Fine needle aspiration cytodiagnosis of liver tumors

OBJECTIVE: To present our experience with liver fine needle aspiration (FNA) diagnosis and the adjunctive use of cell blocks with reticulin stain. STUDY DESIGN: The authors reviewed the results of cytopathologic diagnosis obtained by FNA biopsy over a 1-year period, from January 2000 to December 2000, in patients who presented primarily with ultrasonographically suspected liver nodules. FNA smears from 936 patients and cell blocks from 796 patients were reviewed. RESULTS: Among the 936 aspirates studied, the most common malignancy was hepatocellular carcinoma (HCC), which was diagnosed in 427 cases (45.6%), followed by metastatic adenocarcinoma, with 52 cases (5.6%). The concurrent cell block was available in 796 cases. Among them, 574 (72.1%) contained sufficient tissue for diagnosis. Combining analysis of cytologic and histologic specimens, the sensitivity of ultrasound-guided FNA for diagnosis of liver tumors was 85.1% and the specificity 98.7%. The results were better than isolated cytologic analysis, which gave a sensitivity of 78.4% and specificity of 97.4%. The lower diagnostic accuracy of cytology resulted mainly from its lower ability to distinguish well-differentiated HCC from benign lesions. In the cell block sections with reticulin stain, all HCCs showed a decreased or absent reticulin pattern, whereas all the benign hepatocellular lesions usually had a normal trabecular reticulin framework. CONCLUSION: FNA cytology assisted by cell block examination can be an accurate and minimally invasive method for the definitive pathologic diagnosis of primary benign and malignant liver masses and for confirmation of tumors metastatic to the liver. In addition, reticulin staining should be part of the routine assessment of cell blocks. It enhances diagnostic accuracy, particularly for well-differentiated HCC.     

The role of fine needle aspiration cytology in the diagnosis of lymphoma

The accuracy of fine needle aspiration (FNA) cytology for the diagnosis of lymphoma and other hematolymphoid malignancies was investigated by a review of 158 FNA specimens from 143 patients. Patients included in the study had either a diagnosis of a hematolymphoid malignancy by FNA cytology or a biopsy diagnosis of lymphoma that was preceded by FNA cytology. Biopsy specimens were obtained from 85% of the patients. Of the 158 needle aspirates, 118 (75%) were diagnosed as lymphoma, 13 (8%) as suspicious of lymphoma, 8 (5%) as myelomas, 3 (2%) as leukemias, 12 (8%) as positive for malignancy and 4 (2%) as negative for malignancy. Two of the 118 needle aspirates diagnosed as lymphoma were false positives while 3 of 13 diagnosed as suspicious for lymphoma were found to be benign. Overall, there were four false negatives. Morphologic subclassification of the lymphomas, originally attempted for 60 needle aspirates, was identical to the histologic subclassification in 51 cases (85%). FNA cytology provided the initial diagnosis of a hematolymphoid malignancy in 51% of the cases and allowed the documentation of recurrent disease in 49%. The results demonstrate the usefulness of FNA cytology for the diagnosis and management of patients with lymphoma.     

Transthoracic fine needle aspiration and core biopsy of pulmonary lesions. A study of 296 patients

OBJECTIVE: To retrospectively investigate and compare the usefulness of transthoracic fine needle aspiration (FNA), core biopsy and a combination of the two in the diagnosis of pulmonary lesions. STUDY DESIGN: Two hundred ninety-six patients who had undergone FNA, core biopsy or both for lung lesions were divided into malignant and benign groups according to the final diagnoses, which were based on the cytologic and histopathologic findings combined with clinical features. In each group, the diagnostic usefulness of FNA, core biopsy and a combination of the two were evaluated by comparing the results of each with the final diagnoses. RESULTS: In the malignant group, FNA was diagnostically helpful in 188 of 205 patients (91.7%) and core biopsy in 158 of 180 patients (87.8%). The combination of the two methods improved the result to 172 of 178 patients (96.6%). The sensitivities were 94.6%, 88.3% and 97.2%, respectively, for each result. In the benign group, 71.1% (64/90), 70.1% (47/67) and 74.2% (49/66) of cases received specific or nonspecific diagnoses by FNA, core biopsy and their combination, respectively. The rates of specific diagnoses were 20.1%, 21.0% and 31.8%, respectively. CONCLUSION: The combination of FNA and core biopsy markedly improved the diagnostic yields in the malignant group and, to a lesser degree, also in the benign group.     

Serial fine needle cytology in the diagnosis of esophageal cancer

OBJECTIVE: To describe a method of registering local spread of cancer in the esophageal wall through serial endoscopic fine needle aspiration (FNA), to evaluate FNA as a diagnostic tool as compared to histologic biopsies and brush cytology, and to investigate cytologic appearances of aspirates and correlate them with survival STUDY DESIGN: Fifty-two patients with esophageal cancer were investigated with serial FNA every second centimeter from the upper esophageal sphincter aborally down to the level of macroscopic tumor. Histologic biopsies and brush cytologies were then performed. RESULTS: Of investigated cases, 33% showed malignant or suspect malignant cells from macroscopic tumor, at > or = 4 cm orally, as did 3 of 12 patients at 14 cm. FNA was more sensitive than brush cytology in establishing the diagnosis. A high ratio between the numbers of benign and malignant cells in aspirates from gross tumor tissue correlated with shorter survival (P < .03). CONCLUSION: Serial FNA can demonstrate local microscopic tumor spread in the wall of the esophagus in vivo in esophageal cancer patients. FNA is also a useful adjunct in establishing the diagnosis. Finally, evaluations of tumor cytology may have prognostic value.     

Analysis of fine needle aspiration cytology of the breast: a review of 1,297 cases and correlation with histologic diagnoses

OBJECTIVE: To evaluate the accuracy of fine needle aspiration (FNA) cytology of the breast and to ascertain its usefulness. STUDY DESIGN: The authors reviewed 1,297 cases of FNA cytology of the breast which were performed at Chonnam National University Hospital from 1999 to 2002. Cytologic diagnoses were compared with histologic diagnoses in 457 cases that underwent both cytologic and histologic examination. RESULTS: Of 1,297 cases, 1,201 (92.6%) were satisfactory and 96 (7.4%) unsatisfactory. Subsequent histologic examination was performed on 291 cases (29.7%) out of 981 "benign" lesions, 28 (73.7%) of 38 "suspicious," 124 (68.1%) of 182 "malignant" and 14 (14.6%) of 96 "unsatisfactory." FNA cytology revealed 77.7% sensitivity, 99.2% specificity, 98.4% positive predictive value and 88.0% negative predictive value. Diagnostic accuracy was 91.1%. Of the 291 benign cases on cytology, 35 cases were malignancy on histology. Of the 124 cases reported as malignant, 2 were benign. Interpretive error was the leading cause of false positive diagnoses. CONCLUSION: Although FNA cytology is a useful diagnostic procedure for the evaluation of breast lesions, it should be combined with other diagnostic modalities, such as physical examination, ultrasonography and mammography.     

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.     

Fine needle aspiration biopsy in the diagnosis of thyroid nodules

The fine needle aspiration (FNA) biopsies performed on thyroid nodules at Turku University Central Hospital from 1983 to 1988 were reviewed. Of the 1,054 total aspirated nodules, 194 were investigated histologically after thyroid surgery (191 cases) or at autopsy (3 cases). Two cases with an insufficient FNA sample, 4 with an incidental occult papillary carcinoma and 2 cases with carcinoma outside the nodule investigated by FNA biopsy were excluded from the series, leaving 186 histologically confirmed nodules in the final analysis. Three (3%) of the 107 cases with an FNA biopsy diagnosis of benign, 4 (8%) of the 52 with an FNA diagnosis of equivocal, 3 (20%) of the 15 with an FNA diagnosis of suspicious and all 12 (100%) with an FNA diagnosis of malignant were histologically malignant. If only an unequivocally malignant cytologic finding is considered positive, FNA biopsy had a diagnostic specificity of 100%, a sensitivity of 55% and an accuracy of 95% among the histologically confirmed cases. Follow-up revealed no cases of cancer among the 863 thyroids that were not explored surgically. It is concluded that FNA biopsy is a practical method with considerable diagnostic value in the evaluation of thyroid nodules.     

Cytologic diagnosis of reactive lymphadenopathy in fine needle aspiration biopsy specimens

Reactive or benign lymphadenopathies were cytologically diagnosed in the aspirates of 62 (23.5%) of 265 cases with enlarged lymph nodes of the head, neck or inguinal region subjected to fine needle aspiration (FNA) biopsy. The cytomorphologic features characteristic of reactive lymphadenopathy are described in detail; some of the cell patterns were suggestive of a specific disease process. The similarities of cells and cell patterns that may pose differential diagnostic problems with malignant lymphomas are pointed out. This study emphasizes the role of FNA cytology in the diagnosis of some benign conditions.     

Fine needle aspiration (FNA) of testicular germ cell tumours; a 10-year experience in a community hospital

garcía-solano j., sánchez-sánchez c., montalbán-romero s., sola-pérez j. and pérez-guillermo m. (1998) Cytopathology 9, 248–262
Fine needle aspiration (FNA) of testicular germ cell tumours; a 10-year experience in a community hospital
A retrospective reappraisal is made of the smears of 29 testicular germ cell tumours (TGCT) studied by FNA in which both orchiectomy specimens and histologic diagnoses were available. In 22 cases (75.86%) the yield was sufficient and contained cells suitable for cytologic diagnosis; in these 22 cases a diagnosis of malignancy was reached. In four cases (13.79%) the yield was sparse and diagnostic cells were partially obscured by haemorrhage and necrosis; these cases were categorized as suspicious of malignancy. In three cases (10.34%) the yield was not suitable for cytologic evaluation because haemorrhage and necrosis hampered evaluation of diagnostic cells. The cytologic findings that enable a reliable diagnosis of TGCT are described and those cytologic features that may lead the less experienced cytopathologist into an erroneous diagnosis are discussed. Pure TGCT can be confidently diagnosed with FNA and mixed TGCT can be successfully diagnosed, although it is difficult to recognize every cytologic subtype observed in the histologic sections. Despite the advantages of FNA for the prompt diagnosis of TGCT, FNA can not fully replace the histologic diagnosis and should rather be considered as a helpful tool in the work-up of testicular tumours.     

Fine needle aspiration cytology of pulmonary carcinoid tumors

Twenty-four cases coded as pulmonary carcinoid tumors initially sampled by fine needle aspiration (FNA) biopsy were reviewed in order to determine the cytologic features most useful in making the FNA diagnosis. The diagnosis of carcinoid tumor had been confirmed in 23 cases; the remaining case, though closely resembling a carcinoid tumor on the FNA specimen, proved to be a sclerosing hemangioma of the lung. Comparison of the original and review interpretations of the FNA specimens revealed that all typical spindle cell carcinoids and all atypical carcinoids were correctly diagnosed and classified. Of the 15 typical round cell carcinoids, the original cytologic diagnosis was lymphoma in 2 cases and benign bronchial lining cells in 2 cases. Thus, it appears that diagnostic errors are most likely in "typical" carcinoids. Review of the FNA findings suggests that the frequently stripped cytoplasm (with resulting non-cohesive bare nuclei), coupled with the almost universal plexiform vascularity (seen in 21 of 23 cases), should allow an accurate cytologic diagnosis in virtually all cases.     

Infarction after fine needle aspiration biopsy of pleomorphic adenoma of the parotid gland.

BACKGROUND: Fine needle aspiration (FNA) is a well-established and safe method for the rapid diagnosis of pleomorphic adenoma. A few clinically important complications, including bleeding, infection and inflammatory reactions, result from FNA. In a small number of cases FNA has been followed by varying degrees of necrosis in some organs. In the literature there are a few reports associated with necrosis in a pleomorphic adenoma of the parotid gland following FNA. CASE: A 27-year-old female had a two-year history of a right parotid mass. FNA revealed pleomorphic adenoma. A histologic diagnosis of pleomorphic adenoma of the right parotid with infarction was made. CONCLUSION: Necrosis associated with infarction may cause diagnostic problems. It is not a sufficient sign of malignant transformation.     

Fine needle aspiration of breast lesions in women aged 30 and under

Fine needle aspiration (FNA) biopsies of 1,598 breast masses were performed between 1983 and 1989, and of them, 48 were from women aged 30 and under for whom a cytologic diagnosis was made by FNA and histologic follow-up was available. In 37 (77%) of the cases, both the cytologic and histologic diagnoses were benign. Fibroadenoma (20/37) and fibrocystic changes (14/37) were the most common benign lesions aspirated. Eight (17%) FNAs showed cytologic atypia. Four of these atypical lesions proved to be benign (two fibroadenomas, two fibrocystic changes). Epithelial proliferation in fibroadenomas and fibrocystic changes and cellular stroma in a fibroadenoma mimicking phylloides tumor were the causes of atypia in these biopsies. Four of the eight atypical lesions were shown to be carcinoma at biopsy (three infiltrating duct, one atypical medullary). Low cellularity, epithelial cohesiveness mimicking a fibroadenoma and background lactational changes in a pregnant patient were the causes of the atypical, rather than unequivocally malignant, diagnoses in these cases. In three patients (6%), a diagnosis of carcinoma was made by FNA and confirmed histologically (all were infiltrating duct carcinoma). Although most breast masses in women aged 30 and under are benign, cytologic atypia in a breast fine needle aspirate in this age group warrants a surgical biopsy. Clinical follow-up alone may be appropriate for young women with clinically nonsuspicious breast masses without cytologic atypia.     

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.     

Fine needle aspiration cytology of parathyroid adenoma. A review of seven cases

The value of fine needle aspiration (FNA) cytology in the diagnosis of parathyroid adenomas was demonstrated by a cytohistologic review of seven cases. The cytologic patterns, which were characterized by numerous, mostly isolated epithelial cells and naked nuclei showing anisokaryosis and multiple nucleoli, were consistent with the histologic findings in this neoplasm, which should be considered in the differential (FNA) diagnosis of masses in the neck region. The only diagnostic problem is its differentiation from follicular thyroid neoplasms.     

Negative predictive value of pulmonary fine needle aspiration cytology.

Percutaneous fine needle aspiration (FNA) for cytologic examination is an accepted and reliable technique for diagnosing neoplasia. It is less useful, however, in excluding that diagnosis. We performed a retrospective analysis of a consecutive series of pulmonary FNA specimens at Memorial Sloan-Kettering Cancer Center to determine the negative predictive value (NPV) of this technique in the setting of a large cancer hospital. Fifty-seven cases were studied. Six cases (10.5%) were initially diagnosed as negative but acellular and were not further analyzed, and another 6 were lost to follow-up; 24 cases (42.1%) were subsequently confirmed negative by tissue or clinical follow-up, and 21 of the cases (36.8%) were proven positive for malignancy by repeat aspiration, tissue diagnosis or clinical means. Of these 21 cases, 1 was misdiagnosed as negative, and review demonstrated malignant cells on the slide; 3 of the 21 cases should have been initially rejected as unsatisfactory, and 18 of the 21 contained material sufficient for a cytologic diagnosis but not representative of the lesion. On follow-up the false-negative cases showed primary adenocarcinoma, epidermoid carcinoma, lymphoma, metastatic breast carcinoma and metastatic sarcoma. Specific benign diagnoses were made on the initial cytologic preparation in three cases. No benign tumors were found. The NPV in our series was 53.3%, comparable to values in previous reports. The single largest factor contributing to false-negative diagnoses is sampling error, and we recommend repeat aspiration when no specific benign diagnosis is made. In addition, we suggest that the diagnoses of negative for malignant cells and insufficient for diagnosis or acellular be considered separate categories.     

Ultrasound-guided fine needle aspiration cytology of impalpable breast lesions in a rural setting. Comparison of cytology with imaging and final outcome

OBJECTIVE: To analyze the effectiveness of fine needle aspiration (FNA) cytology in a multidisciplinary setting in rural Australia and to compare the imaging (mammographic and ultrasound) appearances and cytomorphologic findings with the final outcome. STUDY DESIGN: Prospective analysis of ultrasound-guided FNA cytology results from 426 women, aged 40-86 years, with screening-detected mammographic abnormalities. Cases of microcalcification, assessed mainly by stereotactatic core biopsy, were not included in the study. The FNAs were performed at a rural breast screening and assessment program in New South Wales, Australia, over a three-year period between May 1993 and May 1996. RESULTS: Imaging, FNA and combined imaging and FNA results from 426 women were as follows. The imaging diagnoses included 176 (41%) benign, 34 (8%) probably benign, 17 (4%) equivocal, 104 (24%) suspicious and 95 (23%) malignant cases. The FNA findings showed 59 (14%) no epithelial cells seen (nondiagnostic), 175 (41%) benign, 36 (8%) atypical, 41 (10%) suspicious and 115 (27%) malignant. Combined imaging and cytologic results comprised 224 (52.6%) benign, 10 (2.3%) atypical/equivocal, 59 (13.9%) suspicious and 133 (31.2%) malignant cases. All the malignant cases, by combined assessment, had malignant histology, and all the benign cases behaved in a benign fashion. In 80% of the suspicious lesions, the histologic diagnosis was malignant, but only 10% of the atypical/equivocal lesions had malignant histology. The positive predictive value of diagnosis of malignancy by combined imaging and FNA was 100%, and the false negative rate was 0%. CONCLUSION: Despite the recent surge in the popularity of core biopsy, FNA cytology of impalpable, mammographically detected lesions, when practiced in a multidisciplinary setting, is an extremely accurate test with high sensitivity, specificity, predictive values and efficacy. FNA cytology of the breast is a well-tolerated, relatively noninvasive test with a very low risk of complications. The sensitivity and positive predictive values for malignant and suspicious mammographic categories are also very high.     

Value of fine needle aspiration cytology of the breast, with an emphasis on the cytodiagnosis of colloid carcinoma.

The fine needle aspiration (FNA) cytologic evaluation of 6,941 lesions of the breast was reviewed, with an emphasis on the cytodiagnosis of colloid carcinoma. The most common benign breast diseases in this series were fibroadenomas, cysts and fibrocystic conditions. All cases with an FNA diagnosis of suspicious were biopsied; a number of these were found to be carcinoma of the breast. In cases with an FNA diagnosis of carcinoma of the breast, a plan of management was immediately adopted on the basis of that diagnosis. Thirteen cases of colloid (mucinous) carcinoma of the breast were diagnosed by FNA cytology; in all, the cytodiagnosis was confirmed by the subsequent histologic diagnosis. The distinctive cytologic criteria that may be useful for making an FNA diagnosis of colloid carcinoma of the breast are discussed, and the FNA differences between the pure and mixed types of colloid carcinoma are noted.     

Fine needle aspiration cytology of soft tissue tumors

OBJECTIVE: To review of the value of fine needle aspiration (FNA) cytology in the diagnosis of soft tissue tumors (STT). STUDY DESIGN: A review of the literature was coupled with the authors' experience with indications, diagnostic specificity and pitfalls; clinical information; and the final cytology report. RESULTS: Over the last few years, FNA has come to be considered a valuable tool in the management of STT in that it affords a specificity of > 90%. FNA is of particular value in any subcutaneous lesion > 5 cm, in all pediatric tumors and whenever direct incision biopsy is particularly contraindicated. Material from aspirates can be used to obtain cytologic smears for conventional staining, special pigment identification, histochemical techniques, cell blocks for paraffin embedding and ancillary techniques (immunocytochemistry, electron microscopy, and densitometric and cytogenetic analyses). The cytologic diagnosis, like its histologic counterpart, should be based on a correct evaluation of clinical data (age, localization, size, effect on bone, nerve and vessel involvement), radiologic information, cytologic findings (architectural pattern, cell and stroma characteristics) and results of special staining techniques. The final cytology report should place the tumor in one of three basic categories: benign, malignant, and inconclusive or undetermined. Wherever possible, a histopathologic diagnosis should also be provided, either based on purely cytologic criteria or aided by ancillary techniques. CONCLUSION: FNA does not present major complications and permits a swift, preliminary diagnosis in a large number of cases. The method is most effective when the aspiration is performed by an experienced pathologist.     

Differential diagnosis of malignant intrahepatic tumors by ultrasonically guided fine needle aspiration biopsy and by laparoscopic/intraoperative biopsy. A comparative study

Thirty-six cases of ultrasonographically detected liver tumors (28 malignant and 8 benign lesions) were investigated by both fine needle aspiration (FNA) biopsy and laparoscopic or intraoperative tissue biopsy. The sensitivity of FNA biopsy in detecting a neoplasm was 85.7% while that of tissue biopsy was 82.1%. Specificity was 100% in both methods. A correct histologic diagnosis of the neoplasm could be made on the cytologic smear in only 14 cases (50.0%) due to technical and methodologic difficulties. Endoscopic and intraoperative tissue biopsy yielded sufficient material to make a definite histologic tumor diagnosis in 23 of 28 cases. Additional information on tumor spread and sequelae of liver infiltration was obtained by macroscopic tissue observations in nine cases. These results indicate that FNA biopsy is less sensitive in the classification of primary or secondary liver tumors and that tissue biopsies obtained during laparoscopy or laparotomy are required if a suspected hepatic neoplasm needs to be classified exactly to plan therapy and to establish a prognosis.     

Computed tomography-guided fine needle aspiration of peripheral lung opacities. An initial diagnostic procedure?

OBJECTIVE: To evaluate the results of computed tomography (CT)-guided fine needle aspiration (FNA) cytology following negative fiberoptic bronchoscopy and sputum cytology. STUDY DESIGN: Retrospective study of 64 patients who underwent CT-guided needle aspiration of lung opacities over one year. Following a review of the CT studies, patients were selected according to image characteristics of a primary neoplasm and pleural effusion in cases with pleural lesions. The lesions were classified into three categories--intrapulmonary and peripheral pulmonary, pleuropulmonary and pleural--and were localized and aspirated under CT using a fine needle (22-23 gauge) for obtaining cellular material. Lesions diagnosed as benign on FNA cytology were followed by serial CT scans for a period of two years at six-month intervals. RESULTS: Thirty-nine of 64 (61%) lesions were diagnosed as malignant on FNA cytology and 25 of 64 (39%) as benign. There was one false negative case. There were no serious complications from the procedure. CONCLUSION: FNA under CT guidance may be applied as the initial procedure in the diagnosis of peripheral malignant pulmonary lesions, rendering a high diagnostic yield.