False-negative diagnoses at stereotactic vacuum-assisted needle breast biopsy: long-term follow-up of 1,280 lesions and review of the literature.

OBJECTIVE: The purpose of this study was to determine retrospectively the frequency and causes of false-negative diagnoses of lesions evaluated with percutaneous stereotactic biopsy performed with vacuum-assisted probes with the patient prone on a biopsy table. MATERIALS AND METHODS: The records of 1,152 women (median age, 55 years; range, 31-94 years) with 1,280 lesions consecutively biopsied with 14-gauge (n = 159) or 11-gauge (n = 1,121) vacuum probes were reviewed retrospectively. The histologic diagnoses were malignant (n = 489), high-risk (n = 117), and benign (n = 674) lesions. Benign lesions were evaluated with repeated biopsy (n = 46) or mammographic follow-up for 24 months or longer (n = 506) or less than 24 months (n = 57). In 65 cases (10% of all benign lesions), follow-up was not performed. Fisher's exact tests were used to correlate patient, mammographic, and biopsy variables with false-negative diagnoses. RESULTS: Of 508 lesions with a final diagnosis of malignancy, the initial needle biopsy diagnosis was malignant (n = 489), high-risk (n = 14), or benign (n = 5) lesion. The five false-negative diagnoses were related to gauge of the biopsy probe and specimen radiographic findings regarding calcifications but were not related to lesion type. False-negative diagnoses were made in 4.4% (three of 68) of cases in which 14-gauge vacuum biopsy was performed and in 0.45% (two of 440) of cases in which 11-gauge vacuum biopsy was performed (p = 0.019). False-negative diagnoses were made in 25% (one of four) of cases in which specimen radiographs showed no calcifications and 0.67% (two of 300) of cases in which they did show calcifications (p = 0.0390). False-negative diagnoses were made in 1.2% (three of 248) of cases of calcification lesions and 0.8% (two of 260) of cases of mass lesions (p = 0.679). CONCLUSION: False-negative findings at stereotactic biopsy were least common with 11-gauge probes and were similar in frequency for calcifications and masses.

Estrogen receptor-negative invasive breast cancer: imaging features of tumors with and without human epidermal growth factor receptor type 2 overexpression.

PURPOSE: To prospectively determine if estrogen receptor (ER)-negative human epidermal growth factor receptor type 2 (HER2)-positive and ER-negative HER2-negative breast cancers have distinguishing clinical and imaging features with use of retrospectively identified patients and tissue samples. MATERIALS AND METHODS: This HIPAA-compliant study was institutional review board approved. Informed consent was obtained from living patients and waived for deceased patients. Mean patient age at diagnosis was 53 years (range, 31-84 years). Clinical history; histopathologic, mammographic, and breast sonographic findings; and HER2 status as determined with immunohistochemistry or fluorescent in situ hybridization were evaluated in 56 women with ER-negative breast cancer. Imaging appearances and clinicopathologic characteristics were correlated with tumor HER2 status. P < .05 indicated a significant difference. RESULTS: Lesion margins on mammograms (P = .028) and sonograms (P = .023), calcifications on mammograms (P = .003), and clinical cancer stage at diagnosis (P = .029) were significantly associated with HER2 status. In contrast to ER-negative HER2-negative tumors, ER-negative HER2-positive tumors were more likely to have spiculated margins (56% vs 15%), be associated with calcifications (65% vs 21%), and be detected at a higher cancer stage (74% vs 57%). CONCLUSION: Biologic diversity of cancers may manifest in imaging characteristics, and, conversely, studying the range of imaging features of cancers may help refine current molecular phenotypes.

Lobular neoplasia at percutaneous breast biopsy: variables associated with carcinoma at surgical excision.

OBJECTIVE: The purpose of our study was to better define the rate and variables associated with cancer underestimation when lobular neoplasia is found at minimally invasive breast biopsy. MATERIALS AND METHODS: The records of 32,420 patients who underwent imaging-guided needle biopsy of the breast for mammographic or sonographic abnormalities from 1988 to 2000 were retrospectively reviewed. The 278 cases in which lobular neoplasia was the highest-risk lesion at biopsy were included. Of the 278 cases, 164 proceeded to surgical excision, allowing calculation of rates of underestimation from minimally invasive biopsy. RESULTS: Of the 32,420 minimally invasive breast biopsies, lobular neoplasia was found in 278 (0.9%). One hundred sixty-four of the 278 (59%) continued to surgical excision, where cancer was pathologically confirmed in 38 (23%). No difference was seen in the underestimation rates for lesions diagnosed as lobular carcinoma in situ (25%, 17 of 67 lesions) versus atypical lobular hyperplasia (22%, 21 of 97 lesions). Statistically significant underestimation of carcinoma was found with biopsy of masses (with or without associated microcalcifications) rather than calcifications only, a higher BI-RADS category (p < 0.0001), use of a core biopsy device rather than a vacuum device (p < 0.01), and obtaining fewer specimens (p < 0.0001). CONCLUSION: Significant sampling error occurs regardless of the type of core biopsy device, number of specimens obtained, histologic-radiographic concordance, mammographic appearance, and complete excision of the lesion as determined by imaging. For this reason, all patients with lobular neoplasia at core or vacuum-assisted biopsy should undergo surgical excision until further differentiating criteria can be determined.

Breast microcalcifications: retrieval failure at prone stereotactic core and vacuum breast biopsy--frequency, causes, and outcome.

PURPOSE: To retrospectively determine the frequency and causes of failure to retrieve microcalcifications in nonpalpable lesions, as judged on a radiograph of the specimen, and to determine outcome in patients with those lesions. MATERIALS AND METHODS: Informed consent was obtained from each patient prior to biopsy. The institutional review board approved this HIPAA-compliant study and granted a waiver of informed consent. Retrospective review was performed of 1701 consecutive nonpalpable microcalcification lesions in 1511 women aged 29-92 years (median age, 54 years) who underwent percutaneous stereotactic biopsy on a prone biopsy table. Biopsy was successively performed with 14-gauge core, 14-gauge vacuum, and 11-gauge vacuum devices, with mild selection bias, and for each lesion, biopsy was performed with one device. Radiographs of the specimen were obtained to see whether microcalcifications were retrieved. Patient, mammographic, and biopsy variables were correlated with negative radiographs of the specimen. At repeat biopsy or mammographic follow-up, outcome was evaluated in patients with benign histologic results and negative radiographs of the specimen by using Fisher exact test P values. RESULTS: Radiographs of the specimen were negative in 16% (30 of 182) of lesions at 14-gauge core biopsy, in 4% (four of 96) of lesions at 14-gauge vacuum biopsy, and in 1% (19 of 1423) of lesions at 11-gauge vacuum biopsy (P < .001). Substantial bleeding was a significant factor (P < .001) in failure to retrieve microcalcifications at only 11-gauge vacuum biopsy. Histologic results in 53 lesions with negative radiographs of the specimen were malignant (n = 6), indicated atypical hyperplasia (n = 6), or were benign (n = 41). Follow-up in patients with 40 benign lesions was performed with repeat biopsy (n = 17, with malignancy in three lesions) or mammography (n = 23) for 15-128 months (median, 70 months); one patient with one lesion was lost to follow-up. CONCLUSION: Failure to retrieve microcalcifications was least common with 11-gauge directional vacuum-assisted biopsy and occurred in 1% (19 of 1423) of lesions. Cancer was missed in 8% (three of 40) of benign lesions in patients who were followed up.

Stereotactic histologic biopsy in breasts with implants.

PURPOSE: To describe our experience with stereotactic histologic biopsy in patients with breast implants. MATERIALS AND METHODS: Thirty-one (1.3%) of 2,399 consecutive lesions on which stereotactic histologic biopsy was performed were in breasts containing implants. Biopsy difficulties were evaluated for lesions in breasts with and breasts without implants. Biopsy was performed on lesions in patients with implants prone on a dedicated table, with automated large-core (n = 13) or directional vacuum-assisted (n = 18) devices. Follow-up was surgical (11 of 11 malignancies and two of three high-risk lesions) and mammographic (one of three high-risk lesions and 17 of 17 benign lesions). RESULTS: There were no implant ruptures, hematomas requiring drainage, infections requiring treatment, false-negative findings, or histologic underestimations. Difficulties with stereotactic histologic biopsy were more prevalent in breasts with implants and included positioning problems in 10 (50%) of 20 lesions in breasts with subglandular implants and zero (0%) of 10 with subpectoral implants, lesions seen on only one view in four (13%) of 31 lesions, specimen radiographs negative for calcifications in two (10%) of 20 lesions, prominent bleeding in two (6%) of 31 lesions, and suboptimally small tissue samples in three (10%) of 31 lesions. CONCLUSION: Stereotactic histologic biopsy is safe in breasts with implants. Compared with that in breasts without implants, biopsy is often technically more difficult and may eventually prove less accurate.

Clip or marker migration 5-10 weeks after stereotactic 11-gauge vacuum-assisted breast biopsy: report of two cases.

Two women, aged 50 and 51 years, underwent stereotactic, 11-gauge vacuum-assisted biopsy from the cranial approach of small lesions in the upper outer quadrant of the right breast with removal of lesions that were detected with mammography. Postbiopsy mammograms showed the metal clip or marker at the biopsy sites in both patients. Histologic analysis of both lesions indicated atypical hyperplasia. Mammograms obtained prior to surgical excision showed caudal z-axis migration of the clip or marker to be 6.5 cm at 5 weeks and 4.5 cm at 10 weeks, respectively. By ignoring the clip or marker that had migrated to an inaccurate location and by using internal and external breast landmarks to guide presurgical excision needle localization, the biopsy sites were successfully excised in both patients.

Stereotactic histologic biopsy with patients prone: technical feasibility in 98% of mammographically detected lesions.

OBJECTIVE: The purpose of this retrospective study was to determine which mammographically detected lesions in need of imaging-guided biopsy could undergo prone, stereotactic biopsy. MATERIALS AND METHODS: From July 1991 through June 2001, 1687 consecutive patients (age range, 29-94 years; median age, 58 years) with 1894 lesions were referred by clinicians in a multispecialty clinic. The patients underwent stereotactic, prone, histologic biopsy of 1851 lesions (98%) and needle-localized breast biopsy of 43 lesions (2%). We performed stereotactic biopsies successively with 14-gauge automated large-core devices and 14- or 11-gauge vacuum-assisted devices. We evaluated lesions by patient, breast, lesion, and procedural variables to determine why stereotactic biopsy was not performed. RESULTS: Of 1851 lesions referred for stereotactic biopsy, biopsies were canceled in 42 lesions (2%) not considered suspicious enough to warrant biopsy. Of 1809 lesions in which stereotactic biopsy was considered to be warranted, stereotactic biopsy was canceled for technical reasons in 29 lesions (2%). Of 43 lesions referred for surgical biopsy, stereotactic biopsy was thought to be technically problematic in five (12%). Inability to accomplish a stereotactic biopsy in 34 (2%) of 1852 lesions needing a biopsy was due to proximity to the chest wall (n = 10, 29%), inadequate lesion visualization unrelated to lesion depth (n = 19, 56%), and patient factors (n = 5, 15%). CONCLUSION: Stereotactic biopsy had a technical success rate of 98% (1780/1809) and was used for histologic diagnosis in 96% (1780/1852) of mammographically detected lesions. Inadequate lesion visualization accounted for 85% (29/34) of stereotactic biopsy failures.

Atypical ductal hyperplasia: can some lesions be defined as probably benign after stereotactic 11-gauge vacuum-assisted biopsy, eliminating the recommendation for surgical excision?

PURPOSE: To determine if a subset of atypical ductal hyperplasia (ADH) lesions diagnosed at 11-gauge, directional, vacuum-assisted, prone, stereotactic biopsy fit the "probably benign" definition of a less than 2% chance of being carcinoma at subsequent surgical excision. MATERIALS AND METHODS: Clinical, mammographic, and stereotactic biopsy features in 104 consecutive nonpalpable ADH lesions were correlated with the presence of carcinoma at lumpectomy. The results were analyzed with chi(2) statistic, with P <.05 indicative of significant difference. RESULTS: Surgical excision revealed carcinoma in 22 (21%) of 104 ADH lesions. The lowest incidences of carcinoma (each P <.02) were 16% (15 of 92) in patients with no personal history of breast carcinoma, 13% (nine of 67) when maximum lesion diameter was less than 10 mm, and 8% (three of 36) when 100% of the mammographic lesion was removed at stereotactic biopsy. CONCLUSION: No clinical, mammographic, or biopsy features alone or in combination could be used to define a substantial subset of probably benign lesions with a less than 2% chance of carcinoma at lumpectomy.

Stereotactic 11-gauge vacuum-assisted breast biopsy: influence of number of specimens on diagnostic accuracy.

PURPOSE: To determine whether number of specimens obtained at stereotactic 11-gauge vacuum-assisted breast biopsy with the patient prone influences diagnostic accuracy and to determine whether this number varies depending on mammographic appearance of lesions as masses or microcalcifications. MATERIALS AND METHODS: Biopsy was prospectively performed in 100 patients (median age, 55 years; range, 31-81 years) with 100 lesions that were mammographically evident as masses (n = 50) and microcalcifications (n = 50) with standardized protocol to acquire 20 specimens per lesion in three 360 degrees probe rotations at one skin entry site. Specimens were histologically evaluated sequentially, and findings were compared with results of surgical excision or of mammographic follow-up for at least 24 months. Differences in diagnostic yield after each probe rotation and differences in diagnostic yield between masses and microcalcifications were determined with chi(2) test. RESULTS: Up to 12 specimens harvested within two 360 degrees probe rotations were necessary to yield correct diagnosis in 96% of patients with masses and 92% of patients with microcalcifications. Diagnostic yield was not improved with more than 12 specimens for masses or microcalcifications. In two (4%) of 47 patients with lesions that were eventually diagnosed as cancer, results at stereotactic biopsy indicated they were benign. Underestimation of diagnosis of lesions as atypical ductal hyperplasia and ductal carcinoma in situ occurred in two (50%) of four and two (17%) of 12 lesions, respectively. With 20 specimens harvested during three probe rotations, there was no statistically significant difference in diagnostic yield between patients with masses and those with microcalcifications (P =.68). CONCLUSION: At 11-gauge vacuum-assisted biopsy, highest diagnostic yield was achieved with 12 specimens per lesion, independent of mammographic appearance of the lesion. Even with standardized retrieval of 20 specimens per lesion, underestimation of disease still occurs.

Percutaneous core needle biopsy of radial scars of the breast: when is excision necessary?

OBJECTIVE: . This study was conducted to evaluate the outcome of cases of radial scar diagnosed by percutaneous core needle biopsy. MATERIALS AND METHODS: Of 198 nonpalpable lesions diagnosed with radial scars found at core needle biopsy, 157 lesions constituting the study group had undergone surgical excision (n = 102) or mammographic surveillance after biopsy for at least 24 months (median, 38 months; n = 55). Mammographic lesion type, lesion size, biopsy guidance method, biopsy device, number of specimens per lesion, and presence of atypical hyperplasia at percutaneous biopsy were retrospectively analyzed. Results were compared with histologic findings at surgery or mammographic findings during surveillance. RESULTS: . Carcinoma was found at excision in 28% (8/29) of lesions with associated atypical hyperplasia at percutaneous biopsy and 4% (5/128) of lesions without associated atypia (p < 0.0001). In the latter group, carcinoma was found at excision in 3% (2/60) of masses, 8% (3/40) of architectural distortions, and 0% (0/28) of microcalcification lesions. Malignancy was missed in 9% (5/58) of lesions biopsied with a spring-loaded device and in 0% (0/70) of lesions biopsied with a directional vacuum-assisted device (p = 0.01); and in 8% (5/60) of lesions sampled with less than 12 specimens per lesion and 0% (0/68) sampled with 12 or more specimens (p = 0.015). Lesion type, maximal lesion diameter, and type of imaging guidance (stereotactic or sonographic) were not significant factors in determining the presence of malignancy. CONCLUSION: . Diagnosis of radial scar based on core needle biopsy is likely to be reliable when there is no associated atypical hyperplasia at percutaneous biopsy, when the biopsy includes at least 12 specimens, and when mammographic findings are reconciled with histologic findings. When the lesion diagnosed by core needle biopsy as radial scar does not meet these criteria, excisional biopsy is indicated.