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

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.

Comparison between Radiological and Invasive Diagnostic Modalities in Diagnosis of Breast Cancer

BACKGROUND

Breast cancer is the most common cause of deaths of cancer in women. Nowadays, following completion of imaging methods, mainly fine needle aspiration biopsy (FNAB) and core biopsy methods have been used for establishing cytopathological diagnosis although discussions regarding superiority continue.

MATERIALS AND METHODS

Those with a complaint of "mass in breast" along with those diagnosed to have a mass as a result of routine physical examination among all patients applying to our clinic between 01.01.2009 and 31.12.2011 were retrospectively assessed. Totals of 146 and 64 patients with complete radiological observation who had undergone FNAB and core biopsies, respectively, were evaluated. Postoperative pathological results of patients of both groups receiving surgery were also taken into consideration. All results were compared in terms of false positivity/negativity, sensitivity/specifity, surgery types and distribution of postoperative results with regard to diagnoses along with those of malignant/benign masses with regard to quadrants determined.

RESULTS

Diagnostic malignancy power of mammographic BIRADS classification was 87.3%. However, the value was 75% in the core biopsy group. Sensitivity and specifity following comparison of FNAB and postoperative pathology results of those receiving surgery were 85.4% and 92.9% while they were 93.5% and 100% in the core biopsy group. Diagnostic malignancy power, calculated by determining AUC in ROC analysis, of FNAB was 89.1% while that of core biopsy was 96.7%.

CONCLUSIONS

It was shown that core biopsy is superior to FNAB in terms of sensitivity, specificity and accurate histopathological classification. However; quick, cheap and basic diagnosis by means of FNAB should not be ignored. Sensitivity of FNAB is rather high in experienced hands and furthermore it would be expected to be lower than with core biopsy.

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.

Recognizing breast ductal carcinoma in situ on fine-needle aspiration: a diagnostic dilemma

In this study, we evaluated cytomorphologic features of different subgroups of ductal carcinoma in situ (DCIS); we compared seven cytologic features between DCIS and invasive ductal carcinoma (IDC) aspirates to determine whether diagnosis of stromal invasion can be made based on fine-needle aspiration (FNA) findings. There were 142 cases of DCIS and 1,978 cases of IDC enrolled in our study. FNA analysis revealed 80.3% sensitivity for DCIS and 94.7% sensitivity for IDC. High and intermediate grade DCIS exhibited marked nuclear abnormality (92.1% vs. 35.7%, 30.0%; P1 < 0.001, P2 < 0.001) and necrosis (69.7% vs. 0%, 10.0%; P1 < 0.001, P2 = 0.001) in a higher percentage of cases compared to low grade DCIS and intraductal/intracystic papillary carcinoma. The rates of background macrophages (71.3% for DCIS and 21.9% for IDC, P < 0.001) and extensive necrosis (54.0% for DCIS and 16.7% for IDC, P < 0.001) were significantly higher in DCIS compared to IDC. Lymphocytes were observed in conjunction with tumor cells more frequently in IDC (81.3%) compared to DCIS (36.8%, P < 0.001). Stromal fragments associated with tumor cells were only observed in invasive lesions (11.9% micro-invasive DCIS and 52.1% IDC). Tubular structures were found exclusively in IDC (11.5%). Cytologic criteria for diagnosis of high and low grade DCIS are different. The suspicion of DCIS is raised when background macrophages and extensive necrosis are observed. Stromal invasion is suggested by FNA if lymphocytes are entwined around tumor cells or if stromal fragments associated with tumor cells or tubular structures are observed.

Fine-needle aspiration cytology of sclerosing adenosis of the breast: a retrospective review of cytologic features in conjunction with corresponding histologic features and radiologic findings

We retrospectively reviewed 25 fine-needle aspiration cases of sclerosing adenosis of the breast in conjunction with histologic features of the paired core-needle biopsy and radiologic findings. The original cytologic diagnoses were benign (n = 19), focally atypical (n = 3), and suspicious for carcinoma (n = 3). The frequent features, although not specific, were low-to-moderate cellularity, bland epithelial cells that focally formed cohesive groups/tubules or occasionally discohesive clusters or individual cells, and fragments of dense fibrous stroma. Some tubules had an angulated configuration. Myoepithelial cells were present in all cases but were scant or absent in small epithelial groups. These cytologic features closely reflected the histologic appearances (ie, compressed and attenuated tubules and sclerotic stroma), but may cause overinterpretation on cytologic smears, especially when angulated tubules, discohesive or individual epithelial cells, scanty myoepithelial cells, and nuclear atypia are noted concurrently. Familiarity with its cytologic features may prevent false-positive diagnosis. Histologic confirmation is recommended for difficult cases.

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.

Preoperative cytological and histological diagnosis of breast lesions: A critical review

BACKGROUND

Non-operative pathology diagnoses constitute an essential part of the work-up of breast lesions. With fine needle aspiration (FNA) and core needle biopsy (CNB) both having unique advantages, there is an increasing acceptance of CNB. This paper aims to outline the scientific basis of this trend. Additionally, we provide an update on novel techniques that derive cytological specimens from CNB (i.e., touch imprint (TI) and core wash (CW) cytology) in an attempt to get the best of both worlds.

METHODS

In addition to using the authors' experience, we performed a search of the Medline database combining the search terms "breast cancer diagnosis", "core needle biopsy", "fine needle aspiration", "touch imprint cytology", "core wash cytology" and "complications". We defined a conclusive non-operative diagnosis as "malignant" in lesions that were malignant on follow-up and "benign" in lesions that were benign on follow-up.

RESULTS

CNB was more often conclusive than FNA in benign and malignant lesions in 4 prospective studies. Although the more rapid diagnoses by FNA result in less patient anxiety during diagnostic work-up, CNB allows for fairly reliable estimation of invasion, histological type, grade, and receptor expression. CW and TI cytology seem promising techniques with conclusiveness rates that are roughly comparable to that of FNA.

CONCLUSIONS

All new suspicious breast lesions require careful non-operative investigation by CNB. However, additional cytological assessment by FNA can still be useful as a same-day diagnosis decreases patient anxiety and facilitates surgical treatment planning. TI and CW cytology techniques are promising same-day diagnosis modalities.

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.

Cell blocks of breast FNAs frequently allow diagnosis of invasion or histological classification of proliferative changes

Two major limitations of breast fine needle aspiration (FNA) compared with core needle biopsies (CNB) are the inability to determine whether a cancer is invasive and to classify proliferative lesions. We studied 40 consecutive "rapid cell blocks" from breast FNAs with surgical pathology follow-up to test whether cell blocks can overcome these limitations. Of 25 carcinomas, invasion could be identified in the cell block sections in 11 (44%). One cystosarcoma phyllodes was suspected based on the cell block sections. Cell blocks from 12 of 14 benign breast FNAs showed sufficient cells to assign a histologic diagnosis of no hyperplasia (1 case, confirmed on follow-up) and usual hyperplasia (11 cases; confirmed in eight of 11 on follow-up). Specific histologic diagnoses included intraductal papilloma (2 cases), and in situ lobular neoplasia (2 cases). Cell blocks complement smears and monolayers and appear to overcome major limitations of breast FNA.

Cytologic features of ductal carcinoma in situ in fine-needle aspiration of the breast mirror the histopathologic growth pattern heterogeneity and grading

BACKGROUND

Approximately 20% of the breast carcinoma cases detected on mammography screening represent ductal carcinoma in situ (DCIS). Cytopathologists are exposed to cytologic material from DCIS when nonpalpable, mammographic lesions are aspirated during the workup of organized and opportunistic mammography screening.

METHODS

The material in the current study was comprised of 225 representative fine-needle aspiration cytology (FNAC) smears from histologically confirmed DCIS of the breast that were diagnosed between 1990-2003. Smears were rescreened to search for the following features: nuclear size (grading), monolayer sheets, solid and cribriform epithelial aggregates, micropapillary and true papillary structures, comedo-type necrosis, microcalcifications, myoepithelial cells, and discohesion.

RESULTS

There were 174 high-grade lesions (77% were Grade 3) and 51 nonhigh-grade lesions (Grades 1 and 2). The concordance between the cytologic and histologic grading was 97% in the Grade 3 lesions and 94% in the Grade 1/2 lesions. Smears from Grade 3 DCIS contained solid and/or cribriform epithelial aggregates in > 93%% of the cases, whereas smears from Grade 1/2 lesions were found to contain cribriform aggregates in 94% of the cases. Pure subtypes were virtually nonexistent. Monolayer sheets were found in 49% of nonhigh-grade DCIS and in 16% of high-grade DCIS. Myoepithelial cells were demonstrated in 51% of the nonhigh-grade DCIS lesions and 27% of the Grade 3 lesions. Microcalcifications were found on the smears from 96% of nonhigh-grade lesions and 84% of high-grade lesions. Approximately 47% of high-grade DCIS and 31% of nonhigh-grade DCIS were found to harbor a distinct single cell population.

CONCLUSIONS

The findings on FNAC from DCIS of the breast completely mirror the histologic heterogeneity of growth pattern subtypes. Primary cytologic grading can effectively separate the high-grade lesions from the nonhigh-grade lesions.

Stromal infiltration as a predictor of tumor invasion in breast fine-needle aspiration biopsy

Clinical management of in situ carcinoma of the breast is different from invasive carcinomas. Thus, it is important to find cytomorphologic criteria to distinguish between these two entities. The current study is designed to assess whether, by applying strict cytologic criteria, the status of stromal invasion can be predicted. In this retrospective study, 223 consecutive nonpalpable tumors sampled by ultrasound-guided breast fine-needle aspirates with diagnosis of in situ and invasive carcinoma with histologic follow-up evaluation were retrieved. Ten cytologic parameters were evaluated, which included cellular clustering, eosinophilic differentiation, necrosis, tubular structures, dirty background, nuclear anisonucleosis, cellular pleomorphism, cribriform pattern, tubular structures, and stromal infiltration. Among all the parameters examined, stromal infiltration was the most powerful predictor of status of invasion. Stromal infiltration was significantly higher in invasive (88%) than in situ (11%), P < 0.0001. In contrast, cribriform pattern (16% vs 36%) and necrosis (19% vs 59%) were more frequently seen in situ than in invasive carcinomas with P-values of 0.0008 and <0.0001, respectively. This study demonstrates that stromal infiltration defined by strict criteria may predict the status of tumor invasion in breast fine-needle aspirates. The combination of stromal infiltration and cribriform pattern and necrosis in aspirates may provide an opportunity in introducing a "predictive index" to differentiate between an in situ versus an invasive process.

Fine-needle aspiration cytology in nonpalpable mammographic abnormalities in breast cancer screening: results from the breast cancer screening programme in Oslo 1996-2001

Fine-needle aspiration cytology (FNAC) of nonpalpable mammographic lesions has been under attack from two sides for some years. There has been much discussion and controversy as to the ability to differentiate between in situ and invasive carcinomas in cytological material. A further issue is that of optimal sampling to obtain adequate cell material in sufficient quantity. We present the results of FNAC from 832 nonpalpable mammographic abnormalities detected in the course of the breast cancer screening programme in Oslo during 1996-2001. In 11.6% of cases the smears were inadequate, and there were 7% false negatives (FN) and 1.3% false positives. Of the FN, 64% represented microcalcifications and 86% were due to sampling errors. Absolute sensitivity was 74%, complete sensitivity 88% and specificity 88%. In 255 carcinomas a cytological diagnosis of them as in situ or invasive was made. In 93% of the invasive cases (190/205) these had been correctly identified as invasive on FNAC. In 78% of cases proper follow-up could be resolved by cytology/radiology alone. Suboptimal sampling and localization remains the main cause of FN FNAC results. Problems in differentiating between in situ and invasive breast carcinomas can be significantly reduced by applying strict criteria for in situ lesions.

How stereotactic core-needle biopsy affected breast fine-needle aspiration utilization: An 11-year institutional review

To determine the effect of stereotactic core-needle biopsy (SCNB) on the utilization of breast fine-needle aspirate (FNA) biopsy, we retrospectively reviewed 1,568 cases of breast FNAs that were obtained from 1,188 patients between the years 1990 and 2000. There were 378 positive and atypical cases and 497 negative and unsatisfactory cases in the pre-SCNB group (between 1990 and 1996; 7 years); and 225 positive and atypical cases and 468 negative and unsatisfactory cases in the post-SCNB group (between 1997 and 2000; 4 years). The average number of cases per year in the pre- and post-SCNB groups was 125 and 173, respectively. While the average positive/atypical cases per year in both groups remained relatively constant, the average negative/unsatisfactory cases per year were significantly increased in the post-SCNB group (117 in the post-SCNB vs. 71 in the pre-SCNB). The increase in this group was due to a true increase in the negative diagnoses, since unsatisfactory rate decreased in the post-SCNB group (12.6% in the post-SCNB vs. 9.3% in the pre-SCNB). The sensitivity, specificity, positive predictive value, and negative predictive value were 90%, 79%, 92%, and 82% in the pre-SCNB group and 93%, 86%, 91%, and 90% for the post-SCNB group, respectively. In conclusion, the implementation of SCNB did not result in a decrease in the total number of breast FNAs; however, the distribution of cases changed. FNA is increasingly used to complete the triple test in clinically and radiographically negative cases.

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

The advent of mammography screening presents a diagnostic challenge to the cytopathologist as an increasing proportion of breast lesions requiring investigation will be nonpalpable and up to 40% will be accounted for by atypical intraductal hyperplasia and ductal carcinoma in situ, as opposed to previously, when these lesions represented less than 10% of palpable tumors. We studied 133 fine-needle aspirates from breast tumors and found that nuclear morphology, myoepithelial cells, signs of invasion, and degree of cellular dissociation are among the most potent factors discriminating between benign epithelial proliferations, atypical intraductal hyperplasia, ductal carcinoma in situ, and invasive carcinoma.

Fine-needle aspiration cytology vs. core biopsy in the diagnosis of breast lesions

Fine-needle aspiration cytology (FNAC) is an established, highly accurate method for diagnosing breast lesions. However, in recent years there has been increased use of core biopsy (CB) in this setting. The aim of this study was to evaluate the accuracy of FNAC and compare the quality assessment parameters of FNAC and CB in palpable and nonpalpable breast lesions. Data regarding FNAC, CB, and excision biopsy (EB) diagnoses were retrieved from the archives of our department. A total of 4,367 FNAC samples from the years 1999-2001 was reviewed. Of these, corresponding histology results were available for 1,275 lesions, of which 1,248 were primary breast epithelial lesions (788 EB, 199 CB, 261 EB+CB). All cases were analyzed for sensitivity and specificity of FNAC. Cases with both FNAC and CB were compared and quality assessment parameters were calculated using the methodology detailed in the National Health Service Breast Screening Program guidelines. High specificity and sensitivity, as calculated for satisfactory specimens, were achieved with the use of both FNAC and CB. False-positive and false-negative diagnoses were seen in 7/404 (1.7%) and 45/635 (7.1%) of biopsy-proven specimens sampled by FNAC. The corresponding values for CB were 0% and 5.7%, respectively. Inadequate sampling (15.1%) with use of FNAC was particularly seen in collagenous lesions and in submitted specimens sampled by physicians lacking experience with the FNAC procedure. FNAC is a valuable method, although moderately less sensitive than CB. CB is the preferred method for preoperative diagnosis when sampling FNAC provides scarce material and suspicion of a fibrotic and collagenous lesion such as lobular carcinoma and radial scar arises. FNAC is most accurate when experienced cytologists are available and when immediate assessment by professionals is performed for evaluation of material adequacy, so that additional aspirations can be done when needed.

The diagnosis and management of pre-invasive breast disease: the role of new diagnostic techniques

In recent years we have seen significantly increased use of minimally invasive diagnostic techniques in the management of breast disease. There is wide recognition of fine needle aspiration and core biopsy as the principal diagnostic methods. However, concerns exist regarding their reliability. This article provides a brief overview of the major diagnostic issues related to use of fine needle aspiration, core biopsy and ductal lavage. It summarizes areas of use for each technique, outlines the main diagnostic pitfalls and their causes, and provides a perspective on future developments in the field.

Fine needle aspiration cytology in the work-up of mammographic and ultrasonographic findings in breast cancer screening: an attempt at differentiating in situ and invasive carcinoma

This study evaluated the results of fine needle aspiration cytology (FNAC) from the first four years of organized mammography screening for breast cancer in Oslo, particularly our policy in differentiating in situ and invasive carcinoma. Lesions were aspirated directly, ultrasound guided, by stereotaxic device or biopsy localization plate. All lesions were aspirated by cytopathologists working with the radiologists at the breast diagnostic centre. Smears were evaluated immediately for assessment of adequacy and a preliminary diagnosis was given to the surgeon. When FNAC revealed malignancy, diagnostic terms were as follows: (1) invasive carcinoma; (2) ductal carcinoma in situ of comedo type (high nuclear grade), cannot evaluate infiltration; (3) ductal carcinoma in situ of low nuclear grade and (4) papillary tumour, cannot evaluate infiltration. There were 953 cases, 70% of which were nonpalpable. Insufficient material was obtained in 5.8%. Absolute and complete sensitivity were 81% and 91%, respectively. Specificity was 85%. There were 448 histologically proven carcinomas. 383 of these were invasive. 362 carcinomas (in situ and invasive) (80.8%) were diagnosed directly on FNAC. Distinction between invasive and in situ carcinoma was possible in 294 of 320 directly diagnosed invasive carcinomas (91.8%). PPV of a diagnosis of invasive carcinoma was 97%. Our data showed that definitive cytological diagnosis of invasive carcinoma was possible in more than 90% of fully diagnostic smears and allowed definitive primary surgery in these women.

Diagnosis of non-palpable breast cancer: a review

The literature on several methods of diagnosing non-palpable breast carcinoma has been reviewed. Skin projection and dye are methods not frequently used. Several aspects of FNA biopsy/cytology, ultrasound-directed methods, frozen section and MRI localization procedures are highlighted and comparisons are made. Much attention is being payed to needle localization breast biopsy and stereotactic core needle breast biopsy. The management of patients with mammographic abnormalities is shifting from needle localization to breast biopsy stereotactic core needle biopsy. Items of comparison between the two mentioned methods are accuracy, indications, complications and costs. The role of the ABBI system in the management of breast cancer has not yet been defined. A cooperative effort between the mammographer, surgeon and pathologist is critical to a successful image-guided breast biopsy programme.

Fine-needle aspiration cytology of the breast: Invasive vs. in situ carcinoma

The surgical management of invasive breast carcinoma differs from that of in situ disease. Invasive carcinoma necessitates axillary lymph node dissection, a procedure that has associated morbidity. We studied 80 cases (66 invasive, 14 in situ) of breast carcinoma that had a histological diagnosis and a preoperative fine-needle aspirate. All slides were reviewed, with 17 cytologic features assessed. We found that six of these features showed a statistically significant difference between the invasive and in situ cases. These were infiltration of fat or stroma by malignant cells (72% of invasive cases demonstrated this feature, but it was not present in any of the in situ cases, P = 0.0002), the presence of myoepithelial cells overlying clusters of tumor cells (seen in 86% of in situ tumors and 7% of invasive cases, P < 0.00001), calcification (present in 71% of in situ and 15% of the invasive group, P = 0.001), foamy macrophages (noted in 64% of in situ tumors and 16% of invasive carcinomas, P = 0.0007), intracytoplasmic vacuoles (seen in 50% of invasive cases and 21% of in situ lesions, P = 0.08), and tubules (present in 30% of invasive and 7% of in situ tumors, P = 0.10). We demonstrate that invasion can be suggested in fine-needle aspirates of carcinomas, provided that true infiltration of fibrofatty connective tissue by neoplastic cells is present. In situ disease has characteristic features, but the presence of invasion cannot be excluded, even in the presence of stromal or adipose tissue fragments without tumor infiltration.

The cytopathology of ductal carcinoma in situ of the breast. A detailed analysis of fine needle aspiration cytology of 58 cases compared with 101 invasive ductal carcinomas

Bonzanini M., Gilioli E., Brancato B., Cristofori A., Bricolo D., Natale N., Valentini A., and Dalla Palma P. (2001)Cytopathology 12, 107-119. The cytopathology of ductal carcinoma in situ of the breast. A detailed analysis of fine needle aspiration cytology of 58 cases compared with 101 invasive ductal carcinomas. The existence of cytological findings that discriminate ductal carcinoma in situ (DCIS) of the breast from invasive ductal carcinoma (IDC) has not been unanimously accepted and the role of fine needle aspiration cytology (FNAC) remains controversial. We report the cytological findings of a large series of FNAC from histologically proven DCIS compared with those of ductal carcinomas having a different extent of the invasive component. The association of high cohesiveness of atypical cells and absence of tubular aggregates showed good sensitivity (SE) and specificity (SP) for the diagnosis of DCIS vs IDC. The simultaneous presence of necrotic background, atypical cells with abundant eosinophilic cytoplasm and a low percentage of single malignant cells resulted in low sensitivity but high specificity and positive predictive value (PPV) for differential cytological diagnosis of DCIS vs IDC.