微小乳腺癌的直接数字化X线征象与临床查体及病理关系的分析

目的分析微小乳腺癌的直接数字化X线征象,并探讨其与临床查体及病理的关系。方法回顾性分析经手术、病理证实的微小乳腺癌68例。采用直接数字化乳腺X线机后处理工作站屏幕阅读方式。结果X线征象为结节者39例,单纯钙化14例,结构紊乱8例,致密影7例,除单纯钙化外,其他征象伴有钙化者37例。临床触诊阳性42例,阴性26例。本组15例(占22%)为非浸润性癌,不可触及微小癌中46%为非浸润性癌。结论微小乳腺癌X线表现为结节、单纯钙化、结构紊乱或致密影,细钙化是微小癌重要X线征象。直接数字化X线摄影对诊断临床触诊阴性的微小乳腺癌有重要价值。     

Additional value of fine-needle aspiration biopsy in a mammographic screening trial

The Stockholm breast cancer screening trial used single-view mammography as the sole screening method. A majority (63 per cent) of the mammographic selected cases from the first two screening rounds had uncertain mammograms, coded as 3 on an ordinal scale from 1 to 5, where 1 and 2 are dismissed as normal mammograms and 5 stands for a typical cancer. In this group of uncertain mammograms 30 cases were malignant and 431 were non-malignant. The aim of this study was to examine whether surgical biopsy in this group could be replaced by fine-needle aspiration (FNA) biopsy, combined with the information from the mammogram and clinical examination, and whether this diagnostic strategy could select the malignant cases with a high sensitivity. FNA biopsy selected 25 of the 30 mammary carcinomas as definite malignancy or atypia, with a sensitivity of 83 per cent (95 per cent confidence interval: 69-96 per cent), and combined with the information from the mammogram and clinical examination 29 of the malignancies were selected with a sensitivity of 97 per cent (95 per cent confidence interval: 83-100 per cent). In 398 of 431 non-malignant cases the diagnosis was established with the triple diagnostic approach without needing a surgical biopsy. In a clinical follow-up study, up to 64 months after the first screening round, only one false negative case was found, included in the group of 30 malignancies described above. With this strategy the rate of negative surgical biopsies was reduced by 90 per cent in the group with uncertain mammograms and without considerably impairing the reliability of the results.     

Outcome of surgery for non-palpable mammographic abnormalities

Four hundred and ninety-three women underwent 515 localization biopsies for non-palpable mammographic abnormalities. The mammographic abnormality was located with a hooked wire in 509 cases. Specimen radiology was performed on all excised tissue. The mammographic abnormality was visualized in the first piece of tissue excised in 402 (78.1 per cent) cases and complete excision was achieved in 476 (92.4 per cent). A palpable nodule was removed in 38 (7.4 per cent) cases and in 17 (44.7 per cent) was shown to contain a carcinoma. The mammographic abnormality was missed in 14 (2.7 per cent) cases or only partly excised in 13 (2.5 per cent). Overall 144 (28.0 per cent) localization biopsies were malignant. The mammographic abnormality was not visualized on the specimen radiograph more frequently in women aged under 55 years, in women with dense breast (Wolfe grade DM or DY) or in those whose mammographic abnormality contained only microcalcification. The 27 women in whom the mammographic abnormality was not visible on the specimen radiograph underwent repeat mammography 2 months later. Only two women required a further localization biopsy and the mammographic abnormality was recovered in the first piece of tissue excised. Women with a carcinoma underwent mastectomy or wide local excision, and residual carcinoma at the localization biopsy site was found in 64 (44.4 per cent) cases. Oestrogen receptor analysis by ligand binding assay was possible in only 71 (49.3 per cent) carcinomas. If the specimen radiograph does not show the mammographic abnormality within pieces of tissue excised and there is no palpable nodule it may be best to conclude the biopsy. In this series these missed lesions were usually benign. Only rarely is a second localization biopsy required and this is performed without difficulty.     

The use of state-of-the-art mammography in the detection of nonpalpable breast carcinoma

Between November 4, 1984, and September 1, 1988, a total of 16,439 patients were evaluated at the Comprehensive Breast Center at Mount Sinai Medical Center (MSMC) of Miami Beach with clinical examination, state-of-the-art mammography, and, when indicated, complimentary ultrasound mammography. As a result of this, 547 patients had open surgical biopsy, 207 carcinomas were detected in 207 patients, 183 carcinomas (80% of total malignancies) were clinically occult and detected only with breast imaging. Since 207 malignancies were found out of 547 areas examined, our rate was 1 carcinoma in every 2.6 biopsies. One hundred seventy-nine malignant lesions had preoperative needle localization and specimen radiography. Eighty-seven (47%) clinically occult carcinomas were identified because of microcalcifications by mammography alone. Two hundred twenty-six (98%) of the carcinomas were called malignant or suspicious for malignancy with only three (2.4%) false negatives. Twenty-two (10%) patients had axillary lymph-node metastasis. While recent large series report a 15 to 30 per cent rate of carcinoma for nonpalpable, mammographically detected breast biopsy specimens, it is our experience at MSMC with the use of physical exam and mammography, complemented by ultrasound when indicated, that rates of detection of carcinoma are more significantly improved than what the recent literature suggests; therefore, our approach to achieve this better detection will be discussed.     

The natural history of mammographic calcifications subjected to interval follow-up.

The purpose of this investigation was to determine the natural history and risk of malignancy associated with isolated indeterminate microcalcifications subjected to interval follow-up. During a 2-year study, 91 patients were identified with indeterminate microcalcifications alone. Specific roentgenographic features of the calcifications were evaluated on initial and follow-up mammograms. During a mean follow-up of 36 months, 19 (21%) of the women exhibited mammographic changes. Ten patients (11%) with suspicious changes underwent a needle-directed biopsy 6 to 30 months after the initial mammographic screening. Five women (5.5%) were diagnosed as having breast carcinoma; three had invasive ductal carcinoma and two had purely intraductal lesions. Four patients had axillary lymph node dissections and no metastatic disease was found. We found no significant differences in the roentgenographic features associated with malignant vs benign lesions apart from an increased overall estimation of the probability of malignancy rating in the five patients with breast carcinoma. We recommend that patients be followed up with mammography at regular intervals for at least 18 months following recognition of indeterminate microcalcifications.     

Assessment of non-palpable mammographic abnormalities: comparison between screening and symptomatic clinics.

A retrospective study found that a breast screening clinic generated fewer localization biopsies for non-palpable mammographic abnormalities than a symptomatic clinic (3.36 versus 9.89 per 1000 mammograms, respectively) and that a greater proportion of such biopsies were malignant. This study determined the reason for this difference. There were 108 of 304 (35.5 per cent) and 17 of 130 (13.1 per cent) carcinomas in women attending the screening and breast clinics respectively (relative risk 2.72 (95 per cent confidence interval 1.70-4.34)). This difference was regardless of age. The characteristics of the mammographic abnormality, the Wolfe pattern, a family history of breast carcinoma, parity and age at first pregnancy were similar in both groups. Women attending the screening clinic were referred for localization biopsy after assessment by clinicians and radiologists at a joint clinic; there was no joint assessment for patients attending the breast clinic. The same staff attended both clinics, although the proportion of time spent at each varied. This study suggests that all women with a non-palpable mammographic abnormality should be reviewed at a joint assessment clinic before localization biopsy is recommended.     

Wire-guided biopsies of nonpalpable breast lesions

The purpose of this study was to review the results of mammographic wire-guided biopsies of nonpalpable breast lesions and the features of the lesions in the preoperative examinations. Sixty women, mean age 50.2 years (range 31 to 74), underwent a wire-guided biopsy of the lesion. Twenty-nine patients had preoperative fine needle aspiration of the lesion. The radiographic diagnosis was correct in 33 patients (55%); 25 had breast cancer and 8 patients had a benign lesion. In 9 of the 14 patients with clustered microcalcifications in mammography and in 13 of the 15 patients with a mass noted in mammography, the cytological examination was correct. Nonpalpable mammographic masses with regular borders and normal fine needle aspiration examination do not require biopsy. In malignant mammographic appearances associated with a normal fine needle aspiration examination, biopsy of the lesion should always be done.     

The changing mammogram. A primary indication for needle localization biopsy

Screening mammography results in improved detection and survival for women with breast cancer. Interval mammographic changes may be one of the major indications for biopsy. Four hundred fifty-two needle localization biopsies carried out for microcalcifications, mass, asymmetric density, or a combination of calcifications with mass or asymmetric density detected 95 cancers (21%). Interval mammographic changes detected 35 cases (17.9%). Invasive cancers constituted 51% of the initial group but only 34% of the cancers detected because of interval change. Benign breast disease occurred in 160 of 195 women who had undergone biopsy because of interval changes. These changes continued into the postmenopausal period. Hyperplasia and/or atypia was found in 57 (35%) of 160 of the interval group. Interval mammographic abnormalities detect significant pathologic changes in the breast and should be considered a major indication for breast biopsy.     

Outcome of men presenting with clinical breast problems: the role of mammography and ultrasound

The purpose of this study was to determine the outcome of men presenting with clinical breast problems for breast imaging and to evaluate the role of mammography and ultrasound in the diagnosis of benign and malignant breast problems. We retrospectively reviewed clinical, radiographic, and pathologic records of 165 consecutive symptomatic men presenting to Breast Imaging over a 4 year period. We assessed the clinical indication for referral, mammographic findings, sonographic findings, histologic results, and clinical outcomes. Patients ranged in age from 22 to 96 years. Breast Imaging Reporting and Data System (BI-RADS) category 4 and 5 mammograms and solid sonographic masses were considered suspicious for malignancy. Six of 165 men (4%) had primary breast carcinoma, which were mammographically suspicious in all 6 (100%). Five were invasive ductal carcinoma and one was ductal carcinoma in situ (DCIS). Of 164 mammograms, 20 (12%) were suspicious. Six were cancer and 14 were benign. Clinical follow-up for 2 years or biopsy results were available for 138 of the 165 men (84%). Twelve with benign mammographic findings had benign biopsies. All men with benign mammography not undergoing biopsy were cancer free. Sensitivity for cancer detection (mammography) was 100% and specificity was 90%. Positive predictive value (mammography) was 32% (6 of 19) and the negative predictive value was 100%. Sonography was performed in 68 of the 165 men (41%). Three of three cancers (100%) were solid sonographic masses. There were 9 of 68 false-positive examinations (13%). Sensitivity and negative predictive value for cancer detection (ultrasound) was 100% and specificity was 74%. The most common clinical indication for referral was mass/thickening (56%). Mammography had excellent sensitivity and specificity for breast cancer detection and should be included as the initial imaging examination of men with clinical breast problems. The negative predictive value of 100% for mammography suggests that mammograms read as normal or negative need no further examination if the clinical findings are not suspicious. A normal ultrasound in these men confirms the negative predictive value of a normal mammogram.     

The significance of malignancies incidental to microcalcifications in breast spot localization biopsy specimens

BACKGROUND: Incidental breast cancer is occasionally found in spot localization biopsy specimens adjacent to mirocalcifications in benign breast disease. Because this phenomenon could prove problematic for percutaneous sampling of microcalcifications without excisional biopsy, we studied surgical specimens from patients with cancers incidental to microcalcifications and compared them with specimens with microcalcifications within the malignancy. METHODS: The pathology database at the Mount Sinai Medical Center from January 1993 to July 1998 was reviewed to identify breast cancer patients who underwent spot localization biopsy for microcalcifications. Patients presenting with microcalcifications within malignancy (determinate) were compared with patients with mirocalcifications in benign breast tissue adjacent to malignancy (incidental). RESULTS: Thirty-two (13%) of the 241 specimens had microcalcifications in benign tissue adjacent to malignancy and 209 (87%) had microcalcifications within the malignancy. Fifty-six percent of the incidental cases and 65% of the controls had ductal carcinoma in situ. Infiltrating lobular carcinoma accounted for 25% of the incidental cancers and 2% of the determinate cancers (P <0.001). Fifty-seven percent of the infiltrating carcinomas incidental to mammographic findings were infiltrating lobular carcinoma compared with 7% of the nonincidental infiltrating carcinomas. None of the incidental invasive carcinomas were poorly differentiated (P = 0.002). There were no significant differences with regard to age, tumor size, stage, differentiation, estrogen and progesterone receptors, type of surgery and final margin status. In none of the patients with incidental malignancies did local or distant recurrences develop. CONCLUSIONS: Incidental carcinomas were found in 13% of spot localization biopsy specimens obtained for suspicious mammographic microcalcifications and have a favorable prognosis. Infiltrating lobular carcinomas are more commonly found with incidental microcalcifications than with determinate microcalcifications, and incidental invasive carcinomas are less likely to be poorly differentiated. The majority of malignancies, both determinate and incidental to microcalcifications, are due to ductal carcinoma in situ. Incidental malignancies commonly occur adjacent to fibrocystic changes and their other pathologic characteristics are not significantly different from nonincidental carcinomas. Despite the absence of radiographic findings, these patients can be successfully treated with breast conservation.     

The significance of atypical lobular hyperplasia at percutaneous breast biopsy

Atypical lobular hyperplasia (ALH) is occasionally found in specimens obtained by percutaneous stereotactic vacuum-assisted breast biopsy for microcalcifications. Since malignancy is often found at surgical excision when atypical ductal hyperplasia is found at percutaneous biopsy, we reviewed our pathologic findings from surgery for ALH at percutaneous biopsy. This was a retrospective review of all percutaneous breast biopsy specimens for mammographic microcalcifications obtained from a single institution over a 30-month period. The pathologic findings from percutaneous biopsy were correlated with the radiologic appearance and the pathology from surgical excision. ALH was found in 13 of 766 (1.7%) stereotactic vacuum-assisted core needle biopsies performed for mammographic microcalcifications. Subsequent surgery in six patients revealed ductal carcinoma in situ (DCIS) in two patients and one case of invasive ductal carcinoma. Surgical excision is indicated for areas with ALH discovered by percutaneous biopsy for mammographic microcalcifications.     

Screening mammography: a surgeon's strategy for dealing with abnormal mammographic findings

Screening mammography is a valuable tool in the detection of breast cancer at an early stage. Large numbers of patients are being referred to surgeons for biopsies on the basis of mammographic abnormalities alone. As mammograms are complex studies and the findings often subtle, variation in terms of interpretation and recommendations for biopsy can leave the surgeon in a difficult position. We have reported a systematic method for evaluating patients and mammograms. Eighty-eight patients were referred to a single surgeon solely for an abnormal mammographic finding. Physical examination was repeated and the mammogram reviewed with a single consulting radiologist using specific criteria to define a mammographic abnormality. Through this evaluation, biopsy was avoided in 42 of 88 patients, with follow-up mammograms and physical examinations finding no suspicion of malignancy. By becoming educated in regard to mammographic abnormalities, establishing specific criteria with a consistent radiologist, and following patients carefully who are not biopsied, the surgeon can deal effectively with screening mammography.     

Selective nonoperative management of patients referred with abnormal mammograms

Screening mammography provides a means of detecting clinically occult breast carcinoma, but the question of whether all abnormal mammograms require biopsy remains unanswered. We retrospectively reviewed records of 214 women referred over an 8-year period for abnormal mammograms. They were selectively assigned to biopsy or mammographic follow-up based on specific mammographic criteria. Of 114 women initially observed mammographically, 2 were later found by biopsy to have carcinoma. Initial assignment to mammographic observation delayed the recommendation for biopsy 3 and 12 months, respectively, in these patients, but no effect on outcome was documented. Because they have benign lesions by clinical and mammographic criteria, 102 women (53%) have been spared biopsy; they continue to be monitored closely. We believe these data support the use of a selective approach to biopsy based on specific mammographic criteria.     

Mammographic screening in women at increased risk of breast cancer after treatment of Hodgkin's disease

Treatment regimens for Hodgkin's disease (HD) that have included radiation to lymph node regions in the thorax have contributed to high rates of long-term disease-free survival. However, incidental radiation exposure of breast tissue in young women has significantly increased the risk of breast cancer compared to expected rates in the general population. After informing patients about risks associated with previous treatment of HD, we studied screening mammograms and call-back rates in women at increased risk for developing breast cancer at a younger age. We contacted by mail a cohort of 291 women between 25 and 55 years of age who had received thoracic irradiation before 35 years of age for HD with or without chemotherapy. Subjects were offered information about risks identified after HD therapy with questionnaires to assess response to this information. Ten patients refused participation, 93 did not respond, and 21 were excluded after they reported a prior diagnosis of invasive (1) or in situ (2) breast cancer. One hundred and sixty seven women received information about secondary breast cancer risk and were advised to initiate or maintain mammographic screening. Available mammograms were reviewed by two radiologists and classified according to the ACR BI-RADS Mammography Lexicon. Abnormal findings were correlated to pathology results from biopsies. One hundred and fifteen subjects reported that they obtained new mammograms during the period of the study. Ninety-nine were available for secondary review. Patients were studied an average of 16.9 years after HD treatment (Range: 4.5-32.5 years) at an average of 41 years of age (range 25-55 years). High density breast tissue was identified in 60% (60/99). Seventeen of the women (17.2%) were recalled for further imaging. This was more common in women with heterogeneously dense breast tissue. Seven of those recalled (41%) were advised to undergo biopsies that identified ductal carcinoma in situ (DCIS) in one and benign findings in the others. Among 16 women whose mammograms were unavailable for review, three were diagnosed with DCIS; two of these had microscopic evidence of invasive breast cancer. The four in situ or microinvasive cancers were diagnosed in the study participants at 25-40 years of age and from 5 to 23 years after HD therapy. Biopsies were performed because mammograms detected microcalcifications without palpable abnormality in three of these cases. Women who have had thoracic nodal irradiation for Hodgkin's disease have an increased risk of developing secondary breast cancer at an unusually young age. As expected in younger women, high density breast tissue was common on mammography, and the recall and biopsy rates were unusually high. However, early mammographic screening facilitated diagnosis of in situ and early invasive cancer in 3.5% of our subjects.     

Breast biopsy. Changing patterns during a five-year period

The current emphasis on early detection of breast carcinoma prompted an analysis of all breast biopsies performed at an urban teaching hospital between January 1, 1983, and December 31, 1987. There were 1,342 biopsies during this interval in 933 patients with an overall mean age of 45.3 years. Malignancy was diagnosed in 197 patients (14.7%) with a mean age of 57.5 years, while the remaining patients with a benign diagnosis had a mean age of 43.2 years. There were 178 nonpalpable lesions (13.3%) and 22 malignancies were detected in this group (12.4%). Most (91%) of the nonpalpable malignancies were "early" (in situ and stage I), while 71 per cent of the palpable malignancies were "advanced" (stages II and III). Although the yearly number of biopsies remained constant, upward trends were demonstrated in the number of nonpalpable lesions biopsied, the proportion of malignancies detected among all biopsies, and in the yield of proliferative benign forms of breast disease, specifically those with atypia. These trends correlated with a sixfold increase in the yearly number of mammograms performed over the same time interval. These results suggest that a commitment to an expanded use of mammography and to an aggressive approach to breast biopsy can increase the detection of both early forms of breast carcinoma and those benign breast lesions that are known pathologic risk determinants for breast carcinoma. Such a commitment may influence the future survival of this population.     

Benign diagnosis by image-guided core-needle breast biopsy

Image-guided core-needle breast biopsy (IGCNBB) is widely used to evaluate patients with abnormal mammograms; however, information is limited regarding the reliability of a benign diagnosis. The goal of this study was to demonstrate that a benign diagnosis obtained by IGCNBB is accurate and amenable to mammographic surveillance. Records of all patients evaluated by IGCNBB from July 1993 through July 1996 were reviewed. Biopsies were classified as malignant, atypical, or benign. All benign cases were followed by surveillance mammography beginning 6 months after IGCNBB. Of the 1110 patients evaluated by IGCNBB during the study period, 855 revealed benign pathology. A total of 728 of the 855 patients (85%) complied with the recommendation for surveillance mammography. A total of 196 IGCNBBs were classified as malignant; 59 cases were classified as atypical. The atypical cases were excluded from the statistical analysis. Only two patients have demonstrated carcinoma after a benign IGCNBB during the 2-year minimum follow-up period. The sensitivity and specificity of a benign result were 100.0 and 98.9 per cent, respectively. A benign diagnosis obtained by IGCNBB is accurate and therefore amenable to mammographic surveillance. The results of this study support IGCNBB as the preferred method of evaluating women with abnormal mammograms.     

CORE BIOPSY FOR MICROCALCIFICATIONS IN THE BREAST

Background : The conventional method of dealing with clustered mammographic microcalcification in the breast when it is of uncertain aetiology is to undertake either a short-term mammographic review or to surgically excise the abnormal area and submit it for histological examination. Stereotactic wide-bore needle biopsy (core biopsy) of microcalcifications is a suitable alternative to surgical biopsy and experience with this technique forms the basis of the present study. Methods : Percutaneous core biopsy has been used at the Wesley Breast Clinic as a means of assessing clustered calcification in 297 cases from November 1992 to October 1995. The procedure is done under local anaesthesia as an outpatient procedure using a Stereotactic attachment to a standard mammography unit. Results : A diagnosis of frank malignancy was made on core samples in 22 cases (7.4%), and in all of these malignancy was confirmed at open surgical biopsy. In a further six women in whom the core biopsy was reported as ‘suspicious of malignancy’, open surgical biopsy confirmed malignancy in three women, lobular in situ carcinoma was found in two women, and atypical ductal hyperplasia in one woman. In two instances the core sample was reported as showing atypical ductal hyperplasia and in those cases, this was confirmed at open surgical biopsy. In 265 cases (89%) the histology of the core revealed appearances of benign breast tissue. Open surgical biopsy has been undertaken in only six of these cases, but in all instances the histology has confirmed a benign process. In the two remaining cases, the procedure was considered to be technically unsatisfactory, and open surgical biopsy was recommended because of doubt about the appearance of the microcalcification. In both instances, malignancy was demonstrated. Conclusions : Core biopsy of clustered mammographic microcalcification of uncertain aetiology is recommended as a satisfactory and reliable alternative to open surgical biopsy. It is less expensive, can be done quickly, produces few complications, and does not produce subsequent mammographic distortion.     

Changing patterns of care for occult breast lesions in a community teaching hospital

We performed a retrospective analysis of 384 consecutive stereotactic breast biopsies (SBBs) from March 1995 through January 1999 and compared it with our historical breast biopsy experience. Two hundred forty-four patients underwent biopsies for microcalcifications and 135 patients for abnormal mammographic densities. Pathology diagnoses included 302 patients with benign disease, 35 patients with atypical ductal hyperplasia, 4 patients with lobular carcinoma in situ, 29 patients with ductal carcinoma in situ, and 9 patients with invasive breast cancer. These diagnostic rates were compared with our prior needle-localized pathology findings. For the study period, the number of mammograms, open biopsies, and needle-localized biopsies remained stable. The number of SBBs, however, increased progressively in every year. Medicare reimbursement for SBB was $921.19, and for breast biopsy after needle localization, $1566.22. Our study strongly suggests that the availability of SBB has significantly lowered the threshold for recommending biopsy of abnormal mammograms. The increased utilization of SBB almost certainly indicates an increase in the overall cost of breast care. This cost must be balanced against substantial potential benefits of this minimally invasive technique: possible earlier diagnosis of atypical and precancerous lesions, patient reassurance in cases of uncertain mammographic interpretation, and a reduced need for follow-up of indeterminate mammograms.     

The risk of carcinoma in wire localization biopsies for mammographically detected clustered microcalcifications.

A total of 183 consecutive patients undergoing biopsies for unilateral microcalcifications concentrated in one or more segments of the breast in the absence of any palpable findings were analyzed to characterize their risk of cancer. Biopsy findings were benign in 86 patients (47%) and malignant in 97 (53%). Of the clinical and mammographic characteristics evaluated, an increasing number of linear microcalcifications, either without a dominant density (p = 0.014) or with a dominant density (p = 0.019) and the presence of heterogeneous microcalcifications (p = 0.055), were associated with a significantly increased risk of malignancy. Conversely a fibronodular parenchymal pattern (p = 0.008) was associated with a significantly decreased risk of malignancy. A high-risk group was identified, 95% (40/42) of whom had malignant biopsy findings, whose mammograms had more than 10 linear microcalcifications not associated with a dominant density (16/17) or at least one linear microcalcification associated with a dominant density (24/25). Conversely a low-risk group for cancer was identified, 88% (28/32) of whom had benign biopsy findings, whose mammograms had exclusively punctate microcalcifications within a fibronodular parenchymal milieu (26/30) or demonstrated some change in the configuration of the microcalcifications on the various mammographic views (10/10). For the remaining 109 patients there was an almost equal division between malignant and benign diagnoses (49% vs 51%).     

Invasive mammary carcinoma after immediate and short-term follow-up for lobular neoplasia on core biopsy

Lobular neoplasia (LN), including atypical lobular hyperplasia (ALH) and lobular carcinoma in situ, may be encountered in breast core biopsies performed for mammographic abnormalities even though LN is often not, in itself, responsible for the abnormal mammogram. The need for surgical excision following a diagnosis of LN on core biopsy is not well defined. We examined pathologic and mammographic findings in a consecutive series of cases diagnosed as LN to address this issue. Radiology/pathology records were reviewed for cases with a pathology diagnosis of pure LN during the period 1998-2001. Specifically excluded were cases with associated atypical ductal hyperplasia, ductal carcinoma in situ, invasive mammary carcinoma, or any history of breast malignancy. Thirty-five women 39-76 years of age (mean 52 years) were identified. Specimens were obtained as stereotactic core (31) or limited wire-guided biopsy (four). The diagnoses were lobular carcinoma in situ (12), lobular carcinoma in situ/ALH (10), and ALH (13). Fourteen patients did not undergo excisional biopsy and had no subsequent clinical follow-up to warrant additional biopsy (follow-up 6 months to 3 years). Five patients had no immediate excision, but eventually during clinical follow-up for LN (1 month to 3 years), two developed mammographic lesions in the ipsilateral (one patient) or contralateral breast (one patient) that led to diagnoses of invasive mammary carcinoma (lobular and composite ductal-lobular types, 10 and 8 mm, respectively); three patients had subsequent mammographic findings in the ipsilateral or contralateral breast leading to biopsies showing only LN (two patients) or no neoplastic pathology (one patient). The remaining 16 patients (all core biopsied) underwent immediate wire-guided excisions. Thirteen (81%) showed additional foci of LN, one (6.3%) with atypical ductal hyperplasia, and two (12.5%) with invasive lobular carcinoma (3 mm and <1 mm). Three (19%) had no residual disease; however, additional clinical follow-up in one of these patients revealed an invasive mammary carcinoma in the contralateral breast (false-negative mammography). Radiographic findings were calcifications and density/mass lesions in 27 and 8 cases, respectively. Of 27 cases presenting with Ca, 10 showed colocalization of LN and Ca. In the eight cases presenting with density/mass, incidental microscopic microcalcifications colocalized to LN were found in two cases. When present, histologic Ca was associated with LN in 12 of 29 cases studied (41%). Of the 21 patients with immediate or subsequent excision, five (24%) were found to have an associated invasive mammary carcinoma (two on immediate excision and three after short-term follow-up of up to 3 years). The bilaterality of cancer risk was expected; however, the number of invasive carcinomas was not. That the invasive carcinomas detected at follow-up were small implies that they might have been present (but occult) at initial presentation. We conclude that lobular carcinoma in situ detected on core biopsy is potentially a significant marker for concurrent and near-term breast pathology requiring complete intensive multidisciplinary clinical follow-up with specific individualization of patient care.