Clinically and mammographically occult breast lesions: detection and classification with high-resolution sonography.

With recent significant advances in ultrasound technology, the potential of high-resolution sonography to improve the sensitivity of cancer diagnosis in women with dense breasts has become a matter of interest for breast imagers. To determine how often physician-performed high-resolution sonography can detect nonpalpable breast cancers that are not revealed by mammography, 8,970 women with breast density grades 2 through 4 underwent high-resolution sonography as an adjunct to mammography. All sonographically detected, clinically and mammographically occult breast lesions that were not simple cysts were prospectively classified into benign, indeterminate, or malignant categories. Diagnoses were confirmed by ultrasound-guided fine-needle aspiration, core-needle biopsy, or surgical biopsy. In 8,103 women with normal findings at mammography and physical examination, 32 cancers and 330 benign lesions were detected in 273 patients with sonography only. Eight additional cancers were found in 867 patients with a malignant (n = 5) or a benign (n = 3) palpable or mammographically detected index lesion. The overall prevalence of cancers detected with screening sonography was 0.41%, and the proportion of sonographically detected cancers to the total number of nonpalpable cancers was 22%. The mean size of invasive cancers detected only by sonography was 9.1 mm, and was not statistically different from the mean size of invasive cancers detected by mammography. The sensitivity of prospective sonographic classification for malignancy was 100%, and the specificity was 31%. In conclusion, the use of high-resolution sonography as an adjunct to mammography in women with dense breasts may lead to detection of a significant number of otherwise occult cancers that are no different in size from nonpalpable mammographically detected cancers. Prospective classification of these lesions based on sonographic characteristics resulted in an acceptable benign-to-malignant biopsy rate of 6.3:1.

Incidental findings on sonography of the breast: clinical significance and diagnostic workup.

OBJECTIVE: The purpose of this study was to determine how often physician-performed high-resolution sonography can detect nonpalpable breast lesions not revealed by mammography. A sonographic classification scheme was tested for its accuracy in predicting malignancy of incidentally detected breast lesions. SUBJECTS AND METHODS: Six thousand one hundred thirteen asymptomatic women with breast density grades 2-4 and 687 patients with palpable or mammographically detected breast masses underwent sonography as an adjunct to mammography. All sonographically detected, clinically and mammographically occult breast lesions that were not simple cysts were prospectively classified into benign, indeterminate, or malignant categories. Diagnoses were confirmed by sonographically guided fine-needle aspiration or core needle biopsy. RESULTS: In 6113 asymptomatic women, 23 malignancies in 21 patients were detected with sonography only (prevalence, 0.31%). Five additional malignant lesions were found in patients with a malignant (n = 3) or a benign (n = 2) palpable or mammographically detected index lesion. The mean size of invasive malignancies detected only by sonography was 9.1 mm, which was not significantly different from the mean size of invasive cancers detected by mammography (p = .07). The sensitivity of the prospective sonographic classification for malignancy was 100%, and the specificity was 33.5%. CONCLUSION: The use of high-resolution sonography as an adjunct to mammography in women with dense breasts may lead to detection of a significant number of otherwise occult malignancies that are no different in size from nonpalpable mammographically detected lesions. Prospective classification of these lesions based on sonographic characteristics results in a significant reduction in number of unnecessary biopsies performed.

[Value of MR tomography in inconclusive mammography findings]. / Der Stellenwert der MR-Tomographie beim unklaren Mammographiebefund.

PURPOSE: To evaluate the usefulness of magnetic resonance (MR) imaging in the assessment of inconclusive findings at mammography, such as indeterminate focal or diffuse breast abnormalities, post-treatment breasts with extensive scarring, dense breasts, and findings suggesting multifocal or multicentric breast cancer. MATERIAL AND METHODS: 254 patients underwent mammography, sonography, and MRI of the breast. Dynamic MR imaging was done using a thin-section three-dimensional gradient-echo sequence (FLASH, TR = 11.8 ms; TE = 5 ms; flip angle = 25 degrees) which was applied in a dynamic fashion before and every 90 seconds after injection of gadopentetate dimeglumine. Diagnoses were confirmed at biopsy (n = 165) or by follow-up (n = 89). RESULTS: Among various breast anomalies, the highest proportion of breast cancers was associated with dense breast tissue (27.8%), architectural distortion (26.9%), and irregular scars (15.8%). Sensitivity of dynamic MR imaging was 93.7%, and specificity was 83.3%. As compared to mammography and sonography, MR detected 6 occult carcinomas, and showed additional malignant lesions in 19/63 women (30.2%) with biopsy-proven breast cancer. CONCLUSION: MR imaging of the breast may provide valuable additional information in indeterminate breast anomalies. However, because of its inherent limitations, it should not replace core needle biopsy in all lesions which are amenable to biopsy. Because of its high sensitivity in the detection of invasive carcinomas in any type of breast tissue, MR imaging is considered the modality of choice in the evaluation of dense breasts in high-risk patients or in patients with clinical suspicion of occult breast cancer, and for preoperative tumor staging.