Fine needle aspiration cytology of papillary lesions of the breast: how accurate is the diagnosis?

Real-World Diagnostic Accuracy of the On-Site Cytopathology Advance Report (OSCAR) Procedure Performed in a Multidisciplinary One-Stop Breast Clinic

Fine-needle aspiration (FNA) cytology has been widely used for the diagnosis of breast cancer lesions with the objective of differentiating benign from malignant masses. However, the occurrence of unsatisfactory samples and false-negative rates remains a matter of concern. Major improvements have been made thanks to the implementation of rapid on-site evaluation (ROSE) in multidisciplinary and integrated medical settings such as one-stop clinics (OSCs). In these settings, clinical and radiological examinations are combined with a morphological study performed by interventional pathologists. The aim of our study was to assess the diagnostic accuracy of the on-site cytopathology advance report (OSCAR) procedure on breast FNA cytologic samples in our breast OSC during the first three years (April 2004 till March 2007) of its implementation. To this goal, we retrospectively analyzed a series of 1820 breast masses (1740 patients) radiologically classified according to the American College of Radiology (ACR) BI-RADS lexicon (67.6% being either BI-RADS 4 or 5), sampled by FNA and immediately diagnosed by cytomorphology. The clinicoradiological, cytomorphological, and histological characteristics of all consecutive patients were retrieved from the hospital computerized medical records prospectively registered in the central information system. Histopathological analysis and ultrasound (US) follow-up (FU) were the reference diagnostic tests of the study design. In brief, we carried out either a histopathological verification or an 18-month US evaluation when a benign cytology was concordant with the components of the triple test. Overall, histology was available for 1138 masses, whereas 491 masses were analyzed at the 18-month US-FU. FNA specimens were morphologically nondiagnostic in 3.1%, false negatives were observed in 1.5%, and there was only one false positive (0.06%). The breast cancer prevalence was 62%. Diagnostic accuracy measures of the OSCAR procedure with their 95% confidence intervals (95% CI) were the following: sensitivity (Se) = 97.4% (96.19-98.31); specificity (Sp) = 94.98% (92.94-96.56); positive predictive value (PPV) = 96.80% (95.48-97.81); negative predictive value (NPV) = 95.91% (94.02-97.33); positive likelihood ratio (LR+) = 19.39 (13.75-27.32); negative predictive ratio (LR-) = 0.03 (0.02-0.04), and; accuracy = 96.45% (95.42-97.31). The respective positive likelihood ratio (LR+) for each of the four categories of cytopathological diagnoses (with their 95% CI) which are malignant, suspicious, benign, and nondiagnostic were 540 (76-3827); 2.69 (1.8-3.96); 0.03 (0.02-0.04); and 0.37 (0.2-0.66), respectively. In conclusion, our study demonstrates that the OSCAR procedure is a highly reliable diagnostic approach and a perfect test to select patients requiring core-needle biopsy (CNB) when performed by interventional cytopathologists in a multidisciplinary and integrated OSC setting. Besides drastically limiting the rate of nondiagnostic specimens and diagnostic turn-around time, OSCAR is an efficient and powerful first-line diagnostic approach for patient-centered care.

Risk Stratification of Breast Fine-Needle Aspiration Biopsy Specimens Performed without Radiologic Guidance by Application of the International Academy of Cytology Yokohama System for Reporting Breast Fine-Needle Aspiration Cytopathology

BACKGROUND AND OBJECTIVE

The International Academy of Cytology (IAC) Yokohama system for reporting breast fine-needle aspiration biopsy (FNAB) cytopathology has been proposed to standardize breast FNAB reporting. The aim of this study was to categorize breast FNAB cases performed by palpation without radiological guidance according to the IAC system, establish the risk of malignancy (ROM) for the categories and assess the system's utility, pitfalls, and implications in low-resource/financial constraint settings.

METHODS

A retrospective analysis of palpation-guided FNAB of breast lesions performed without radiological guidance between January 2016 and December 2019 was carried out and was correlated with follow-up biopsies wherever available. A total of 1,089 cases were recategorized using the IAC Yokohama system. Histopathology follow-up was available for 400 cases. The data were analysed for ROM, positive predictive value (PPV), and negative predictive value (NPV).

RESULTS AND DISCUSSION

Out of 1,089 cases, 4.3% (n = 47) cases were categorized as insufficient, 82% (n = 893) as benign, 2.8% (n = 31) as atypical, 2.7% (n = 29) as suspicious of malignancy, and 8.2% (n = 89) as malignant. Some 400 cases had a follow-up biopsy, based on which, the ROM for the categories were 33.3%, 0.4%, 37.5%, 96%, and 100%. The NPV for the benign category was 99.6%. The PPV of the malignant category was 100%, that of combined suspicious of malignancy and malignant categories was 99%, and of combined atypical, suspicious of malignancy, and malignant was 90.6%.

CONCLUSION

The IAC Yokohama system is useful in standardizing the reporting of cytopathology of breast lesions. FNAB with radiological guidance is ideal but in cases of finance/resource constraints, FNAB by palpation alone is satisfactory if the test result is in the benign, suspicious of malignancy, or malignant categories, which constitute 91.5% of the cases in this study. A repeat ultrasound-guided FNAB and/or core needle biopsy should be recommended for cases in the insufficient/inadequate or atypical categories.

The International Academy of Cytology Yokohama System for Reporting Breast Cytopathology showed improved diagnostic accuracy

BACKGROUND

The aim of the International Academy of Cytology Yokohama System for Reporting Breast Fine Needle Aspiration Biopsy Cytopathology is to improve cytology practice. This study assessed cytologic diagnoses made with the system and its efficacy when it was applied by pathologists with different levels of experience.

METHODS

In all, 1080 cases of breast fine-needle aspiration biopsy (FNAB) over a period of 16 years were reviewed and reclassified with the system. The category distribution and the diagnostic performance were compared with the original diagnoses. The concordance rates for diagnoses from pathologists with different levels of experience were also determined.

RESULTS

The distribution of cytologic diagnoses made with the system was as follows: 11.7% were insufficient, 56.6% were benign, 20.1% were atypical, 6.1% were suspicious for malignancy, and 5.6% were malignant. The rates for the insufficient and atypical categories were lower than the original diagnosis rates (13.1% and 23.8%, respectively). Overall, 120 cases (11.1%) were recategorized. Among those recategorized as benign, suspicious, or malignant with follow-up data, 96.7% were correctly reclassified. A significant improvement in diagnostic performance was found with the system (P < .001). Such improvement was also seen in problematic breast lesions, including fibroepithelial lesions, papillary lesions, and low-grade carcinomas. Pathologists with intermediate experience showed a higher concordance with an expert pathologist in the diagnoses than those with short experience (κ, 0.838 vs 0.634).

CONCLUSIONS

The system effectively categorized the diagnoses, and the diagnostic performance of FNAB reporting was improved. The structured reporting also enhanced the reproducibility of reporting by pathologists with intermediate experience and, to some extent, those with short experience.

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.

Papillary lesions of the breast: A systematic evaluation of cytologic parameters

BACKGROUND

The cytologic diagnosis of papillary lesions of the breast is challenging because of the diverse morphology, including epithelial hyperplasia, atypia, low-grade malignancy, and neuroendocrine differentiation; also, traditional malignant features such as necrosis and myoepithelial cell loss can be lacking. Thus, the diagnostic criteria for papillary lesions may differ from those for other breast lesions. This study evaluated various cytologic parameters in a large cohort to identify useful diagnostic features.

METHODS

Cytologic preparations of papillary lesions with histologic follow-up were reviewed for features related to cellularity, epithelial cohesiveness, cellular and stromal architecture, cytomorphology, and background. Corresponding histologic slides were also reviewed.

RESULTS

In all, 153 cases were included. Epithelial discohesion, solid and cribriform patterns, atypical nuclear features, and mitoses (P ≤ .001 to P = .017) were associated with malignancy. Cell balls, monolayer sheets, and features of cystic change (P < .001 to P = .016) were associated with benign lesions. Complex (P = .031) and slender (P = .026) papillae and neuroendocrine features (P < .001) were associated with malignancy. Hemorrhage, background, and infiltrating neutrophils (P < .001 to P = .025) were associated with malignancy; fibrotic broad papillary stromal fragments (naked papillary fronds [NPFs]; P = .043) were associated with benignity. The presence of any single parameter, including the absence of myoepithelial cells within epithelial structure, the presence of cytoplasmic granules, an increased amount of cytoplasm, and a nuclear to cytoplasmic (N/C) ratio greater than 0.7, which were identified by principal component analysis, yielded a sensitivity of 95.1% and a specificity of 100.0% in predicting malignancy.

CONCLUSIONS

Methodological assessment of multiple features is recommended. Myoepithelial cells, cytoplasmic granules, the amount of cytoplasm, and the N/C ratio are key features for diagnosis.

The Conundrum of Papillary Breast Lesions within the C3 Category

OBJECTIVES

To identify features that could define papillary ductal cell proliferation within the C3 category and to subcategorise papillary lesions into benign papillomas which can be managed conservatively and atypical/malignant papillary neoplasms which require surgical intervention.

STUDY DESIGN

A blind microscopic rescreen of all C3 cases was conducted. The corresponding histological outcome was compared with the cytology. Statistical analysis was performed using papillary versus non-papillary outcomes and benign versus atypical/malignant papillary lesions. In addition, macropapillary lesions (papilloma and encysted papillary carcinoma) were plotted against micropapillary ductal carcinoma in situ.

RESULTS

Two hundred thirty FNA cases reported as C3 included 72 papillary neoplasms (52 benign papillomas and 20 atypical/malignant papillary lesions). Features specific to papillary lesions within C3 include macropapillary fragments, complex sheets, palisading strips, cystic background, cohesion and a decreased nuclear-to-cytoplasmic ratio. Features favouring atypical/malignant papillary lesions include decreased numbers of bare bipolar nuclei, discohesion and a non-cystic background. These features are common to most breast malignancies; however, identification of papillary features often results in a downgraded diagnosis from C5.

CONCLUSIONS

This study supports the ability to reliably identify papillary ductal cell proliferation within C3. Certain features can distinguish papillary lesions from other C3 pathologies. This separation is likely to be clinically useful as papillary lesions may require a different management approach.

Liquid-based cytology in fine-needle aspiration of breast lesions: a review

OBJECTIVE

Fine-needle aspiration (FNA) is a safe and cost-effective technique for the diagnosis of breast lesions, especially when correlated with clinical and imaging studies. However, the success of breast FNA is highly dependent on the adequate preparation of cytological conventional smears (CS). The liquid-based cytology (LBC) technique consists of an automated method for preparing thin-layer cytological samples from cell suspensions collected in alcohol-based preservative. LBC is designed to improve CS by avoiding limiting factors such as obscuring material, air-drying and smearing artifacts.

STUDY DESIGN

We performed a review of the published literature about LBC applied to breast FNA.

RESULTS

LBC preparations of breast aspirates demonstrated better cellular preservation, less cell overlapping and elimination of blood and excessive inflammation compared to CS. Conversely, alterations in architecture and cell morphology as well as loss of myoepithelial cells and stromal elements have been described in LBC specimens, requiring training before applying this technique for diagnosis. Studies have shown a similar accuracy between LBC and CS for the diagnosis of breast lesions. LBC also permits the use of residual material for ancillary tests, which is an important advantage compared to CS.

CONCLUSIONS

LBC can be safely applied to breast FNA, showing a similar diagnostic accuracy to CS.

The microscopic complexities of C3 in breast cytology

BACKGROUND

Fine-needle aspiration (FNA) of difficult breast lesions often results in an atypical (C3) report. The assortment of outcomes generated by C3 reports varies widely, and this has given rise to different clinical management pathways.

OBJECTIVE

To identify and objectively assess microscopic features associated with atypical/C3 breast FNA cases.

MATERIALS AND METHODS

A total of 230 atypical breast FNAs were subjected to a blind microscopic rescreen using a range of robust qualitative and quantitative cytological criteria including cellularity, architectural qualities, cytomorphology and background features. A logistic regression with a receiver operating characteristic (ROC) curve and the resultant forward stepwise analysis were conducted to assess the results. This statistical testing was measured against malignant, benign proliferative and benign non-proliferative outcomes.

RESULTS

The malignant and benign proliferative outcomes showed a mixture of opposing protective and predictive individual cytological criteria. The stepwise analysis produced models demonstrating the best combination of individual cytological criteria for malignancy, proliferative and benign non-proliferative entities. In the malignancy model, discohesion, nuclear crowding within sheets, diminished numbers of bare bipolar nuclei and myoepithelial cells, the presence of tubules or necrosis and the absence of a cystic background were important features. The benign proliferative model suggested the same criteria but with the opposite implication and with the addition of several others, such as the presence of apocrine metaplasia, retained polarity and a speckled or coarse chromatin pattern. Age was a significant factor in malignant and proliferative outcomes. The benign non-proliferative stepwise analysis produced a model with fewer criteria (complex sheets, bare bipolar nuclei and a cystic background) limiting clinical application.

CONCLUSION

Atypical/C3 breast cytology remains a legitimate reporting category. However, it is associated with a number of different histological outcomes. The incidence of the C3 category can be significantly reduced by controlling extrinsic factors and understanding the associated microscopic features.

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.

Fine needle aspiration cytology of the breast: the nonmalignant categories

Currently, accurate diagnosis of breast lesions depends on a triple assessment approach comprising clinical, imaging and pathologic examinations. Fine needle aspiration cytology (FNAC) is widely adopted for the pathologic assessment because of its accurracy and ease of use. While much has been written about the atypical and maliganant categories of FNAC diagnosis, little covers the non-malignanat category which represents a sheer number in all FNAC cases. Moreover, any false-negative diagnosis of the non-malignant cases may lead to missed diagnosis of cancer. This paper aims to discuss the issues of smear adequacy, the cytologic features of benign breast lesions and the dilemma of a false-negative aspirate. Much has been suggested about the smear adequacy criterion, including quantifying epithelial clusters, whereas others advocate basing adequacy on qualitative quantum of using noncellular features of FNAC. Various benign lesions could be easily diagnosed at FNAC; however, they have cytologic features overlapped with malignant lesions. False negativity of FNAC does occur; this could be caused by either “true” false-negative cases attributed to suboptimal sampling technique, poor localization of the mass or nonpalpable lesions or “false” false-negative cases due to interpretational errors. Though false-positive cases are less commonly found, they will also be discussed briefly.

Papillary lesions of breast - An introspect of cytomorphological features

Background:

True papillary lesions of the breast have a significantly high error rate on fine needle aspiration cytology (FNAC), as many other nonpapillary breast lesions exhibit overlapping features on cytosmears.

Aim:

To evaluate the utility of individual morphological features in offering a more precise cytodiagnosis in papillary lesions of the breast.

Materials and Methods:

Cytology smears reported as papillary lesions on nipple discharge / FNAC and histopathology over a period of two years were studied and correlated. A subjective assessment of morphological features, namely, the cellular yield, presence of three-dimensional papillary clusters, stromal bare nuclei, presence of cyst macrophages and cellular atypia was carried out on cytosmears.

Results:

Fourteen cases of papillary lesions were identified. Thirty-six per cent of the cases were found to be true positive, 43% false negative and 21% false positive with a sensitivity of 42% for papillary lesions. Eight of nine papillary lesions showed cyst macrophages. Stromal bare nuclei were seen in three of four malignant papillary lesions. However, the number of stromal bare nuclei was less compared to benign lesions. None of the malignant nonpapillary lesions showed stromal bare nuclei.

Conclusions:

Cytomorphological features alone are inadequate for the precise diagnosis of papillary lesions of the breast.

Breast intracystic papillary carcinoma: an update

Intracystic papillary carcinoma (IPC), a breast tumor mainly occuring in the elderly, has long been considered as a variant of ductal carcinoma in situ (DCIS). This is now debated since metastatic cases have been reported. In this study, surgical pieces of 20 IPCs were reassessed, and markers of myopepithelial layer (p63, CD10 and Smooth Muscle Actin) as well as estrogen receptors (ER) and progesterone receptors (PgR) and C-erb-B2 oncoprotein expression were systematically performed and quantified. In 10 cases, an associated unequivocal invasive component was found. In all 20 cases, no myoepithelial layer was found. Eighteen tumors were ER positive, 14 were PgR positive. Moreover, none of the tumors over-expressed C-erb-B2 oncoprotein. Therefore this study showed that in all cases of IPC there were microscopic features of invasive carcinoma despite good clinical prognostic indicators, and that precise characterization of tumors requires extensive paraffin embedding of surgical pieces.