Grading follicular lymphoma on fine needle aspiration specimens. Comparison with proliferative index by DNA image analysis and Ki-67 labeling index

OBJECTIVE: To determine whether follicular lymphoma (FL) can be graded on fine needle aspiration (FNA) biopsies by determining the percentage of centroblasts in the neoplastic follicles on the smears. STUDY DESIGN: Eighty-nine cases of histologically confirmed cases of FL, including 31 grade 1, 46 grade 2 and 12 grade 3, were evaluated. Proliferative index (PI) by DNA image analysis (DIA) and Ki-67 labeling index (LI) were obtained on all cases. A minimum of 200 cells were counted per case (range, 200-800 cells) at 40x magnification, and the number of large cells (centroblasts) was expressed as a percentage of the total number of cells counted within the follicles. RESULTS: The percentage of centroblasts in the follicular aggregates was 9.7 +/- 2.9% in grade 1 FLs, 24.7 +/- 5.6% in grade 2 and 48.4 +/- 7.5% in grade 3. These differences were significant (P < .05). DNA image analysis of PI and Ki-67 LI differed significantly between grade 1 FLs and grade 2 and 3 FLs (P < .05), but there were no significant differences between grade 2 and 3 FLs. CONCLUSION: Determining the percentage of centroblasts in the follicular aggregates on FNA specimens is a good method of grading FLs. Using the percentage of centroblasts per follicular structure, FL grades 1, 2 and 3 were adequately distinguished. PI by DIA and Ki-67 LI clearly distinguished FL grade 1 from FL grades 2 and 3; however, it did not clearly distinguish between grades 2 and 3.     

Papillary breast lesions diagnosed on cytology. Profile of 65 cases

OBJECTIVE: To analyze the cytologic features of nipple discharge and fine needle aspiration (FNA) cytologic smears from breast lesions reported as showing papillary features and to correlate them with histopathologic features. STUDY DESIGN: The study group consisted of FNA smears and/or nipple discharge smears from 65 breast lesions diagnosed on cytology as duct papilloma, papillary lesion, fibrocystic condition, fibroadenoma, papillary neoplasm or papillary carcinoma. Cytomorphologic features assessed included cellularity, cell pattern (clusters, papillary, 3-dimensionality, etc.) and cell characteristics (monomorphism, pleomorphism, apocrine change, plasmacytoid features). Histological material was available for review and cytohistologic correlation in all cases. RESULTS: Forty-six specimens were FNA smears, and 16 were nipple discharge smears; in 3 cases FNA and nipple discharge cytologic smears were available for review. Cytologic study could predict the presence of a papillary pattern in all neoplasms with pure or focal papillary differentiation. There was an overlap in cytomorphologic features between papillary and nonpapillary benign lesions as well as between benign and malignant papillary neoplasms. Frank blood in the aspirate, cell dissociation and atypia, however, were more frequent in the last. CONCLUSION: Overlap of cytologic features in nonneoplastic and neoplastic benign papillary lesions and between benign and malignant papillary neoplasms necessitates histologic evaluation in all cases diagnosed as papillary on cytology. Since 49.2% of lesions showing papillary features on cytology prove to be malignant, all cases reported as papillary on cytology should be excised urgently for histologic assessment.     

Clinicopathologic analysis of fine needle aspiration cytology of the thyroid. A review of 1,613 cases and correlation with histopathologic diagnoses

OBJECTIVE: To evaluate the accuracy of fine needle aspiration (FNA) of thyroid lesions at our institution and to ascertain its usefulness in determining the therapeutic approach. STUDY DESIGN: The authors reviewed the results of 1,613 cases of FNA cytology of thyroid nodules performed from 1999 to 2001 at the Department of Pathology, Chonnam National University Hospital. Cytologic diagnoses were compared with histologic diagnoses in 207 cases that included both FNA and thyroid surgery. RESULTS: The sensitivity for the detection of neoplasms (carcinoma and follicular adenoma) was 78.4% and the specificity 98.2%. A false positive diagnosis was made in 1 case (1.8%) and false negative ones in 28 cases (21.5%). The diagnostic accuracy was 84.4%, with a positive predictive value of 99.0% and negative predictive value of 66.3%. The predictive value of a cytologic diagnosis was 100% in papillary carcinoma. CONCLUSION: FNA is a useful test in determining the therapeutic approach of thyroid lesions.     

The role of FNA in the initial management of thyroid lesions: 7-year experience in a district general hospital

Fine needle aspiration (FNA) cytology plays a major role in the diagnosis of the thyroid lesions in university hospitals and tertiary referral institutions. Our aim was to find out if this was possible in small district hospitals with limited resources. Over a 7-year period, from October 1994 to April 2002, 303 patients with thyroid swellings underwent FNA with an overall adequacy rate of 97.7%. FNAs were performed specifically by the pathologists, so that our inadequacy rate, 2.3% was far lower than 11-29% reported elsewhere. The FNA findings were compared with subsequent histology results in 67 cases. The diagnosis of benign and neoplastic lesions was predicted accurately by FNA in 93% and 94.7% of cases, respectively. The latter reached 100% if results of FNA in follicular neoplasms were excluded. Sensitivity and specificity were 85.6% and 97.6%, respectively, which is comparable with results from tertiary institutions. The commonest thyroid lesions in our hospital were nodular goitre (52.4%), followed by thyroiditis (17.6%) and neoplasia (13.9%). We conclude that, with the availability of appropriate personnel, FNA is feasible as the major modality in district general hospitals. FNA in follicular lesions remains challenging but could be overcome in part by recognizing the criteria to differentiate follicular variant of papillary carcinoma and other follicular proliferations. Aspiration, smearing, staining and interpretation should be left to pathologists or other well-trained personnel to ensure good quality and consistency.     

Fine needle aspiration cytologic study of the solitary thyroid nodule. Profile of 308 cases with histologic correlation

The cytologic features and diagnoses of 308 solitary thyroid nodules subjected to fine needle aspiration (FNA) are presented and correlated with the histopathology. The findings reconfirmed the overall utility of FNA cytology in the differentiation of benign from neoplastic lesions and in the specific diagnosis of most types of thyroid lesions. The difficulty in the diagnosis of follicular carcinoma and in its differentiation from follicular adenoma is highlighted. Of note was the finding of Hürthle-cell populations in several types of lesions, which represents a potential diagnostic problem; this potential difficulty was lessened by sampling two or three areas within a nodule, thus obtaining a more truly representative specimen.     

Fine needle aspiration cytology of the thyroid: a cytohistologic study with evaluation of discordant cases

OBJECTIVE: To analyze the diagnostic efficacy of fine needle aspiration cytology (FNAC) in the initial evaluation of thyroid nodules, with special emphasis on discrepant cytologic diagnoses. STUDY DESIGN: A total of 192 thyroid fine needle aspirates with subsequent histopathologic follow-up were analyzed. The cytologic diagnoses were divided into 4 categories: positive for malignancy, negative for malignancy, indeterminate for diagnosis and nondiagnostic. The detailed cytologic features were studied along with histopathology sections in all these cases by 2 observers (S.J. and P.D) independently. RESULTS: Cytohistologic correlation was seen in 78.1% of cases and discordance in 21.9%. Indeterminate diagnoses accounted for 15.1% of cases. The majority of these were "follicular neoplasms." The overall sensitivity was 84.44% and specificity 99.11 %. A false positive diagnosis was made in 1 case (0.5%), proven a follicular adenoma on histopathologic examination. A false negative diagnosis was seen in 3.6% of cases. These were cases of papillary microcarcinoma. CONCLUSION: FNAC is a safe, sensitive and specific technique in the initial evaluation of thyroid nodules. A correct cytologic diagnosis can be achieved in a majority of cases, thus obviating the need for a second surgical intervention. A careful and diligent search for various cytologic features and accurate sampling can help in reducing the number of indeterminate, false positive and false negative diagnoses.     

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.     

Use of a thin-layer technique in thyroid fine needle aspiration

OBJECTIVE: To investigate the efficacy of the ThinPrep Processor (Cytyc Corporation, Boxborough, Massachusetts, U.S.A) in fine needle aspiration (FNA) of thyroid gland lesions. STUDY DESIGN: This study included 459 thyroid FNA specimens obtained from patients who came to our endocrinology department with various thyroid disorders over 3 years. The cytologic material was prepared using both the conventional and ThinPrep method in the first 2 years (285 cases), while in the last one only the ThinPrep method was used (1 74 cases). The smears were stained using a modified Papanicolaou procedure and May-Grünwald-Giemsa stain. Immunocytochemistry was performed on thin-layer slides using specific monoclonal antibodies when needed. Thin-layer and direct smear diagnoses were compared with the final cytologic or histologic diagnoses, when available. RESULTS: Our cases included 279 adenomatoid nodules, 15 cases of Hashimoto thyroiditis, 45 follicular neoplasms, 14 Hürthle cell tumors, 58 papillary carcinomas and 1 5 anaplastic carcinomas. Thin-layer preparations showed a trend toward a lower proportion of inadequate specimens and a lower false negative rate. Cytomorphologic features showed some differences between the 2 methods. Colloid was less frequently observed on ThinPrep slides, while nuclear detail and micronucleoli were more easily detected with this technique. Moreover, ThinPrep appeared to be the appropriate method for the use of ancillary techniques in suspicious cases. CONCLUSION: Thin-layer cytology improves the diagnostic accuracy of thyroid FNA and offers the possibility of performing new techniques, such as immunocytochemistry, on the same sample in order to detect malignancy as well as the type and origin of thyroid gland neoplasms.     

Fine needle aspiration cytology of endocrine neoplasms of the pancreas. Morphologic and immunocytochemical findings in 20 cases

OBJECTIVE: To analyze the role of fine needle aspiration (FNA) cytology in the preoperative diagnosis of pancreatic endocrine neoplasms. METHODS: Cytologic and histologic diagnoses of pancreatic endocrine tumors were reviewed. A total of 20 FNA cytologic procedures from 20 patients were selected. A false positive case, a retroperitoneal paraganglioma, was also reviewed. Two groups of patients were established: (1) those in whom a surgical biopsy with an immunohistochemical study was available (n = 13), and (2) those with a pancreatic tumor in which the diagnosis was confirmed by immunocytochemical studies (n = 7). In 13 cases the pancreatic tumor was aspirated, while in 7, liver metastases were studied. The immunoexpression of chromogranin and synaptophysin was evaluated in alcohol-fixed smears from 12 and 11 cases, respectively. RESULTS: One false negative and 1 false positive diagnosis were present. In the remaining 19 cases a cytologic diagnosis of pancreatic endocrine tumor was given. Main cytologic features were: (1) a prominent cellular dissociation with many single cells and small, poorly cohesive groups; (2) intermediate to large size cells with ill-defined cytoplasm, naked or eccentric nuclei, and frequent binucleation; and (3) variable nuclear pleomorphism with the characteristic finely granular distribution of the chromatin. Immunocytochemical evidence of endocrine differentiation (chromogranin or synaptophysin) was present in the 12 cases analyzed. CONCLUSION: FNA cytology offers the possibility of a precise preoperative, noninvasive diagnosis of pancreatic endocrine tumors. Cytologic features differ considerably from those of pancreatic adenocarcinoma, allowing differentiation from nonfunctioning endocrine neoplasms. In difficult cases immunocytologic studies are very helpful.     

Fine needle aspiration cytology of thyroid gland diseases

From 1982 to 1987, 2,433 lesions of the thyroid gland in 1,796 patients were examined by fine needle aspiration (FNA). Cytopathology classified 66.91% of the aspirates as benign, 10.76% as thyroiditis, 4.89% as suspected (unspecified) neoplasia, 1.31% as positive for malignancy and 16.11% (392) as unsatisfactory. The histologic diagnoses in 257 cases were compared with cytologic diagnoses to determine the accuracy of FNA cytology of thyroid lesions, yielding a sensitivity of 71.43%, a specificity of 100% and an accuracy of 95.09%. This data strongly supports thyroid FNA as an important preoperative diagnostic tool. Follicular carcinomas were difficult to cytologically differentiate from nonmalignant follicular neoplasms, and papillary thyroid carcinomas less than 2 cm in diameter in elderly patients were frequently misdiagnosed or diagnosed only as "suspect lesion."     

Accuracy of cytologic interpretation of pancreatic neoplasms by fine needle aspiration and pancreatic duct brushings

OBJECTIVE: To investigate the accuracy of fine needle aspiration (FNA) specimens and pancreatic duct brushings in the detection of pancreatic lesions and to compare the results with follow-up biopsy and/or surgical interpretation. STUDY DESIGN: We reviewed a total of 57 specimens (37/20), 37 FNA specimens and 20 pancreatic duct brushings, from 45 patients treated at Froedtert Memorial Lutheran Hospital, affiliated with the Medical College of Wisconsin, Milwaukee, over a 4-year period. The FNA and brushing samples were categorized as follows: positive for malignancy (21/3 = 24), suspicious for malignancy (8/7 = 15) and atypical (8/10 = 18). The results were then correlated with the tissue diagnosis. RESULTS: The 24 cytologic samples positive for malignancy included 23 (20/3) pancreatic ductal carcinoma (CA) and 1 (1/0) neuroendocrine CA; in the suspicious category, 11 (6/5) were pancreatic ductal CA; 2 (0/2) mucinous neoplasms and (2/0) neuroendocrine neoplasms; in the atypical category; 2 (2/0) suggestive of mucinous neoplasia, 1 (1/0) suggestive of serous neoplasia and 9 (2/7) favor reactive; and 6 (3/3) without further categorization. Tissue diagnoses were available in 26 cases: 12 (10/2) cases positive for malignancy, 8 (5/3) suspicious for malignancy and 6 (5/1) atypical. The 12 cytologically positive cases confirmed by histology showed 10 ductal CA, 1 neuroendocrine CA and 1 negative. All 8 cases (100%) suspicious for malignancy revealed positive results, including 5 ductal CA, 1 neuroendocrine neoplasm, 1 mucinous cystic neoplasm and 1 lymphoma. Of the 6 atypical lesions, 1 showed ductal CA, 2 mucinous cystic neoplasm and 3 chronic pancreatitis. CONCLUSION: Pancreatic FNA and duct brushings [table: see text] are accurate methods in identifying pancreatic lesions, particularly ductal CA. Accuracy can be improved in the case of mucinous and other lesions with adequate cellularity of the smear and recognizing the limitations of brush samples in the case of mucinous cystic lesions. False negative results may occur in cases of poor representation of malignant cells or poor sampling.     

Fine needle aspiration biopsy diagnosis of mucoepidermoid carcinoma. Statistical analysis

Fine needle aspiration (FNA) biopsy is an increasingly popular method for the evaluation of salivary gland tumors. Of the common salivary gland tumors, mucoepidermoid carcinoma is probably the most difficult to diagnose accurately by this means. A series of 96 FNA biopsy specimens of salivary gland masses, including 34 mucoepidermoid carcinomas, 51 other benign and malignant neoplasms, 7 nonneoplastic lesions and 4 normal salivary glands, were analyzed in order to identify the most useful criteria for diagnosing mucoepidermoid carcinoma. Thirteen cytologic criteria were evaluated in the FNA specimens, and a stepwise logistic regression analysis was performed. The three cytologic features selected as most predictive of mucoepidermoid carcinoma were intermediate cells, squamous cells and overlapping epithelial groups. Using these three features together, the sensitivity and specificity of accurately diagnosing mucoepidermoid carcinoma were 97% and 100%, respectively.     

Fine needle aspiration biopsy in the diagnosis of intrathoracic masses.

During a 3.5-year period (January 1, 1987, to June 30, 1990) 420 percutaneous fine needle aspiration (FNA) biopsies were performed on 390 patients (309 males, 81 females) suffering from one or more intrathoracic, radiologically visible lesions. Aspirations were carried out using 21- or 23-gauge Chiba needles under fluoroscopic or computed tomographic control. The aspirates were used to make minibiopsies and cytologic smears. Diagnosis was possible in 373 cases (95.64%): on the first pass in 344 cases, on the second in 28 cases and on the third in 1. In 17 cases (4.36%) the aspirate was inadequate for diagnosis. There were complications in 10 cases (2.56%) (9 pneumothorax and 1 hemophtysis) requiring intensive care. The 373 percutaneous FNA biopsy diagnoses included 256 malignant tumors (68.63%), of which 234 were primary and 22 were secondary, and 117 benign lesions (31.37%), 5 of them neoplastic and 112 nonneoplastic. Three hundred two of 373 percutaneous FNA biopsy diagnoses were followed (80.96%). One hundred twenty-three follow-ups were histologic (40.73%), including secondary tumors, which could be compared with the primary histotype. Twenty-eight follow-ups were cytologic (9.27%), and 151 were clinical (50.00%), using progression of the disease or the beginning of chemoradiotherapy as a criterion for malignancy and a stable condition or regression of the lesion with nononcologic medical treatment as a criterion for benignity. Percutaneous FNA biopsy diagnoses were confirmed in 288 cases (221 true positives and 67 true negatives) and unconfirmed in 14 (1 false positive and 13 false negatives). Specificity, sensitivity, negative predictive value, positive predictive value and total diagnostic accuracy were, respectively, 98.52, 94.44, 83.75, 99.54 and 95.36%. The histologic typing accuracy of percutaneous FNA biopsy on 70 specimens of surgically removed malignant epithelial neoplasias was 70.00%. These results confirm that percutaneous FNA biopsy is a reliable method of diagnosing intrathoracic masses and reduces the need for diagnostic thoracotomy.     

Accuracy and consistency in application of a probabilistic approach to reporting breast fine needle aspiration

OBJECTIVE: To determine the application of a probabilistic/categorical approach for reporting breast fine needle aspiration (FNA) and its dependence on the cytopathologist's level of experience. STUDY DESIGN: All breast surgical specimens that had preoperative breast FNA at our institution during a 3-year period were identified. The cytologic results were reported as 1 of 6 categories: positive, suspicious, atypical, epithelial proliferative, unremarkable and nondiagnostic, according to well-defined criteria. Five cytopathologists were responsible for all cytology sing-out during the study period. The histologic and cytologic diagnoses were correlated. RESULTS: A total of 297 cases were identified. Overall, there were no false positive cases (positive predictive value [PPV] = 100%). Two false negative cases (negative predictive value [NPV] = 96%) were due to sampling error. This indicates that the PPV and NPV for each of the 5 pathologists were also all 100% except for the 1 pathologist who had two false negative cases due to sampling errors. The probability of finding carcinoma on histology for suspicious and atypical cytologic categories ranged from 67% to 100% and 8% to 31%, respectively, for the individual pathologists. Fifteen cases were signed out by > or = 2 pathologists. The involvement of consultants was significantly associated with diagnosis (P = .02). Ten of the 15 cases were in the suspicious (5) or atypical (5) category. CONCLUSION: The probabilistic approach with defined diagnostic criteria is an accurate method and can be consistently applied in reporting breast FNA. Although use of the indeterminate (suspicious and atypical) categories is variable, a definite and considerable difference in the probability of carcinoma between these 2 categories was observed for all pathologists. The involvement of consultants did not move the cases out of these indeterminate categories.     

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.     

Fine needle aspiration cytology of head and neck masses. Seven years' experience in a secondary care hospital

OBJECTIVE: To study the value of fine needle aspiration (FNA) in the diagnosis of head and neck masses in a secondary care hospital. STUDY DESIGN: FNA from 225 patients with head and neck masses were reviewed. The results were analyzed, according to anatomic location, into 3 groups: inflammatory, congenital and neoplastic. FNA diagnoses were retrospectively correlated with available histologic findings or with the outcome of treatment. Accuracy, sensitivity, specificity, positive predictive value and negative predictive value in the diagnosis were computed. The numbers of lymph node biopsies performed before and after introduction of the procedure were compared. RESULTS: The most common diagnoses were reactive/nonspecific lymphadenitis and tuberculous (TB) lymphadenitis (33% and 21%, respectively). Sensitivity and negative predictive value for TB were 97% and 93%, respectively. The next most common masses were malignant neoplasms, cysts, benign neoplasms and sialadenitis, in 13%, 11%, 9% and 5%, respectively. Carcinomas metastatic to the lymph node were the most common type of cancer, followed by lymphoma and salivary gland carcinoma. The primary site of metastatic carcinomas were nasopharynx (44%) and thyroid (22%). The sensitivity and negative predictive values for the diagnosis of cancer were 95% and 96%, respectively, but reached 100% when lymphoma was excluded. The introduction of FNA reduced the number of lymph node biopsies performed in this hospital by 90%. CONCLUSION: FNA of head and neck masses proved to be a very useful diagnostic tool in separating inflammatory lesions (no surgical excision required) from cystic and neoplastic lesions. It enhanced surgical planning for malignant diseases, allowing rapid referral of lymphomas and cancer cases to tertiary care centers for management. FNA is simple, cost effective and suitable for developing countries and small, secondary care hospitals with limited resources. Skilled personnel and routine audits are the keys to success.     

Morphometric image analysis of follicular lesions of the thyroid

OBJECTIVE: To determine the role of image morphometry in distinguishing various follicular lesions of the thyroid in cytologic smears. STUDY DESIGN: Archival fine needle aspiration smears of 10 cases each of follicular hyperplasia, follicular adenoma, follicular carcinoma and follicular variant of papillary carcinoma were used for the study. All cases were histopathologically proven. At least 100 random nuclei from each case were subjected to analysis with an image cytometer. Area, convex area, length, width, perimeter, convex perimeter and roundness of nuclei were measured using a 40 x objective (1 pixel = 0.446 micron). RESULTS: ANOVA showed that all the nuclear variables studied were significantly different (P < .05) in follicular hyperplasia as compared to follicular carcinoma and papillary carcinoma. All nuclear variables except roundness were also significantly different (P < .05) between follicular hyperplasia and follicular adenoma. However, between follicular adenoma, follicular carcinoma and papillary carcinoma there was considerable overlap of nuclear morphometric parameters. CONCLUSION: Image morphometry may help to distinguish nonneoplastic follicular lesions (hyperplasia) from neoplastic lesions (adenomas and carcinomas). However, to distinguish benign from malignant follicular lesions, image morphometry might not improve the accuracy of standard cytologic examination.     

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.     

Fine needle aspiration of the thyroid. Distinction between colloid nodules and follicular neoplasms using cell blocks and 21-gauge needles

Although fine needle aspiration (FNA) of the thyroid has been found to be useful in selecting patients for surgery in most cases, the cytologic differentiation of cellular colloid nodules from follicular neoplasms has not been possible because of the scanty amount of tissue obtained by this technique and because of the infrequent preparation of cell blocks, thus precluding appreciation of the tissue architecture. Review of the histology of nodular goiters and follicular neoplasms and comparison of their morphology in smears and cell blocks from FNA specimens with the histology of the surgically excised specimens in 74 cases revealed the presence of hyperplastic papillae and fragments of dilated follicles in the aspirates of most cases of colloid nodules. These two features appear to be specific for colloid nodules and are useful for distinguishing colloid nodules from follicular neoplasms. The merits of using a 21-gauge needle and of preparing cell blocks in thyroid studies are also discussed.     

Fine needle aspiration cytology of atypical carcinoid of the lung

The cytologic features of eight atypical carcinoid tumors of the lung, as observed in fine needle aspiration (FNA) specimens, are described in detail. They were compared with 21 pulmonary squamous-cell carcinomas, 16 adenocarcinomas, 5 small-cell undifferentiated carcinomas, 3 large-cell undifferentiated carcinomas and 1 typical carcinoid tumor. Atypical carcinoid tumor was easily distinguished from the other pulmonary neoplasms in most instances. Only two poorly differentiated squamous-cell carcinomas (one of which had atypical carcinoid as a component) and one small-cell undifferentiated carcinoma had similar cytologic features. One atypical carcinoid also had cytologic features similar to small-cell undifferentiated carcinoma. Because atypical carcinoid and small-cell undifferentiated carcinoma, at times, may be difficult to separate in FNA specimens, surgical resection of all stage I neoplasms with cytologic features evocative of either neoplasm is recommended.