Cytological criteria for the diagnosis of intraductal hyperplasia, ductal carcinoma in situ, and invasive carcinoma of the breast

Overcoming Pitfalls in Breast Fine-Needle Aspiration Cytology: A Practical Review

BACKGROUND

Fine-needle aspiration cytology (FNAC) is a cornerstone technique for the initial assessment of breast lesions, offering a rapid and minimally invasive option for cytological evaluation. While FNACs can forego the need for core needle biopsies (CNBs), variations in technique, subjective interpretation, and intrinsic limitations present diagnostic challenges. The International Academy of Cytology (IAC) established the Yokohama system and is developing the WHO Reporting System for Breast Cytopathology jointly with IARC, to standardize diagnostic criteria, aiming to enhance diagnostic precision and consistency. Due to the preference for CNBs, expertise in breast FNAC is low in the developed world.

SUMMARY

This review assesses common pitfalls in breast cytopathology. These common and uncommon entities may easily lead to false-negative or false-positive diagnoses, due to morphological overlap or misleading clinical and radiological contexts. For instance, pauci-cellular lesions, such as lobular carcinomas, often lead to false-negative diagnoses, whereas complex sclerosing lesions, fibroadenomas, and papillary lesions may show concerning features, resulting in a false positive. The same is true for some benign inflammatory pathologies, such as steatonecrosis, and uncommon lesions, such as collagenous spherulosis. Ductal carcinoma in situ can lead to both false-negative and false-positive diagnoses, and high-grade lesions are impossible to tell apart from invasive carcinomas. These are discussed in detail. Procedural and preanalytical conditions, and the role of ancillary testing, are also briefly addressed.

KEY MESSAGES

Breast FNAB is a powerful diagnostic technique, fast and minimally invasive. Even in contexts which lack expertise, this technique can be successfully adopted with a cautious approach and as long as pitfalls are kept in mind, benefiting patients and healthcare systems.

Cytomorphological Assessment in Aspirates of Ductal Carcinoma in situ: Correlations with Histopathologic Grade, Architectural Pattern, and Invasion

INTRODUCTION

Fine-needle aspiration biopsy (FNAB) of the breast is an effective and widely adopted diagnostic technique. Histopathologic grading of ductal carcinoma in situ (DCIS) has prognostic significance. In this current study, FNAB of DCIS was reviewed to identify parameters that predict grading, histopathologic architecture, and presence of invasion in DCIS.

METHODS

Aspirates from histopathology-proven cases of DCIS were retrieved and reviewed for cytomorphologic parameters including cellularity, composition, epithelial fragment architecture cellular/nuclear features.

RESULTS

In total 104 aspirates were reviewed. Cytopathologic cellular features - large nuclear size (p = 0.005), prominent nucleoli (p = 0.011), increased nuclear membrane irregularity (p = 0.043), high variation in nuclear size (p = 0.025), and presence of apoptotic figures in epithelial structures (p < 0.001); and background debris (p = 0.033) correlated with a high-grade diagnosis. Cytoplasmic vacuolation (p = 0.034) was seen exclusively in non-high-grade aspirates. Epithelial fragment architecture did not correlate with grading. A predominance (≥50%) of solid aggregates and papillary fragments on FNAB correlated with histopathologically solid (p = 0.039, p = 0.005) and papillary (p = 0.029, < p = 0.001) patterns. No parameter showed correlation with invasion.

CONCLUSION

FNAB is effective in predicting DCIS grading. Epithelial fragment architecture assessment is limited to papillary or solid types, and FNAB cannot predict focal invasion in DCIS.

Immunohistochemistry Applied to Breast Cytological Material

Fine-needle aspiration biopsies (FNABs) of the breast are minimally invasive procedures enabling the diagnosis of suspicious breast lesions. Unfortunately, they are often perceived as inferior to core-needle biopsies, namely because they are supposedly unable to differentiate between high-grade ductal carcinoma in situ and invasive carcinoma or provide material for ancillary testing. Several studies have shown, however, that FNAB samples, when handled properly, are indeed capable of providing sufficient and adequate material for ancillary testing, namely immunocytochemistry (ICC). We reviewed the published literature regarding the use of ICC for both diagnostic and theranostic uses in the different types of cytological samples obtained from FNABs of the breast, including smears, liquid-based cytology samples, and cellblocks. We found that p63 and 34βE12 show promise in aiding in the differential diagnosis between in situ and invasive lesions and that most other diagnostic markers may be used as in tissue. Regarding theranostic ICC markers, results vary between publications, but with care, these can successfully be performed in cytological samples. Air-dried smears should be avoided, and cellblocks are overall more versatile than cytology slides, enabling the evaluation of not only hormonal receptors and HER2 by ICC, but also of Ki-67. Particular attention should be paid to fixation and antigen retrieval procedures in all cases. We recommend that laboratories without experience perform short validation runs before adopting these techniques into clinical practice.

Correlation of ultrasound, cytological, and histological features of 110 benign BI-RADS categories 4C and 5 nonpalpable breast lesions. The Institut Curie's experience

BACKGROUND

The purpose of this study was to determine the pathological and ultrasound (US) features of benign nonpalpable breast lesions (NPBLs) classified as Breast Imaging Reporting and Data System (BI-RADS) category 4C or 5.

METHODS

Between 2003 and 2007, 849 consecutive NPBLs detected at US and classified as BI-RADS category 4C (505) or 5 (344) initially underwent US-guided fine needle aspiration (FNA) at our institution. Benign diagnoses were established according to surgical excision findings or during a minimal 6-month imaging follow-up (mean, 3.7 years [SD, 2.6 years]). US BI-RADS features were reviewed and compared retrospectively using a chi-square test for the following pathological categories: epithelial and fibrous proliferation (EFP), cystic and papillary lesion (C&P), inflammatory lesion (IL), benign tumor (BT), intramammary lymph node (ILN), intraepithelial proliferative lesion (IPL), and nonspecific morphological alteration (NMA). The performance of FNA in the diagnosis of benignity was assessed.

RESULTS

Of 849 NPBLs, 110 (12.9%) NPBLs were benign: 88 (17.4%) were BI-RADS category 4C, and 22 (6.4%) were BI-RADS category 5. Forty-four (40%) were EFPs, 21 (19%) were C&Ps, 13 (12%) were NMAs, 11 (10%) were ILs, 11 (10%) were BTs, 8 (7%) were IPLs, and 2 (2%) were ILNs. Lesion shape, US pattern distribution, and posterior features showed statistically significant differences between these categories (P < .05): 33 (75%) EFPs exhibited posterior shadowing, 18 (86%) C&Ps were homogenous, 9 (82%) ILs were heterogeneous, 11 (100%) BTs were homogeneous, 9 (82%) BTs were oval, and 6 (75%) IPLs were irregularly shaped. Of the 110 benign NPBLs, FNA diagnosis was falsely positive in 7 (6%), suspicious in 10 (9%), and benign in 90 (82%), and 3 (3%) were inadequate for diagnosis.

CONCLUSION

A diverse array of benign NPBLs can be classified as BI-RADS category 4C or 5 on US, each showing specific imaging presentations.

Breast fine needle aspiration biopsy cytology: the potential impact of the International Academy of Cytology Yokohama System for Reporting Breast Fine Needle Aspiration Biopsy Cytopathology and the use of rapid on-site evaluation

The present report reviews the current problems associated with the routine use of breast fine needle aspiration biopsy (FNAB) and discusses the potential impact that the new International Academy of Cytology (IAC) Yokohama Reporting System and the use of rapid on-site evaluation (ROSE) should have on reducing these problems to optimize breast care for patients. The recently reported IAC System aims to establish the best practice guidelines for breast FNAB, emphasizing the importance of the FNAB technique and the skillful preparation of direct smears. The IAC System proposes a standardized report and established clear terminology for defined reporting categories, each of which has a risk of malignancy and is linked to management options. The FNAB techniques that will optimize the biopsy specimen and reduce poor quality smears are reviewed and the benefits of ROSE are discussed. FNAB can diagnose accurately the vast majority of breast lesions, and ROSE has been recommended whenever possible to reduce the rate of insufficient/inadequate cases and increase the number of specific benign and malignant diagnoses. ROSE performed by a cytopathologist provides a provisional diagnosis, reducing patient anxiety and facilitating management through cost-effective immediate triage and patient selection for ancillary testing. Thus, patients can be selected for immediate core needle biopsy, as required.

International Academy of Cytology Yokohama System for Reporting Breast Fine-Needle Aspiration Biopsy Cytopathology: A Review of Predictive Values and Risks of Malignancy

OBJECTIVE

We aimed to assess the risk of malignancy (ROM) and predictive values in prior breast cytology studies as a basis for the new International Academy of Cytology (IAC) Yokohama system for reporting breast fine-needle aspiration biopsy (FNAB) cytology, which classifies cytologic diagnoses into 5 categories: (1) insufficient material, (2) benign, (3) atypical, (4) suspicious of malignancy, and (5) malignant.

STUDY DESIGN

Publications between January 1, 1997, and December 31, 2017, that studied the performance characteristics of FNAB from palpable and nonpalpable breast masses were identified through the PubMed database. Data for number of total cases and cases within each diagnostic category, if available, were collected. Performance characteristics, including absolute sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and ROM for each category were recorded or, when possible, calculated.

RESULTS

The literature review resulted in a case cohort of 33,341 breast FNABs, drawn from 27 studies. Pooling these cases together, the ROM for insufficient material, benign, atypical, suspicious, and malignant were 30.3, 4.7, 51.5, 85.4, and 98.7%, respectively. The complete sensitivity and specificity were 96.3 and 98.8%, correspondingly. The PPV and NPV were 98.7 and 95.3%, correspondingly. The false-negative and false-positive rates were 3.7 and 1.0%, respectively.

CONCLUSIONS

This meta-analysis demonstrates that the diagnostic categories of the new IAC Yokohama System each carry an implied ROM, which increases from the benign to malignant categories. This study also shows the high sensitivity and specificity of FNAB for breast lesions.

The International Academy of Cytology Yokohama System for Reporting Breast Fine-Needle Aspiration Biopsy Cytopathology

The International Academy of Cytology (IAC) gathered together a group of cytopathologists expert in breast cytology who, working with clinicians expert in breast diagnostics and management, have developed the IAC Yokohama System for Reporting Breast Fine-Needle Aspiration Biopsy (FNAB) Cytology. The project was initiated with the first cytopathology group meeting in Yokohama at the 2016 International Congress of Cytology. This IAC Yokohama System defines five categories for reporting breast cytology, each with a clear descriptive term for the category, a definition, a risk of malignancy (ROM) and a suggested management algorithm. The key diagnostic cytopathology features of each of the lesions within each category will be presented more fully in a subsequent atlas. The System emphasizes that the crucial requirements for diagnostic breast FNAB cytology are a high standard for the performance of the FNAB and for the making of direct smears, and well-trained experienced cytopathologists to interpret the material. The performance indicators of breast FNAB, including specificity and sensitivity, negative predictive value, positive predictive value and ROM stated in this article have been derived from the recent literature. The current practice of breast FNAB has evolved with the increasing use of ultrasound guidance and rapid on-site evaluation. Two recent publications have shown a range of ROM for the insufficient/inadequate category of 2.6-4.8%, benign 1.4-2.3%, atypical 13-15.7%, suspicious of malignancy 84.6-97.1%, and malignant 99.0-100%. The management algorithm in the System provides options because there are variations in the management of breast lesions using FNAB and core-needle biopsy in those countries utilizing the "triple test" of clinical, imaging, and FNAB assessment, and also variations in the availability of CNB and imaging in low- and middle-income countries. The System will stimulate further discussion and research, particularly in the cytological diagnostic features of specific lesions within each category and in management recommendations. This will lead to continuing improvements in the care of patients with breast lesions and possible modifications to the IAC Yokohama System.

The International Academy of Cytology Yokohama System for Reporting Breast Fine Needle Aspiration Biopsy Cytopathology: A Single Institutional Retrospective Study of the Application of the System Categories and the Impact of Rapid Onsite Evaluation

OBJECTIVES

To review the performance and utility of the International Academy of Cytology (IAC) Yokohama System for Reporting Breast Fine Needle Aspiration Biopsy (FNAB) Cytology five category stratification and evaluate the impact of rapid onsite evaluation (ROSE).

METHOD

A retrospective analysis of breast FNAB cytology cases with matched histopathological results at a single institution over a 32 months period using a structured reporting system with 5 diagnostic categories ("inadequate/insufficient," "benign," "atypical," "suspicious of malignancy" and "malignant") closely paralleling the proposed IAC System.

RESULTS

Of 2,696 breast FNAB cases, there were 579 with matched histopathology and 456 of these had ROSE. ROSE decreased the number in the "insufficient" category (17.1% without ROSE to 4.0% with ROSE) and increased the number in the "malignant" (17.9 to 39.0%) with a lesser impact on the "atypical," "benign" and "suspicious of malignancy" categories. The performance data showed a positive predictive value of 96.4%, negative predictive value of 97.6%, and a risk of malignancy of a FNAB categorized as "insufficient" to be 2.6%, "benign" 1.7%, "atypical" 15.7%, "suspicious of malignancy" 84.6%, and "malignant" 99.5%.

CONCLUSION

Breast FNAB is an accurate test enabling effective diagnosis of breast lesions. ROSE improved the performance by decreasing the proportion of "insufficient" and "atypical" and increasing the "suspicious of malignancy" and "malignant" diagnoses and enabling immediate triage for further biopsy where necessary.

Pulmonary loose tumor tissue fragments and spread through air spaces (STAS): Invasive pattern or artifact? A critical review

The concept of loose tumor tissue fragments as a pattern of invasion in lung carcinoma has recently been proposed and is included in the 2015 WHO fascicle on the classification of lung tumors, so-called "spread through airs paces" or STAS. This inclusion is controversial, as there are significant data to support that this histologic finding represents an artifact of tissue handling and processing rather than a pattern of invasion. These data are summarized in this review. These data are summarized in this review and support the conclusion that the inclusion of STAS in the WHO classification for lung cancer as a pattern of invasion was premature and erroneous. In our opinion, these tumor cell clusters or loose cells appear to be simply an artifact, although one which may or may not pinpoint to a high-grade tumor with discohesive cells and adverse prognosis.

Fine needle aspiration cytology of lobular breast carcinoma and its variants

OBJECTIVE

To identify associations between cytological criteria in fine needle aspiration (FNA) specimens and histological subtypes of lobular breast carcinoma (classical and other types).

STUDY DESIGN

FNA cytology and mastectomy specimens from 72 cases of invasive lobular breast carcinoma were consecutively retrieved from the files of the Amaral de Carvalho Hospital, Jaú-São Paulo, Brazil. All cases were reviewed regarding five cytological criteria: cellularity, cellular cohesion, presence of inflammation, nucleoli and nuclear atypia. The χ2 test or Fisher's exact tests with 95% confidence intervals (CI) were used.

RESULTS

The classical type showed lower initial cytological diagnosis of malignancy compared to the other variants (p=0.017; odds ratio (OR) 0.26, 95% CI 0.89-0.80). Moderate/intense cellular cohesion (p=0.011; OR 0.18, 95% CI 0.04-0.73) and mild atypia (p=0.000; OR 16.15, 95% CI 3.20-81.48) were significantly associated with the classical type of lobular breast carcinoma, while the absence of inflammation (p=0.082; OR 0.36, 95% CI 0.12-1.15) was marginally associated with the classical type.

CONCLUSIONS

In cytology, the characterization of lobular carcinoma as malignant is difficult, especially the classical type. The association between cell cohesion and the classical type of lobular breast carcinoma may be one of the factors that complicate this diagnosis.

Fine needle aspiration of breast masses in pregnant and lactating women: experience with 28 cases emphasizing Thinprep findings

BACKGROUND

Fine needle aspiration (FNA) of breast masses in pregnant or lactating women is an uncommon procedure, and cytological interpretation is considered problematic due to atypia inherent to secretory change in glandular epithelia. Previous descriptions of "lactating adenoma" (LAd), the most common tumor in this population, have been on direct smears (DS), while ThinPrep (TP, Hologic, Boxborough, MA) findings therein remain largely uncharacterized.

METHODS

FNA cases from breast masses in pregnant or lactating women (2005-2012), processed as TP and/or DS were retrospectively reviewed.

RESULTS

28 cases from as many patients (mean age 36 years), at 23 weeks of pregnancy to 10 months postpartum, were reviewed. Size of mass ranged from 1.0 to 4.5 cm. Corresponding histopathology was available in 21/28 cases. TP was available in 24/28 cases. Relative to DS, in TP, LAd showed "lacy" fragments, tissue paper-like texture, and globular clumps of "milky" background material, with embedded singly dispersed "bare" epithelial cell nuclei containing cherry-red macronucleoli. Architecture appeared disrupted in TP with isolated cells, smaller cell clusters, and lobules in LAd. Cellular morphology was better preserved in TP. Cytological features of carcinoma on TP were similar to DS. There were no false-positive cases. In this series, LAd was the most common diagnosis for breast masses in pregnant and lactating women (78.5%) and demonstrated background, architectural, and cellular alterations on TP.

CONCLUSION

In this setting, malignancy is an important consideration (encountered in 3/28, 11% of cases, including one false-negative angiosarcoma case).

Fine-needle aspiration cytology of the breast

Fine-needle aspiration cytology (FNAC) is an established, highly accurate, and cost-effective method for diagnosing lesions in different organs, including the breast. The method is minimally invasive without unwanted side effects. FNAC forms part of the triple assessment of breast lesions. Despite some shortcomings of the reporting categories, FNAC as part of the triple assessment has proved its value in describing the findings most accurately. The diagnostic impact depends on experience of the operator, quality of preparation, and diagnostic skills of the cytopathologist. The highest accuracy is achieved at centers with a multidisciplinary approach. FNAC is often palpation guided from palpable breast masses, whereas ultrasonography guidance is more widely used on nonpalpable lesions. Inadequate sampling with FNAC is particularly seen in collagenous lesions and in submitted specimens sampled by physicians lacking experience with the FNAC procedure. A diagnostic biopsy is recommended when FNAC provides scant material. FNAC is considered to be a safe method for screening purposes, although moderately less sensitive than core needle biopsy. FNAC is most accurate when experienced cytopathologists are available to assess the adequacy of the aspirated material and advise on additional aspirations for ancillary tests when needed.

Immunomarker studies of fine-needle cytopuncture cell blocks for tumor response prediction after preoperative chemotherapy and prognosis in operable nonmetastatic primary breast carcinoma

Neo-adjuvant chemotherapy of breast cancer provides an opportunity to evaluate predictive factors at initial tumor biopsy. We evaluated these factors on cell blocks obtained by diagnostic fine-needle cytopuncture (FNC), with respect to tumor regression and outcome. A prospective study (1996-2003, median follow-up 82 months) involved 163 patients with breast carcinoma (T2 ≥ 3 cm, T3, T4 noninflammatory) diagnosed by means of FNC. Malignancy, cytologic grade, and the presence of lymphocytes were determined on cytologic smears. Ki67, estrogen receptor (ER), progesterone receptor (PgR), HER2, and p53 expression was assessed on cell blocks by means of immunohistochemistry. All the patients received anthracycline-based chemotherapy. A combined clinical and pathologic tumor regression score was calculated. Twelve cases (7.5%) showed a complete regression, 72 cases (44%) a partial regression and 79 cases (48.5%) no regression. Factors predictive of regression were high grade, presence of lymphocytes, pN0, high Ki67 expression, hormone receptor negativity, and the "triple negative" phenotype. In univariate analysis 5-year metastasis-free survival rate (MFS) correlated with cytologic grade, pN, ER, and p53 status, while overall survival (OS) correlated with cytologic grade, type of surgery, pN, and ER status. In multivariate analysis, MFS was significantly influenced by the regression score, Ki67, age, ER status, pN, HER2, and initial tumor size. Except for age, the same parameters correlated with OS. FNC with the cell block technique is a rapid, minimally invasive, reliable, and inexpensive method for analyzing predictive biomarkers, and may thus be useful in the management of breast cancer patients requiring neo-adjuvant chemotherapy.

Role of myoepithelial cells in breast tumor progression

Myoepithelial cells form a semi-continuous protective sheet separating the human breast epithelium and the surrounding stroma. They suppress stromal invasion of tumor cells by the secretion of various anti-angiogenic and anti-invasive factors. The disruption of this cell layer results in the release of the growth factors, angiogenic factors, and reactive oxygen species causing an alteration in the microenvironment. This helps in the proliferation of surrounding cells and increases the invasiveness of tumor cells. Two theories are proposed for the mechanism of tumor epithelial cells progression from in situ to invasive stage. According to the first theory, tumor cell invasion is triggered by the overproduction of proteolytic enzymes by myoepithelial cells and surrounding tumor cells. The second theory states that tumor invasion is a multistep process, the interactions between damaged myoepithelial cells and the immunoreactive cells trigger the release of basement membrane degrading enzymes causing tumor progression. Further studies in understanding of molecular mechanism of myoepithelial cell functions in tumor suppression may lead to the identification of novel therapeutic targets for breast cancer.

Multinomial goodness-of-fit tests for logistic regression models

We examine the properties of several tests for goodness-of-fit for multinomial logistic regression. One test is based on a strategy of sorting the observations according to the complement of the estimated probability for the reference outcome category and then grouping the subjects into g equal-sized groups. A g x c contingency table, where c is the number of values of the outcome variable, is constructed. The test statistic, denoted as Cg, is obtained by calculating the Pearson chi2 statistic where the estimated expected frequencies are the sum of the model-based estimated logistic probabilities. Simulations compare the properties of Cg with those of the ungrouped Pearson chi2 test (X2) and its normalized test (z). The null distribution of Cg is well approximated by the chi2 distribution with (g-2) x (c-1) degrees of freedom. The sampling distribution of X2 is compared with a chi2 distribution with n x (c-1) degrees of freedom but shows erratic behavior. With a few exceptions, the sampling distribution of z adheres reasonably well to the standard normal distribution. Power simulations show that Cg has low power for a sample of 100 observations, but satisfactory power for a sample of 400. The tests are illustrated using data from a study of cytological criteria for the diagnosis of breast tumors.

Myoepithelial cells: any role in aspiration cytology smears of breast tumors?

AIMS AND OBJECTIVE

To study the role of myoepithelial (ME) cells in distinguishing benign, proliferative breast diseases (PBD) and frank malignant breast lesions.

MATERIALS AND METHODS

In this study, histology proven 71 cases of fine needle aspiration cytology (FNAC) of palpable breast lesions were selected. There were 30 invasive carcinomas (24 infiltrating duct carcinoma and 6 infiltrating lobular carcinoma), 25 cases of benign lesion (21 fibroadenomas and 4 fibrocystic lesions) and 11 proliferative breast diseases (other than carcinoma in situ) and five cases of carcinoma in situ. The number of ME cells were estimated in respect to 1000 ductal cells. In every case at least 20 high power fields (x 40) were studied. Quantitative estimation of ME cell was correlated with the final diagnosis. Corresponding histopathology cases were also evaluated for diagnostic confirmation along with the pattern of distribution of ME cells. The ME cells were also quantitated on histopathology sections on smooth muscle actin (SMA) immunostained sections.

RESULTS

The mean number of ME cells per 1000 ductal cells on cytology smears was 5.1 +/- 5.5, 30.8 +/- 25, 28.3 +/- 20.2, and 38.4 +/- 38.8 in malignant, carcinoma in situ, PBD and benign breast lesions respectively. The non parametric Mann Whitney test showed significant difference in number of the ME cells between benign and malignant groups (p < .000), PBD and malignant groups (p < .000) and carcinoma in situ and malignant group (p < .001). However, it was insignificant between benign and PBD group, and PBD and carcinoma in situ (p > .01). In SMA stained histopathology sections, ME cell in benign, PBD, carcinoma in situ and malignant cases were 741.12 +/- 248, 238 +/- 172, 121.6 +/- 115 and 15.6 +/- 25.1 respectively. Statistical analysis showed significantly different number of ME cell between benign versus PBD group, carcinoma in situ and malignant group. It was also significant between PBD versus malignant, and carcinoma in situ versus malignant (p < .001, Mann Whitney test). However number of ME cell was not significant between PBD versus carcinoma in situ.

CONCLUSION

The number of ME cell in breast lesions may be helpful in distinguishing PBD versus invasive malignant tumors on FNAC smears. However it is not helpful to distinguish benign lesions versus PBD.

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.

Fine needle aspiration for evaluation of breast masses

PURPOSE OF REVIEW

Fine needle aspiration has been used for many years as a diagnostic tool for breast lesions, with high sensitivity and specificity. There is controversy as to whether this technique should be replaced by other diagnostic procedures such as core biopsy. This review aims to re-evaluate the usefulness of breast fine needle aspiration.

RECENT FINDINGS

During the past 10 years many institutions have replaced fine needle aspiration by core biopsy and related techniques such as vacuum-assisted core biopsy and advanced breast biopsy instrument action. Other institutions continue to use fine needle aspiration as a first line of investigation for breast lesions. This technique is especially useful in radiologically benign lesions and when combined with image guidance. The use of the 'triple test' (combined cytologic, clinical and radiologic findings) decreases false-negative and false-positive results.

SUMMARY

Fine needle aspiration continues to be an acceptable and reliable procedure for the preoperative diagnosis of breast lesions, particularly in developing countries, and when used as part of the 'triple test'. Accurate diagnosis requires experience in both aspiration technique and specimen interpretation. Clinicians should be mindful of the limitations of the technique. The choice between fine needle aspiration and core biopsy should be individualized for the patient.

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.

Cytology is useful in breast screening: results and long-term follow-up of the Singapore Breast Screening Pilot Project

OBJECTIVE

The Singapore Breast Screening Pilot Project (SBSPP) was embarked upon (1994-1997) to determine if mammography was useful in early breast cancer detection among Asian women.

PATIENTS AND MEASUREMENTS

Of 28 231 women screened, fine needle aspiration cytology (FNAC) was performed in 232 individuals as part of the triple assessment.

RESULTS

Absolute and complete sensitivities for the diagnosis of carcinoma were 46.7% and 82.2%, respectively, based on the results of FNAC. Specificity was 63.3%. The inadequate rate was 31%. Five women who were considered cancer-free on triple assessment and, in two cases open diagnostic biopsy during the SBSPP, subsequently developed breast cancer after a median follow-up of 6 years.

CONCLUSION

Although our FNAC results compared relatively well with international standards, they reflect a small cohort, and may face additional difficulties in a larger programme.

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.