesions than for the malignant lesions (1.50 × 10^–3 mm²/s vs. 0.97 × 10⁻³ mm²/s), the difference being statistically significant (p < 0.001). The ADC cut-off point with the greatest sensitivity and specificity on the receiver operating characteristic curve was 1.03 × 10⁻³ mm²/s. When the DWI and conventional MRI findings were combined, the accuracy reached 95.9%, with a sensitivity of 95.7% and a specificity of 96.4%. CONCLUSION: The use of DWI could facilitate the characterization of breast lesions, especially those classified as BI-RADS 4, increasing the specificity and diagnostic accuracy of MRI.

Keywords: Breast neoplasms; Mammography; Ultrasonography, mammary; Magnetic resonance imaging.

OBJECTIVE: To assess the impact of magnetic resonance imaging (MRI) on the locoregional staging of breast cancer. MATERIALS AND METHODS: We evaluated 61 patients with breast cancer who underwent pre-treatment breast MRI, between August 2015 and April 2016. An experienced breast surgeon determined the surgical treatment, on the basis of the findings of conventional imaging examinations, and made a subsequent treatment recommendation based on the MRI findings, then determining whether the MRI changed the approach, as well as whether it had a positive or negative impact on the treatment. RESULTS: The mean age was 50.8 years (standard deviation, 12.0 years). The most common histological type was invasive breast carcinoma of no special type (in 68.9%), and the most common molecular subtype was luminal B (in 45.9%). Breast MRI modified the therapeutic management in 23.0% of the cases evaluated, having a positive impact in 82.7%. CONCLUSION: Breast MRI is an useful tool for the locoregional staging of breast cancer, because it provides useful information that can have a positive impact on patient treatment.

Keywords: Breast neoplasms; Magnetic resonance imaging; Neoplasm staging; Breast/diagnostic imaging.

OBJECTIVE: To evaluate the accuracy of magnetic resonance imaging (MRI) of the breasts in the identification of a pathological complete response in patients with breast cancer undergoing neoadjuvant chemotherapy (NAC). MATERIALS AND METHODS: This was a single-center, retrospective, observational study designed to validate a diagnostic test. The following variables were evaluated: age; results of the histological and immunohistochemical analysis of the biopsy; post-NAC MRI findings; and results of the histological analysis of the surgical specimen, using the residual cancer burden index. The radiological response, as assessed by MRI, was compared with the pathological response, as assessed by histological analysis of the surgical specimen (the gold standard method). RESULTS: We evaluated 310 tumors in 308 patients. The mean age of the patients was 47 years (range, 27–85 years). For identifying a pathological complete response, breast MRI had an overall accuracy of 79%, with a sensitivity of 75%, specificity of 83%, positive predictive value of 75%, and negative predictive value of 83%. When that accuracy was stratified by molecular subtype, it was best for the HER2 subtype, with a sensitivity and specificity of 82% and 89%, respectively, followed by the triple-negative subtype, with a sensitivity and specificity of 78% and 83%, respectively. CONCLUSION: Breast MRI showed good accuracy in the prediction of a pathological complete response after NAC. The sensitivity and positive predictive value were highest for the HER2 and triple-negative subtypes.

Keywords: Breast neoplasms; Drug therapy, combination; Magnetic resonance imaging; Triple negative breast neoplasms; Receptor, ErbB-2.