Telomerase activity in thyroid fine needle aspirates

OBJECTIVE: To study the utility of telomerase activity (TA) detection in thyroid fine needle aspirates (FNAs). STUDY DESIGN: One hundred two thyroid nodules were studied: 70 in FNA samples and 32 in frozen tumors. From among FNA samples, there were 57 nodules of the goiter, 1 adenoma, 7 papillary carcinomas, 1 medullary carcinoma and 1 lymphoma. Three cases of thyroiditis were excluded. The 32 frozen tissue tumors consisted of 5 follicular adenomas, 4 follicular carcinomas and 23 papillary carcinomas. TA was analyzed by Telomerase PCR ELISA (Roche Diagnostics, Indianapolis, Indiana, U.S.A.). RESULTS: TA was negative in the 57 nonneoplastic nodules and 6 follicular adenomas and positive in 3 of 4 follicular carcinomas and 10 of 30 papillary carcinomas. TA sensitivity was 41.4% and specificity 100%. Sensitivity for malignancy was higher (85.7%) in FNAs than in TA. CONCLUSION: TA seems highly specific for neoplasms of the thyroid. Further studies are needed to confirm whether TA detection could contribute to identifying neoplasms when FNAs are inconclusive for malignancy and in cases of scanty material.     

Immunocytochemistry of fine needle aspirates. A tactical approach

To maximize the potential of immunocytodiagnosis for fine needle aspiration (FNA) samples, it is necessary to be aware of the pitfalls and limitations of these techniques and to formulate a strategy to deal with the many variables involved. Five cases are presented to illustrate some of these variables, which include determining the adequacy of the FNA specimen, selecting tactics for cytologic and immunocytochemical studies, selecting methods for processing the FNA sample, preparing smears to enrich and preserve cells of interest, selecting enzyme labeling methods to optimize sensitivity and specificity, selecting monoclonal antibodies to make the study efficient and pertinent and interpreting the study results. The adequacy of the FNA specimen could be determined by an immediate cytologic assessment of the aspirate as it was obtained. Alcohol-fixed smears and formalin-fixed tissue sections prepared from the aspirate were used for diagnosis; the immunocytochemical studies were used as a diagnostic adjunct for accurate cell identification. Immunocytochemical studies were done on air-dried cytocentrifuge smears of pre-washed cells. While both immunoperoxidase and immunoalkaline phosphatase methods were suitable, we recommend the immunoperoxidase method for the study of aspirates from nonhemopoietic tissues and the immunoalkaline phosphatase method for the study of aspirates with many blood cells present. The proper selection of monoclonal antibodies and the interpretation of the results are best made in the context of the cytologic characteristics of the FNA sample and the clinical features of the patient.     

Computerized microscopic analysis of prostatic fine needle aspirates. Comparison with breast aspirates

Computerized image analysis was employed to analyze fine needle aspiration smears of the prostate and breast using both high-resolution images of individual cells and medium-resolution images of scenes and clusters (contextual analysis). A linear discriminant analysis was used to demonstrate the computer's ability to discriminate between benign and malignant categories for both types of tissue. Correct classification as benign or malignant using contextual analysis was achieved in 22 of 26 prostatic aspirates and in 15 of 18 breast aspirates, as determined by comparison with histology. The addition of high-resolution single-cell analysis resulted in correct classification of 24 of 26 prostatic aspirates and all breast aspirates. For virtually all features, the distinction between benign and malignant was more subtle for prostatic than for breast tissue. The data indicate that contextual analysis may be less effective as an adjunct to high-resolution single-cell microscopy of prostatic specimens than it is for breast specimens.     

Microfilariae in fine needle aspirates from epididymal lesions

Microfilariae of Wuchereria bancrofti were observed in fine needle aspiration smears from three epididymal nodules, and degenerating microfilariae suggestive of Brugia malayi were found in the smears from a fourth case. The smears in all four cases showed a polymorphonuclear inflammatory cell component as well as epithelioid cell granulomata. While blood eosinophilia was present in all four cases, eosinophilia was present in the aspiration smears in only one case. Microfilariae could be demonstrated in the peripheral blood in only one case.     

Immunocytochemistry on fine needle aspirates in paraffin miniblocks

A simplified method of processing of fine needle aspirates for paraffin miniblocks suitable for both morphologic and immunocytochemical evaluation is described. Aspirates were fixed in ethanol at 4 degrees C, dehydrated in acetone and xylene and embedded in paraffin (58 degrees C). All steps were carried out in a single Eppendorf centrifuge tube; the total process took less than four hours. Deparaffinized sections were stained using the alkaline phosphatase-antialkaline phosphatase technique with monoclonal and conventional antibodies helpful in the differential cytologic diagnosis of alcohol-fixed aspiration biopsy specimens. Antibodies to keratin, vimentin, desmin, neurofilaments, glial fibrillary acidic protein, leukocyte-common antigen, synaptophysin and immunoglobulin kappa and lambda light chains reacted positively on the miniblock material. Since the paraffin miniblocks combine the histologic pattern of the tumor with the differentiation-specific information provided by immunocytochemistry, their use can improve the accuracy of tumor typing in aspirates.     

Ewing's sarcoma. Cytologic features in fine needle aspirates in two cases

The cytologic findings of two cases of Ewing's sarcoma in fine needle aspiration biopsies are presented in relation to the subsequent histologic findings. The malignant cells were arranged in monocellular layers, pseudorosettes and in perivascular palisades in a fibrillar background. The nuclei were monomorphous with small nucleoli and finely granular chromatin. These features may be helpful in distinguishing this tumor from other small-cell neoplasms; the differential diagnosis between Ewing's sarcoma and such tumors is discussed.     

Ringlike structures in fine needle aspirates from the breast

Spherical ringlike structures of various sizes resembling Liesegang rings (LRs) are described in four fine needle aspirates (FNAs) from breast lesions over a period of 13 years. A characteristic finding in these structures was a distinct double layer outer wall with striations and an amorphous central nidus. Under polarized light they were non-refractile and no birefringence was noted in Congo red. Immunohistochemical stains for calcium, iron, mucus, glycogen, amyloid, cytokeratin and epithelial membrane antigen in all the cases were found to be negative. Since LRs can be mistaken for ova or parasites, their presence in aspirates of breast should be kept in mind to avoid misdiagnosis.     

Adult rhabdomyoma in fine needle aspirates. A report of two cases

BACKGROUND: Adult rhabdomyoma (ARh) is a rare, benign tumor arising most frequently in the head and neck region and sometimes mimicking malignant tumors clinically. Correct preoperative evaluation of this tumor is of crucial importance as its treatment is complete excision only and not radical surgery. CASES: Two patients with ARh, one tumor presenting near the submandibular gland and the other in the thyroid area, are reported. The first tumor was correctly diagnosed by fine needle aspiration cytology. The second, clinically suspected to be a colloid goiter, was preoperatively diagnosed as such cytologically as well. After the tumor was excised, reexamination of the cytologic specimen disclosed follicle cells admixed with single cells from ARh; these had been interpreted as colloid fragments at the time of primary evaluation. CONCLUSION: Fine needle aspiration evaluation of ARh may be problematic due to the rarity of the tumor and to the similarity of the tumor cells to normal striated muscle and to other tumors in which cells with abundant granular cytoplasm are characteristic. With an awareness of the cytologic features of this uncommon tumor, cytopathologists can render a correct diagnosis.     

Gynecomastia: cytologic features and diagnostic pitfalls in fine needle aspirates.

OBJECTIVE: To illustrate some of the uncommon cytologic findings of gynecomastia, such as apocrine metaplasia, cellular atypia and foamy macrophages, that can be misinterpreted as evidence of malignancy. STUDY DESIGN: The clinical data and fine needle aspiration (FNA) cytologic material from 100 men with the diagnosis of gynecomastia were retrospectively reviewed. The excisional biopsy slides were available for 16 cases. For comparison, FNA smears from five men with breast lesions other than gynecomastia were studied. RESULTS: The patients ranged in age from 23 to 91 years. Cytologic findings were as follows: cohesive sheets of cells containing 20-1,000 cells (98%); scattered, single, bipolar cells (78%); spindle cells (68%); ductal epithelial atypia (26%); apocrine metaplasia (8%); and foamy histiocytes (12%). In nine cases the atypia was marked, and in two of them the possibility of malignancy could not be ruled out. Surgical follow-up on 16 patients, including the cases with marked atypia, showed gynecomastia. In one case, gynecomastia was associated with intraductal papilloma. No correlation between the underlying etiology and atypical cytologic features of gynecomastia was identified. CONCLUSION: Apocrine metaplasia and epithelial atypia are common findings in gynecomastia. Attention to the cell patterns, the presence of sheets of ductal cells and absence of atypical single cells will point to the correct diagnosis.     

Diagnostic schemes for fine needle aspirates of breast masses

A comparison was made of four statistically based schemes for classifying epithelial cells from 243 fine needle aspirates of breast masses as benign or malignant. Two schemes were computer-generated decision trees and two were user generated. Eleven cytologic characteristics described in the literature as being useful in distinguishing benign from malignant breast aspirates were assessed on a scale of 1 to 10, with 1 being closest to that described as benign and 10 to that described as malignant. The original computer-generated dichotomous decision tree gave 6 false negatives and 12 false positives on the data set; another tree generated from the current data improved performance slightly, with 5 false negatives and 10 false positives. Maximum diagnostic overlap occurred at the cut-point of the original dichotomous tree. The insertion of a third node evaluating additional parameters resulted in one false negative and seven false positives. This performance was matched by summing the scores of the eight characteristics that individually were most effective in separating benign from malignant. We conclude that, while statistically designed, computer-generated dichotomous decision trees identify a starting sequence for applying cytologic characteristics to distinguish between benign and malignant breast aspirates, modifications based on human expert knowledge may result in schemes that improve diagnostic performance.     

Morphometric analysis of fine needle aspirates from breast lesions

In an attempt to discover the morphometric variables with the most diagnostic power in the differentiation of benign from malignant breast disease, 20 unequivocally benign and 20 unequivocally malignant and histologically confirmed breast aspirates were examined on an image analyser. It was found that standard deviation of nuclear area was the most discriminant variable. Then 23 aspirates initially diagnosed as 'suspicious of malignancy' were measured by the same technique, and standard deviation of nuclear area correctly differentiated all but three cases.     

Pseudoepithelial pattern in smears prepared from fine needle aspirates of plasmacytomas

A pseudoepithelial pattern was observed in smears prepared from fine needle aspirates (FNA) from three plasmacytomas. In one case cells displayed a markedly granular, 'oncocytic' cytoplasm. Granularity of the cytoplasm was due to a large number of mitochondria as shown by electron microscopy. B-lymphocytic origin of the neoplasms was confirmed by immunocytochemistry.     

Nucleolar organizer regions in the fine needle aspirates of lung tumours

Nucleolar organizer region associated proteins (AgNOR proteins) have been identified by means of an argyrophil technique in smears of 60 consecutive fine needle aspirates from lung tumours. AgNOR proteins were visualized as silver-positive granules distributed in loose, intranuclear aggregates. Variations in the number as well as differences in the distribution pattern of AgNOR granules were found among different types of tumours. Except for small cell lung carcinoma, the count of AgNOR granules increased when the differentiation of tumours decreased. In particular well differentiated tumours had relatively few AgNOR granules, distributed in cohesive aggregates. Poorly differentiated tumours had many AgNOR granules organized in loose clusters and small cell lung carcinoma had relatively few granules dispersed throughout the nucleoplasm, showing characteristics unique among all lung neoplasms. The application of the AgNOR technique in cyto-preparations is useful in discriminating between small cell and non-small cell lung carcinomas. Moreover, the pattern of distribution of AgNOR proteins may be of diagnostic value in the assessment of tumours displaying overlap in AgNOR counts.