Morphologic subtypes of lobular carcinoma in situ diagnosed on core needle biopsy: clinicopathologic features and findings at follow-up excision.

Lobular carcinoma in situ (LCIS) is currently classified as classic (CLCIS), florid (FLCIS), and pleomorphic (PLCIS). Given the rarity of FLCIS and PLCIS, information on their clinico-pathologic features and biologic potential remains limited. We evaluated the upgrade rates at excision of FLCIS and PLCIS diagnosed on inhouse core needle biopsy (CNB) and their clinical presentation and follow-up. Over a period of 11 and a half years, there were a total of 36 inhouse CNBs with pure PLCIS (n = 8), FLCIS (n = 24), or LCIS with pleomorphic features (LCIS-PF) (n = 4). The upgrade rates to invasive carcinoma or ductal carcinoma in situ (DCIS) were 25% for PLCIS (2/8), 17% for FLCIS (4/24), and 0% for LCIS-PF (0/4). The overall upgrade rate of PLCIS and FLCIS combined was 19% (6/32). All but one case (not upgraded at excision) were radiologic-pathologic concordant. Apocrine features, previously reported only in PLCIS, were also noted in FLCIS. HER2 overexpression was seen in 13% of cases. This study highlights the more aggressive biologic features of PLCIS and FLCIS compared to CLCIS and supports surgical management for these lesions.

Long-Term Outcomes After Surgical Treatment of Malignant/Borderline Phyllodes Tumors of the Breast.

BACKGROUND: Malignant/borderline phyllodes tumors (PTs) are rare, and little is known about their long-term prognosis. This study sought to evaluate recurrence rates and identify factors associated with local and distant failure. METHODS: From 1957 to 2017, we identified 124 patients with 125 PTs (86 malignant and 39 borderline). Recurrence rates and survival were assessed using the Kaplan-Meier method, and correlated with clinicopathologic factors using the log-rank test. RESULTS: The median age of the patients was 44 years, and the median tumor size was 5 cm. Breast-conserving surgery was performed for 57% of the patients. At a median follow-up of 7.1 years, 14 patients experienced a locoregional recurrence (LRR), with a 10-year cumulative LRR incidence of 12%. On univariable analysis, age younger than 40 years (p = 0.02) and close/positive margins (p = 0.001) were associated with increased risk of LRR. Seven patients developed distant disease, all occurring in malignant PTs. The 10-year distant recurrence-free survival was 94%. Uniformly poor pathologic features consisting of marked stromal cellularity, stromal overgrowth, infiltrative borders, and 10 or more mitoses per 10 high-power fields (hpf) were identified in 25 PTs (20%), and all distant recurrences occurred in this group. For the patients who did not have uniformly poor features, the 10-year disease-specific survival was 100%, and the overall survival was 94% compared with 66% and 57%, respectively, among those with poor features. CONCLUSION: Malignant/borderline PTs without uniformly poor histologic features have an excellent prognosis after surgical resection, with a 10-year disease-specific survival of 100%. The presence of uniformly poor pathologic features predicts a poor prognosis. Efforts should be directed toward new treatment approaches for these tumors.

Secretory carcinoma of the breast: clinicopathologic profile of 14 cases emphasising distant metastatic potential.

AIMS: Secretory carcinoma of the breast (SCB) is a rare histological type of breast carcinoma with a generally indolent clinical behaviour. We aim to elucidate the clinical, pathological and molecular findings of SCB cases and identify characteristics associated with aggressive clinical courses. METHODS AND RESULTS: Fourteen patients with SCB were identified, including 12 women and two men, with a median age of 56 years (range = 8-81 years). Clinical data, histological diagnosis, molecular findings and follow-up were reviewed. Eight patients presented with palpable masses and four patients with radiographic abnormalities. All cases were unilateral. Surgical procedures included excisional biopsies and ipsilateral mastectomies. In 10 cases, oestrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER2) results were obtained, with six cases positive for ER and three positive for PR. All cases lacked HER2 overexpression. Sentinel lymph node biopsy was performed in 10 cases, and two patients had axillary lymph node metastasis. Follow-up ranged from 21 to 212 months (median = 70 months). Two patients developed distant metastasis of SCB. Molecular analysis of these aggressive tumours revealed amplification of the 16p13.3 locus, a TERT promotor mutation and loss of 9p21.3 locus. Review of the literature for SCB cases with distant metastasis was performed. CONCLUSIONS: Although SCBs are generally associated with a favourable prognosis, our study and review demonstrate that a subset of SCBs may develop distant metastases. Further studies are warranted to identify markers predictive of more aggressive clinical behaviour in this rare breast cancer subtype.

Benign vascular lesions of the breast diagnosed by core needle biopsy do not require excision.

AIMS: Surgical excision of all benign vascular lesions of the breast identified by core needle biopsy has been recommended in the past to rule out a more serious lesion. In this study we investigated the clinical, radiological and pathological findings in patients diagnosed with a benign vascular lesion at our institution to assess whether excision may be spared for lesions without atypia. METHODS AND RESULTS: We searched the electronic medical record for patients with a vascular lesion of the breast diagnosed between 2000 and 2015. The study population consisted of 84 patients, 83 females and one male. The index diagnoses included 76 benign vascular lesions, five vascular lesions with cytological atypia and three angiosarcomas. A radiologist reviewed all pre- and post-biopsy imaging studies; all cases had concordant radiological and pathological findings. Based on radiological and histological correlation, the vascular lesion accounted for the radiological target in 40 (48%) cases and was deemed an incidental finding in 44 (52%). Seven of 32 (22%) targeted and 10 of 44 (23%) incidental benign vascular lesions underwent surgical excision; there were no upgrades at excision. No recurrences or clinical events were observed in patients with a targeted or incidental benign vascular lesion with a median follow-up of 39 months and 40.6 months, respectively. CONCLUSION: Our data suggest that benign vascular lesions diagnosed on core biopsy with concordant radiological and pathological findings do not warrant surgical excision.

Myxoid fibroadenomas differ from conventional fibroadenomas: a hypothesis-generating study.

AIMS: Breast myxoid fibroadenomas (MFAs) are characterized by a distinctive hypocellular myxoid stroma, and occur sporadically or in the context of Carney complex, an inheritable condition caused by PRKAR1A-inactivating germline mutations. Conventional fibroadenomas (FAs) are underpinned by recurrent MED12 mutations in the stromal components of the lesions. The aim of this study was to investigate the genomic landscape of MFAs and compare it with that of conventional FAs. METHODS AND RESULTS: Eleven MFAs from patients without clinical and/or genetic evidence of Carney complex were retrieved. DNA samples of tumour and matching normal tissue were subjected to massively parallel sequencing using the Memorial Sloan Kettering-Integrated Mutation Profiling of Actionable Cancer Targets (MSK-IMPACT) assay, an assay targeting 410 cancer genes. Genetic alterations detected by MSK-IMPACT were tested in samples in which the stromal and epithelial components were separately laser capture-microdissected. Sequencing revealed no germline PRKAR1A mutations and non-synonymous mutations in six MFAs. Interestingly, in three of the MFAs in which the stromal and epithelial components were separately microdissected, the mutations were found to be restricted to the epithelial rather than the stromal component. The sole exception was a lesion harbouring a somatic truncating PRKAR1A mutation. Upon histological re-review, this case was reclassified as a breast myxoma, consistent with the spectrum of tumous observed in Carney complex patients. In this case, the PRKAR1A somatic mutation was restricted to the stromal component. CONCLUSION: MFAs lack MED12 mutations, and their stromal components seem not to harbour mutations in the 410 cancer genes tested. Whole-exome and/or whole-genome analyses of MFAs are required to elucidate their genetic drivers.

Breast MR imaging for the assessment of residual disease following initial surgery for breast cancer with positive margins.

OBJECTIVES: To determine the accuracy of post-operative MR in predicting residual disease in women with positive margins, emphasizing the size thresholds at which residual disease can be confidently identified. METHODS: This IRB-approved HIPAA-compliant retrospective study included 175 patients with MR after positive margins following initial surgery for breast cancer. Two expert readers independently re-evaluated MR images for evidence of residual disease at the surgical cavity and multifocal/multicentric disease. All patients underwent definitive surgery and MR findings were correlated to histopathology. RESULTS: 139/175 (79.4%) patients had residual disease at surgery. Average overall sensitivity, specificity, PPV and NPV for residual disease at the surgical cavity were 73%, 72%, 91% and 45%, respectively. The readers identified 42/45 (93%, reader 1) and 43/45 (95%, reader 2) patients with residual invasive disease at the cavity of ≥5 mm and 22/22 (100%, both readers) patients with disease ≥10 mm. Average sensitivity, specificity, PPV and NPV for unknown multifocal/multicentric disease were 90%, 96%, 93% and 86%, respectively. CONCLUSIONS: Post-operative breast MR can accurately depict ≥5-mm residual disease at the surgical cavity and unsuspected multifocal/multicentric disease. These findings have the potential to lead to more appropriate selection of second surgical procedures in women with positive margins. KEY POINTS: • Post-operative breast MRI accurately defines residual disease of ≥5 mm. • Surgical cavity sensitivities were high for both invasive carcinoma and DCIS. • Post-surgical changes and very small residual disease (<5 mm) may overlap. • Post-operative breast MRI may help planning an accurate re-resection.

Breast intraductal papillomas without atypia in radiologic-pathologic concordant core-needle biopsies: Rate of upgrade to carcinoma at excision.

BACKGROUND: The surgical management of mammary intraductal papilloma without atypia (IDP) identified at core-needle biopsy (CNB) is controversial. This study assessed the rate of upgrade to carcinoma at surgical excision (EXC). METHODS: This study identified women with a CNB diagnosis of intraductal papilloma without atypia or carcinoma at a cancer center between 2003 and 2013. Radiologic-pathologic concordance was assessed for all cases, and discordant cases were excluded. The radiologic and clinicopathologic features of patients with a CNB diagnosis of IDP were correlated with an upgrade to carcinoma at EXC. RESULTS: The study population consists of 189 women with 196 IDPs; 166 women (171 IDPs) underwent EXC. The upgrade rate was 2.3% (4 of 171). The upgraded lesions were 2 invasive lobular carcinomas and 2 cases of ductal carcinoma in situ (DCIS). One case of DCIS involved the residual IDP, whereas the other 3 carcinomas were ≥ 8 mm away. Twenty-four women (25 IDPs) did not undergo EXC and had stable imaging on follow-up (median, 23.5 months). CONCLUSIONS: The upgrade rate at EXC for IDPs diagnosed at CNB with radiologic-pathologic concordance was 2.3%. These findings suggest that observation is appropriate for patients with radiologic-pathologic concordant CNB yielding IDP, regardless of its size. Cancer 2016. © 2016 American Cancer Society. Cancer 2016;122:2819-2827. © 2016 American Cancer Society.

How Often Is Treatment Effect Identified in Axillary Nodes with a Pathologic Complete Response After Neoadjuvant Chemotherapy?

BACKGROUND: False-negative rates (FNR) of sentinel node biopsy (SNB) after neoadjuvant chemotherapy (NAC) in node-positive (N+) breast cancer patients are <10 % when ≥3 negative SNs are obtained. Marking positive nodes has been suggested to reduce FNR. Identification of treatment effect in the nodes post-NAC is an alternative to decrease FNR. We evaluated the frequency of treatment effect in N+ patients after a pathologic complete response (pCR) with NAC. METHODS: Biopsy-proven N+ patients receiving NAC were identified. Patients with nodal pCR after axillary lymph node dissection (ALND) or SNB with dual mapping and ≥3 SNs removed were evaluated for treatment effect; ALND and SNB patients were compared. RESULTS: From January 2009 to December 2015, 528 N+ patients received NAC. Of these, 204 had a nodal pCR, 135 had an ALND, and 69 had SNB. Median age was 49 years, 15 % were hormone receptor positive (HR+)/HER2-, 27 % triple negative, and 58 % HER2+. The median number of nodes removed in ALND patients was 17 versus 4 in SNB patients. Treatment effect in nodes was identified in 192 patients (94 %) and was more common in ALND versus SNB patients (97 vs 88 %; p = .02). HR+ patients and patients without a breast pCR were less likely to have treatment effect in the nodes (p = .05). Other characteristics did not differ. CONCLUSIONS: Following NAC, SNs with treatment effect were retrieved in 88 % of patients without marking nodes, suggesting that nodal clipping may not be necessary to achieve an acceptable FNR. Longer follow-up is needed to determine regional recurrence rates in the SN-only cohort.

Classic lobular carcinoma in situ and atypical lobular hyperplasia at percutaneous breast core biopsy: outcomes of prospective excision.

BACKGROUND: No consensus exists on the need to excise breast lesions that yield classic lobular carcinoma in situ (LCIS) or atypical lobular hyperplasia (ALH) (known together as classic lobular neoplasia [LN]) as the highest risk lesion at percutaneous core-needle biopsy (CNB). Here, the authors report findings from 72 consecutive lesions with LN at CNB and prospective surgical excision (EXB). METHODS: Lesions that yielded LN at CNB at the authors' center have been referred for EXB since June 2004, regardless of imaging-histologic concordance. A lesion was "concordant" if histologic findings provided sufficient explanation for imaging. An upgrade consisted of ductal carcinoma in situ and/or invasive carcinoma at EXB. Statistical analysis, including 95% confidence intervals (CIs), was performed. RESULTS: Between June 2004 and May 2009, CNB of 85 consecutive lesions yielded LN without other high-risk histologies. Eighty of 85 lesions (94%) underwent prospective EXB. Seventy-two of 85 lesions (90%; 42 LCIS, 30 ALH) had concordant imaging-histologic findings. EXB yielded low-grade carcinoma in 2 of 72 cases (3%; 95% CI, 0%-9%). In both patients, stereotactic, 11-gauge, vacuum-assisted biopsy of calcifications yielded calcifications in benign parenchyma and ALH. CNB results were discordant in 8 of 80 lesions (10%; 4 LCIS, 4 ALH), and EXB yielded cancer in 3 of those 8 lesions (38%; 95% CI, 9%-76%). The upgrade rate was significantly higher for discordant lesions versus concordant lesions (38% vs 3%; P < .01). CONCLUSIONS: Prospective excision of LN identified carcinoma in 3% (95% CI, 0%-9%) of concordant cases versus 38% (95% CI, 9%-76%) of discordant cases. The current data provide an unbiased assessment of the upgrade rate of LN diagnosed at CNB.

Stromal MED12 exon 2 mutations in complex fibroadenomas of the breast.

AIMS: Here we explore the presence of mediator complex subunit 12 (MED12) exon 2 and telomerase reverse transcriptase (TERT) promoter hotspot mutations in complex fibroadenomas (CFAs) of the breast. METHODS: The stromal components from 18 CFAs were subjected to Sanger sequencing of MED12 exon 2 and the TERT promoter hotspot loci. The epithelial and stromal components of two MED12 mutated CFAs were subjected to laser capture microdissection, and Sanger sequencing of MED12 exon 2, TERT promoter and PIK3CA exons 9 and 20, separately. RESULTS: MED12 exon 2 mutations were identified in the stroma of 17% of CFAs. The analyses of epithelial and stromal components, microdissected separately, revealed that MED12 mutations were restricted to the stroma. No TERT promoter or PIK3CA mutations in exons 9 and 20 were detected in analysed CFAs. CONCLUSIONS: Like conventional fibroadenomas, MED12 exon 2 mutations appear to be restricted to the stromal component of CFAs, supporting the notion that CFAs are stromal neoplasms.

Sentinel lymph node biopsy in the management of early-stage cervical carcinoma.

OBJECTIVES: We aimed to determine the sentinel lymph node detection rates, accuracy in predicting the status of lymph node metastasis, and if pathologic ultrastaging improves the detection of micrometastases and isolated tumor cells at the time of primary surgery for cervical cancer. METHODS: A prospective, non-randomized study of women with early-stage (FIGO stage IA1 with lymphovascular space involvement--IIA) cervical carcinoma was conducted from June 2003 to August 2009. All patients underwent an intraoperative intracervical blue dye injection. Patients who underwent a preoperative lymphoscintigraphy received a 99m Tc sulfur colloid injection in addition. All patients underwent sentinel lymph node (SLN) identification followed by a complete pelvic node and parametrial dissection. SLN were evaluated using our institutional protocol that included pathologic ultrastaging. RESULTS: SLN mapping was successful in 77 (95%) of 81 patients. A total of 316 SLN were identified, with a median of 3 SLN per patient (range, 0-10 SLN). The majority (85%) of SLN were located at three main sites: the external iliac (35%); internal iliac (30%); and obturator (20%). Positive lymph nodes (LN) were identified in 26 (32%) patients, including 21 patients with positive SLN. Fifteen of 21 patients (71%) had SLN metastasis detected on routine processing. SLN ultrastaging detected metastasis in an additional 6/21 patients (29%). Two patients had grossly positive LN at exploration, and mapping was abandoned. Three of 26 (12%) patients had successful SLN mapping; however, the SLN failed to identify the metastatic LN. Of these 3 false negative cases, 2 patients had a metastatic parametrial node as the only positive LN with multiple negative pelvic nodes including negative SLN. One patient with stage IA1 disease and lymphovascular invasion had unilateral SLN mapping and a metastatic common iliac LN identified on completion lymphadenectomy of the contralateral side that did not map. The 4 (5%) patients with unsuccessful mapping included 1 who had grossly positive nodes identified at the time of laparotomy; the remaining 3 occurred during each surgeon's initial SLN mapping learning phase. CONCLUSION: SLN mapping in early-stage cervical carcinoma yields high detection rates. Ultrastaging improves micrometastasis detection. Parametrectomy and side-specific lymphadenectomy (in cases of failed mapping) remain important components of the surgical management of selected cases.

Interobserver Variation of PD-L1 SP142 Immunohistochemistry Interpretation in Breast Carcinoma: A Study of 79 Cases Using Whole Slide Imaging.

CONTEXT.­: The Ventana programmed death ligand-1 (PD-L1) SP142 immunohistochemical assay (IHC) is approved by the US Food and Drug Administration as the companion diagnostic assay to identify patients with locally advanced or metastatic triple-negative breast cancer for immunotherapy with atezolizumab, a monoclonal antibody targeting PD-L1. OBJECTIVE.­: To determine interobserver variability in PD-L1 SP142 IHC interpretation in invasive breast carcinoma. DESIGN.­: The pathology database was interrogated for all patients diagnosed with primary invasive, locally recurrent, or metastatic breast carcinoma on which PD-L1 SP142 IHC was performed from November 2018 to June 2019 at our institution. A subset of cases was selected using a computerized random-number generator. PD-L1 IHC was evaluated in stromal tumor-infiltrating immune cells using the IMpassion130 trial criteria, with positive cases defined as immunoreactivity in immune cells in 1% or more of the tumor area. IHC was interpreted on whole slide images by staff pathologists with breast pathology expertise. Interobserver variability was calculated using unweighted κ. RESULTS.­: A total of 79 cases were assessed by 8 pathologists. Interobserver agreement was substantial (κ = 0.727). There was complete agreement among all 8 pathologists in 62% (49 of 79) of cases, 7 pathologists or more in 84% (66 of 79) of cases, and 6 pathologists or more in 92% (73 of 79) of cases. In 4% (3 of 79) of cases, all of which were small biopsies, pathologists' interpretations were evenly split between scores of positive and negative. CONCLUSIONS.­: The findings show substantial agreement in PD-L1 SP142 IHC assessment of breast carcinoma cases among 8 pathologists at a single institution. Further study is warranted to define the basis for discrepant results.

Micrometastasis of endometrial cancer to sentinel lymph nodes: is it an artifact of uterine manipulation?

OBJECTIVE: To determine if micrometastasis (MM) and isolated tumor cells (ITCs) in sentinel lymph nodes (SLNs) of endometrial cancer patients are artifactual and related to uterine manipulation at the time of diagnosis and surgery. METHODS: We reviewed a prospectively maintained database of all patients with endometrial cancer undergoing SLN mapping between 2005 and 2009. MM was defined as a focus of metastatic cancer ranging from 0.2 to 2mm. ITCs were defined as metastasis measuring ≤ 0.2mm, including the presence of single, non-cohesive cytokeratin-positive tumor cells. We reviewed the effect of diagnostic procedure such as dilatation and curettage (D&C) versus biopsy and type of hysterectomy performed on the presence of MM and ITCs in SLNs. RESULTS: In all, 175 patients had successful SLN mapping. Of these, 145 (83%) had negative nodes, 11 (6%) had positive nodes, and 19 (11%) met the criteria for MM and ITC. The uterine procedure used to diagnose endometrial cancer, type of hysterectomy, tumor grade, histology, positive pelvic washings, and type of uterine manipulator utilized, did not appear to be associated with MM/ITC. However, the presence of lymphovascular invasion (P < 0.001) and the depth of myometrial invasion (P = 0.01) were significantly higher in the MM/ITC group. CONCLUSIONS: These data demonstrate that the presence of MM and ITCs in SLNs of endometrial cancer patients is not an artifact of uterine manipulation or instrumentation. Rather, it is a real pathologic finding likely associated with lymphovascular invasion and depth of myoinvasion.

Lobular carcinoma, not only a classic.

Lobular carcinoma in situ (LCIS) and atypical lobular hyperplasia are rare lesions, found incidentally in breast biopsies. They have been regarded traditionally as high-risk lesions, but recent genetic evidence and follow-up data indicates that they also constitute nonobligate precursors of invasive carcinoma. In addition to 16q deletion, a genetic alteration common across the spectrum of low-grade mammary epithelial neoplasia, lobular lesions consistently demonstrate deletion or functional inactivation of the CDH1/E-cadherin gene, with consequent loss of membranous immunoreactivity for the same antigen. The use of E-cadherin in the evaluation of solid mammary carcinoma in situ with ambiguous morphology has identified variants of LCIS characterized by massive acinar expansion and necrosis with calcifications, and/or marked nuclear pleomorphism or signet ring cell formation. In contrast to classic LCIS, these rare lesions are detected mammographically and often occur in association with invasive carcinoma. Genetic analysis of these tumors has confirmed lobular lineage and demonstrated more extensive chromosomal alterations than in classic LCIS. A pleomorphic variant of invasive lobular carcinoma has also been described. Here, we summarize our evolving knowledge of in situ and invasive lobular neoplasia and highlight the implications for patient management.

Recurrent MED12 exon 2 mutations in benign breast fibroepithelial lesions in adolescents and young adults.

AIMS: Most benign breast fibroepithelial lesions (FEL) in adults harbour recurrent somatic MED12 exon 2 mutations and rare TERT promoter hotspot mutations. We sought to determine the frequency of MED12 exon 2 and TERT promoter hotspot mutations in fibroadenomas (FA) and benign phyllodes tumours (BePT) in adolescents and young adults. METHODS: DNA from 21 consecutive FAs and eight consecutive BePTs in adolescents and young adults was subjected to Sanger sequencing of the exon 2 of MED12 and the TERT promoter hotspot locus. RESULTS: We identified MED12 exon 2 mutations in 62% and 88% of FAs and BePTs, respectively, and no TERT promoter hotspot mutations. The majority of the MED12 exon 2 mutations identified were in-frame deletions (60%). CONCLUSIONS: As in adults, benign FELs in juvenile patients harbour recurrent MED12 exon 2 mutations.

Is pleomorphic lobular carcinoma really a distinct clinical entity?

BACKGROUND: Attempts to define the clinical behavior of pleomorphic lobular carcinoma (PLC) have been limited to small series, and clinical management strategies have yet to be established. We describe our experience with PLC as compared to classic ILC and invasive ductal carcinoma (IDC). METHODS: From 9/1996 to 5/2003, clinical and histopathologic data for 5,635 patients undergoing primary surgical treatment and sentinel lymph node biopsy for breast cancer were collected. Four hundred eighty one (8.5%) patients were diagnosed with ILC; 3,978 (70.6%) with IDC. Of those with ILC, 356 (74%) patients had material available for pathologic re-review and comprise our study population: 52 were classified as PLC; 298 were classified as classic ILC; and 6 cases were reclassified as IDC. We compared clinical, pathologic, and treatment factors for patients with PLC, ILC, and IDC using the Wilcoxon rank sum and Fisher's exact tests. RESULTS: PLC were larger than ILC and IDC (20 vs. 15 vs. 13, P < 0.001), had more positive nodes (median 1 vs. 0 vs. 0, P < 0.05) and more frequently required mastectomy (63.5% vs. 38.7% vs. 28.8%, P < 0.001). In addition, more patients with PLC had developed metastatic disease compared to patients with ILC (11.5% vs. 3.7%, P < 0.05). CONCLUSIONS: These findings suggest that PLC is a distinct clinical entity that presents at a more advanced stage and may require more aggressive surgical and adjuvant treatment.

Complete excision of the MRI target lesion at MRI-guided vacuum-assisted biopsy of breast cancer.

OBJECTIVE: The purpose of our study was to determine the frequency of complete removal of the imaging target at MRI-guided vacuum-assisted biopsy of breast cancer and to assess the residual cancer rate at surgery in these lesions. MATERIALS AND METHODS: With the approval of our institutional review board, retrospective review was performed of 416 consecutive lesions that underwent MRI-guided 9-gauge vacuum-assisted biopsy, of which 76 (18%) yielded cancer. Medical and pathology records were reviewed. RESULTS: Vacuum-assisted biopsy histology in 76 cancers was ductal carcinoma in situ in 39 (51%) and invasive cancer in 37 (49%). Median MRI lesion size in these 76 cancers was 1.2 cm (range, 0.4-8.0 cm). The median number of samples obtained was 12 (range, 6-24 samples). Among 76 cancers, the MRI target was completely excised in 23 (30% [95% CI, 20-42%]), sampled in 52 (69% [57-79%]), and possibly missed in one (1% [0-7%]). Complete MRI target excision rather than sampling was significantly more likely in lesions < or = 1 cm than in lesions >1 cm (18/34 = 53% vs 5/41 = 12%; p < 0.001). Surgery, performed in 67 of 76 cancers, showed residual cancer in 55 (82% [71-90%]). The residual cancer rate was significantly lower if the MRI target was completely excised rather than sampled (14/22 = 64% vs 40/44 = 91%; p < 0.02). CONCLUSION: Complete excision of the MRI target occurred in 30% of breast cancers diagnosed at MRI-guided vacuum-assisted biopsy. Among cancers in which the MRI target was percutaneously excised, surgery yielded residual cancer in 64%. Complete removal of the MRI target does not ensure complete histologic excision of the cancer.

Underestimation of DCIS at MRI-guided vacuum-assisted breast biopsy.

OBJECTIVE: The study objective was to assess the rate of underestimation of ductal carcinoma in situ (DCIS) at MRI-guided 9-gauge vacuum-assisted breast biopsy. MATERIALS AND METHODS: An institutional review board-approved retrospective review was performed of 373 consecutive lesions that had undergone MRI vacuum-assisted breast biopsy. In 34 lesions with subsequent surgery, vacuum-assisted breast biopsy yielded DCIS without frank microinvasion or invasion. DCIS underestimates were lesions for which vacuum-assisted breast biopsy yielded DCIS without frank microinvasion or invasion at biopsy and surgery yielded invasive cancer. Records and pathology findings were reviewed. RESULTS: Among 34 lesions, vacuum-assisted breast biopsy histology was DCIS in 29 and DCIS with possible microinvasion in five. Of 29 lesions yielding DCIS at MRI vacuum-assisted breast biopsy, surgical excision revealed invasive cancer in five (17%; 95% CI, 6-36%). The DCIS underestimation rate was significantly higher in lesions 6 cm or larger versus smaller lesions (60% vs 8%, p = 0.02). MRI lesion type, kinetics, number of specimens, menopausal status, and target sampling versus excision did not significantly affect underestimation. Of five lesions yielding DCIS with possible microinvasion at MRI vacuum-assisted breast biopsy, surgery revealed invasive carcinoma in four (80%; 95% CI, 28-99%). DCIS underestimation was significantly more likely if MRI vacuum-assisted breast biopsy showed possible microinvasion than if it did not (80% vs 17%, p =0.01). CONCLUSION: Underestimation occurred in 17% of lesions yielding DCIS and in 80% of lesions yielding DCIS with possible microinvasion at MRI vacuum-assisted breast biopsy. DCIS underestimation was significantly more likely in lesions measuring 6 cm or larger. No other patient or lesion factors significantly affected DCIS underestimation at MRI vacuum-assisted breast biopsy.

Underestimation of atypical ductal hyperplasia at MRI-guided 9-gauge vacuum-assisted breast biopsy.

OBJECTIVE: The purposes of this study were to determine the frequency of diagnosis of atypical ductal hyperplasia (ADH) at MRI-guided 9-gauge vacuum-assisted breast biopsy and to assess the rate of underestimation of ADH at subsequent surgical excision. MATERIALS AND METHODS: We conducted a retrospective review of medical records of 237 lesions consecutively detected with MRI and then subjected to MRI-guided 9-gauge vacuum-assisted breast biopsy during a 33-month period. Underestimated ADH was defined as a lesion yielding ADH at vacuum-assisted biopsy and cancer at surgery. Scientific tables were used to calculate 95% CI. RESULTS: Histologic analysis of MRI-guided vacuum-assisted breast biopsy specimens yielded ADH without cancer in 15 (6%) of 237 lesions. Among 15 patients in whom vacuum-assisted breast biopsy yielded ADH, the median age was 52 years (range, 46-68 years). The median number of specimens obtained was nine (range, 8-18 lesions). Median MRI lesion diameter was 1.3 cm (range, 0.7-7.0 cm). Among 15 MRI lesions, 10 (67%) were nonmasslike enhancement and five (33%) were masses. Surgical excision was performed on 13 lesions. Surgical histologic findings were malignancy in five (38%) of the cases, all ductal carcinoma in situ; high-risk lesion in six (46%) of the cases, including ADH without other high-risk lesions (n = 2), ADH and lobular carcinoma in situ (LCIS) (n = 1), ADH, LCIS, and papilloma (n =1), ADH and papilloma (n = 1), and LCIS (n = 1); and benign in two (15%) of the cases. These data indicated an ADH underestimation rate of 38% (95% CI, 14-68%). CONCLUSION: ADH without cancer was encountered in 6% of MRI-guided 9-gauge vacuum-assisted breast biopsies. ADH at MRI-guided vacuum-assisted breast biopsy is an indication for surgical excision because of the high (38%) frequency of underestimation of these lesions.

Imaging histologic discordance at MRI-guided 9-gauge vacuum-assisted breast biopsy.

OBJECTIVE: The purpose of this study was to determine the frequency of discordance at MRI-guided vacuum-assisted biopsy and to assess the cancer rate in discordant lesions. MATERIALS AND METHODS: With institutional review board approval, retrospective review was performed of a database of 342 lesions that had MRI-guided vacuum-assisted biopsy during a 39-month period. Biopsy samples were obtained in a 1.5-T magnet using a 9-gauge MRI-compatible vacuum-assisted biopsy device. Medical and pathology records were reviewed to determine the number of discordant lesions and surgical outcome. Statistical analysis was performed. RESULTS: Among 342 lesions that had MRI-guided vacuum-assisted biopsy, results were discordant in 24 (7% [95% CI, 3-14%]) lesions. The discordance rate was significantly (p < 0.001) higher among MRI target lesions that were possibly missed rather than sampled. A trend was seen (p < 0.06) toward a higher discordance rate in MRI lesions that were sampled rather than excised at MRI-guided vacuum-assisted biopsy. Subsequent surgery in 20 discordant lesions yielded cancer in six (30% [12-54%]), including ductal carcinoma in situ (DCIS) in two and invasive carcinoma in four (three ductal and one lobular, all with DCIS). The cancer rate among discordant lesions was significantly higher in postmenopausal women than in premenopausal women (p <0.05). CONCLUSION: Imaging-histologic discordance was found in 7% of lesions that had MRI-guided vacuum-assisted biopsy. Among discordant lesions, surgical excision revealed cancer in 30%. Imaging-histologic correlation is essential after MRI-guided vacuum-assisted biopsy to avoid delay in the diagnosis of breast cancer.