Interval carcinomas in the Malm? Mammographic Screening Trial: radiographic appearance and prognostic considerations.

OBJECTIVE. Interval carcinoma is the term used to describe malignant breast tumors that are detected in the intervals between mammographic screenings. These tumors are important because they contribute significantly to breast cancer mortality in the screened population. MATERIALS AND METHODS. Two radiologists retrospectively reviewed the mammograms of the 96 interval carcinomas (17% of all malignant neoplasms in the screened group) that were detected during the 10-year Malm? Mammographic Screening Trial in Malm?, Sweden (average time between screenings, 21 months), including one sarcoma, 75 invasive carcinomas, and 20 noninvasive carcinomas. We recorded the interval between screening and detection, and noted the tumor's appearance on the prior screening mammogram and at the time of diagnosis; these data were correlated with histologic tumor type and the patients' mortality. The doubling time for tumor volume of the invasive carcinomas was estimated. RESULTS. Excluding the sarcoma, 72 carcinomas (75%) were detected within 18 months of screening. Retrospective review of the available preceding screening mammograms (94 cases) indicated that 10 tumors were missed (observer's error), 63 studies showed no tumor (true interval carcinomas), and 21 studies showed subtle signs of malignancy, mostly nonspecific densities or asymmetries (unrecognized sign). Of 66 invasive carcinomas in which doubling times for tumor volume could be calculated, 27 (41%) had doubling times of less than 100 days. At the end of the study, 20 of the 96 patients had died of breast cancer. CONCLUSION. Interval carcinomas in this series were dominated by comedo, medullary, and mucinous carcinomas that often had a nonspecific appearance (when present) on prior screening mammograms. The interval carcinomas also contained a subset of rapidly growing tumors with a grave prognosis.     

Mammographic features of local recurrence after conservative surgery and radiation therapy: comparison with that of the primary tumor

Purpose: To compare the mammographic features of recurrent breast cancer with those of the primary tumor and to determine whether certain mammographic features are associated with a higher risk of local recurrence after breast-conserving therapy.

Material and Methods: A retrospective review of mammograms of 421 patients who were treated with conservative surgery and radiotherapy revealed 41 recurrent tumors. Mammographic findings, location, and histopathologic characteristics were retrospectively compared between primary and recurrent tumors.

Results: Recurrent tumors were similar in mammographic appearance to primary tumors in 27 (66%) cases. Of 27 primary tumors that occurred as masses without calcifications, 19 (70%) recurred as a mass, and of the six isolated calcifications, five (83%) recurred with calcifications. Ten (53%) of the 19 recurrent masses and five (100%) of the five recurrent calcifications had morphologic features that were similar to those of the primary tumor. Ninety-two percent (11/12) of the recurrences containing microcalcifications (isolated or associated with a mass) had microcalcifications in their primary tumor. Of 27 masses that recurred, the morphology of the primary tumor was obscured in 13 (48%), ill defined in 10 (37%), and spiculated in four (15%) of the masses. Seventy-six percent (31/41) of recurrences were within the lumpectomy quadrant. In 25 (61%) cases, the histologic findings from the primary tumor and the recurrence were identical.

Conclusion: The majority of recurrent tumors appear to be mammographically similar to primary tumors. Therefore, it is important to review preoperative mammograms during follow-up of these patients. Although the study population is small, it was noted that mass with spiculated contour is associated with a lower risk for local recurrence.     

Adenomyoepithelial tumors of the breast: imaging findings with histopathologic correlation

OBJECTIVE: The purpose of this essay is to describe the imaging characteristics of adenomyoepithelial tumors of the breast. CONCLUSION: Adenomyoepithelial tumors of the breast are rare, and most are benign. The predominant mammographic and ultrasound feature is an irregular mass with suspicious imaging findings. This uncommon condition should be included in the differential diagnosis of noncalcified masses found on mammograms and of solid masses with associated hypervascularity on ultrasound images. Biopsy is necessary for histologic evaluation, and the management is surgical excision.     

Mucinous (colloid) breast cancer: mammographic and US features with histologic correlation

OBJECTIVE: Mucinous carcinoma of the breast presents with different survival rates in pure and mixed types. The purpose of this study was to correlate the mammographic and ultrasonographic findings of mucinous carcinoma with histologic features in different types and mucin rates. MATERIAL AND METHODS: Thirty-four patients (2.3%) had mucinous cancer after retrospective review of the 1439 breast cancers diagnosed between 1990 and 1996. Twenty-seven patients, 19 pure and eight mixed type of mucinous carcinomas of the breast, were included in this study to evaluate the imaging findings. In 22 of these, the microscopic slides were available and re-evaluated to estimate the volume of extracellular mucin. The volume of the extracellular mucin was classified histologically as: (+), less than 50% of mucin; (++), 50-80% of mucin; and ( ), more than 80% of mucin. Mammographic features with emphasis on margin characteristics and sonographic echo pattern of tumors were correlated with histologic findings. RESULTS: Ten cases (53%) of pure mucinous type carcinomas had a circumscribed mass lesion on the mammograms. The well-defined, lobulated margins of the masses were well correlated with pure histologic type (P<0.01; chi(2) analysis) Two-thirds of these tumors had high volume extracellular mucin. All mixed type mucinous carcinomas demonstrated poorly defined or spiculated margins with no relation to the mucin rates (P<0.01). The sonographic appearances of the tumors showed correlation with histologic types. Most of the pure type carcinomas (53%) were seen with isoechogenic echo texture relative to that of subcutaneous fat, while all of the mixed type carcinomas were hypoechogenic (P<0.01). CONCLUSION: The mammographic and sonographic features of mucinous breast carcinoma show differences in pure and mixed types of the tumor. The most common mammographic appearance of pure mucinous carcinomas with high percentages of mucin is a mass lesion having well-defined margins, which is isoechogenic relative to fat on the sonographic examination. Pure type of carcinomas with small percentages of mucin and mixed type carcinomas have more aggressive imaging characteristics.     

The correlation of mammographic-and histologic patterns of breast cancers in BRCA1 gene mutation carriers, compared to age-matched sporadic controls

Breast cancers in BRCA1 gene mutation carriers often have specific histologic features: grade III tumors with pushing margins. Our purpose was to compare the mammographic and histologic features of breast cancers in carriers with those in age-matched sporadic controls. The features of breast cancers in 27 BRCA1 carriers found during annual surveillance were compared to those in 107 age-matched sporadic controls. The carriers had no (classic) spiculated mammographic lesions, a high percentage of well-defined masses and hardly any masses with microcalcifications, whereas the controls had significantly fewer well-defined ones and only in 27% spiculated lesions on the mammogram. The well-defined mammographic tumors correlated in 83% of the carriers and in 70% of the controls with histologic circumscribed tumor margins. Spiculated mammographic lesions in the controls were in 90% grade I or II tumors. DCIS with or without infiltration was seen in 22% of the carriers and in 45% of the controls. In conclusion, breast cancers diagnosed in BRCA1 carriers do not have classic malignant mammographic features. A minority of the young sporadic controls show the classic malignant lesion on the mammogram. Both carriers and controls generally show a good correlation between their mammographic- and histologic tumor pattern.     

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.     

Computer-aided diagnosis in full digital mammography

RATIONALE AND OBJECTIVES: The authors clarify the detection rates for breast cancerous tumors and clustered microcalcifications with computer-aided diagnosis (CAD) based on Fuji Computed Radiography. The authors also determine whether mammographic reading with CAD contributes to the discovery of breast cancer. METHODS: Data acquired by Fuji Computed Radiography 9000, which consisted of 4148 digital mammograms including 267 cases of breast cancer, was transferred directly to an analysis workstation where an original software program determined extraction rates for breast tumors and clustered microcalcifications. Furthermore, using another 344 mammograms from 86 women, observer performance studies were conducted on five doctors for receiver operating characteristic (ROC) analysis. RESULTS: Sensitivity to breast cancerous tumors and clustered microcalcifications were 89.9% and 92.8%, respectively false-positive rates were 1.35 and 0.40 per image, respectively. The observer performance studies indicate that an average Az value for the five doctors was greater with the CAD system than with a film-only reading without CAD, and that a reading with CAD was significantly superior at P < 0.022. CONCLUSIONS: It has been shown that CAD based on Fuji Computed Radiography offers good detection rates for both breast cancerous tumors and clustered microcalcifications, and that the reading of mammograms with this CAD system would provide potential improvement in diagnostic accuracy for breast cancer.     

Solitary breast papilloma: comparison of mammographic, galactographic, and pathologic findings.

OBJECTIVE. Our purpose was to determine the mammographic/galactographic features of solitary breast papillomas and to correlate these features with the pathologic findings. MATERIALS AND METHODS. Retrospective review of pathology files revealed 72 women in whom breast biopsy reports described a solitary papilloma. All patients with additional pathologic abnormalities were excluded from this study. Patients meeting the pathologic criteria and for whom mammograms, galactograms, or both were available and had been obtained within 6 months before biopsy were included. Twenty-four women met these criteria and form the basis of this study. Presenting clinical signs and symptoms were reviewed. Abnormal mammographic/galactographic findings were correlated with pathologic features. RESULTS. Nipple discharge was present in 21 (88%) of 24 patients, two (8%) of 24 patients had abnormal findings on screening mammography, and one patient had a palpable mass that was visible on mammograms. Eight (42%) of 19 mammograms had abnormal findings, including dilated duct(s) in five cases (26%), nodules in two cases (11%), and microcalcifications in one case (5%). All technically adequate galactograms (13/15) had abnormal findings, with 12 (92%) of 13 showing an intraluminal filling defect. The other technically adequate galactogram (8%) showed only a solitary obstructed duct. Ductal dilatation was greatest at or central to the papilloma on 12 (92%) of 13 galactograms. Imaging features correlated well with the histologic findings. CONCLUSION. Patients with solitary papillomas most commonly have nipple discharge, normal mammographic findings, and a galactographic filling defect. Galactography is useful for localizing papillomas.     

Breast hamartomas: variable mammographic appearance

The mammograms of 17 women with pathologically proved breast hamartomas were reviewed. Abnormal masses were detected on 12. Nine women had masses with benign features. Two of these had findings considered classic for hamartoma. In three cases, the appearance of the mass was suggestive of carcinoma. The breasts were very dense in four of five women without detectable mass. The findings suggest that the classic mammographic appearance of breast hamartomas is less common than previously reported, which may be explained by earlier detection of small hamartomas.     

Screening mammography-detected cancers: sensitivity of a computer-aided detection system applied to full-field digital mammograms

PURPOSE: To retrospectively evaluate the sensitivity of the performance of a computer-aided detection (CAD) system applied to full-field digital mammograms for detection of breast cancers in a screening group, with histologic findings as the reference standard. MATERIALS AND METHODS: This study had institutional review board approval, and patient informed consent was waived. A commercially available CAD system was applied to the digital mammograms of 103 women (mean age, 51 years; range, 35-69 years) with 103 breast cancers detected with screening. Sensitivity values of the CAD system according to mammographic appearance, breast composition, and histologic findings were analyzed. Normal mammograms from 100 women (mean age, 54 years; age range, 35-75 years) with no mammographic and clinical abnormality during 2-year follow-up were used to determine false-positive CAD system marks. Differences between the cancer detection rates in fatty and dense breasts for the CAD system were compared by using the chi(2) test. RESULTS: The CAD system correctly marked 99 (96.1%) of 103 breast cancers. The CAD system marked all 44 breast cancers that manifested as microcalcifications only, all 23 breast cancers that manifested as a mass with microcalcifications, and 32 (89%) of 36 lesions that appeared as a mass only. The sensitivity of the CAD system in the fatty breast group was 95% (59 of 62) and in the dense breast group was 98% (40 of 41) (P = .537). The CAD system correctly marked all 31 lesions of ductal carcinoma in situ (DCIS), all 22 lesions of invasive ductal carcinoma with DCIS, the single invasive lobular carcinoma lesion, and 45 (92%) of 49 lesions of invasive ductal carcinoma. On normal mammograms, the mean number of false-positive marks per patient was 1.80 (range, 0-10 marks; median, 1 mark). CONCLUSION: The CAD system can correctly mark most (96.1%) asymptomatic breast cancers detected with digital mammographic screening, with acceptable false-positive marks (1.80 per patient).     

Phyllode tumor of the breast: mammographic experience in 99 cases.

The clinically variable course of phyllode tumor with its complex histological picture--ranging from benign to malignant--poses problems for the preoperative diagnosis and, in particular, the therapeutic approach. Mammograms of 99 patients with this disease, observed and treated from 1975 to 1989, were reviewed to determine mammographic/histologic correlations useful for early diagnosis. Opacity, size, shape, margin characteristics, the presence of calcifications and radiolucent halo were determined from the mammograms. The most useful characteristics were opacity and the character of the tumor's margins. However, mammographic features alone could not distinguish phyllode tumor from fibroadenoma.     

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.     

Computer-aided detection output on 172 subtle findings on normal mammograms previously obtained in women with breast cancer detected at follow-up screening mammography

PURPOSE: To evaluate, by using a computer-aided detection (CAD) program, the nonspecific findings on normal screening mammograms obtained in women in whom breast cancer was later detected at follow-up screening mammography. MATERIALS AND METHODS: Four hundred ninety-three mammogram pairs-an initial negative screening mammogram and a subsequently obtained screening mammogram showing cancer-were collected. The mean interval between examinations was 14.6 months. In 169 cases, in which 172 cancers were later depicted, findings on the initial mammogram were subtle enough that either none or only one or two of five blinded radiologists recommended screening recall. On the initial negative mammograms, of the 172 areas where cancer later developed, 137 (80%) had subtle nonspecific findings and were retrospectively judged as having a benign or normal appearance. The mammograms with these subtle findings were evaluated with a commercially available CAD program, and the numbers of CAD marks on these nonspecific findings were analyzed. RESULTS: Of the 172 cancers, 129 (75%) were invasive and 43 (25%) were ductal carcinoma in situ. The CAD program marked 72 (42%) of the 172 findings that subsequently developed into cancer: 24 (29%) of 82 findings recalled by none, 25 (49%) of 51 findings recalled by one, and 23 (59%) of 39 findings recalled by two of the five radiologists. Among the 137 areas with nonspecific normal or benign findings, 41 (30%) areas where cancer subsequently developed were marked by the CAD program. CONCLUSION: A subset of cancers have perceptible but nonspecific mammographic findings that may be marked by a CAD program, even when the findings do not warrant recall as judged at blinded and unblinded radiologist review. The authors believe failure to act on such nonspecific but CAD-marked findings prospectively does not constitute interpretation below a reasonable standard of care.     

Lymphoma of the breast

The mammograms of 25 women and six men (33 breasts) with lymphoreticular disease of the breast were reviewed. Three patients had HD, 21 NHL (one bilateral), three had leukemic involvement of the breast, and four had plasmacytoma (one bilateral). All patients had identifiable and localized abnormalities in their breasts, many of which were well-defined masses ranging in diameter from 2 to 9 cm. From this series it would seem that lymphomatous involvement of the breast has a noticeable predilection to form relatively circumscribed masses on the mammogram. However, they lacked tumor calcifications or secondary changes such as the surrounding distortion or localized skin retraction often associated with primary breast carcinomas. This nonspecific appearance usually compromises the proper diagnosis in a primary clinical presentation of a lymphomatous breast mass without associated axillary lymphadenopathy or known lymphomatous disease of the breast.     

Atypical hyperplasia of the breast: mammographic appearance and histologic correlation

The mammograms and histologic slides of 58 cases of atypical hyperplasia (AH) of the breast were retrospectively reviewed to determine the geographic correlation (direct, near, or remote) between mammographic abnormalities (if present) and the histologic findings. A direct mammographic-histologic correlation was found in 24 of the 58 cases (41%), near correlation in 15 (26%), and remote correlation in 19 (33%). Clustered microcalcifications were the most common mammographic abnormality that was directly correlated with AH at histologic examination. Atypical ductal hyperplasia was much more frequently associated with a direct mammographic-histologic correlation than was atypical lobular hyperplasia (48% vs 9%). The authors conclude that, although no pathognomonic appearance of AH was discovered, mammographic abnormalities similar to those of small cancers could be directly correlated with histologic findings in 41% of cases. Since AH has been shown to be associated with a five- to tenfold increased risk of subsequent invasive carcinoma, frequent clinical and at least yearly mammographic follow-up is suggested once AH is discovered.     

Circumscribed intraductal carcinoma of the breast

In a retrospective evaluation of 350 cases of proved intraductal carcinoma detected over a 3-year period, 13 had mammographic features similar to those of benign tumors. The carcinomas were sharply circumscribed, round or oval lesions that contained microcalcifications. These calcifications were smaller and more likely to be asymmetrically located within the nodule than those of the fibroadenomas that they mimicked. While the carcinomas appeared circumscribed on mammograms, microinvasion of surrounding tissue was proved histologically in five of 13 cases, and in another case biopsy revealed metastasis to an axillary lymph node. Although these carcinomas are relatively rare, mammographic detection is important as none were palpable at the time of diagnosis.     

Invasive cancers detected after breast cancer screening yielded a negative result: relationship of mammographic density to tumor prognostic factors

PURPOSE: To evaluate common breast tumor prognostic characteristics, including estrogen receptor (ER) status, grade, size, and method of detection, in relationship to mammographic density. MATERIALS AND METHODS: The study involved 121 women who had negative results at both screening mammography and breast physical examination within 17 months before a diagnosis of breast cancer. Mammographic density was classified according to Breast Imaging Reporting and Data System patterns 1 through 4 (where 1 indicates a fatty breast and 4 indicates a dense breast). Axillary nodal status and tumor histologic ER status, histologic grade, size, stage, and method of detection (mammography alone, palpation alone, or both palpation and mammography) were analyzed by density category and tested for statistically significant differences across categories by using analysis of variance. RESULTS: Statistically significant differences (P <.05) by density category were found for the following variables: ER positivity (15 of 15 tumors in category 1 breasts, 32 of 41 tumors in category 2 breasts, 37 of 49 tumors in category 3 breasts, and eight of 16 tumors in category 4 breasts were ER positive), occurrence of grade 1 tumors (eight, 11, 19, and four tumors in category 1, category 2, category 3, and category 4 breasts, respectively, were grade 1), mean tumor size (11.3, 13.0, 14.7, and 19.7 mm for category 1, category 2, category 3, and category 4 breasts, respectively), detection with mammography alone (13, 31, 36, and four tumors in category 1, category 2, category 3, and category 4 breasts, respectively, were detected with mammography alone), and occurrence of stage I tumors (10, 25, 28, and five tumors in category 1, category 2, category 3, and category 4 breasts, respectively, were stage I). CONCLUSION: In women with negative results at clinical and mammographic screening within 17 months before breast tumor detection, subsequently diagnosed cancers tend to be ER negative, of higher grade, and larger in size in those with dense tissue patterns than in those with fat patterns.     

Apparent ipsilateral decrease in breast size at mammography: a sign of infiltrating lobular carcinoma

PURPOSE: To assess if infiltrating lobular carcinoma (ILC) is associated with an ipsilateral mammographic decrease in breast size. MATERIALS AND METHODS: Mammographic change in size was evaluated by measuring the distance from the nipple to the pectoralis major muscle on the mediolateral oblique view of the diagnostic mammogram and on a preceding mammogram in 30 patients with ILC. Clinical, mammographic, and histopathologic findings were retrospectively reviewed. RESULTS: Five patients (17%) had an ipsilateral decrease in mammographic size. No patients noticed a physical decrease in breast size. Patients with an ipsilateral decrease in mammographic size most commonly had breast thickening at examination (four of five patients [80%], P < .001) and either a focal asymmetry density (three of five patients [60%]) or architectural distortion (one of five patients [20%]) at mammography; those patients with no change in size most commonly had a palpable mass (six of 25 patients [24%]) or normal findings (19 of 25 patients [76%]) and a mass (13 of 25 patients [52%]) at mammography. The mean tumor size was 66 mm for those with an ipsilateral size decrease and 16 mm for those with no size decrease (P < .001). At histologic analysis, tumors associated with an ipsilateral decrease in mammographic size had more diffuse involvement of the breast, and discrete masses were not seen. CONCLUSION: An apparent decrease in mammographic size may help identify cases of ILC, especially when associated with thickening at clinical examination and focal asymmetric density at mammography.     

Evaluation of pectoralis major muscle in patients with posterior breast tumors on breast MR images: early experience

PURPOSE: To evaluate the ability to use breast magnetic resonance (MR) imaging to assess disease extent in patients with posterior breast masses who are suspected to have tumor invasion into underlying muscle. MATERIALS AND METHODS: Nineteen patients with posterior breast masses underwent three-dimensional, gradient-echo, 1.5-T MR imaging before and after the administration of gadopentetate dimeglumine. Thirteen had deep palpable masses that were clinically determined to be fixed to the underlying chest wall. Twelve had mammographic findings that caused muscle involvement to be suspected, and seven had normal mammograms. All patients underwent surgery. MR images were reviewed and were correlated with histologic findings. RESULTS: Enhancing masses were identified on MR images in all 19 patients. Five (26%) of the 19 patients had masses that abutted the muscles, with obliteration of the fat plane and muscle enhancement. All five had muscle involvement at surgery. In the remaining 14 (74%) patients, no enhancement of muscle was seen; none of these had invasion of the muscle at surgery. CONCLUSION: Extension of adjacent tumor into underlying musculature was indicated by abnormal enhancement within these structures. Violation of the fat plane between tumor and muscle, without other findings, did not indicate tumor involvement of these deep structures.