Fine needle aspirate cell blocks are reliable for detection of hormone receptors and HER-2 by immunohistochemistry in breast carcinoma

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.

Fine-Needle Aspiration Cytology (FNAC) is a reliable diagnostic tool for small breast lesions (≤ 1.0 cm): a 20-year retrospective study

Background

Breast cancer is a major public health problem worldwide. It is recommended that small breast lesions or those suspicious for malignancy be evaluated via histopathological examination (“core biopsy” or surgical specimens), and lesions that are probably benign and palpable should be examined via fine-needle aspiration cytology (FNAC). This study aimed to assess the accuracy of FNAC for the diagnosis of small breast lesions.

Methods

We reviewed all anatomopathological reports of FNACs collected between January 1, 2000 and December 31, 2019 (n = 24,721) in a private community pathology service. Lesions up to 1.0 cm (≤1.0 cm) (n = 8334) were included for evaluation and classified according to the recommendation of the International Academy of Cytology Yokohama System for Reporting Breast Fine Needle Aspiration Biopsy Cytopathology in the following categories: (1) insufficient/inadequate; (2) benign; (3) atypical, probably benign; (4) suspicious of malignancy; and (5) malignant. Subsequently, the results of the FNACs were compared to those of the respective histopathological examinations (n = 785).

Results

FNAC had a specificity of 99.6%; sensitivity, 97.4%; positive predictive value, 99.6%; negative predictive value, 97.6%; and accuracy, 98.5%.

Conclusions

FNAC is a reliable method for diagnosing small breast lesions (≤1.0 cm).

Evaluating Estrogen Receptor Immunohistochemistry on Cell Blocks From Breast Cancer Patients in a Low-Resource Setting

CONTEXT.—

Breast cancer biomarker assessment is critical in determining treatment and prognosis. In Tanzania, immunohistochemistry (IHC) is limited to surgical specimens and core biopsies. However, performing IHC on fine-needle aspiration biopsy cell blocks would offer numerous advantages.

OBJECTIVE.—

To compare the performance between estrogen receptor (ER) IHC performed at Muhimbili National Hospital (MNH) in Tanzania and ER IHC performed at University of California, San Francisco (UCSF), to demonstrate feasibility of performing IHC using cell blocks in Tanzania.

DESIGN.—

Patients with breast masses were recruited prospectively from the fine-needle aspiration biopsy clinic at MNH. Estrogen receptor IHC results on cell blocks, performed at both MNH and UCSF, and corresponding tissue blocks, performed at MNH, were compared to determine concordance.

RESULTS.—

Eighty-six cell blocks were evaluated by ER IHC at MNH, with 41 of 86 (47.7%) positive and 45 of 86 (52.3%) negative. Among 65 UCSF and MNH cell block pairs, overall ER IHC concordance was 93.8% (61 of 65) and positive concordance was 93.5% (29 of 31) (κ = 0.88, P > .99). Among 43 paired UCSF cell blocks and MNH tissue blocks, overall ER IHC concordance was 88.3% (38 of 43) and positive concordance was 90.5% (19 of 21) (κ = 0.77, P > .99). We compared 62 MNH cell block and tissue block pairs. Overall ER IHC concordance was 90.3% and positive concordance was 87.9% (κ = 0.81, P = .69).

CONCLUSIONS.—

Pairwise comparisons between ER IHC at MNH, on cell blocks and tissue blocks, with ER IHC at UCSF on cell blocks showed excellent concordance. We demonstrate that ER IHC on fine-needle aspiration biopsy specimens can be implemented in resource-constrained settings.

Clinical significance of evaluating hormone receptor and HER2 protein using cell block against metastatic breast cancer: a multi-institutional study

Hormone receptor and human epidermal growth factor receptor 2 (HER2) protein tests in metastatic breast cancer tissue are recommended in the guidelines of the American Society of Clinical Oncology/American Pathology Association. As part of a multi-institutional study by the National Hospital Organization, we conducted an investigation to examine these molecular markers, using cytological specimens as a substitute for tissue specimens from breast cancer metastasis. To confirm the usefulness of receptors tested in metastatic lesions, the treatment course of registered metastatic breast cancer patients was analyzed. During the April 2015 to March 2016 registration period, there were 62 registrations. Types of metastatic lesions include pleural fluid (44 samples), ascites (14 samples), lymph nodes (2 samples), pericardial fluid (1 sample), and dorsal subcutaneous mass (1 sample). A stable test result was obtained by adopting the receptor examination method, using cell block for immunostaining cytological specimens. The discordance rates of estrogen receptor (ER), progesterone receptor (PR), and HER2 protein expression were 18.2% (95% confidence interval (CI): 7.9–28.8%), 36.4% (95% CI: 23.7–49.1%), and 8.2% (95% CI: 0.1–16.3%), respectively, between the primary tumor and metastatic lesion. Patients who changed from primary negative to metastatic positive ER status had taken a significantly longer time for metastatic foci to appear. Patients with positive ER status in metastatic lesions had significantly better prognosis than ER-negative cases (P = 0.030) by the Log-Rank test. The ER status of the metastatic lesion and the metastatic site were independent prognostic factors by Cox multivariate analysis. Receptor examination with cytological specimens in metastatic lesions has been useful as it provides guidance for the treatment of metastatic breast cancer.

Hormone Receptors and Human Epidermal Growth Factor (HER2) Expression in Fine-Needle Aspirates from Metastatic Breast Carcinoma - Role in Patient Management

Introduction:

Estrogen receptors (ER), progesterone receptors (PR), and epidermal growth factor (HER2) are prognostic and predictive factors for breast carcinoma. We determined them by immunohistochemistry (IHC) on cell blocks from fine-needle aspirates (FNA) of metastatic breast carcinoma to axillary lymphnodes and compared them with that reported in the primary breast carcinoma (PBC) to document any change in their expression for future management.

Materials and Methods:

ER, PR, and HER2 by IHC and HER2 oncogene by fluorescent in-situ hybridization (FISH) were studied on cell blocks of FNA of axillary lymphnodes in 53 of 94 PBC cases from 2012 to 2016.

Results:

In 25 of 38 (65.8%) ER, PR negative PBC the metastasis on FNA was ER, PR+, whereas the 15 (28.3%) ER, PRPBC remained negative. In 10 of 11 (91%) of HER2-IHC+, PBC the metastatic tumor was HER2-IHC+. 7 of 32 (21.9%) HER2-IHC negative PBC were HER2-IHC+ in metastatic tumor. HER2-FISH was performed in 37 cases on FNA. Six of 37 were HER2 amplified/positive, whereas 9 and 19 remained equivocal and negative for HER2 copy number, and 3 were not interpretable. All the 6 HER2-FISH+ cases were positive by IHC. In our study, 34.2% of ER, PR+ cases of PBC became ER, PR– in the metastatic tumor and 21.9% of HER2-IHC negative PBC became HER2-IHC+ in the metastatic aspirate.

Conclusion:

ER, PR, and HER2 by IHC in cell blocks of metastatic lymphnodes are reliable. Change in receptor (34.2%) and HER2 status (21.9%) was documented, which is of clinical significance as these patients warrant a change of management.

Modified Plasma-Thrombin Method of Cell Block Preparation for Fine-Needle Aspiration Biopsies in Resource-Limited Settings

OBJECTIVES

The plasma-thrombin method is commonly used to make cell blocks from fine-needle aspiration (FNA) samples but requires centrifugation. We describe a modification to this method that does not require centrifugation for use in resource-limited settings.

METHODS

Pooled fresh plasma is aliquoted into 2-mL Eppendorf tubes and the FNA sample directly rinsed into the plasma. Two drops of reconstituted thrombin are added and gently mixed. A cell clot is transferred to a tissue bag, fixed in formalin, and processed. This method was applied to FNA samples from 44 patients presenting to the Mbarara University of Science and Technology FNA clinic.

RESULTS

The cell blocks were less cellular than the smears but contained adequate material to confirm morphologic impression or perform immunocytochemistry in 36 of 44 cases (82% adequacy rate).

CONCLUSIONS

The modified plasma-thrombin method is a reliable cell block preparation method that can be easily applied in resource-limited settings.

HER2 Testing and Clinical Decision Making in Gastroesophageal Adenocarcinoma: Guideline From the College of American Pathologists, American Society for Clinical Pathology, and the American Society of Clinical Oncology

Context ERBB2 (erb-b2 receptor tyrosine kinase 2 or HER2) is currently the only biomarker established for selection of a specific therapy for patients with advanced gastroesophageal adenocarcinoma (GEA). However, there are no comprehensive guidelines for the assessment of HER2 in patients with GEA. Objectives To establish an evidence-based guideline for HER2 testing in patients with GEA, formalize the algorithms for methods to improve the accuracy of HER2 testing while addressing which patients and tumor specimens are appropriate, and to provide guidance on clinical decision making. Design The College of American Pathologists (CAP), American Society for Clinical Pathology (ASCP), and the American Society of Clinical Oncology (ASCO) convened an Expert Panel to conduct a systematic review of the literature to develop an evidence-based guideline with recommendations for optimal HER2 testing in patients with GEA. Results The Panel is proposing 11 recommendations with strong agreement from the open comment participants. Recommendations The Panel recommends that tumor specimen(s) from all patients with advanced GEA, who are candidates for HER2-targeted therapy, should be assessed for HER2 status before the initiation of HER2-targeted therapy. Clinicians should offer combination chemotherapy and an HER2-targeted agent as initial therapy for all patients with HER2-positive advanced GEA. For pathologists, guidance is provided for morphologic selection of neoplastic tissue, testing algorithms, scoring methods, interpretation and reporting of results, and laboratory quality assurance. Conclusion This guideline provides specific recommendations for assessment of HER2 in patients with advanced GEA while addressing pertinent technical issues and clinical implications of the results.

HER2 Testing and Clinical Decision Making in Gastroesophageal Adenocarcinoma: Guideline From the College of American Pathologists, American Society for Clinical Pathology, and American Society of Clinical Oncology

CONTEXT

- ERBB2 (erb-b2 receptor tyrosine kinase 2 or HER2) is currently the only biomarker established for selection of a specific therapy for patients with advanced gastroesophageal adenocarcinoma (GEA). However, there are no comprehensive guidelines for the assessment of HER2 in patients with GEA.

OBJECTIVES

- To establish an evidence-based guideline for HER2 testing in patients with GEA, to formalize the algorithms for methods to improve the accuracy of HER2 testing while addressing which patients and tumor specimens are appropriate, and to provide guidance on clinical decision making.

DESIGN

- The College of American Pathologists, American Society for Clinical Pathology, and American Society of Clinical Oncology convened an expert panel to conduct a systematic review of the literature to develop an evidence-based guideline with recommendations for optimal HER2 testing in patients with GEA.

RESULTS

- The panel is proposing 11 recommendations with strong agreement from the open-comment participants.

RECOMMENDATIONS

- The panel recommends that tumor specimen(s) from all patients with advanced GEA, who are candidates for HER2-targeted therapy, should be assessed for HER2 status before the initiation of HER2-targeted therapy. Clinicians should offer combination chemotherapy and a HER2-targeted agent as initial therapy for all patients with HER2-positive advanced GEA. For pathologists, guidance is provided for morphologic selection of neoplastic tissue, testing algorithms, scoring methods, interpretation and reporting of results, and laboratory quality assurance.

CONCLUSIONS

- This guideline provides specific recommendations for assessment of HER2 in patients with advanced GEA while addressing pertinent technical issues and clinical implications of the results.

HER2 Testing and Clinical Decision Making in Gastroesophageal Adenocarcinoma: Guideline From the College of American Pathologists, American Society for Clinical Pathology, and American Society of Clinical Oncology

CONTEXT

ERBB2 (erb-b2 receptor tyrosine kinase 2 or HER2) is currently the only biomarker established for selection of a specific therapy for patients with advanced gastroesophageal adenocarcinoma (GEA). However, there are no comprehensive guidelines for the assessment of HER2 in patients with GEA.

OBJECTIVES

To establish an evidence-based guideline for HER2 testing in patients with GEA, to formalize the algorithms for methods to improve the accuracy of HER2 testing while addressing which patients and tumor specimens are appropriate, and to provide guidance on clinical decision making.

DESIGN

The College of American Pathologists, American Society for Clinical Pathology, and American Society of Clinical Oncology convened an expert panel to conduct a systematic review of the literature to develop an evidence-based guideline with recommendations for optimal HER2 testing in patients with GEA.

RESULTS

The panel is proposing 11 recommendations with strong agreement from the open-comment participants.

RECOMMENDATIONS

The panel recommends that tumor specimen(s) from all patients with advanced GEA, who are candidates for HER2-targeted therapy, should be assessed for HER2 status before the initiation of HER2-targeted therapy. Clinicians should offer combination chemotherapy and a HER2-targeted agent as initial therapy for all patients with HER2-positive advanced GEA. For pathologists, guidance is provided for morphologic selection of neoplastic tissue, testing algorithms, scoring methods, interpretation and reporting of results, and laboratory quality assurance.

CONCLUSIONS

This guideline provides specific recommendations for assessment of HER2 in patients with advanced GEA while addressing pertinent technical issues and clinical implications of the results.

Breast fine needle aspiration continues to be relevant in a large academic medical center: experience from Massachusetts General Hospital

Fine needle aspiration (FNA) is increasingly being supplanted by core needle biopsy. However, breast surgeons continue to rely on FNA at our institution. This retrospective study evaluated breast FNA for its diagnostic accuracy and breast cancer biomarker testing utility. All breast FNAs performed at Massachusetts General Hospital 2009-2015 were reviewed. Cytology diagnoses were compared with subsequent tissue or clinical diagnoses. Immunohistochemistry and fluorescence in situ hybridization (FISH) results using formalin-fixed paraffin-embedded (FFPE) cell blocks and histologic tissue blocks were compared. 1654 consecutive breast FNAs were included. Breast FNA demonstrated the following diagnostic performance: positive predictive value of malignant cytology diagnosis 100 %, negative predictive value of benign cytology diagnosis 97.5 %, complete sensitivity 91.6 %, and specificity 95.5 %. Concordance rates for estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2 (HER2) immunohistochemistry, and HER2 FISH were 98.2 % (κ = 0.95, p < 0.001), 100.0 % (κ = 1.000, p < 0.001), 83.1 % (κ = 0.69, p < 0.001), and 93.5 % (κ = 0.785, p < 0.001), respectively. Review of consecutive breast FNAs in a large cohort confirmed the excellent accuracy of this biopsy technique for breast lesion diagnosis. FNA FFPE cell blocks collected in the course of routine clinical care are adequate, practical, and reliable for breast cancer biomarker testing.

Estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2 expression in breast cancer FNA cell blocks and paired histologic specimens: A large retrospective study

BACKGROUND

Molecular analysis represents an increasingly important component of the pathologic examination of tumor specimens. Notably, the characterization of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) expression in breast cancer specimens provides critical prognostic and predictive information. The objective of the current study was to compare the concordance of these markers as determined on fine-needle aspiration (FNA) cell blocks compared with tissue blocks prepared from surgical specimens.

METHODS

A total of 134 cases of breast carcinoma were identified from 2002 through 2014 with both FNA cell blocks (fixed in 10% formalin) and corresponding available tissue blocks and ER, PR, and HER2 were characterized in both specimens. Negative and positive concordances were determined for ER and PR in cell blocks compared with tissue blocks, and for HER2 immunohistochemistry on cell blocks and tissue blocks versus the corresponding reference method, fluorescence in situ hybridization (FISH).

RESULTS

Concordance for ER expression evaluated on a cell block compared with the corresponding tissue block was 96.2%. Concordance for PR expression was 77.5%. Overall agreement of HER2 FISH testing between cell blocks and tissue blocks was 96.7%. For both cell blocks and tissue blocks, HER2 expression by immunohistochemistry demonstrated ≥98% positive and negative concordance with the FISH reference method.

CONCLUSIONS

ER, PR, and HER2 determination on FNA-acquired cell block (fixed exclusively in 10% formalin) showed excellent agreement for ER and HER2 and moderate agreement for PR with the corresponding tissue block. These findings support the equivalency of ER and HER2 evaluation performed on FNA cell blocks compared with surgical tissue blocks. Cancer Cytopathol 2016;124:828-35. © 2016 American Cancer Society.

HER 2 immunohistochemistry for breast cancer cell blocks can be used in the same way as that used for histological specimens

Background

Human epidermal growth factor receptor 2 (HER2) testing of samples from recurrent or metastatic breast cancer is recommended by the 2013 update of the American Society of Clinical Oncology/College of American Pathologists guidelines. Although cytological analysis can be applied to several types of metastatic lesions, the practical method for HER2 testing of cytological specimens is yet to be resolved. We conducted immunohistochemical (IHC) staining for HER2 in breast cancer cell blocks (CBs) and compared the results with those from the corresponding histological specimens. In cases of discrepancy between the two types of specimen, the bright‐field HER2 dual in situ hybridization (DISH) assay was performed.

Methods

CBs were prepared from 54 surgically excised breast cancers. The cells were fixed in 10% buffered formalin and embedded in paraffin. A Ventana BenchMark ULTRA (Roche Diagnostics) with anti‐HER‐2/neu (4B5) rabbit monoclonal primary antibody and INFORM HER2/neu Dual ISH DNA Probe Cocktail was used for the assays.

Results

Successful results were obtained in 52 of 54 CBs. Forty cases showed agreement between CBs and the histological specimens. No discrepancy was observed between the two types of specimens in cases where HER2 expression was positive. IHC results of CB in 12 discrepant cases were HER2 intermediate or negative. The DISH results of 11 of these cases were negative.

Conclusion

IHC staining of HER2 for breast cancer CBs can be used in the same way as that used for histological specimens, although the number of equivocal cases in CBs is greater than that in histological specimens. Diagn. Cytopathol. 2016;44:274–279. © 2016 The Authors Diagnostic Cytopathology Published by Wiley Periodicals, Inc.

Bright-field HER2 dual in situ hybridization (DISH) assay on breast cancer cell blocks: a comparative study with histological sections

BACKGROUND

HER2 testing for samples from recurrent or metastatic disease is recommended by the 2013 update of the American Society of Clinical Oncology/College of American Pathologists (ASCO/CAP) guidelines and cytological analysis can be applied to several types of metastatic lesions. However, the practical method to assess the HER2 testing of breast cancer cytology specimens has yet to be resolved. Therefore, we conducted the bright-field HER2 dual in situ hybridization (DISH) assay on cell blocks (CBs) prepared from breast cancer cell samples as a validation study before clinical use.

METHODS

CBs were prepared from tumor cell samples collected from 54 surgically excised breast tumors. The cells were fixed in 10 % buffered formalin for 16-28 h, and embedded in paraffin. The INFORM HER2/neu Dual ISH DNA Probe Cocktail was used for the DISH assay on the Ventana BenchMark ULTRA (Roche Diagnostics).

RESULTS

Successful results were obtained in 51 of 54 CB specimens, and the results from the CB specimens were in agreement with those from the histological sections in 48 of the 51 cases (concordance rate, 94 %; kappa, 0.846). The intraclass correlation coefficient (ICC) between the CB and histological specimens in the continuous HER2/CEP17 signal count ratio was 0.89 (95 % CI 0.81-0.93), and the Pearson's CC was 0.91 (95 % CI 0.85-0.94).

CONCLUSION

The HER2 DISH assay, utilizing 10 % buffered formalin-fixed CB, would be a reliable and ideal method to assess the HER2 gene status of breast cancer cytological specimens.

Assessment of Hormone Receptor and Human Epidermal Growth Factor Receptor 2 Status in Breast Carcinoma Using Thin-Prep Cytology Fine Needle Aspiration Cytology FISH Experience From China

Estrogen receptor (ER) and progesterone receptor (PR) overexpression can be used to predict patient prognosis in breast cancer (BC). Human epidermal growth factor receptor 2 (HER2) is a reliable predictive marker in invasive breast cancer (IBC). Thin-Prep (TP) specimens are commonly utilized for immunocytochemistry (ICC) in fine needle aspiration cytology (FNAC). Thus, we sought to investigate if the incorporation of molecular diagnosis performed on TP-processed specimens is applicable in clinical practice. Hormone receptors (HRs) and HER2 immunocytochemistry was performed on 542 primary breast cancer FNAC specimens using the TP method. One hundred fourteen HER2 fluorescence in situ hybridization (FISH) analyses were performed on HER2 ICC 2+ FNAC specimens and the corresponding tissue samples. HRs results of TP slides and those of formalin-fixed paraffin-embedded (FFPE) slides were correlated well for ER (concordance rate =  3.3%, kappa value = 0.85) and PR (concordance rate = 88.6%, kappa value = 0.75). HER2 results for the TP slides and those of the matched FFPE slides also correlated well (concordance rate = 80.0%, kappa value = 0.62). The specificity of HER2 was 97.3%; however, the sensitivity was only 67.1%. Cytological specimens and histological samples showed a strong correlation (concordance rate = 99.1%, kappa value = 0.98) while being used to evaluate HER2 gene amplification. FNAC is a minimally invasive technique that can be used as an alternative method to collect tissue especially in cases where an excisional or core biopsy is difficult to obtain, or when recurrence is present. The results of ICC HRs in FNAC TP specimens may be used instead, but HER2 assessment may not be reliable enough for clinical use. FISH testing is necessary in this setting.

Cell blocks in cytopathology: a review of preparative methods, utility in diagnosis and role in ancillary studies

The cell block (CB) is a routine procedure in cytopathology that has gained importance because of its pivotal role in diagnosis and ancillary studies. There is no precise review in the published literature that deals with the various methods of preparation of CB, its utility in diagnosis, immunocytochemistry (ICC) or molecular testing, and its drawbacks. An extensive literature search on CB in cytology using internet search engines was performed for this review employing the following keywords: cell block, cytoblock, cytology, cytopathology, methods, preparation, fixatives, diagnostic yield, ancillary and molecular studies. Ever since its introduction more than a century ago, the CB technique has undergone numerous modifications to improve the quality of the procedure; however, the overall principle remains the same in each method. CBs can be prepared from virtually all varieties of cytological samples. In today's era of personalized medicine, cytological specimens, including CBs, augment the utility of cytological samples in analysing the molecular alterations as effectively as surgical biopsies or resection specimens. With the availability of molecular targeted therapy for many cancers, a large number of recent studies have used cytological material or CBs for molecular characterization. The various techniques of CB preparation with different fixatives, their advantages and limitations, and issues of diagnostic yield are discussed in this review.

Determination of HER2/neu status: a pilot study comparing HER2/neu dual in situ hybridization DNA probe cocktail assay performed on cell blocks to immunohistochemisty and fluorescence in situ hybridization performed on histologic specimens

CONTEXT

Validation of new methodologies for determining human epidermal growth factor receptor 2 gene (HER2/neu) amplification status is crucial for advancing the standard of care and determining treatment for patients with primary and/or metastatic breast carcinoma.

OBJECTIVE

To compare results of HER2/neu gene amplification status by 2-color chromogenic in situ hybridization (ISH) on cell block material to HER2/neu status by immunohistochemistry (IHC) and/or fluorescence in situ hybridization (FISH) in the corresponding resection specimen or previous biopsy specimen.

DESIGN

Formalin, thrombin, and Cellient cell blocks were prepared from cytologic samples obtained from resection specimens from 27 patients with invasive breast carcinoma. In situ hybridization was performed on cell block sections from 18 of the collected cases, on both the Ventana BenchMark ULTRA and the Ventana BenchMark XT, and the HER2/neu gene amplification status was determined. This was then compared to the HER2/neu status by IHC and/or FISH in the resection specimen or previous biopsy specimen.

RESULTS

Comparison of HER2/neu status by ISH on the quantifiable cell block sections showed 100% correlation with the HER2/neu status determined by IHC or FISH in the corresponding histologic specimens. The results from thrombin and formalin cell blocks were statistically superior to the results from Cellient cell blocks on both Ventana instruments.

CONCLUSIONS

While further validation and study are needed, preliminary results show that the HER2/neu gene amplification status of breast carcinomas can reliably be determined on thrombin and formalin cell block material by using ISH. More consistent staining and better signal integrity was obtained with the Ventana BenchMark ULTRA than the BenchMark XT.

Endoscopic ultrasound-guided tissue acquisition

Endoscopic ultrasound (EUS) is an indispensable tool for tissue acquisition in patients with gastrointestinal tumors. While fine-needle aspiration (FNA) has been routinely carried out for establishing tissue diagnosis, the emerging concept of tailoring chemotherapeutic agents based on molecular markers has increased the demand for core tissue procurement by means of EUS-guided fine-needle biopsy (EUS-FNB). In addition, FNB may offset the limitations of FNA wherein the diagnostic sensitivity is incumbent on the availability of an onsite cytopathologist. Given the increasing number of procedures being done, developing a unit-specific algorithmic approach for needle selection is important to improve the procedural efficiency and utilization of resources. Finally, the best outcomes can be attained only by practicing evidence-based techniques, procuring adequate quantity of sample for ancillary studies and processing the specimens appropriately.

Assessment of Her-2/neu status using immunocytochemistry and fluorescence in situ hybridization on fine-needle aspiration cytology smears: experience from a tertiary care centre in India

Breast carcinoma shows amplification/overexpression of Her-2/neu in ∼20-30% of cases. The determination of Her-2/neu expression accurately is vital in clinical practice as it has significant predictive value and eligibility for anti Her-2/neu therapy. Amplification and overexpression of Her-2/neu gene is traditionally identified by fluorescence in situ hybridization (FISH) and immunohistochemistry (IHC) on tissue sections; only a few studies have evaluated feasibility of these techniques on cytological smears. One hundred cases of breast cancer with fine-needle aspiration cytology (FNAC) samples and corresponding surgically resected specimen were selected. Immunocytochemistry (ICC) and FISH for Her-2/neu was done on FNA smears, whereas IHC was performed on corresponding tissue sections. Diagnostic accuracy of ICC was 99% when compared with IHC. Comparison of FISH results with IHC showed 100% concordance. Unlike many centers in West, FNAC is still routinely performed in developing countries like India where vast majority of breast cancer cases present as palpable lumps. The high rates of accuracy of ICC and FISH for Her-2/neu detection can make FNAC a relevant first line of investigation as a cost effective model with a rapid turn-around time, providing complete information necessary for initial management of breast cancer patients.

From cytomorphology to molecular pathology: maximizing the value of cytology of lymphoproliferative disorders and soft tissue tumors

OBJECTIVES

The field of cytopathology has been rapidly advancing in the era of molecular pathology and personalized medicine. On-site cytologic evaluation for adequacy and triaging specimens for small core biopsy or fine-needle aspiration (FNA) are often required. Cytopathologists face the challenge of how to best triage small specimens for diagnosis, molecular testing, and personalized treatment. Owing to its minimally invasive nature, FNA alone or combined with core biopsy for lymphoproliferative disorders and soft tissue tumors has gained popularity.

METHODS

Literature review and author's institutional experience are used for this review article. This article will focus mainly on lymphoproliferative disorders and soft tissue tumors.

RESULTS

Evaluation combining cytomorphology, immunohistochemistry, and/or molecular pathology is often needed to accurately diagnose and classify lymphomas and soft tissue tumors. Many molecular tests have been performed on cytologic specimens, such as tests for BRAF and RET in thyroid FNA.

CONCLUSIONS

Molecular pathology has been widely integrated into conventional cytopathology for diagnosing lymphoproliferative disorders and soft tissue tumors, and the diagnostic value of FNA on those tumors has increased significantly. Cytology will play a more important role in the era of personalized medicine.