Fine-needle aspiration cytology of ductal hyperplasia with and without atypia and ductal carcinoma in situ

Efficacy of Modified Masood Scoring System (MMSS) in Cytological Diagnosis of Breast Lesions

Introduction: Fine-needle aspiration cytology (FNAC) breast is generally considered a reliable diagnostic tool to distinguish non-proliferative from proliferative breast lesions. Nevertheless, differentiating these breast lesions on FNAC poses a diagnostic challenge. Modified Masood Scoring System (MMSS) based on cytomorphological examination has been used to help in differentiating these lesions.

Material and methods: A total of 67 patients were included in this prospective study done from November 2012 to May 2014 and the breast lesions were cytologically categorized by conventional and as per MMSS criteria, followed by comparison to a histopathological examination, which was taken as a gold standard. Relevant frequencies and proportions were calculated along with the sensitivity and specificity of the MMSS.

Results: The age of the patients ranged from 15 to 85 years with a mean age of 44.3 ± 14.8 years. Females predominated in the study and right-sided breast lesions were more common compared to the left side. Overall diagnostic specificity (100%) and accuracy (97%) were higher using MMSS as compared to conventional cytology in which case specificity was 83.6% and accuracy was 82.1%.

Conclusions: Cytological grading system based on MMSS allowed accurate and reproducible diagnosis compared to the standard histopathological diagnosis. It is essential to differentiate non-proliferative lesions from proliferative lesions as the line of treatment and prognosis varies.

Effect of Intraoperative Imprint Cytology Followed by Frozen Section on Margin Assessment in Breast-Conserving Surgery

PURPOSE

Intraoperative margin assessment can reduce positive margins in patients undergoing breast-conserving surgery. However, reports on intraoperative margin assessment have described only the use of either imprint cytology or frozen section. This study was designed to elucidate the effect of intraoperative margin assessment using imprint cytology followed by frozen section.

METHODS

Overall, 522 patients were enrolled. First, the entire surgical margin was subjected to imprint cytology. Frozen section was performed only in cases with "positive" or "suspicious" imprint cytology results. An additional intraoperative excision was performed in patients with frozen section-positive lesion sites. All margins were evaluated using postoperative permanent sections after excision.

RESULTS

Among 522 patients, 136 (26.1%) were imprint cytology-positive, and 386 (73.9%) were imprint cytology-negative. Among the 386 imprint cytology-negative patients not subjected to frozen section, 11 (2.1%) were permanent sections-positive (imprint cytology-false-negative). In 47 of the 136 imprint cytology-positive patients, additional intraoperative excision was unnecessary due to the frozen section-negative diagnosis. Moreover, these patients could avoid reoperation, because they were permanent section-negative. The false-positive rate of imprint cytology alone was 13.4%, but adding frozen section to imprint cytology decreased the overall false-positive rate to 2.5%. After undergoing excision, four patients still had positive margins. The overall positive margin rate in the final pathology based on permanent sections was 2.9% (15/522).

CONCLUSIONS

Imprint cytology followed by frozen section led to a markedly decreased positive margin rate. This is considered the best method for intraoperative margin assessment, as it can overcome the limitations of cytology and histology performed individually.

Cytological Scoring of Breast Lesions and Comparison with Histopathological Findings

Context

Cytological assessment using various morphological parameters helps segregate breast lesions in fine-needle aspiration cytology (FNAC) into different categories. The prognosis and the line of management of each category differ accordingly.

Aims

This study aims at assessing the validity of Modified Masood's Scoring Index (MMSI) by the evaluation of cytomorphological features of various breast lesions compared with histopathological findings.

Settings and Design

This is a cross-sectional study done in 65 female patients with palpable or nonpalpable breast lesions, undergoing FNAC and biopsy over a period of 18 months from December 1, 2012, to May 31, 2014.

Materials and Methods

MMSI categorizes breast lesions, based on six cytological parameters into different categories such as nonproliferative breast disease (NPBD), proliferative breast disease (PBD) without atypia, PBD with atypia, and malignancy. The findings are compared with gold standard histopathological diagnosis.

Statistical Analysis Used

Percentage of agreement, Kappa statistics, and Chi-square test.

Results

Of the total 65 cases, all cases in MMSI category I and IV showed good histopathological correlation. The agreement between MMSI and histopathology was 93.8% which is more when compared with 72.3% agreement between cytology without scoring and histopathology. MMSI has increased the diagnostic accuracy of FNAC to 93.8% from 80%.

Conclusion

The scoring system is easily reproducible, simple, and reliable. MMSI proved good histopathological correlation in category I and IV. This scoring technique has clearly demarcated those cases requiring surgical management. It is applicable for palpable and nonpalpable cases.

Efficacy of telecytopathology for preliminary assessment of fine-needle aspirations performed at a remote facility

INTRODUCTION

The need for real time anatomic pathology services has grown as healthcare systems, traditionally found at large medical centers, expand into smaller communities. The placement of a pathologist is not cost-, time-, or resource-efficient. Telecytopathology can provide rapid offsite evaluation of cytology tissues. This study evaluated the accuracy rate of rendered preliminary assessments for telecytopathology of ultrasound (US)-guided fine-needle aspirations (FNAs) for an offsite facility by comparing preliminary assessment results with the final diagnosis.

MATERIALS AND METHODS

The pathology database was searched for telecytopathology US-guided FNAs with rapid offsite evaluation performed at a regional care center from August 2014 to June 2016. A total of 674 consecutive US-guided FNAs from 444 patients were obtained. FNA sites included lymph node (345 cases), breast (178 cases), thyroid gland (71 cases), and others (80 cases).

RESULTS

Preliminary assessments of the 674 FNAs were adequate/benign in 275 (41%) cases, adequate/malignant in 182 (27%) cases, adequate/further review needed in 162 (24%) cases, indeterminate/borderline cellularity in 37 (5%) cases, and nondiagnostic in 18 (3%) cases. Final FNA diagnoses rendered included 391 (58%) negative for malignancy, 205 (30%) malignant, 34 (5%) atypical/suspicious for malignancy, 26 (4%) indeterminate cellularity-favor benign, and 18 (3%) nondiagnostic specimens. Concurrent core biopsy was performed in 42 cases and 83 cases were triaged for ancillary studies. The majority (99%) of US-guided FNAs demonstrated concordant preliminary assessments with the final diagnoses. A major discrepancy occurred in 1 case; 5 cases had minor discrepancies.

CONCLUSIONS

Remote facility telecytopathology can be utilized as an accurate modality in guiding appropriate tissue acquisition and final diagnosis.

Evaluation of Masood's and Modified Masood's Scoring Systems in the Cytological Diagnosis of Palpable Breast Lump Aspirates

INTRODUCTION

Fine Needle Aspiration Cytology (FNAC) has a leading role in the assessment of breast lesions. Masood's Scoring Index (MSI) and its modification (Modified Masood's scoring index; MMSI) has been proposed to aid in sub-grouping breast lesions and to help in subsequent management.

AIM

To assess and compare the diagnostic accuracy of MSI and MMSI by subsequent correlation with histopathology.

MATERIALS AND METHODS

The study was cross-sectional in nature and was conducted in a tertiary care setting. The study included 207 cases presenting as palpable breast lump, which had undergone FNAC and subsequent excision biopsy for histopathology.

STATISTICAL ANALYSIS

The cases were grouped into four categories as suggested by Masood et al., (MSI) and Nandini et al., (MMSI) and concordance analysis with reference to histopathological diagnosis was done.

RESULTS

In comparison to MSI, MMSI showed better concordance with histopathological diagnosis and superior diagnostic accuracy in non-proliferative breast disease category (p-value = 0.046) as well as in proliferative breast disease without atypia category. The overall diagnostic accuracy of the cytological scoring was 97.5%, with 94.5% sensitivity and 100% specificity.

CONCLUSION

Though both MSI and MMSI were found effective in subcategorizing breast lesions, MMSI was found to have better concordance with histopathology. Inclusion of cellular pattern and background material may further help in increasing the accuracy.

Fine-needle aspiration and core biopsy in the diagnosis of breast lesions: A comparison and review of the literature

In recent times, the diagnosis of breast lesions has mostly become dependent on core needle biopsies (CNBs) with a gradual reduction in the rate of performing fine-needle aspiration cytology (FNAC). Both the procedures have their pros and cons and outsmart each other taking into account different parameters. Both the methods are found to be fraught with loopholes, taking into account different performance indices, diagnostic accuracy and concordance, patient benefit, and cost-effectiveness. Unlike the popular belief of an absolute superiority of CNB over FNAC, the literature review does not reveal a very distinct demarcation in many aspects. We recommend judicious use of these diagnostic modalities in resource-limited settings and screening programs taking into account parameters such as palpability and availability of an experienced cytopathologist.

Grey zone lesions of breast: Potential areas of error in cytology

Fine-needle aspiration cytology (FNAC) of the breast is a rapid, cost-effective, and sensitive procedure to diagnose breast lesions, and was widely employed to diagnose breast lesions in the past. However, in recent times, core needle biopsy of the breast is gaining popularity and acceptability, although FNAC still looms large. There are some intrinsic disadvantages to FNAC, of which the most important is probably difficulty in classification of a significant percentage of breast lesions. Such lesions are usually denoted by the rubric “grey zone lesions of the breast.” This article attempts to review these grey zone lesions and highlight the difficulties in diagnosing them.

Inconclusive or erroneous fine-needle aspirates of breast with adequate and representative material: a cytologic/histologic study

Adequately cellular and representative fine-needle aspirates (FNAs) of breast have a high diagnostic accuracy. There is, however, a recognized category designated as "gray zone" where a definitive diagnosis cannot be reached. We reviewed our experience in this category to identify useful diagnostic parameters. Twenty-four such FNAs with surgical follow-up were retrieved from AUBMC files (2003-2009). Cytology slides were reviewed blindly. All cases were females, 29-73 years. There were three erroneous and 21 inconclusive diagnoses. The majority (15) was invasive adenocarcinomas: two cribriform, four tubular, one lobular, and eight not otherwise specified. The remaining cases were papillary and fibroepithelial tumors (three each), ductal carcinoma in situ, cribriform (two), and one adenomyoepithelioma (AME). Useful diagnostic features included: (1) Biphasic cell population with focal nuclear atypia and intranuclear and cytoplasmic vacuolar inclusions (AME). (2) Complex clusters of epithelial cells with cribriform architecture (cribriform carcinoma). (3) Rigid tubular epithelial structures with abrupt change in diameter, ending in pointed tips with abnormal branching (tubular carcinoma). (4) Cellular stromal fragments (fibroepithelial tumors). (5) Papillary fibrovascular cores, columnar cells, and three-dimensional papillary epithelial fragments (papillary tumors). Myoepithelial cells classically described in benign aspirates were not always a discriminatory factor. The "gray zone" in breast FNA is usually due to overlapping cytologic features of some benign and malignant lesions. Useful distinguishing cytologic features are described.

Indeterminate and erroneous fine-needle aspirates of breast with focus on the 'true gray zone': a review

OBJECTIVE

To review our experience and the literature on inconclusive/erroneous fine-needle aspirates (FNAs) of breast with the focus on the 'true gray zone'. To describe the cytology, differential diagnosis, pitfalls and limitations of common and rare lesions.

STUDY DESIGN

We conducted a literature search focusing on breast FNAs with statistical data of C3 and C4 categories including false-positive and false-negative cases. Similar data from 2003 to 2009 was obtained from our institution.

RESULTS

C3 and C4 categories account for 3-17% of breast FNAs. Contributing factors are technical difficulties, inexperienced pathologists interpreting FNAs of breast and overlap of cytologic features of certain benign and malignant conditions; this last, 'true gray zone' accounts for 2% of cases. Fibroadenoma, proliferative breast lesions, gynecomastia, infiltrating and in situ low-grade adenocarcinomas and tubular, cribriform, lobular and mucinous carcinomas are the most common problematic lesions. Granular cell tumor, adenomyoepithelioma, pregnancy-related lesions, fat necrosis, inflammatory and radiation changes, adenoid cystic carcinoma, spindle-cell lesions and Phyllodes tumor are less common.

CONCLUSION

Inconclusive/erroneous FNAs of breast due to the 'true gray zone' are rare. Most are due to the overlapping cytologic features of some benign and malignant conditions. Practical features that may help arrive at the correct diagnoses are elucidated.

[The "gray zone" in organized mammography screening: histocytological correlations]

The National Public Health Program has established the organized mammography screening in Hungary. The aim of this study was to conduct an audit of "gray zone" smears of the organized mammography screening in comparison with histopathological diagnoses.

METHODS

Cytology results were rated to C3 atypia probably benign and C4 suspicious of malignancy.

RESULTS

1361 women had aspiration cytology performed from a total of 47,718 mammography non-negative lesions. 105 (7.8%) were diagnosed as C3, whereas 78 (5.7) as C4. Of the 105 patients with C3 diagnosis 61 (58%) patients underwent surgical biopsy. Histology proved malignancy in 20 (32.8%) cases, and benign lesion in 41 (67.2%) cases. All (100%) of the 78 patients with C4 diagnosis had open biopsies; 69 (88.4%) cases were histologically malignant and 9 (11.6%) cases were benign lesions.

CONCLUSION

The auditing results of fine needle aspiration cytology of "gray zone" in organized mammography screening meet the proposed threshold values. Authors conclude that the "gray zone" category in breast cytology is useful and of value if used judiciously.

Ultrasonographically and stereotactically guided fine-needle aspiration cytology of non-palpable breast lesions: cyto-histological correlation

OBJECTIVE

To determine the diagnostic accuracy of ultrasonographically (US) and stereotactically guided fine needle aspiration cytology (FNAC) for the diagnosis of non-palpable breast lesions.

PATIENTS AND METHODS

From January 2002 to December 2004, 470 women with 478 mammographically detected non-palpable breast lesions had US or stereotactically guided FNAC of the breast lesion. Subsequent histological evaluation of the same lesion was performed at the Institute of Oncology Ljubljana, Slovenia. The correlation between the original cytological and histological diagnosis was assessed and the sensitivity, specificity, positive predictive value and negative predictive value were calculated.

RESULTS

Among US-guided FNACs, 144 (53.5%) were histologically verified benign lesions and 125 (46.5%) were carcinomas. Cytological diagnoses were: true positive (TP) in 63 cases (50.4%), suspicious in 35 (28%), false negative (FN) in eight (6.4%), and in 19 (15.2%) cases, the material was inadequate for diagnosis. In the stereotactically guided FNAC group, there were 209 women with 209 lesions, with 95 (45%) histologically proven carcinomas and 114 (55%) benign lesions. Cytological diagnoses were TP in 49 (51.6%) cases, true suspicious in 21 (22.1%), FN in nine (9.5%), and in 16 (16.8%) cases, the material was not adequate for the diagnosis.

CONCLUSION

The sensitivity of 88.7% and specificity of 98.6% for US-guided FNAC and 84.5% and 100% for stereotactically guided FNAC, respectively, suggest that clinicians can rely upon cytological diagnosis for planning further management of women with non-palpable breast lesions.

The fine needle aspiration biopsy diagnostic criteria of proliferative breast lesions: A retrospective statistical analysis of criteria for papillomas and radial scar lesions

This study aimed to analyze statistically the accuracy of fine needle aspiration biopsy cytological criteria in diagnosing epithelial hyperplasia with atypia (EHA), papillary lesions (PAP), and radial scar/complex sclerosing lesions (RS/CSL). The 42 criteria studied were extracted from a literature review and those developed and used in our department. Cytological cases with diagnoses of EHA, PAP, and RS/CSL for the period of 1997-2001 were correlated with relevant histological follow-up and the positive predictive power of these diagnoses have been presented in an earlier publication. Some 77 cases with definite, specific histological diagnoses of atypia or a more severe lesion, PAP and RS/CSL, were reviewed and scored using 55 cytological criteria. As the group of EHA and RS/CSL yielded a smaller number of cases, these were grouped together in the statistical analysis and compared to PAP. The cytological features, which were most diagnostic for PAP, were stellate (Odds ratio 1.75) and meshwork (Odds ratio 3.29) tissue fragments, while the presence of tubular structures was inversely proportional to the histological outcome of PAP. True papillary fragments were uncommon and not statistically significant in diagnosing PAP of the breast.

Positive predictive value of the breast FNAB diagnoses of epithelial hyperplasia with atypia, papilloma, and radial scar

Proliferative breast lesions are a spectrum of lesions that have overlapping cytological features and are difficult to subclassify in fine-needle aspiration biopsies (FNABs). This study of breast FNABs from the period of 1997-2001 aimed to correlate the cytological diagnoses of epithelial hyperplasia with atypia (EHA), papilloma (PAP), and radial scar/complexing sclerosing lesions with relevant histological follow-up, and to assess the positive predictive value (PPV) of the cytological diagnosis. The PPV for the three categories were found to be 0.16, 0.74, and 0.63 respectively. The low value observed in the cytological category of EHA was due to the heterogeneous nature of the group, which makes it difficult to correlate cytological appearances with the varying histological lesions. However, it was found that 70% of these EHA cases had benign histological diagnoses, matching the expected outcome. The PPV of 0.74 for the cytological diagnosis of PAP of the breast compares favorably to similar published studies, and we suggest that the specific diagnosis of PAP can be made reliably using cytological criteria.

Cytomorphology of fibrocystic change, high-risk proliferative breast disease, and premalignant breast lesions

In a prospective study using mammographically guided fine needle aspirates in 100 nonpalpable breast lesions, the author's group assessed the reliability of a cytological grading system to define the cytological features of proliferative and nonproliferative breast disease and to differentiate between benign, premalignant and malignant breast lesions. We developed a cytological grading system evaluating the aspirates for the cellular arrangement, the degrees of cellular pleomorphism and anisonucleosis, presence of myoepithelial cells and nucleoli and the status of the chromatin pattern. This grading system, now recognized as the Masood Cytology Index, is commonly used as a surrogate end point biomarker in chemoprevention trials.

Cytomorphology as a risk predictor: experience with fine needle aspiration biopsy, nipple fluid aspiration, and ductal lavage

Primary prevention of breast cancer requires identification and elimination of cancer-causing agents, which is an incredibly difficult task to follow. Secondary prevention involves screening individuals who are at increased risk for breast cancer in hopes that early intervention will affect survival. In the 1980s, chemoprevention received serious attention. This approach was aimed at reducing cancer risk by administration of natural or synthetic clinical compounds that prevent, reverse, or suppress carcinogenesis in individuals at increased risk for cancer. It was not until 1998, however, when the first report from the National Surgical Adjunct Breast and Bowel Project (Breast Cancer Prevention Trial BCPT; P-1) randomized clinical trial appeared in the literature supporting the hypothesis that breast can-cer can be prevented. This study showed that administration of tamoxifen reduced the risk for invasive and noninvasive breast cancer by almost 50% in all age groups. With the current availability of tamoxifen as a chemopreventive agent and with the increasing emphasis on early breast cancer detection and prevention, more women seek consultation to determine their risk for breast cancer. However, in the absence of any detectable breast lesion, clinically and mammographically, only a few women may volunteer to have their breasts sampled by surgical biopsy for risk assessment. Other non-surgical procedures include fine needle aspiration biopsy (FNAB), nipple aspirate fluid (NAF), and the recently introduced procedure, ductal lavage. These techniques may provide better alternatives. These minimally invasive procedures are capable of recruiting cellular material for cytomorphologic interpretation and biomarker studies.

Fine needle biopsy cytology of breast lesions: a review of interpretative difficulties

Screening mammography and greater community awareness of breast carcinoma have led to an increase in fine needle biopsies of the breast. As a consequence, a wide variety of cytologic patterns have been encountered and studied in benign, proliferative, and malignant breast lesions. We review the main reasons for diagnostic difficulties in breast cytology, the situations in which either a false positive or a false negative diagnosis is possible, as well as conditions whose incorrect typing can lead to inappropriate management.

'Atypical' and 'suspicious' diagnoses in breast aspiration cytology

BACKGROUND

In 1996, the National Cancer Institute (NCI) recommended five categories for the diagnosis of breast aspiration cytology: benign, atypical, suspicious, malignant, and unsatisfactory. The authors evaluated the usefulness of separating inconclusive diagnoses into the aforementioned atypical and suspicious categories. The current study examined the correlation between cytologic and histologic findings made in breast aspiration cytology specimens that were categorized in accordance with these NCI guidelines.

METHODS

From 1992 to 2000, 7727 breast aspirations were performed at the University of Miami/Jackson Memorial Medical Center (Miami, FL). Aspirates were classified using criteria similar to the NCI recommendations. Four hundred eighty-nine aspirates (6%) were classified as being cytologically 'atypical' or 'suspicious'. Of those, 225 'atypical' aspirates and 162 'suspicious' aspirates had available histologic follow-up data and were included in the study.

RESULTS

Among the 'atypical' aspirates, 118 (52%) yielded malignant findings on histologic evaluation. Infiltrating ductal carcinoma (n = 87; 74%) was the most common malignant diagnosis, followed by infiltrating lobular carcinoma (n = 12; 10%). Among 'suspicious' aspirates, 135 (83%) yielded malignant findings on histologic analysis. The most common benign diagnosis in both 'atypical' and 'suspicious' aspirates was proliferative fibrocystic changes with or without atypia, followed by fibroadenoma.

CONCLUSIONS

Most aspirates that yielded suspicious findings on cytologic examination proved to be malignant, as did > 50% of aspirates that yielded atypical findings. Infiltrating lobular carcinoma commonly was underdiagnosed as being atypical on cytologic examination. Benign lesions with atypical or suspicious cytologic diagnoses included certain cases of atypical ductal hyperplasia. The authors concluded that the distinction between the atypical and suspicious categories, as recommended by the NCI, is not warranted. Therefore, they suggest the use of a single term, such as 'equivocal', to describe inconclusive diagnoses on breast fine-needle aspiration cytology.

Interobserver agreement of a probabilistic approach to reporting breast fine-needle aspirations on ThinPrep®

We have previously demonstrated the accuracy and reproducibility of a probabilistic/categorical approach for reporting breast fine-needle aspiration (FNA). However, the interobserver agreement in the application of this approach has not been assessed. Twenty breast FNA cases (each on one ThinPrep slide) were pulled from the cytology files of Beth Israel Deaconess Medical Center. The cases included benign epithelial proliferative lesions (6), DCIS (4), and infiltrating carcinoma (10), as shown by subsequent histology. Six pathologists with 14-25 yr of experience in interpreting breast FNA and 0-8 yr of experience with ThinPrep preparations rendered diagnoses according to the probabilistic approach. The kappa statistic for the unremarkable/proliferative, atypical, suspicious, and positive categories were 0.64, 0.08, 0.43, and 0.75, respectively (P < 0.001 for all except for the atypical category [P = 0.09]). Spearman's rho correlating the individual pathologist's diagnosis and the histologic diagnosis ranged from 0.51 (P = 0.02) to 0.78 (P < 0.0001). This was not correlated with the pathologists' years of experience interpreting breast FNA (P = 1.0) or with their years using ThinPrep preparations for breast FNA (P = 0.96). In conclusion, the interobserver agreement was excellent for the positive category in the probabilistic approach, poor for the atypical category, and fair to good for the other categories. The specific level of experience interpreting breast FNA or using ThinPrep among experienced pathologists did not seem to influence their accuracy in reporting the cases in our study.

Differentiating nonhigh-grade duct carcinoma in situ from benign breast lesions

This study was undertaken to determine the discriminating cytological features between nonhigh-grade duct carcinoma in situ (NHGDCIS) and benign breast lesions and to determine any histological characteristics which would influence the cytological categorization. Smears of 12 each of histologically confirmed NHGDCIS and benign breast lesions were reviewed with regard to cellularity, cell discohesion, nuclear atypia, crowding of cells, tubule formation, necrosis, and presence of bare atypical nuclei and regular bare bipolar nuclei, and statistically analyzed. Architectural pattern, presence of necrosis, and the size of the lesion assessed at histological examination were compared with the initial cytological categorization. NHGDCIS lesions showed more cell discohesion (P = 0.04), bare atypical nuclei (P = 0.05), necrosis (P = 0.03), and sparse bare bipolar nuclei (P = 0.02) than benign lesions. These differences were statistically significant. Cellularity (P = 0.8), nuclear atypia (P = 0.06), crowding of cells (P = 0.1), and tubule formation did not show a significant difference. Six (out of six lesions) with a solid architectural pattern and six (of seven) with necrosis could be cytologically categorized as suspicious or malignant. Size of the lesion did not influence this. We conclude that cell discohesion, bare atypical and bare bipolar nuclei, and necrosis are discriminating features between NHGDCIS and benign breast lesions and NHGDCIS lesions with a solid architectural pattern and necrosis are more likely to be satisfactorily categorized cytologically.

The significance of the diagnosis of atypia in breast fine-needle aspiration

The diagnosis of atypia in breast fine-needle aspiration (FNA) continues to be an area of debate in cytology practice. The aim of this study was to assess the clinical significance of this term and to evaluate potential morphological criteria, which would determine the patient's outcome. A computer-based search was carried out to retrieve breast FNAs performed between 1990 and 2000 that were diagnosed as atypical. Cases followed by surgical resection were reexamined for the presence of morphological features potentially differentiating benign and malignant lesions. Out of 1,568 breast FNAs, there were 64 cases (4%) with a diagnosis of atypia. Thirty-eight cases had surgical follow-up material that revealed malignancy in 14 cases (37%) and benign lesions in 24 cases (63%). The benign diagnostic categories included fibrocystic change (12/24), fibroadenoma (3/24), tubular adenoma (2/24), and nonspecific findings (7/24). The malignant diagnoses included ductal carcinoma (9/14), lobular carcinoma (3/14), ductal carcinoma in situ (DCIS; 1/14), and tubular carcinoma (1/14). The evaluation of cytological criteria used to differentiate benign from malignant lesions (i.e., cellularity, loss of cohesion, myoepithelial cells, nuclear enlargement, nuclear overlap, prominent nucleoli) revealed significant overlap between benign and malignant cases, particularly in cases of fibroadenoma, tubular adenoma, and proliferative breast disease. The surgical follow-up of four hypocellular cases revealed lobular carcinoma in two cases and ductal carcinoma in the remaining two cases. Our study confirmed that the diagnosis of atypia is clinically significant because it is associated with a high probability of malignancy. No morphological criterion is able to reliably differentiate benign and malignant lesions in cases diagnosed with atypia. Diagnosis of atypia is particularly significant in hypocellular cases. We recommended that breast FNAs with a diagnosis of atypia be evaluated further histologically.

p63 Staining of myoepithelial cells in breast fine needle aspirates: a study of its role in differentiating in situ from invasive ductal carcinomas of the breast

AIMS

One of the limitations of fine needle aspiration biopsy (FNAB) of the breast is in distinguishing invasive carcinoma (IDC) from ductal carcinoma in situ (DCIS). It has been proposed that the presence of myoepithelial cells overlying epithelial malignant cell clusters suggests DCIS. However, the recognition of myoepithelial cells in aspirates may be difficult. The aim of this study was to investigate a new nuclear myoepithelial cell marker, p63, a p53 homologue nuclear transcription factor, in a series of breast FNABs in an attempt to distinguish IDC from DCIS.

METHODS

Papanicolaou stained smears from eight cases of pure DCIS and 15 cases of pure IDC with a histologically confirmed diagnosis were submitted to immunocytochemical analysis using the antibody 4A4 against p63. Two pathologists evaluated the presence of p63 positive cells overlying malignant cell clusters and admixed with malignant cells. The frequency of p63 positive cells in DCIS and IDC was compared using Fisher's exact test.

RESULTS

p63 consistently stained the nuclei of myoepithelial cells, either overlying malignant cell clusters and/or admixed with malignant cells. p63 positive myoepithelial cells were seen in all DCIS cases and in nine of the 15 cases of IDC (p = 0.0375). In eight cases (three DCIS and five IDC), scattered p63+ epithelial malignant cells were seen.

CONCLUSIONS

Although p63 positive myoepithelial cells are found more frequently in DCIS cases, their presence cannot be used as a criterion to rule out invasion in breast FNABs because they are present in up to 60% of invasive cases.

Fine-needle aspiration cytology findings of an uncommon micropapillary variant of pure mucinous carcinoma of the breast: review of patients over an 8-year period

BACKGROUND

Previous attempts at subclassifying pure mucinous carcinomas of the breast based on architectural patterns and other associated features are on record. A distinctive micropapillary variant with most tumor cells arranged in micropapillae/pseudoacini has not been described previously.

METHODS

The author reviewed the histologic slides from all 556 patients who underwent wide excision/mastectomy for mammary ductal carcinoma, either in situ or invasive, at Pamela Youde Nethersole Eastern Hospital, Hong Kong, during an 8-year period from early 1994 to the end of 2001. Five patients with pure mucinous carcinoma with diffuse micropapillary architecture were noted. The cytologic features (if available) were correlated with clinical, radiologic, and pathologic findings.

RESULTS

Among the five patients with pure mammary mucinous carcinoma (micropapillary variant), three patients underwent preoperative fine-needle aspiration biopsies and had specimens available for review. The direct smears and cytospin preparations were of moderate cellularity and showed cohesive clusters and micropapillae of mildly pleomorphic tumor cells among a mucoid background. True tumor papillae with fibrovascular cores were not present. Nuclear hobnailing was observed commonly, and occasional psammoma bodies were found. There were also scanty isolated tumor cells scattered around. The pseudoacinar pattern was appreciated more readily in the cell block sections. Histologic examination of the surgical specimens showed features of pure mucinous carcinoma with diffuse micropapillary architecture. The micropapillary arrangement was confirmed further by the demonstration of a reverse polarity immunostaining pattern for epithelial membrane antigen and the identification of microvilli rimming the periphery of tumor cell clusters under the electron microscope. Peritumoral lymphovascular permeation and ipsilateral axillary lymph node metastasis was found in one of the patients.

CONCLUSIONS

The micropapillary variant of mammary mucinous carcinoma demonstrates characteristic cytologic and histologic features that warrant special attention. It may represent the mucinous counterpart of invasive micropapillary carcinoma. Further analysis of a larger series of patients, however, will be required to delineate its prognostic significance, especially its propensity for lymph node metastasis.

Fine needle aspiration cytology versus percutaneous biopsy of nonpalpable breast lesions

Fine needle aspiration (FNA) and core biopsy (CB) are efficient alternatives to surgical biopsy: FNA provides a sampling of cells and is very cost effective. The main limits are insufficient sampling rate and the impossibility to diagnose invasion. CB allows architectural description and the diagnosis of specific benign and malignant lesions, but is more expensive and time-consuming.

False-positive reports in fine needle biopsy of breast lesions

A review of the literature reveals considerable variations in the diagnostic accuracy of fine needle biopsy (FNB) of breast lesions between series, partly due to different methods of calculation, different definitions, and insufficient numbers of cases with adequate follow-up to provide reliable statistics. The best larger series have a false-positive rate between 0.2 and 0.3%, slightly higher for non-palpable than for palpable lesions. The cytological patterns of a range of benign lesions which may cause diagnostic difficulties and may be misdiagnosed as malignant by FNB are described, and guidelines to reduce the risk of false-positive diagnoses are proposed.

Adenocarcinoma in colonic brushing cytology: High-grade dysplasia as a diagnostic pitfall

Cytologic evaluation of brushing specimens obtained from the colon may be useful in the diagnosis of neoplastic and inflammatory lesions, as previous studies have reported favorable sensitivity and specificity figures for this procedure. In this study, we report our experience with 80 colonic brushings examined over a 5-yr period. Thirty cases received an atypical or malignant cytologic diagnosis. Nineteen of 20 cases diagnosed cytologically as adenocarcinoma revealed adenocarcinoma on biopsy; one case showed only adenomatous epithelium on biopsy and subsequent resection. Cases diagnosed cytologically as "atypical" or "adenomatous" showed adenocarcinoma, adenoma, and inflammatory conditions upon biopsy. Slides from 30 atypical/malignant cases were retrospectively reviewed for a number of cytomorphologic features and were correlated with the histologic diagnosis. Cases from histologically confirmed adenocarcinoma tended to show greater degrees of altered nuclear polarity, nuclear pleomorphism, membrane irregularities, and chromatin pattern alterations than those from histologically proven adenomatous or inflammatory lesions. The most likely cause of a false-positive diagnosis in this setting is sampling of an adenoma with high-grade dysplasia which fails to meet histologic criteria for adenocarcinoma (invasion of the underlying muscularis mucosae). Thus, in the second part of the study, we examined histologic sections from surgically excised adenomas to determine the frequency with which profound nuclear atypia is at least focally present, potentially resulting in a false-positive cytology diagnosis upon brushing. Slides from 51 cases were reviewed; cytologic atypia beyond that typically observed in adenomas was not observed in 43% of cases. However, profound nuclear atypia was present in 6% of cases; cytologic evaluation of a brushing specimen from these lesions may have resulted in a false-positive diagnosis of adenocarcinoma, despite the histologic diagnosis of adenoma with severe dysplasia. The remaining cases demonstrated intermediate degrees of atypia. These findings serve to quantitate the frequency with which cytohistologic discrepancies might be expected for mass lesions of the colon.

The spectrum of cytologic features in nonproliferative breast lesions

BACKGROUND

The reliability of cytologic criteria to classify nonproliferative breast lesions (NPBL) is still debated. Sampling error and heterogeneity of breast lesions complicates the histologic correlation of fine-needle aspiration results further.

METHODS

To provide optimal cytohistologic correlation, two smears (one that was stained with hematoxylin and eosin and one that was stained with Diff-Quik [American Scientific Products, McGraw Park, IL]) were prepared from specific tissue sections from breast biopsies without mass lesions. The 42 cases classified as NPBL histologically were included in the current study. The cytologic features of the smears were evaluated.

RESULTS

Cellularity ranged from low (40% of cases) to moderate (50% of cases) to high (7% of cases). The cells were arranged in small clusters in 79% of cases, were mixed with large sheets in 17% of cases, and were in large sheets in 2% of cases. Intact lobules were noted in 31%. The configuration of the epithelial groups was complex in 62% of cases. Myoepithelial cells in the background and within the epithelial groups were noted in all the specimens. The percentage of single epithelial cells was < 10 in 38% of cases, 10-20 in 41%, and 20-30 in 19%. Mild nuclear enlargement and overlap, micronucleoli, and mild chromatin clumping were noted in a significant number of cases.

CONCLUSIONS

NPBL have been found to have a wide spectrum of cytologic appearances. At one end of the spectrum, smears are cellular with up to 30% single cells and large sheets in a complex configuration and exhibit nuclear enlargement and overlap and prominent nucleoli, features that overlap with those described in proliferative breast lesions.

Cytologic features of proliferative breast disease: a study designed to minimize sampling error

BACKGROUND

Assessment of cytologic features that allow accurate classification of proliferative breast disease has been hampered by sampling errors when fine-needle aspirations have been compared with their corresponding histologic sections.

METHODS

To allow for optimal cytohistologic correlation, 2 smears (1 hematoxylin and eosin-stained and 1 Diff-Quik-stained) were prepared from each of 98 breast biopsies without mass lesions and compared with the corresponding histologic sections of the scraped area. Each smear was reviewed in a blinded fashion and assessed for cellularity, background elements, cytoarchitectural features of cell groups, and nuclear features by 2 reviewers. Smears were then classified as nonproliferative breast disease (NPBD), proliferative breast disease without atypia (PBD) or with atypia (PBDA), or DCIS, based on review of the corresponding histologic sections.

RESULTS

When comparing NPBD/PBD (n = 86) with PBDA/DCIS (n = 12), smears from PBDA/DCIS were significantly (by the Fisher exact test or Wilcoxon rank sum P values with adjustment for multiple comparisons) more likely to be cellular; contain single cells and necrosis; exhibit nuclear overlap and cytoplasmic vacuoles; have large nuclei, macronucleoli, pleomorphism, clumped chromatin, and hyperchromasia; and were less likely to have complex cell groups, monolayers, swirling, cohesion, and myoepithelial cells in epithelial sheets and the smear background. When NPBD (n = 53) and PBD (n = 33) were similarly compared, smears from PBD were more likely to exhibit larger and more complex cell groups, but they were otherwise similar to smears from NPBD.

CONCLUSIONS

There are many cytologic features that will allow a distinction of NPBD/PBD from PBDA/DCIS, but relatively few that can aid in separating NPBD from PBD.

Changing trends in breast fine-needle aspiration: results of the Papanicolaou Society of Cytopathology Survey

Following the NCI-sponsored consensus conference on fine-needle aspiration of the breast, the Criteria and Nomenclature Task Force of the Papanicolaou Society of Cytopathology undertook a survey to assess the status of these issues and recommendations among practicing cytopathologists. The survey was designed to assess the impact of the changing trends in the diagnosis of breast lesions on cytopathology laboratories. It also intended to assess the impact of the recommendations of the consensus conference concerning the inclusion of a statement in breast FNA reports recommending the use of the triple test, the use of the proposed diagnostic terminology, and to evaluate criteria for specimen adequacy in breast FNAs used in different institutions. The results of this survey indicate the impact of an increasing use of core biopsies on the number of breast FNAs performed over the last several years. The recently recommended diagnostic terminology for breast FNA has quickly gained wide acceptance, as has the fundamental concept of the triple test. The issue of specimen adequacy, however, remains controversial, with some laboratories utilizing quantitative criteria, while the majority do not. Diagn. Cytopathol. 2000;22:126-130.

Cytomorphometric differentiation of intraductal proliferative breast lesions

BACKGROUND

Although cytologic examination has been an indispensable procedure for the diagnosis of various breast diseases, it is often difficult to make a precise diagnosis of intraductal proliferative breast lesions preoperatively. The present study attempts to clarify the differentiation of the lesions by the cytologic morphometric approach.

METHODS

Cytologic specimens from 21 intraductal lesions, including nine ductal carcinomas in situ (DCIS), seven ductal hyperplasias (DH), and five papillomas were evaluated. Using a microscope connected to a computerized video system, the mean nuclear area, the perimeter, the form factor, the largest to smallest diameter ratio of the nuclei (LS ratio), and the coefficient of variation of the nuclear area (NACV) were measured and analyzed.

RESULTS

The mean nuclear area and perimeter were significantly higher in the cases of DCIS than in DH (p < 0.01) and papilloma (p < 0.005). Similarly, DCIS had higher NACV values than the other groups (p < 0.05 and p < 0.005, respectively). There were no significant differences in form factor or LS ratio.

CONCLUSIONS

The quantitative estimation of cytologic nuclear features is useful for preoperative differential diagnosis of intraductal proliferative lesions of the breast.

Radial scar/complex sclerosing lesion--a problem in the diagnostic work-up of screen-detected breast lesions

During the first 7.5 years of breast cancer screening in South Australia, 88 radial scar/complex sclerosing lesions were among the mammographically detected abnormalities. A false-positive cytological diagnosis by fine needle biopsy was given in three of 69 such cases with satisfactory smears, a false-positive rate of 4.3% in this particular group. A review of the smears suggested that the false-positive diagnoses could have been avoided if a total or near total absence of a benign epithelial component had been included among the criteria for a malignant diagnosis. However, even after review, atypia was considered sufficiently worrying to be reported as a suspicion of malignancy in 7% of cases.

Cytologic score and DNA-image analysis in the classification of borderline breast lesions: a prospective study on 47 fine-needle aspirates

We prospectively evaluated the accuracy of the cytologic score system developed by Masood et al. combined with DNA-image analysis in the subclassification of 47 fine-needle aspiration samples with cytologic features of borderline breast lesions. Cytologic scores ranged between 12-18. All cases underwent surgical excision of the lesion, and histology revealed 24 cases of florid hyperplasia, 8 of atypical hyperplasia, and 11 noninvasive and 4 invasive ductal carcinomas. DNA-image analysis demonstrated 33 diploid and 14 aneuploid cases. Diploid samples were divided into slowly proliferating (S + G2/M < or = 13%) and rapidly proliferating (S + G2/M > 13%) cases. By considering florid hyperplasia a "low-risk" lesion and by amalgamating atypical hyperplasia, and in situ and invasive ductal carcinoma in the category of "high-risk" lesions, the positive predictive value of a score value > 16 was 100%. In cases scoring < or = 16, the slowly proliferating pattern had a negative predictive value of 95%, while the aneuploid and rapidly proliferating patterns had a positive predictive value of 100% and 63%, respectively. We conclude that a combination of cytologic score evaluation and DNA-image analysis is very useful in differentiating "low-risk" from "high-risk" cases in the field of breast borderline lesions, thus improving the impact of fine-needle aspiration diagnosis on patient management.

Is a diagnosis of infiltrating versus in situ ductal carcinoma of the breast possible in fine-needle aspiration specimens?

BACKGROUND

With widespread use of mammographic screening, more cases of ductal carcinoma in situ (DCIS) are being detected. Fine-needle aspiration (FNA) is an established and reliable method for diagnosing breast carcinoma. However, its usefulness in distinguishing infiltrating ductal carcinoma (IDC) from DCIS is controversial.

METHODS

The authors retrospectively reviewed 36 breast FNAs (23 palpable lesions and 13 nonpalpable lesions) that were confirmed histologically as being exclusively DCIS. On review, 27 cases (75%) were categorized as carcinomas, and 9 cases (25%) were categorized as proliferative lesions with atypia. Findings of only these 27 carcinomas were compared with findings of 42 breast FNAs that surgically were proven to be IDC (> or = 85% invasive). Five key cytologic features compared included the presence of fibroadipose tissue, stromal fragments, benign epithelial groups, angulated tumor cell clusters, and tubular structures of tumor cells; for the first three features, the proximity with tumor cells also was noted.

RESULTS

The presence of stromal fragments associated with tumor cells was significantly different between cases of DCIS (9 of 27; 33%) and IDC (29 of 42; 69%) (P = 0.006). Tubular structures were present only in IDCs (10 of 42; 24%) (P = 0.02). Nine of ten IDCs that had tubular structures also contained stromal fragments. No other cytologic features were different statistically between IDC and DCIS on FNA specimens.

CONCLUSIONS

Tubular structures of tumor cells and the presence of stromal fragments in breast FNA are significant indicators of stromal invasion. However, the low occurrence rate of tubular structures (24% in this series) in IDC and the low specificity of stromal fragments limit their utility in separating IDC from DCIS. Nonetheless, if present, tubular structures in conjunction with stromal fragments can be used to evaluate stromal invasion in patients whose disease is being managed surgically.

Nuclear grooves in fine-needle aspiration biopsies of breast lesions: do they have any significance?

Nuclear grooving is a recognized morphologic feature frequently seen in papillary carcinoma of the thyroid. This feature is also occasionally seen in other nonneoplastic and neoplastic conditions. Nuclear grooves have been described in tubular carcinoma of the breast. However, the significance of nuclear grooves in benign and malignant conditions of the breast has been rarely studied. In a retrospective study, we searched for the presence of nuclear grooves in Papanicolaou-stained and Diff-Quik-stained fine-needle aspiration biopsies (FNAB) of 50 cases of primary breast carcinomas, 25 cases of proliferative breast disease, and 25 cases of fibroadenoma. In addition, 10 cases of metastatic breast carcinoma diagnosed by FNAB were reviewed. Nuclear grooves were identified in 39 of 50 (78%) of the histologically confirmed primary breast carcinomas and in 9 of 10 (90%) of the cases of metastatic breast carcinomas in the Papanicolaou-stained smears. Nineteen of 50 (38%) of the cases of proliferative breast disease/fibroadenoma showed nuclear grooves in the Papanicolaou-stained smears. The difference between the percentage of cases showing nuclear grooves seen in the Papanicolaou-stained primary breast carcinomas and metastatic breast carcinomas compared with the benign breast lesions was statistically significant (P < 0.001 in the primary breast carcinoma cases and P < 0.01 in the metastatic breast cancer cases). Nuclear grooves were identified less often in the Diff-Quik-stained smears, and their presence in malignant lesions versus cases diagnosed as benign breast disease was not statistically significant. This study suggests that although the presence of nuclear grooves is more frequently seen in malignant breast lesions, their presence cannot totally exclude the possibility of benign breast disease. The presence of nuclear grooves, however, may serve as a diagnostic clue in metastatic tumors of unknown primary.

Interobserver variability in the classification of proliferative breast lesions by fine-needle aspiration: results of the Papanicolaou Society of Cytopathology Study

This study evaluates the applicability of the published cytologic criteria in the categorization of proliferative breast lesions by assessing the diagnostic accuracy and interobserver reproducibility of a panel of experts. Twelve breast fine-needle aspiration (FNA) specimens of biopsy-proven nonproliferative breast lesion (NPL) (1 case), proliferative lesions without atypia (PL) (7 cases), proliferative lesion with atypia (PLA) (1 case), and low-nuclear grade ductal carcinoma in situ (DCIS) (3 cases) were selected. Six FNAs were Papanicolaou (PAP) and 6 were Diff-Quik-stained (DQ). Six expert cytopathologists classified the smears using a summary of published criteria as a guideline. All 6 participants rendered the same cytologic diagnosis in 2/12 (16%) cases. The agreement among the 6 raters was low (Kappa = 0.35). Cytohistologic correlation was achieved in 26/72 (36%) FNA diagnoses. The correlation of the PAP-stained cases was better than the DQ: 17/36 (47%) PAP and 9/36 (25%) DQ correlated. Improving the correlation was achieved by amalgamation of NPL and PL into "low risk" and PLA and DCIS into "high risk" categories: 47/72 (65%) FNA diagnoses then correlated with histology [29/36 (81%) PAP and 18/36 (50%) DQ]. We conclude that the cytologic criteria of proliferative breast lesions need to be further defined and assessed. Consideration should be given to minimizing the number of diagnostic categories and adopting a terminology that has a direct effect on patient management.

Fine-needle aspiration is limited in the classification of benign breast diseases

Fine needle aspiration (FNA) has been proven to be accurate for the detection of breast carcinomas. However, its utility in the classification of benign breast lesions is less clear. We therefore undertook a study of 76 adequate preoperative FNAs of the breast from patients whose surgical biopsies of the breast were shown to be benign (18 nonproliferative diseases, 30 fibroadenomas, 19 proliferative breast diseases without atypia, and 9 proliferative breast diseases with atypia). A number of architectural and cellular features on cytology were evaluated. Histology slides were also reviewed. Both cytology and histology specimens were categorized as nonproliferative disease, fibroadenoma, proliferative breast disease without atypia, and proliferative breast disease with atypia. There was exact diagnostic correlation between cytology and histology in only 42 (55%) of the 76 cases. No cellular or architectural features on FNA examined correlated with the presence of epithelial proliferation on histology. The presence of two epithelial cell populations (one unremarkable and one atypical), small but prominent nucleoli, and nuclear pleomorphism on FNA significantly correlated with the presence of atypia on histology. However, these features are also present in breast lesions without proliferation or atypia, and are not diagnostic of atypical proliferative lesions of the breast. Therefore, FNA of the breast is limited in classifying benign breast diseases.

Association of breast cancer with the finding of atypical ductal hyperplasia at core breast biopsy

OBJECTIVE

The purpose of the study is to evaluate the prevalence of occult breast carcinoma in surgical breast biopsies performed on nonpalpable breast lesions diagnosed initially as atypical ductal hyperplasia (ADH) by core needle biopsy.

BACKGROUND

Atypical ductal hyperplasia is a lesion with significant malignant potential. Some authors note that ADH and ductal carcinoma in situ (DCIS) frequently coexist in the same lesion. The criterion for the diagnosis of DCIS requires involvement of at least two ducts; otherwise, a lesion that is qualitatively consistent with DCIS but quantitatively insufficient is described as atypical ductal hyperplasia. Thus, the finding of ADH in a core needle breast biopsy specimen actually may represent a sample of a true in situ carcinoma.

METHODS

Between May 3, 1994, and June 12, 1996, image-guided core biopsies of 510 mammographically identified lesions were performed using a 14-gauge automated device with an average of 7.5 cores obtained per lesion. Atypical ductal hyperplasia was found in 23 (4.5%) of 510 lesions, and surgical excision subsequently was performed in 21 of these cases. In these 21 cases, histopathologic results from core needle and surgical biopsies were reviewed and correlated.

RESULTS

Histopathologic study of the 21 surgically excised lesions having ADH in their core needle specimens showed seven (33.3%) with DCIS.

CONCLUSIONS

In the authors' patient population, one third of patients with ADH at core biopsy have an occult carcinoma. A core needle breast biopsy finding of ADH for nonpalpable lesions therefore warrants a recommendation for excisional biopsy.

Can nonproliferative breast disease and proliferative breast disease without atypia be distinguished by fine-needle aspiration cytology?

BACKGROUND

Cytologic criteria reported to be helpful in the distinction of proliferative breast disease without atypia (PBD) from nonproliferative breast disease (NPBD) have not been rigorously tested.

METHODS

Fifty-one air-dried, Diff-Quik-stained fine-needle aspirates (FNA) of palpable breast lesions with biopsy-proven diagnoses of NPBD (34 cases) or PBD (17 cases) were reviewed. The smears were evaluated for the cellularity, size, and architectural arrangement of the epithelial groups; the presence of single epithelial cells and myoepithelial cells; and nuclear characteristics.

RESULTS

The only cytologic feature found to be significantly different between PBD and NPBD was a swirling pattern of epithelial cells. A swirling pattern was noted in 13 of 17 PBD cases (76%) and 12 of 34 NPBD cases (35%) (P = 0.008).

CONCLUSIONS

Because there is significant overlap in cytologic features between NPBD and PBD, the distinction between the two entities is difficult in cytologic sampling.

The woman at high risk for breast cancer. Importance of hyperplasia

In summary, some histopathologically identifiable lesions within the human breast indicate later development of invasive breast cancer at an increased incidence over that of the general population. Many of these may be regarded as markers of increased risk because they are indicative of cancers presenting anywhere in either breast, whereas the noncomedo DCIS lesions are unique in indicating a high likelihood of invasive disease at the same site of detection of the initial high-risk lesion (Table 2).