Ultrasonography of malignant breast neoplasms. Analysis of carcinomas missed as tumor.

PURPOSE: To analyze the malignant breast neoplasms missed as tumor on ultrasonography (US). MATERIAL AND METHODS: A total of 355 malignant tumors were confirmed at histology among 2,985 consecutive patients who underwent breast US. There were no prospectively recorded mammographic findings in 28 of the 355 tumors. The remaining 327 tumors included 16 ductal carcinomas in situ (DCIS) and 66 invasive carcinomas with suspicious microcalcifications on mammography. Excluding these 82 tumors because US would not have been indicated using strict criteria, a subpopulation of 245 noncalcified invasive malignant tumors remained for analysis. The neoplasms missed as tumor on US were analyzed for the whole tumor group (n=355) and the subpopulation (n=245). RESULTS: 42 (11.8%) of the 355 malignant neoplasms were missed as tumor on US, including 6 (2.5%) of the 243 palpable and 36 (32.1%) of the 1 12 nonpalpable malignancies. Most of the missed tumors were DCIS and microinvasive ductal carcinomas dominated by DCIS. In the subpopulation, 14 (5.7%) of the 245 malignancies were missed as tumor on US, including 4 (2.2%) of the 180 palpable and 10 (15.4%) of the 65 nonpalpable lesions. Of the 245 malignancies, 6 (2.4%) had a normal US finding, including 2 palpable retropapillary tumors and 4 incidental findings at histology. CONCLUSION: Using strict criteria for performing US as an adjunct to mammography, by far the most malignant breast neoplasms are diagnosed as a tumor on US.     

Variability in the interpretation of ultrasonography in patients with palpable noncalcified breast tumors

PURPOSE: To analyze interobserver variability of ultrasonography (US) as an adjunct to mammography in patients with palpable noncalcified breast tumors. MATERIAL AND METHODS: Mammographic, US, and combined reading of 200 patients with palpable noncalcified breast masses were performed independently by four experienced radiologists. Nonneoplastic abnormalities and mammographically obvious cancers were excluded. Receiver operating characteristic (ROC) analysis based on 115 tumors was carried out for mammography, US, and both combined for each radiologist. The US diagnoses of the 45 cancers excluded from ROC analysis and the 55 cancers included were compared. RESULTS: One radiologist revealed a significantly higher diagnostic performance with US than with mammography. Combined reading showed the highest performance for all observers, but the improvement as compared with mammography was significant for only two. Higher accuracy on combined reading was mainly caused by correct upgrading of tumors with benign or indeterminate mammographic findings. One radiologist had benefit of US for downgrading of tumors. All four radiologists made a malignant US diagnosis twice as often in mammographically obvious cancers than in mammographically nonconclusive tumors. CONCLUSION: Radiologists differ substantially in interpretation of breast imaging. Combined reading offers the highest diagnostic accuracy mainly by correct upgrading of tumors on US. The role of US for downgrading tumors is operator-dependent.     

Ultrasonography of invasive lobular carcinoma of the breast: sonographic patterns and diagnostic value: report of 102 cases

The aim of this study was to define the ultrasonographic (US) features of the invasive lobular carcinoma (ILC). For this purpose, the clinical histories and the mammographic and sonographic findings observed in 102 patients affected by documented ILC were retrospectively reviewed, and the role and value of US in the diagnosis of palpable and nonpalpable breast tumors were evaluated. At US, five proven tumors were not visualized (sensitivity: 95%), while the remaining 97 showed sonographic images that are considered typically malignant: irregular heterogenic, hypoechoic irregular masses in 94 cases, which were associated with posterior shadowing in 87. The presence of only a posterior shadowing was observed in three cases. There were 16 subclinical tumors, and in two of the four in which a mammography showed an indeterminate lesion, US demonstrated a malignant pattern. All the palpable tumors that were not detected mammographically were demonstrated by US. In 13 of the 102 patients (12.7%), the correct diagnosis of malignancy was established by US. On the basis of the data obtained, it is felt that because of its sensitivity and high specificity for malignancy, US plays a very important role in the diagnosis of ILC, whenever in a patient with positive clinical findings, the mammography is negative or the mammographic features are equivocal.     

Ultrasonographic evaluation of invasive lobular carcinoma.

PURPOSE: To compare ultrasonographic (US) and mammographic findings and tumor size measurements of invasive lobular carcinoma (ILC). MATERIAL AND METHODS: US diagnoses and mammographic findings were compared in 95 patients with pure ILC, including 46 palpable and 49 nonpalpable tumors. The diameters of tumors measured by mammography, US, and pathology were compared in 70 of the 95 patients using scatter plots and correlation analysis. RESULTS: Eighty-two (86.3%) of the ILCs were correctly diagnosed as malignant tumor, 5 (5.3%) were diagnosed as focal abnormality, and only 2 patients had normal findings on US. The most common mammographic findings were a spiculated mass (57%) and a focal asymmetric density (15%). US correctly diagnosed 8 of 12 patients with normal or equivocal mammographic findings. The correlation of tumor size assessment on imaging and pathology revealed that US measurements including the "halo" (r=0.69) was superior to that of mammography (r=0.59). ILCs larger than 30 mm were heavily underestimated by both methods. CONCLUSION: Malignant tumor was diagnosed on US in most of the patients with ILC. US tumor measurement including the "halo" predicted tumor size most accurately. The correlation between imaging measurements and tumor diameter on histology was lower for ILCs than reported for populations of mixed carcinomas.     

The clinical value of bilateral breast MR imaging: is it worth performing on patients showing suspicious microcalcifications on mammography?

The purpose of this study was to evaluate the clinical value of bilateral breast magnetic resonance (MR) imaging (MRI) in patients showing suspicious microcalcifications on mammography and negative ultrasound findings. Fifty patients underwent MRI before stereotactic vacuum-assisted breast biopsy (SVAB). MR findings were classified into five types for interpretation, and types 4 and 5 were considered malignant. SVAB revealed 13 carcinomas and 37 benign lesions. Malignant lesions were more frequently found in cases of positive MRI diagnoses than in negative MRI diagnoses (P < 0.001). Mammography had a sensitivity of 100%, a specificity of 24% and an accuracy of 44%, whereas mammography plus MRI had a sensitivity of 85%, a specificity of 100% and an accuracy of 96%. In the evaluation of mammographically detected microcalcifications, bilateral breast MRI is of good diagnostic value and may alter the indications for SVAB.     

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.     

Mammographic pattern of microcalcifications in the preoperative diagnosis of comedo ductal carcinoma in situ: histopathologic correlation.

OBJECTIVE: The comedo subtype of ductal carcinoma in situ (DCIS) is more aggressive than noncomedo DCIS. Differentiating noncomedo DCIS from the more aggressive comedo subtypes on mammography would allow the surgeon to excise comedo DCIS with a wider margin. The mammographic features of microcalcifications associated with nonpalpable comedo DCIS, noncomedo DCIS and benign disease were compared to determine the usefulness of this finding in diagnosis of comedo DCIS. METHODS: The authors retrospectively and blindly reviewed the mammograms of 91 consecutive patients in whom DCIS was diagnosed by needle localization and surgical excision. An equal number of cases of benign microcalcifications were also reviewed. Microcalcifications were evaluated with respect to pattern, density, configuration and size. These results were correlated with the pathologic findings. RESULTS: All 16 cases (100%) of linear branching calcifications and 34 (80%) of the 43 cases of linear calcifications were associated with comedo DCIS (p < 0.001). The number of calcifications, the density and the size of clustering were not diagnostic of comedo DCIS. Granular calcifications occurred in noncomedo DCIS and in benign disease associated with noncalcifying DCIS. CONCLUSION: Comedo DCIS is suggested by the presence of linear and linear branching microcalcifications on mammography.     

Multicentric and multifocal cancer: whole-breast US in preoperative evaluation

PURPOSE: To evaluate preoperative whole-breast ultrasonography (US) in the management of breast cancer. MATERIALS AND METHODS: The ipsilateral breast in 40 patients with known breast cancer or in whom there was high suspicion of breast cancer was evaluated with whole-breast US. Biopsy was performed on all discrete solid lesions. RESULTS: US depicted 45 (94%) of 48 invasive tumor foci and seven (44%) of 16 foci of ductal carcinoma in situ (DCIS). Mammography depicted 39 (81%) of 48 invasive tumor foci and 14 (88%) of 16 foci of DCIS. The nine (14%) of 64 malignant foci seen only at US included three infiltrating ductal carcinomas, two mixed infiltrating and intraductal carcinomas, two infiltrating lobular carcinomas, and two foci of DCIS. Two (18%) of 11 foci of infiltrating lobular carcinoma were missed at both US and mammography. Of 20 patients mammographically suspected of having unifocal disease, three (15%) required wider excision on the basis of US findings. Two additional foci were depicted only at US in one of 16 patients mammographically suspected of having multicentric or multifocal disease. Of four patients with mammographically occult disease, US correctly depicted the diffuse (n = 2) or unifocal (n = 2) extent of the cancer. CONCLUSION: Whole-breast US complements mammography in the preoperative evaluation of patients with breast cancer, particularly when breast conservation is contemplated.     

Breast US in patients who had microcalcifications with low concern of malignancy on screening mammography

PURPOSE: To review ultrasound (US) findings in patients who have suspicious microcalcifications with low concern of malignancy (BI-RADS category 4A) on screening mammography and to evaluate helpful findings in differentiating benign and malignant lesions. MATERIALS AND METHODS: Between August 2005 and July 2006, 192 patients showed microcalcifications only, without mass or associated density, on screening mammography. Among them, we selected 82 patients who had microcalcifications with low concern of malignancy (category 4A) that were pathologically confirmed by surgical excision after wire localization (n=23) or biopsy (n=59). Breast US was performed in 37/82 cases and we analyzed the US findings for the calcification areas in these patients, evaluating the findings with benign or malignant pathological results. We correlated US findings with mammographic calcifications using mammography-guided 2D-localization for the calcifications before US examination. RESULTS: There were 12 malignant lesions (32.4%) including 3 invasive ductal carcinomas (IDC), one microinvasive ductal carcinoma (MIDC), 8 ductal carcinoma in situ (DCIS) and 25 benign lesions (67.6%) including 2 atypical ductal hyperplasias (ADH). IDC showed calcifications within heterogeneous hypoechoic parenchyma or calcifications within complex hypoechoic masses of taller-than-wide shape on US. One MIDC showed calcifications within heterogeneous hypoechoic parenchyma and six DCIS showed negative findings, or calcifications with a small nodule, or only calcifications on US. The most common positive US finding in benign lesions was cysts with calcifications. In 24/37 cases (64.8%) with negative US findings, 18 (75%) were benign lesions and 6 (25%) were DCIS. CONCLUSION: In patients with category 4A microcalcifications without associated findings on screening mammography, negative US findings had a high rate of benign results (18/24, 75%). Visible calcifications within heterogeneous hypoechoic parenchyma or mass on US increased the probability of malignancy.     

Real-time US elastography in the differentiation of suspicious microcalcifications on mammography

The purpose of this study was to retrospectively evaluate the use of US elastography in the differentiation of mammographically detected suspicious microcalcifications, using histology as the reference standard. Between May 2006 and April 2007, real-time US elasticity images were obtained in 77 patients (age range, 24–67 years; mean, 46 years) with 77 mammographically detected areas of microcalcifications (42 benign and 35 malignant lesions) prior to needle biopsy. Two experienced radiologists reviewed cine clips of elasticity and B-mode images and assigned an elasticity score of 1 to 3 in consensus, based on the degree of strain in the hypoechoic lesion without information of mammography and histology. For the elasticity score, the mean ± standard deviation was 1.5 ± 0.7 for benign and 2.7 ± 0.7 for malignant lesions (P < 0.001). When a cutoff point between elasticity scores of 1 and 2 was used, US elastography showed 97% (34/35) sensitivity, 62% (26/42) specificity, 68% (34/50) PPV, and 96% (26/27) NPV with an Az value of 0.852 (0.753–0.923, 95% confidence interval) in the differentiation of benign and malignant microcalcifications. Our results suggest that US elastography has the potential to differentiate benign and malignant lesions associated with microcalcifications detected at screening mammography.     

MR lesion detection in a breast cancer population

Implementation of MR imaging of the breast as an extension of the existing imaging modalities in the diagnosis of breast cancer was evaluated in a university cancer center. MR imaging of the breast was performed in 54 patients, in whom the MR results were compared with the triple test (the combination of clinical examination, mammographic evaluation, and cytology) and the final histological diagnosis. MR imaging of the breast depicted 30 of the 33 malignancies (sensitivity, 91%). In two of the malignancies, the carcinoma was clinically and mammographically occult. For the three patients with a false-negative MRI diagnosis, the conventional mammography showed suspicious clustered microcalcifications as a sign of in situ carcinoma. For seven patients, MR imaging of the breast incorrectly suggested the presence of a malignant lesion (specificity, 67%). To improve MR specificity, we perform MR-guided ultrasonographic fine-needle aspiration biopsy (FNAB). Although MR imaging of the breast is a highly sensitive examination, conventional x-ray mammography remains the most efficient imaging modality in the diagnosis of breast cancer. In our patient population, MR imaging of the breast had additional value for women with mammographically dense breast tissue and especially for patients with clinical evidence of breast carcinoma that could not be detected with conventional diagnostic methods.     

Ultraschallgezielte Stanzbiopsie der Mamma: Technik,Ergebnisse, Indikationen

Purpose. The purpose of this retrospective analysis was to assess the diagnostic accuracy and complication rate of sonographically guided core needle biopsy in palpable breast masses, mammographically detected nonpalpable lesions, and sonographically detected clinically and mammographically occult lesions. Patients and methods. Sonographically guided core needle biopsy was performed in 590 lesions in 572 patients, by using an automated biopsy gun with a 14-gauge large core needle and a coaxial system. Core needle biopsy results were compared with surgical biopsy in 265 cases. 325 lesions with benign histologic diagnoses were followed up for at least 18 months. Results. 234 carcinomas and 356 benign abnormalities were found in the 572 patients. Core needle biopsy reached a sensitivity of 98.7% at a specificity of 99.7%. Understimation rates for lesions initially diagnosed as DCIS and for lesions initially diagnosed as ADH were 3/10 and 6/14, respectively. Of three false-negative results, two were immediately recognized, and one was identfied at follow-up. Serious bleeding occured in one patient (0.2% complication rate). Conclusions. This report confirms that sonographically guided large core needle biopsy is a safe, reliable and cost-effective method for the assessment of both palpable and nonpalpable, mammographically and sonographically detected breast abnormalities.     

US of ductal carcinoma in situ.

Little is known about the ultrasonographic (US) features of ductal carcinoma in situ (DCIS) of the breast because this entity usually manifests as pure mammographic calcifications and is rarely evaluated with US. US findings were recorded in 70 patients with DCIS and then analyzed and correlated with mammographic and histologic findings. A microlobulated mass with mild hypoechogenicity, ductal extension, and normal acoustic transmission was the most common US finding in DCIS. Spiculated margins, marked hypoechogenicity, a thick echogenic rim, and posterior acoustic shadowing at US often suggested the presence of invasion. US performed with a 10-13-MHz transducer and optimal technique can be used as a complement to mammography in detecting and evaluating DCIS of the breast, as it demonstrates breast lesions associated with malignant microcalcifications in most cases. The main benefit of identifying a US abnormality in women with mammographically detected DCIS is to allow the use of US to guide interventional procedures (eg, needle biopsy, needle localization). US may also be helpful in detecting DCIS without calcifications and in evaluating disease extent in women with dense breasts. Nevertheless, further research is needed to delineate the role of US in the evaluation of patients with DCIS.     

Nonpalpable breast lesions: evaluation by means of fine-needle aspiration cytology

A prospective study was undertaken to assess the utility of fine-needle aspiration (FNA) cytology in women with nonpalpable suspicious microcalcifications or masses detected at mammography. Ninety-six breast lesions were aspirated during wire localization with standard mammographic technique. Cytologic results were compared with surgical pathology results. Sixty-one of the 96 aspirates were adequate for diagnosis. Nine were positive for malignant cells; seven, suspicious; 12, atypical; and 33, negative. All lesions demonstrating positive or suspicious cytologic findings were found to be malignant at biopsy; five of the 12 with atypical cytologic findings were malignant. Of 33 lesions deemed negative by means of cytology, two were biopsy-proved carcinomas. Cytologic examination permitted accurate diagnosis of 21 of the 23 (91%) carcinomas in which an adequate sample was obtained. Insufficient cellular material was obtained from 35 lesions, 16 of which showed marked fibrosis at histologic examination. The authors conclude that FNA cytology can aid in establishing a diagnosis in many cases in which nonpalpable breast lesions are detected at mammography.     

Needle-localized biopsy of occult breast lesions: an update.

We have performed 207 needle-localized breast biopsies for nonpalpable, mammographically suspicious lesions over the past 6 years. A mass lesion and grouped microcalcifications were associated with malignancy, while a mass with microcalcifications was never associated with malignancy. Biopsy revealed malignancy in 26 cases (12.6%), with 19 of 22 (86.4%) having no histologic evidence of axillary spread. Advanced age and a past history of a breast cancer were again the risk factors present in a significant number of the patients with a positive biopsy result. There were 11 complications (5.3%): three hematomas (1.4%), one infection (0.5%), and seven (3.4%) required a repeat biopsy to remove the suspicious lesion missed on the original biopsy. We conclude that needle-localized breast biopsy continues to be a reliable method of detecting early breast carcinoma. Given the minimal morbidity, this procedure should be done in all patients with mammographically suspicious nonpalpable breast lesions.     

Diagnostic value of ultrasonography in patients with palpable mammographically noncalcified breast tumors

PURPOSE: To analyze the diagnostic accuracy of mammography, ultrasonography (US), and both methods combined in evaluation of palpable noncalcified breast tumors. MATERIAL AND METHODS: Mammograms and sonograms of 200 patients with palpable noncalcified breast masses were retrospectively analyzed independently by four experienced radiologists in 3 sessions: Mammography or US interpretations in the first two and combined reading in the last session. Nonneoplastic abnormalities and mammographically obvious cancers were excluded. Receiver operating characteristic (ROC) analyses were performed for 115 (60 benign and 55 malignant) tumors and subgroups according to tissue density and tumor size. A single ROC curve for each diagnostic test was obtained by pooling the individual ratings. The area under the ROC curve was used as a measure of diagnostic performance. RESULTS: US revealed significantly higher diagnostic performance than mammography for tumors larger than 2 cm. Combined reading showed significantly higher performance than mammography except for tumors smaller than 2 cm. The performance of all three tests was reduced in dense parenchyma, and significantly so for mammographic and combined interpretation. CONCLUSION: The accuracy of US in patients with palpable mammographically noncalcified and not obviously malignant breast tumors is lower than reported for mixed sample populations. The accuracy of US may be influenced by breast parenchyma density. Combined reading offers the highest diagnostic accuracy.     

Retrieval Rate and Accuracy of Ultrasound-Guided 14-G Semi-Automated Core Needle Biopsy of Breast Microcalcifications

Objective

To evaluate the retrieval rate and accuracy of ultrasound (US)-guided 14-G semi-automated core needle biopsy (CNB) for microcalcifications in the breast.

Materials and Methods

US-guided 14-G semi-automated CNB procedures and specimen radiography were performed for 33 cases of suspicious microcalcifications apparent on sonography. The accuracy of 14-G semi-automated CNB and radiology-pathology concordance were analyzed and the microcalcification characteristics between groups with successful and failed retrieval were compared.

Results

Thirty lesions were successfully retrieved and the microcalcification retrieval rate was 90.9% (30/33). Thirty lesions were successfully retrieved. Twenty five were finally diagnosed as malignant (10 invasive ductal carcinoma, 15 ductal carcinoma in situ [DCIS]) and five as benign. After surgery and mammographic follow-up, the 25 malignant lesions comprised 12 invasive ductal carcinoma and 13 DCIS. Three lesions in the failed retrieval group (one DCIS and two benign) were finally diagnosed as two DCIS and one benign after surgery. The accuracy of 14-G semi-automated CNB was 90.9% (30/33) because of two DCIS underestimates and one false-negative diagnosis. The discordance rate was significantly higher in the failed retrieval group than in the successful retrieval group (66.7% vs. 6.7%; p < 0.05). Punctate calcifications were significantly more common in the failed retrieval group than in the successful retrieval group (66.7% vs. 3.7%; p < 0.05).

Conclusion

US-guided 14-G semi-automated CNB could be a useful procedure for suspicious microcalcifications in the breast those are apparent on sonography.     

US of mammographically detected clustered microcalcifications

PURPOSE: To determine whether ultrasonography (US) can depict breast masses associated with mammographically detected clustered microcalcifications and whether the visibility at US is different between benign and malignant lesions. MATERIALS AND METHODS: Ninety-four patients with 100 mammographically detected microcalcification clusters prospectively underwent US with a 10- or 12-MHz transducer before mammographically guided presurgical hook-wire localization. The visibility of breast masses at US was correlated with histologic and mammographic findings. RESULTS: Surgical biopsy revealed 62 benign lesions, 30 intraductal cancers, and eight invasive cancers. At US, breast masses associated with microcalcifications were seen in 45 (45%) of 100 cases. US depicted more breast masses associated with malignant (31 [82%] of 38) than with benign (14 [23%] of 62) microcalcifications (P: <.001). In malignant microcalcification clusters larger than 10 mm, US depicted associated breast masses in all 25 cases. There was no statistically significant difference in shape and distribution of calcific particles, as well as in breast composition, at mammography between US visible and invisible groups. CONCLUSION: Given a known mammographic location, US with a high-frequency transducer can depict breast masses associated with malignant microcalcifications, particularly clusters larger than 10 mm. US can be used to visualize large clusters of microcalcifications that have a very high suspicion of malignancy.     

Real-time breast sonography: application in 300 consecutive patients

Sonography, disappointing as a primary screening method, has emerged as the single most helpful adjunct to mammography in evaluation of the clinically and/or mammographically abnormal breast. Sonography can reliably diagnose simple cysts presenting as palpable masses or as indeterminate, nonpalpable lesions on mammography. However, differentiation of benign from malignant solid masses cannot be reliably accomplished by sonography. The expense of an automated breast sonographic scanner has deterred many radiologists from the purchase of such a unit. The authors have used both an automated breast scanner and a real-time 10-MHz hand-held unit. This paper describes their experience with the real-time unit, demonstrating both normal and pathologic anatomy. Special emphasis has been placed on the sonographic diagnosis of a simple cyst because this lesion was the cause of one-quarter of all palpable masses and nonpalpable, mammographically dominant masses. Cysts are sharply marginated and anechoic. Posterior enhancement visible in 78 of 80 cysts was not demonstrable on all images in 25% of cysts.     

Differentiation of benign and malignant local tumor recurrence after lumpectomy

During a 5-year period, 28 women who had been treated conservatively for breast carcinoma had 29 reexcisions of the lumpectomy site because of suspicion of a recurrent malignant tumor. Biopsy results were benign in 19 cases and malignant in 10 cases. Sixteen of the 19 benign tumors had developed within 2 years after therapy. In 16 benign cases, a palpable lump developed at the scar and was found on biopsy to be fat necrosis or fibrosis. Seven of these cases had normal mammographic findings. Three women with abnormal mammographic findings but a normal breast examination had punctate microcalcifications develop at the scar; these were due to fibrosis in two and sclerosing adenosis in the other. Of the 10 malignant recurrent tumors, seven were palpable, four of which also were identifiable by mammography. Of seven mammographically identifiable recurrent tumors at the surgical site, four were palpable. Mammographic findings were a single mass in two cases, multiple masses in one, microcalcification in three, and a mass with microcalcifications in one. Malignant microcalcifications were all linear, irregular, and in one case branching. Mean time to recurrence in these 10 women was 3 years. This experience suggests that benign disease usually occurs at the scar within 2 years after the original therapy and when palpable may not show changes on mammography. When microcalcifications do occur, they are usually punctate.