Sonographically occult screen detected breast masses: a retrospective analysis of cases undergoing biopsy

OBJECTIVE: The purpose of this study was to evaluate nonpalpable breast masses identified on mammograms that are sonographically occult. METHODS: The pathology data base at the Woman's Place for Breast Care of the Woman's Hospital of Texas was searched to identify patients who had undergone biopsy for a nonpalpable breast mass identified on mammograms in which a mass was not visible at sonography. RESULTS: There were 32 of 231 such nonpalpable masses that were sonographically occult. Twenty-eight of the masses were histologically benign; four were malignant. CONCLUSION: A small percentage of mammographically visible nonpalpable breast masses are sonographically occult; a majority of these masses are benign. However, biopsy of such masses should be considered and the decision to biopsy based on mammographic features and interval change.     

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.     

Sonographic detection and sonographically guided biopsy of breast microcalcifications

OBJECTIVE: The purpose of this study was to evaluate the ability of sonography to depict and guide biopsies of mammographically suspicious microcalcifications and to reveal the mammographic features and histologic outcomes of lesions amenable to sonographically guided biopsy. SUBJECTS AND METHODS:. Suspicious clusters of microcalcifications without other mammographic abnormalities were evaluated on sonography before biopsy and divided into two groups: those with and those without microcalcifications seen on sonography. Sonographically detected lesions underwent sonographically guided biopsy; lesions not seen on sonography underwent mammographically guided biopsy. Imaging features and histologies were correlated, and the positive predictive value of sonography was determined. RESULTS: Of 111 lesions (105 patients), 26 lesions (23%) were identified and underwent sonographically guided biopsy; 85 lesions (77%) were not identified sonographically. The diameters of microcalcification clusters in the sonographically identified group were significantly larger (p = 0.0005) and contained larger numbers of microcalcification particles (p = 0.038) compared with clusters not identified sonographically. Sonographically identified lesions were seen as masses (77%) or dilated ducts (23%) with echogenic foci. Sonographically identified lesions were more likely to be malignant than those not seen on sonography (69% vs 21%, respectively; p < 0.00002). Of 38 malignant lesions, those visible on sonography were more likely to be invasive than those not seen on sonography (72% vs 28%, respectively; p = 0.018). In malignant lesions undergoing core biopsy and surgical excision, the extent of disease was underestimated less with sonographically guided biopsy (7%, 1/15) than with stereotactic biopsy (33%, 5/15). CONCLUSION: Suspicious microcalcifications are seen infrequently on sonography (23%) but, when detected, can be successfully biopsied with sonographic guidance and more frequently are malignant and represent invasive cancer than those seen on mammography alone.     

Breast sonography

Sonographic equipment for breast imaging has continued to improve, and the role of breast sonography has evolved to that of an indispensable adjunct to mammography. Breast sonography is not useful for screening for breast cancer in any age group. Its main use is for the differentiation of cystic vs solid palpable and mammographically visible masses. If strict sonographic criteria are used for a simple cyst, the diagnostic accuracy approaches 100%. Sonographic diagnosis of a simple cyst precludes the need for further workup, including aspiration, biopsy, or followup. This article emphasizes the technical aspects of breast sonography, especially those factors that alter the diagnostic information on the images. These factors can be especially problematic in differentiating cysts and solid masses, the most common diagnostic use of breast sonography. Selection of equipment depends largely on the requirements of a specific practice. Optimally, the sonographic equipment is located close to where mammography is performed, and the sonographic and mammographic findings are interpreted together.     

Mixed form, diffusely scattered calcifications in breast cancer with apocrine features

Diffusely scattered calcifications visible with mammography are almost always benign. Certain patterns, however, should arouse concern. For example, extensive comedocarcinoma is associated with large areas of mammographically visible calcium deposition. The authors identified 10 women in whom calcifications were visible throughout large volumes of breast tissue at mammography. The calcifications did not resemble those typical of extensive comedocarcinoma, yet they were associated with extensive breast cancer. Their mammographic pattern was characterized by a strikingly wild, chaotic appearance with profuse deposition of calcium. As in many cancers, the particles were heterogeneous, but unlike in most carcinomas, many deposits had a typically benign morphology. Histologic examination showed that even these typically benign calcifications were associated with malignant cells. The authors believe that the apocrine features displayed by many of the cancer cells in these 10 patients may explain the unusual profusion of calcium deposits.     

Metaplastic carcinoma of the breast: clinical,mammographic, and sonographic findings with histopathologic correlation

OBJECTIVE: The purpose of this study was to investigate the mammographic and sonographic findings of metaplastic carcinoma of the breast and to correlate the radiologic features with clinical and histopathologic findings. CONCLUSION: Metaplastic carcinoma of the breast often manifests as a rapidly growing, palpable mass that has high density on mammography and may be microlobulated on sonography. Complex echogenicity with solid and cystic components may be seen sonographically and is related to necrosis and cystic degeneration found histopathologically. Although it is a rare breast malignancy and these features are not unique, metaplastic carcinoma should be included in the differential diagnosis for breast masses with these imaging features.     

Original report. Mucocele-like tumors of the breast: mammographic and sonographic appearances

OBJECTIVE: The purpose of our study was to describe the mammographic and sonographic appearances of the mucocele-like tumor of the breast. CONCLUSION: The mucocele-like tumor is a rare lesion of the breast, the benign form of which has a nonspecific mammographic appearance. The tumor can present as indeterminate microcalcifications or as a nodule, often containing calcifications. The sonographic findings are of multiple well-defined hypoechoic oval or tubular structures with low-level internal echoes resembling complex cysts. Mucocele-like tumors of the breast can be associated with atypical hyperplasia or carcinoma. If a mucocele-like tumor is diagnosed at core needle biopsy, complete surgical excision is recommended, with careful evaluation of the entire specimen to exclude the presence of atypia or carcinoma.     

Granulomatous mastitis: mammographic and sonographic appearances.

OBJECTIVE: The objective of our study is to describe the mammographic and sonographic appearances of granulomatous mastitis. CONCLUSION: Granulomatous mastitis can mimic breast carcinoma clinically and mammographically, but the sonographic appearance of multiple clustered, often contiguous tubular hypoechoic lesions that are sometimes associated with a large hypoechoic mass should suggest the possibility of granulomatous mastitis.     

Occult breast masses: use of a mammographic localizing grid for US evaluation.

To determine if there was a problem of misidentification of mammographically detected masses with freehand ultrasound (US), the authors examined 50 mammographically distinct masses in 47 patients who were scheduled to undergo needle localization. In only six cases were the masses to be localized in an area of the breast that contained other mammographic opacities that could have led to problems of identification. The patients were first studied with freehand US. Results were then compared with those subsequently obtained with a fenestrated mammographic compression grid to guide the US evaluation. Needle localization was then performed. In five of 50 cases, masses detected with freehand US and initially believed to correspond to the mammographically detected mass were subsequently found to represent different areas of the breast when US was used with the compression grid. These results suggest that the potential for misidentification of masses with freehand US is real and that a mammographic grid localization device can be used to overcome this problem.     

Breast cancer: mammographic and sonographic findings after augmentation mammoplasty

The authors retrospectively reviewed 11 cases of breast cancer in patients who had undergone augmentation mammoplasty. The mammogram or sonogram was abnormal in 10 patients, including six with an abnormal mammographic density or ultrasound study and four with calcifications. One patient had dense breasts and no suspicious findings at mammography. In four patients without palpable findings in the breast, the malignancy was initially detected by means of mammography. In five of six patients with a palpable breast mass, special mammographic views and sonography were helpful in evaluating the mass. Lymph nodes were not involved in six (60%) of the 10 patients with ductal carcinomas. The detection of breast cancer in the augmented breast by means of mammography is possible, even in patients without palpable findings. Modified-position views and sonography may be helpful in evaluating palpable masses. Patients with implants who develop cancer do not necessarily present at a more advanced stage.     

Imaging features of metaplastic carcinoma with chondroid differentiation of the breast

OBJECTIVE: The purpose of this study was to evaluate the imaging features--including the mammographic, sonographic, MRI, and bone scintigraphic findings--in 12 patients with metaplastic carcinoma with chondroid differentiation of the breast and to correlate the imaging findings with the pathologic features. CONCLUSION: Metaplastic carcinoma with chondroid differentiation of the breast manifests as a palpable mass and should be included in the differential diagnosis of a large indistinct highdensity mass with amorphous or coarse calcifications on mammography and a relatively circumscribed complex echoic mass with posterior enhancement on sonography. A relatively circumscribed mass with a nonenhancing T2 intermediate- to high-signal-intensity internal component on MRI and an area of intense uptake of 99mTc methylene diphosphonate (MDP) on bone scintigraphy might be useful in suggesting the diagnosis of metaplastic carcinoma with chondroid differentiation.     

Sonographic, mammographic, and histopathologic correlation of symptomatic ductal carcinoma in situ

OBJECTIVE: The purpose of this study was to describe the features of symptomatic ductal carcinoma in situ (DCIS) of the breast shown on high-resolution sonography and to correlate them with findings from mammography and histopathology to evaluate the prognostic ability of sonographic findings. MATERIALS AND METHODS: We retrospectively reviewed mammographic and sonographic images of 60 DCIS lesions from 55 symptomatic women. Images were reviewed by a radiologist who knew that the patients had DCIS but had no other information regarding pathology. Lesions were evaluated pathologically and classified using the Van Nuys classification system. Statistical comparisons were made using Fisher's exact test. RESULTS: Of the 60 lesions, 33 were classified as Van Nuys group 1, 19 as Van Nuys group 2, and eight as Van Nuys group 3. Six (10%) of the 60 lesions were not visible on sonography, and 12 lesions (20%) were not visible on mammography. Sonography revealed a mass in 43 cases (72%), ductal changes in 14 cases (23%), and architectural distortion in four cases (7%). Eight lesions had more than one of these features. A sonographically visualized, irregularly shaped mass with indistinct or angular margins and no posterior acoustic shadowing or enhancement was associated with a high Van Nuys classification (p < 0.05). Microcalcifications were visible on sonography in 13 (22%) of the 60 lesions or on mammography in 25 lesions (42%). Both findings were associated with a high Van Nuys classification (p < 0.05). CONCLUSION: Although sonography can reveal microcalcifications within masses, it is unreliable in depicting and characterizing the morphology and extent of microcalcifications, particularly when they are in isolation. Therefore, sonography should not be used to replace mammography but instead as an adjunctive tool to increase the sensitivity of mammography in breast diagnosis.     

Tubular carcinoma of the breast: mammographic and sonographic features

OBJECTIVE: The purpose of this study was to define specific mammographic and sonographic features of tubular carcinoma of the breast. MATERIALS AND METHODS: Seventeen pathologically confirmed cases of tubular carcinoma were characterized retrospectively by two radiologists. Mammograms and sonograms were available for all patients. RESULTS: Fifteen of the 17 tubular carcinomas appeared as irregularly shaped masses with spiculated margins on mammography. Sixteen of the 17 masses had central densities. Spicules longer than the diameter of the central lesion were noted in eight (53%) of 15 tubular carcinomas. Eight tubular carcinomas had associated calcifications, with calcifications suspected of being malignant in four cases. On sonography, 15 hypoechoic masses were seen. The margins of the masses on sonography were described as ill-defined in 14 (93%) of the 15 cases. Posterior acoustic shadowing was present in 14 of the 15 cases. CONCLUSION: Tubular carcinomas are usually seen on mammography as irregularly shaped masses with central densities and spiculated margins, and most tubular carcinomas can be identified on sonography as hypoechoic masses with ill-defined margins and posterior acoustic shadowing. Although the mammographic and sonographic features of tubular carcinoma are not sufficiently specific to differentiate tubular carcinomas from radial scars, sonography can be useful for guiding biopsies and evaluating for multifocal and multicentric disease.     

The spectrum of sonographic findings of fibroadenoma of the breast

There are a number of sonographic findings seen in fibroadenoma of the breast. In a retrospective study, we examined the biopsy results of 59 masses given the sonographic diagnosis of fibroadenoma. We also reviewed the sonograms of an additional 26 biopsy-proven fibroadenomas that were not diagnosed as such with ultrasound. The ultrasound diagnosis was correct in 50 of 76 fibroadenomas (65.8%). Only 12 of the 76 biopsy-proven fibroadenomas had the classic sonographic appearance of a smooth round or oval mass with homogeneous internal echoes. Fourteen fibroadenomas were not visible on the sonograms, even in retrospect. The remaining 50 biopsy-proven fibroadenomas demonstrated one or more "atypical" signs of border irregularity, lobulation, inhomogeneous internal echo texture, or posterior shadowing. There were nine sonographic false positives: five patients had other benign lesions on histology, and four masses believed to be sonographically compatible with fibroadenoma were found to be carcinomas. While breast sonography is frequently a useful modality for breast mass detection, particularly as an adjunct to x-ray mammography, the common overlap in characteristics of benign and malignant masses makes histologic evaluation of all solid masses essential.     

Magnetic resonance imaging in the diagnosis of breast disease

Magnetic resonance imaging (MRI) of the breast was performed in 10 volunteers and 102 women with suspected breast disease, using a 0.35-T superconducting magnet. All patients had prior x-ray mammography. MRI was superior to mammography in differentiating solid from cystic lesions and equivalent to mammography in providing information regarding different parenchymal patterns. Of 21 surgically proven carcinomas of the breast, MRI correctly identified 18 and mammography identified 19. The major disadvantage of MRI is its inability to show calcifications, benign or malignant. Future studies will be needed to show the relative values of sonography and MRI in detecting small cysts. In addition, MRI in future should be able to demonstrate small, noncalcified masses in mammographically dense, fibrocystic breasts.     

Early breast cancer: detection of recurrence after conservative surgery and radiation therapy

To determine the clinical and mammographic features of recurrent breast cancer after tumorectomy and radiation therapy, the authors reviewed the clinical history and serial mammograms of 48 patients with suspected recurrence. Of patients with recurrent disease, seven had positive mammograms alone, nine had positive findings at physical examination alone, and eight had both positive mammograms and positive results of physical examination. Positive mammographic findings included the development of new fine calcifications (six patients), a new mass (five patients), mass and calcifications (one patient), increasing opacity (two patients), or skin thickening (one patient). Patients in whom the breast recurrence was detected mammographically alone were less likely to develop metastatic disease in subsequent follow-up than when results of physical examination were positive at the time of breast recurrence. Serial mammographic and clinical examinations are complementary for optimal detection of recurrence after conservative surgery and radiation therapy.     

Differentiation of phyllodes tumors versus fibroadenomas

Purpose: To determine if mammographic and sonographic findings allow discrimination between phyllodes tumor and large sized fibroadenoma, which mimic each other in the clinical, radiologic and histopathologic appearances.Material and Methods: Thirty-one histopathologically proven masses including 12 phyllodes tumors and 19 fibroadenomas 3 cm or greater in diameter were compared. In total 28 women were retrospectively evaluated by mammography and pre-operative sonography.Results: Mammography revealed a high-density mass compared with surrounding fibroglandular breast tissue to be present in 9 of the 12 (75%) phyllodes tumors and 7 of the 19 (37%) fibroadenomas. At sonography a mass, which had a round or lobulated shape, marked posterior acoustic enhancement and intramural cystic areas, were statistically significantly more likely to be phyllodes tumors than fibroadenomas. None of the other mammographic or sonographic characteristics proved to be useful in differentiating phyllodes tumors and fibroadenomas.Conclusion: Although masses of high density at mammography, circumscribed border associated with posterior acoustic enhancement and internal cystic areas at sonography should suggest the diagnosis of phyllodes tumors rather than large sized fibroadenomas, there was a substantial overlap in the mammographic and sonographic characteristics of these two tumors. Therefore, an excisional biopsy would be necessary for equivocal masses.     

Periodic mammographic follow-up of probably benign lesions: results in 3,184 consecutive cases

The author prospectively evaluated the value of periodic mammographic surveillance among 3,184 consecutive cases of nonpalpable, probably benign breast lesions detected with mammography. Follow-up consisted of four mammographic examinations during a 3- or 3.5-year period. Clinical outcome was ascertained in each case after the study period, whether or not patients complied with the protocol. Probably benign lesions were subsequently found to be malignant in 17 cases (positive predictive value for cancer, 0.5%). Fifteen of the 17 cancers were identified by means of interval mammographic change prior to development of a palpable mass; all 17 were stage 0 or stage 1 tumors. All 17 women who had cancer currently show no evidence of tumor recurrence (median duration of follow-up, 5 years). These results should help establish the validity of managing mammographically detected, probably benign lesions with periodic mammographic surveillance. By decreasing the number of biopsies of benign lesions and thereby substantially reducing costs, this approach may help overcome a major barrier to widespread use of mammographic screening.     

Phylloides tumor: findings on mammography, sonography, and aspiration cytology in 10 cases.

Phylloides tumor is a rare fibroepithelial breast tumor that occasionally has unpredictable clinical behavior. In nine cases of histologically benign tumors and one case of malignant phylloides tumor, the findings on physical examination, mammography, sonography, and aspiration biopsy were correlated retrospectively with the histologic diagnosis of resected specimens. Mammograms showed a round or lobulated benign-appearing opacity in nine cases; one small tumor was missed mammographically. Sonography depicted all tumors as mostly solid masses. Sonographic features included low-level internal echoes, either uniform or scattered; smooth contours; and no significant posterior shadowing. Intramural cysts were shown in six cases. Neither mammography nor sonography allowed reliable differentiation between benign and malignant phylloides tumors. Aspiration biopsy permitted accurate diagnosis of seven benign tumors. The malignant phylloides tumor was classified as a malignant tumor, but the definite differentiation from a carcinoma could not be made. Two histologically benign phylloides tumors were misdiagnosed as carcinomas. Although uncommon, phylloides tumor should be considered in the differential diagnosis of mammographically benign-appearing breast masses, especially if sonography shows intramural cysts within a well-defined solid lesion. Aspiration cytology is unreliable because of the inhomogeneity of the tumor; both intraoperative frozen section and permanent sections are needed for correct histologic diagnosis.     

Benign and malignant mucocele-like tumors of the breast: mammographic and sonographic appearances

OBJECTIVE: The purpose of this study was to analyze and compare the mammographic and sonographic appearances of benign and malignant mucocele-like tumors. CONCLUSION: The mammographic appearance of mucocele-like tumor of the breast is characterized as pleomorphic calcifications, often increasing in number. Microcalcifications in malignant mucocele-like tumors extended over a wider area than those in benign mucocele-like tumors. Sonography often shows cysts with calcified or noncalcified mural nodules.