Analysis of immunoglobulin and T-cell receptor gene rearrangement in cytologic specimens

Recombinant DNA techniques to detect the rearrangement of genes encoding immunoglobulins and T-cell-antigen receptors have been used to identify clonality in lymphoid lesions. To determine the utility of such techniques in cytologic specimens, DNA was analyzed in 24 effusions and 6 fine needle aspirates. Immunophenotypic studies were also performed on the 19 specimens with suspected hematopoietic malignancies. Sufficient material for DNA analysis was present in 28 of the 30 specimens. Immunoglobulin or T-cell-receptor gene rearrangement was present in 13 specimens with atypical cytologic findings; DNA studies provided more information than did the immunologic studies in 3 cases. One T-cell malignancy showed T-cell receptor and heavy-chain gene rearrangement, and one B-cell malignancy showed immunoglobulin and T-cell receptor gene rearrangement. In all patients except one with no evidence of gene rearrangement, the morphologic and immunologic studies also favored a reactive process. Control specimens showed a germline configuration. This study demonstrated that DNA gene rearrangement studies are feasible on many cytologic specimens and may be useful in diagnostically difficult cases.     

The gray zone in breast fine needle aspiration cytology. How to report on it?

OBJECTIVE: To study the "gray zone" in breast fine needle aspiration cytology in which an unequivocal diagnosis cannot be reached with fine needle aspiration cytology findings. STUDY DESIGN: This study compared cytology and histopathology of 72 breast lesions in which an initial cytologic diagnosis of atypia was given. RESULTS: There were 36 benign (50%) and 36 malignant (50%) histologic biopsy cases in the cytologic atypia group. Anisonucleosis, chromatin and nuclear membrane irregularity, and presence of myoepithelial cells were significantly different in benign and malignant cases. CONCLUSION: The gray zone in breast fine needle aspiration cytology is a broad spectrum that changes from proliferative fibrocystic disease to sclerosing adenosis to malignancy. Diagnosing gray zone pathology as atypical in fine needle aspiration cytology causes no delay in treatment as excisional biopsy is recommended for all equivocal cases.     

Fine needle aspiration cytology of lobular breast carcinoma. Comparison with other breast lesions

OBJECTIVE: To analyze the detailed cytomorphology of lobular breast carcinoma and to compare the cytologic smears of benign, borderline and infiltrating duct carcinoma. STUDY DESIGN: Fine needle aspiration cytology (FNAC) smears of histopathologically proven infiltrating lobular carcinoma (ILC), infiltrating ductal carcinoma (IDC), borderline lesions and benign breast lesions were selected for study. Detailed cytomorphologic analysis of the smears was carried out on hematoxylin and eosin- and May-Grünwald-Giemsa--stained slides, and a comparison of results was done. The various cytologic features were also graded semi-quantitatively with the numerical score; logistic regression analysis was done. RESULTS: There were 25 cases of ILC, 30 of IDC, and 10 borderline and 18 benign lesions. Cytologic diagnosis of malignancy on FNAC smears of ILC was offered in 19 cases; of them, 2 cases were diagnosed as ILC. The remaining six cases were diagnosed as borderline (four) and benign lesions (two). Overall sensitivity in detection of malignancy in ILC cases was 76%. FNAC smears of ILC showed moderate (52%) to abundant (32%) cellularity. The cells of ILC were arranged both in clusters and in dissociation (72%). Individual cells were monomorphic (40%) to mildly pleomorphic (60%), and the cells were smaller. The cells showed a smooth, regular nuclear margin; bland chromatin; and indistinct nucleoli. Indian file arrangement was frequently observed (28%). Nuclear molding (28%) and intranuclear inclusions (16%) were also noted. Intracytoplasmic lumina were seen in occasional cases. Logistic regression analysis was carried out, and a comparison between lobular carcinoma and ductal carcinoma, and borderline and benign lesions was done. Logistic regression analysis of cytomorphologic features showed that cellularity and nuclear margin irregularities were the two most important features to distinguish ILC from IDC. In comparison to borderline lesions, cell dissociation was more common in ILC. The salient cytologic features that helped to distinguish ILC from benign lesions was cell size, cellularity, cell uniformity and chromatin pattern. CONCLUSION: There are overlapping cytologic features between ILC, IDC and borderline breast lesions on FNAC smears. Logistic regression analysis may be helpful in this regard.     

Stereotaxic fine needle aspiration cytology of clinically occult malignant and premalignant breast lesions

Stereotaxic fine needle aspiration (FNA) cytology was used to study clinically occult (nonpalpable) breast lesions in 114 consecutive patients with mammographically suspicious findings prior to excisional biopsy. The aspirate contained insufficient material for cytologic evaluation in 15 cases (13.2%), which were histologically diagnosed as benign (7 cases), atypical hyperplasia (7 cases) or carcinoma in situ (1 case). The cytologic findings indicated a benign lesion in 77 cases (67.5%), which were histologically diagnosed as benign (71 cases) or atypical ductal hyperplasia (6 cases). The cytologic sample showed atypia in eight cases (7.0%), which were histologically diagnosed as severe atypical ductal hyperplasia (three cases), carcinoma in situ (one case) or proliferative fibrocystic disease (four cases). In the eight cases (7.0%) cytologically interpreted as probably malignant, histology confirmed six invasive carcinomas, one carcinoma in situ and one fibrocystic disease. Of six cases (4.4%) cytologically reported as malignant, five were histologically diagnosed as invasive carcinoma and one as carcinoma in situ. Overall, stereotaxic FNA cytology reported as malignant or probably malignant 14 of the 15 cases with a histologic confirmation of malignancy, for a sensitivity of 93.3%. Cytology correctly identified 78 of the 83 histologically negative cases, for a specificity of 94.0%. The 16 cases histologically diagnosed as ductal hyperplasia, which carries a high risk for subsequent malignancy, were studied in detail in an effort to define histologic and cytologic criteria for this entity. Using selected histologic criteria, 11 of these cases were graded as showing mild-to-moderate atypical hyperplasia and 5 as showing severe atypical hyperplasia. Three of the latter cases were similarly identified by an analogous cytologic grading; the other two cases had insufficient cytologic samples. The total results in this series of 114 cases support the use of stereotaxic FNA cytology in the diagnosis of these nonpalpable breast lesions, examples of which are illustrated. In particular, it may help to raise the low specificity yielded by mammography alone, which would represent a significant advance for the patient in terms of the accuracy, expediency and reduced cost of diagnosing these lesions.     

Differential diagnosis of oncocytic lesions of the breast and thyroid utilizing a semiquantitative approach.

OBJECTIVE: To assess whether a light microscopic, semiquantitative approach could reliably distinguish between benign nonneoplastic, benign neoplastic and malignant oncocytic lesions of the breast and thyroid. STUDY DESIGN: Alcohol-fixed, Papanicolaou-stained fine needle aspiration smears of histologically proven goiter and chronic thyroiditis (18 cases), Hürthle cell adenomas (7 cases), Hürthle cell carcinomas (6 cases), fibrocystic disease (17 cases), papillomas and papillomatosis (7 cases) and apocrine carcinomas (6 cases) were rated by three independent observers using the following 10 cytologic criteria: cellularity, nuclear-cytoplasmic ratio, multinucleation, nuclear size, nuclear shape, anisonucleosis, multinucleolation, nucleolar-nuclear ratio, nucleolar size and nucleolar shape. Each of these 10 cytologic criteria was rated using a 1-3 scale. The scores for all 10 features were summed to give a total score for each case. The total scores were statistically analyzed to determine the validity and reproducibility of the summed criteria. RESULTS: The summed criteria of the total scores were reproducible between the three observers, with standard deviations ranging from 1.36 to 2.88 for thyroid and 1.72 to 2.00 for breast oncocytic lesions. The ability of the total scores to differentiate benign from malignant oncocytic lesions of the breast and thyroid was confirmed by a positive predictive value for malignancy of 67% for thyroid and 72% for breast and a negative predictive value for malignancy of 100% for nonneoplastic oncocytic lesions and > 90% for benign oncocytic neoplasms in both. The Kruskal-Wallis test revealed that the total scores were able to distinguish three diagnostic categories of nonneoplastic, benign neoplastic and malignant oncocytic breast and thyroid lesions, with P < .005. CONCLUSION: Without the expenditures of additional time, costs or materials, this semiquantitative approach compared favorably with contemporary morphometric studies involving the differential diagnosis of oncocytic cell pathology in fine needle aspiration cytology.     

Cytology of prostatic carcinoma. Quantification and validation of diagnostic criteria

The validity of diagnostic criteria for the cytologic differentiation between benign and malignant cases and between normal (hyperplastic) and inflammation-activated (prostatitis) prostatic cells was tested by means of semiautomated image analysis and cytophotometry. The following criteria were found to have significant differences between benign and malignant prostatic cells: nucleoli (number, size and size variability), regularity of nuclear arrangement, anisonucleosis, nuclear size, nuclear polymorphism and dissociation of cells. The following criteria were found to be invalid for the detection of prostatic cancer cells: nuclear-cytoplasmic ratio, hyperchromasia and anisochromasia. the cytologic diagnosis of prostatic cancer was achieved by observing a variable constellation of at least three of six pathognomically altered diagnostic criteria. No fixed pattern of diagnostic criteria was found either for prostatic cancer cells in general or for the different malignancy grades.     

Computerized morphometric image analysis of cytologic nuclear parameters in breast cancer

The value of nuclear morphometry in the preoperative fine needle aspiration (FNA) cytologic diagnosis of mammary lesions was investigated and correlated with the lymph node status of the patients. The subjects consisted of four groups of patients: 49 with invasive ductal carcinomas (18 with no positive nodes, 16 with one to three positive nodes and 15 with four or more positive nodes) and 14 patients with benign lesions. The FNA specimens were smeared onto slides and stained by the May-Grünwald-Giemsa technique. The area, perimeter and maximum diameter of 100 randomly chosen nuclei were both measured with the IBAS image analysis system and semiquantitatively estimated with an eyepiece micrometer. For all three parameters, significant differences were found between benign and malignant lesions. The mean nuclear perimeter allowed the morphometric discrimination between all four groups with statistical significance; nuclear area and maximum diameter did not discriminate patients with invasive carcinoma and one to three positive nodes from those with no positive nodes or more than three positive nodes. Morphometry proved to be far superior to eyepiece measurements with respect to accuracy and reproducibility of the results. The results suggest that nuclear perimeter can be used as an additional parameter not only for the FNA cytologic diagnosis of breast cancer, but also for the estimation of patients' prognosis.     

Application of the probabilistic approach to reporting breast fine needle aspiration in males

OBJECTIVE: To apply the probabilistic approach to a series offine needle aspiration (FNA) samples of male breast lesions and determine the accuracy and reproducibility of this method of reporting in men. STUDY DESIGN: All male breast surgical specimens with a preoperative breast FNA at our institution from 1994 to 2005 were identified. The FNAs were blindly reviewed by 2 groups of observers and classified in 1 of 5 categories using published reporting guidelines: positive, suspicious, atypical, proliferative without atypia and unremarkable. The histologic and cytologic diagnoses were correlated. The interobserver variation was determined. RESULTS: A total of 138 FNAs were performed for 123 male patients. Histologic correlation was available for 23 satisfactory FNAs. A total of 11 of 11 carcinomas (100%) were classified as positive, suspicious or atypical. Of 12 benign masses, 11 (91.6%) were classified as proliferative without atypia or unremarkable. One case of gynecomastia was classified as atypical by 1 observer but deemed not atypical with consensus review. The kappa statistic for benign and atypical/suspicious/malignant categories was 0.90. CONCLUSION: Based on this series, the probabilistic approach can be applied to the reporting of FNAs of male breast lesions. Gynecomastia may result in an atypical cytologic diagnosis.     

Early detection of precancerous lesions in dysplasias of the lung by rapid DNA image cytometry

Hematoxylin-and-eosin-stained cytologic smears of sputum from 28 patients with dysplastic and suspicious cell findings were subjected to DNA image cytometry after Feulgen restaining. The nuclear DNA contents were measured with a TV-based image-analysis system, the Leitz TAS plus, combined with an automatic microscope. Computation of DNA data was performed according to an algorithm for the diagnosis and grading of malignancy. Of the 19 cases that were proven to be malignant in the follow-up, either by histologic examination, sputum cytology, fine needle aspiration biopsy or autopsy, the algorithm identified 17 as malignant in a stage (dysplasia) in which cytology was not yet able to present a definite diagnosis of malignancy. Only two cases of bronchial carcinoma were not detected in the state of dysplasia by this procedure. The periods between the DNA diagnosis of malignancy in dysplasia and the morphologic evidence of cancer varied from three days up to six months. Of the 11 cases that had been classified as benign by the algorithm, 9 were confirmed as benign during the clinical follow-up. Rapid DNA image cytometry appears able to separate squamous dysplasias of the lung into precancerous and nonprecancerous lesions.     

Nuclear image morphometry and cytologic grade of breast carcinoma

OBJECTIVE: To correlate visual cytologic grade with automated nuclear morphometry of carcinoma of the breast. STUDY DESIGN: We randomly selected 24 histologically proven infiltrating ductal carcinomas of the breast and 10 benign breast lesions (fibroadenoma). Hematoxylin-eosin-stained fine needle aspiration cytology (FNAC) smears were selected for both cytologic grade and automated image morphometry. The same hematoxylin-eosin-stained FNAC smears were studied for area, convex area, standard deviation of nuclear area, diameter, perimeter and convex perimeters of nucleus. At least 100 cells from each case were measured with an image cytometer. RESULTS: Mean nuclear area, standard deviation of nuclear area, nuclear diameter, convex area, convex perimeter and perimeter were significantly increased from benign versus grade 1 carcinomas and grade 1 versus grade 2 and 3 carcinomas (one way ANOVA test). However, there was no significant difference in grade 2 versus grade 3 carcinomas. CONCLUSION: Automated image cytometry rapidly and successfully measures various nuclear parameters. The measurement of various nuclear parameters would be helpful in future applications of automated diagnosis and grading of breast carcinomas from cytologic material.     

Cytologic grading of invasive breast carcinoma. Correlation with clinicopathologic variables and predictive value of nodal metastasis

OBJECTIVE: To estimate cytologic grade and correlate it with the other known prognostic factors, such as tumor differentiation, growth fraction, estrogen receptor status and nodal status. STUDY DESIGN: Fine needle aspirates from 104 invasive ductal carcinomas were stained by the Papanicolaou method and examined for necrosis, cellular size, nuclear/cytoplasmic ratio, nuclear pleomorphism, nucleoli, chromatin granularity and density of chromatin. We established a semiquantitative scoring system based on the above features and correlated cytologic findings with clinicopathologic variables. RESULTS: Histologic grade correlated positively with cytologic grade and negatively with estrogen receptor positivity. Moreover, high cytologic grade was associated with nodal metastasis and proliferative index labeling by MIB-1. CONCLUSION: This study showed that our grading system for breast cancer on fine needle aspiration cytology is feasible on a routine diagnostic basis. Cytologic grading can provide more information than usual on tumor biologic behavior.     

Fine needle aspiration cytology of apocrine carcinoma of the breast. Review of cases in a three-year period

OBJECTIVE: To describe the fine needle aspiration cytology findings of apocrine carcinoma of breast and correlate them with the histologic appearance. STUDY DESIGN: The author reviewed the fine needle aspiration cytology findings of two cases of pure apocrine carcinoma of the breast in the files of Pamela Youde Nethersole Eastern Hospital during a three-year period, 1998-2000. RESULTS: The cytologic findings in both cases were similar. The smears were of moderate to high cellularity, consisting of predominantly dispersed or loosely cohesive tumor cells in a focally granular background. The carcinoma cells contained abundant, dense to granular cytoplasm; round or oval and sometimes eccentrically located nuclei; a smooth nuclear outline; evenly dispersed chromatin; and solitary macronucleoli. The cell borders were mostly discrete. In contrast to benign apocrine cells, the malignant cells showed nuclear overlapping, more frequent nuclear pleomorphism, increased nuclear/cytoplasmic ratios and occasional mitotic figures. Histologic examination of the excised specimens showed extensive, solid apocrine carcinoma in situ with focal stromal invasion. CONCLUSION: Apocrine carcinoma, a subtype of breast carcinoma characterized mainly by its cytologic features, needs to be distinguished from benign apocrine lesions or other eosinophilic and granular cell tumors of the breast. Recognition of the subtle cytologic differences renders a definitive preoperative diagnosis possible.     

Aspiration cytology of tubular breast carcinoma

The cytologic features in smears of fine needle aspirates from 34 tubular breast carcinomas were studied. Uniform and bland epithelium in cohesive clusters dominated all specimens; two-thirds also showed some degree of cellular dissociation. Characteristic (but not quite pathognomonic) angular epithelial clusters with a tubular structure occurred in about 50% of the smears. Sparsely occurring atypical nuclei and/or cytoplasmic vacuoles, similar to those seen in lobular cancer, were found in half of the cases. Although a lack of myoepithelial cells was apparent in the majority of the smears, one-fourth of them showed a quite prominent myoepithelial component. Various combinations of atypical features resulted in a picture that was considered diagnostic of malignancy in 50% of the cases; the remaining specimens showed less pronounced atypia. Other pitfalls associated with the cytologic diagnosis of tubular carcinoma are discussed, and the importance of basing the management of small breast lesions on the mammographic as well as on the cytologic findings is emphasized.     

Algorithm for a DNA-cytophotometric diagnosis and grading of malignancy

An algorithm for processing data on nuclear DNA content obtained cytophotometrically was developed (1) to obtain an objective discrimination between benign and malignant lesions in conventional cytologic smears secondarily stained according to Feulgen and (2) to obtain an objective degree of tumor malignancy on a continuous scale of malignancy grades. Investigations in 258 malignant tumors (95 malignant lymphomas, 52 uterine cervix carcinomas, 28 prostate carcinomas, 18 breast carcinomas, 45 malignant bone tumors and 19 larynx carcinomas) and in 74 benign lesions in these organs yielded a diagnostic accuracy of no false-positive, no false-negative and 21% suspicious diagnoses. The probability that "suspicious" cases were malignant was 81%. The overall diagnostic accuracy for non-negative cases thus amounted to 100%. Results in 95 patients with different malignant lymphomas and in 16 patients with squamous-cell carcinoma of the larynx demonstrated the prognostic validity of the DNA-grading system.     

Loss of cell cohesion in breast cytology as a characteristic of neuroendocrine carcinoma

OBJECTIVE: To characterize a specific group of breast cancers displaying a scattered single cell pattern in cytology and correlate it with histologic and immunohistochemical findings. STUDY DESIGN: Of 135 consecutive malignant breast cytologic specimens, 12 cases were selected for their scattered single cell pattern on aspiration cytology. Immunohistochemical staining for neuroendocrine markers and prognostic parameters was performed on paraffin sections of corresponding primary breast carcinomas. RESULTS: In the smears of the 12 cases, highly cellular neoplastic cells with a single cell pattern were observed predominantly. The tumor cells had relatively wide, granular cytoplasm and a low to moderate nuclear/cytoplasmic ratio. Histologically, they were arranged mainly in relatively large, solid nests and occasionally contained a tubular pattern with small amounts of stromal tissue. Five of the 12 cases demonstrated neuroendocrine differentiation with a positive immunoreaction for chromogranin A and synaptophysin. Except for the small mean size of the tumors (P < .01), no significant differences were identified among the prognostic parameters, including a nodal status, estrogen receptor status, growth fraction by Ki-67 or immunoreactivity for c-erbB-2, as compared with the other 123 cases. CONCLUSION: Loss of cell cohesion in breast cytology is a good morphologic marker for identifying neuroendocrine breast carcinoma.     

Cytometric evidence that cervical intraepithelial neoplasia I and II are dysplasias rather than true neoplasias. An image analysis study of factors involved in the progression of cervical lesions.

Image analysis was performed on 40 Feulgen-stained histologic samples and 48 Feulgen-stained cytologic preparations representing normal squamous epithelium and all grades of cervical lesions (from mild dysplasia to invasive carcinoma) in order to characterize the evolutionary progressive changes in cervical epithelial proliferative disease toward malignancy. Quantitative studies included the analysis of proliferative features, differentiation features, nuclear morphology and DNA content. The data obtained on the histologic sections showed that the various features, to a different extent, detected a gradual increase in phenotypic cellular disarrangements related to the progression of the cervical lesions toward malignancy--that is, the modifications to nuclear area, perimeter, DNA content, percentage of nuclei with nucleoli, nuclear/cytoplasmic ratio and percentage of cells with no membrane positivity for soybean agglutinin lectin were progressively greater, moving from normal epithelium and mild dysplasia toward infiltrating carcinoma. In particular, all the morphologic and histochemical features appeared to parallel a diploid reduction and the appearance of aneuploidy. The simultaneous evaluation of proliferation- and differentiation-related features, together with those of nuclear DNA content, showed two main successive preneoplastic lesions: one characterized by an increase in cell turnover without alterations in its organization and another by a true neoplastic disorder. The data obtained on sequential cytologic examinations showed that individual cell changes are detectable and seem basically to be characterized by the appearance of clusters of cells with somatic characteristics not observed in previous cytologic checks. From the results of our study, the cervical intraepithelial neoplasia (CIN) concept appears to be inaccurate. In fact, only CIN III (severe dysplasia/carcinoma in situ) lesions have the morphologic and proliferative alterations of true neoplasia. In contrast, CIN I and some cases of CIN II lesions lack these characteristics and seem to be properly classified as dysplasia, thus avoiding the term neoplasia, implicit in CIN. Moreover, the multivariate study of data sets of features related to the progressive somatic changes, both in histologically and cytologically studied cases, allows us to detect the steps of progression; they are marked by the appearance of cell clusters with qualitatively different phenotypic characters when compared to the cell populations from which they presumably arise. These results seem to provide a further argument against the CIN theory, which stresses the concept that progression is related only to a gradual numerical increase in an initially established phenotype with the characteristics of malignancy.     

Fine needle aspiration of poorly defined indurated and well-defined breast lesions: a cytopathologic comparative study

OBJECTIVE: To compare the cytologic findings and diagnoses of breast fine needle aspiration (FNA) samples of well-defined lesions (WDL) with those of poorly defined indurated lesions. STUDY DESIGN: We examined 371 consecutive breast FNA specimens obtained without diagnostic image guidance. Fifty-eight lesions were described by the examining pathologists as PDILs, and the remaining 313 lesions were described as WDLs. RESULTS: Compared with WDLs, PDILs were more likely to yield hypocellular specimens deemed unsatisfactory for diagnostic evaluation (37.9% vs. 14.1%). However, a substantial number of atypical, suspicious for malignancy and malignant cases (12.1%, 5.2%, and 13.8%, respectively) were identified with PDILs. In addition, benign diagnoses were more frequently rendered with aspirates of WDLs, compared with PDILs (47.9% vs. 31.0%). In our study, FNAs of PDILs were more often diagnostic in white women < 49 years of age and in lesions measuring > 2 cm. CONCLUSION: Given the relatively high frequency of malignant, suspicious and atypical lesions detected with PDILs, FNA is a suitable first diagnostic approach for PDILs, especially considering the relatively low cost and simplicity of FNA procedures without diagnostic imaging guidance.     

Fine needle aspiration cytology of neoplasms metastatic to the breast

The fine needle aspiration (FNA) cytologic findings in 18 cases of metastatic neoplasms of the breast are reported. The cases were encountered in a combined series of 2,529 FNA breast biopsies, of which 666 were malignant; the metastatic neoplasms of the breast thus constituted 2.7% of all the malignant breast tumors. The series consists of 15 women and 3 men, with a mean age of 48 years (range of 11 to 73 years). Sixteen biopsies confirmed metastatic malignancy in patients with known extramammary primaries; the prebiopsy clinical diagnoses in six of the patients were benign breast lesions. In eight patients, the clinical differential diagnosis was either a benign or malignant primary breast lesion versus a metastatic malignancy. In two additional patients, the FNA biopsy identified metastatic neoplasms from unsuspected extramammary primaries. The metastatic neoplasms included three small-cell carcinomas of the lung, one squamous-cell carcinoma of the lung, two malignant melanomas, three ovarian malignancies, including a dysgerminoma, and one each of carcinoma of the fallopian tube, endometrial carcinoma, transitional-cell carcinoma of the urinary bladder, prostatic carcinoma, acute granulocytic leukemia, lymphoma, mycosis fungoides, hepatoma and neuroblastoma of the retroperitoneum. Recognition of unusual cytologic patterns raised the suspicion of, or confirmed the diagnosis of, malignancy in all cases, with no false-negative diagnoses. None of the cases were cytologically interpreted as a primary breast malignancy. Ancillary studies performed on the FNA material, including immunocytochemistry, contributed to a definitive diagnosis in three cases. FNA diagnosis of metastatic malignancy of the breast is essential in order to avoid unnecessary mastectomy and to ensure appropriate chemotherapy and/or irradiation treatment.     

Immunocytochemistry and fluorescence in situ hybridization in HER-2/neu status in cell block preparations

OBJECTIVE: Recent studies have validated the use of cytologic materials to determine HER-2/neu status. Good concordance has been shown between results obtained by immunocytochemistry (ICC), immunohistochemistry (IHC), fluorescence in situ hybridization (FISH) on cytologic and surgical specimens. However, the utility of cytologic cell block material in determining HER-2/neu status has not been reported and is the subject of this study. STUDY DESIGN: HER-2/neu status was determined in 25 cases of primary or metastatic breast carcinoma by IHC and FISH. All cases were formalin-fixed, paraffin-embedded (FPPE) cell block preparations. ICC was performed using monoclonal antibodies TAB250 (Zymed) and CB11 (Novacastra Laboratories). FISH analysis was performed using the PathVysion HER-2 probe kit (Vysis, Inc.). Results of ICC and FISH were compared in each case. RESULTS: Of 25 cases studied, 17 showed no protein overexpression or amplification. Five cases showed protein overexpression and amplification. The remaining 3 cases showed 2+ staining intensity by ICC in 10, 20, and 50% of carcinoma cells, respectively, and all demonstrated lack of amplification. CONCLUSION: Immunocytochemistry performed on FFPE cell block material is a reliable method for determining HER-2/neu status in cytologic specimens. We recommend routine preparation of FFPE cell block material in instances of suspected primary of metastatic breast carcinoma.