Significance of nondiagnostic fine-needle aspiration of the thyroid

BACKGROUND: Fine-needle aspiration biopsy (FNAB) has been shown to be rapid and cost effective in the evaluation of thyroid nodules. The significance of nondiagnostic (unsatisfactory) FNAB is uncertain, however. METHODS: We reviewed 345 consecutive thyroid FNABs and identified 59 patients with initially unsatisfactory specimens. These patients had follow-up to determine whether their thyroid nodules proved to be malignant. RESULTS: Three patients (5.1%) were found to have organ-confined papillary carcinoma of the thyroid, the largest tumor mass measuring 1.2 cm. Six patients (10.2%) had benign adenomas. CONCLUSIONS: In most cases of initially nondiagnostic FNAB of a thyroid nodule, neoplasia is not found subsequently. A minority of cases may still harbor malignancy. None of our patients in whom repeated FNA was either nondiagnostic or suggestive of benign disease were ultimately found to have a malignancy.     

Seqalert--a daily sequence alertness server for the EMBL and SWISSPROT databases

OBJECTIVE: Fine-needle aspiration biopsy (FNAB) is the preferred diagnostic study for evaluating thyroid nodules. Despite its accuracy, many patients undergo thyroidectomy for benign nodules. This study was undertaken to identify risk factors that might increase the specificity of FNAB. METHODS: Medical records of 422 patients who underwent thyroid surgery between 1986 and 1996 were reviewed. All patients had FNAB prior to surgery. RESULTS: Of the 422 patients, 36% had benign cytology, 46% had indeterminate cytology, and 13% had cancer. In the indeterminate group, 29% of patients had cancer at surgery. Of patients with papillary cytology, 84% had malignancies. Five percent of FNABs were nondiagnostic. Neither age, gender, nor tumor size was associated with increased specificity of FNAB. CONCLUSION: There is no subpopulation of patients with indeterminate FNAB cytology at increased risk of having well-differentiated thyroid cancer.     

Role of ultrasound-guided fine-needle aspiration biopsy in evaluation of nonpalpable thyroid nodules

To determine the role of ultrasound-guided fine-needle aspiration biopsy (US-FNAB) in the evaluation of incidentally diagnosed nonpalpable thyroid nodules (NP-TN), we compared the diagnostic yield of US-FNAB in NP-TN larger than 10 mm in diameter, with palpation-guided (P-FNAB) in palpable thyroid nodules (P-TN) in the same hospital setting. Of 108 consecutive patients with NP-TN (female/male: 97/11, age: 55.2 +/- 14.3, mean +/- SD), malignancy was identified in 8 patients (7 with thyroid papillary carcinoma, 4 of which had extrathyroidal spread, and 1 patient had metastasis of pulmonary adenocarcinoma). Male gender was associated with higher prevalence of malignancy (p = 0.09) while calcification and/or cystic degeneration of the nodule did not predict the cytological findings. Malignancy was identified in 16 of 151 consecutive patients with P-TN (female/male: 139/12, age: 44.1 +/- 9.5, mean +/- SD) indicating a similar rate of malignancy in both NP-TN and P-TN. In the P-TN group thyroid cancer was more common in males (p = 0.007), and the US properties of the nodule did not predict its cytological diagnosis. In conclusion, because similar rates of cancer are detected by FNAB in both NP-TN and P-TN, an FNAB is recommended for NP-TN larger than 10 mm.     

Refined use of scintigraphy in the evaluation of nodular thyroid disease

BACKGROUND: Scintigraphy has been advocated in patients with a thyroid nodule when fine needle aspiration biopsy (FNAB) is not definitive. The purpose of this study was to determine the incidence of hyperfunctioning nodules in patients without a definitive FNAB, the correlation of serum thyrotropin (TSH) levels with the functional status of a nodule, and whether a sensitive TSH assay can be used in lieu of scintigraphy. METHODS: From 1990 to 1996, patients with a thyroid nodule were evaluated with FNAB and serum TSH measurement. Iodine-123 scintigraphy was reserved for patients without a definitive FNAB and was correlated with TSH levels. RESULTS: Of 356 patients with a thyroid nodule, 102 did not have a definitive FNAB. A hyperfunctioning nodule was diagnosed in 14 of the 102 patients. A low TSH level was detected in 12 (86%) of 14 patients with a hyperfunctioning nodule (mean = 0.04 +/- 0.38 microIU/mL) and only 20 (23%) of 88 patients with a hypofunctioning nodule (mean = 0.87 +/- 4.11 microIU/mL) (P < .05). Only 2 of 70 (2.8%) patients with a normal or increased TSH level had a hyperfunctioning nodule. CONCLUSIONS: A 14% incidence of hyperfunctioning nodules in patients without a definitive FNAB warrants the use of scintigraphy but only when serum TSH levels are low, thus avoiding unnecessary scans in 91% of patients with a thyroid nodule.     

Primary mucoepidermoid carcinoma of the thyroid: diagnosis by fine-needle aspiration biopsy

Fine-needle aspiration biopsy (FNAB) has been recognized as a safe and reliable procedure in the evaluation of thyroid nodules. We herein report a case of a low-grade mucoepidermoid carcinoma of the thyroid that was diagnosed with this technique. Examination of an intra-operative FNAB showed cohesive clusters of polygonal squamoid cells with distinct cellular borders, uniform round nuclei, distinct nucleoli, and homogeneous amphophilic to cyanophilic cytoplasm. Focal keratin "pearl" formation was apparent, along with extracellular, lightly basophilic mucin deposits mantled by squamoid cells. These cytologic features are characteristic of low-grade mucoepidermoid carcinoma, as seen in other anatomic sites. This impression was confirmed by examination of paraffin sections. Previous reports have indicated that mucoepidermoid thyroid carcinoma is an indolent, locally recurring lesion. However, in spite of low-grade histology in our case, the neoplasm presented with distant metastases to bones, pleura, and lung.     

The value of immediate cytologic evaluation for needle aspiration lung biopsy

RATIONALE AND OBJECTIVES: The authors evaluate the role of immediate cytologic evaluation (ICE) with fine-needle aspiration biopsy (FNAB) for lung lesions at highest risk for pneumothorax. METHODS: A prospective randomized study was conducted of 80 patients with lung lesions surrounded by aerated parenchyma undergoing FNAB with and without ICE (47 and 33 patients, respectively). An analysis of needle passes, procedure time, complications, specimen adequacy, diagnostic yield, and accuracy of procedure was made. RESULTS: There was an increased number of needle passes with ICE (> or = three passes: 23% [11 biopsies] versus 3% [1 biopsy]; P = 0.01). Fluoroscopic procedures took longer with ICE (median time: 15 versus 9 minutes; P = 0.002) with no difference in complication rates. Specimen adequacy was similar (74% and 64%) and the procedure was diagnostic in 79% (37 biopsies) with ICE and in 70% (33 biopsies) without ICE. There were no significant differences in the sensitivity, specificity, or accuracy of the biopsy. CONCLUSIONS: Immediate cytologic evaluation improved results marginally with increased procedure time and needle passes. Immediate cytologic evaluation may be most useful for lesions at lowest risk of complications to assure that a second procedure is not required.     

Bactericidal activity of a fermented hot-water extract from Stevia rebaudiana Bertoni towards enterohemorrhagic Escherichia coli O157:H7 and other food-borne pathogenic bacteria

AIMS: To evaluate the correlation of fine needle aspiration (FNA) cytology and frozen section biopsy in the diagnosis of thyroid nodules. METHODS: The medical records of 662 patients who underwent FNA cytology of the thyroid and thyroid surgery were analysed. Frozen section biopsies were taken from 586 of the 662 patients. The diagnostic correlations of FNA cytology, frozen section, and both FNA cytology and frozen section with definitive histological assessment were evaluated. RESULTS: Among the 662 patients who received FNA cytology, there were 356 cases (53.8%) diagnosed as benign, 114 cases (17.2%) as malignant, 148 cases (22.4%) as indeterminate, and 44 cases (6.6%) as unsatisfactory. The positive predictive value for the detection of malignancy by FNA cytology was 92.1% and the negative predictive value was 95.2%. The incidence of malignancy in the indeterminate cytological diagnosis was 23%. The diagnosis from frozen sections was benign in 445 cases (75.9%), malignant in 134 cases (22.9%), and deferred in 7 cases (1.2%). By frozen section, the positive and negative predictive values were 97% and 95.5%, respectively. Diagnostic accuracy up to 98% was achieved when FNA cytology and frozen section diagnoses were in agreement. No false positives were observed when FNA cytology and frozen sections were both positive for malignancy. When FNA cytology and frozen section diagnoses were discordant, frozen section showed a higher accuracy (78.9%) than FNA cytology (21.1%). In the face of an indeterminate or unsatisfactory cytological diagnosis, the diagnostic accuracy of frozen sections reached 92.6%. CONCLUSIONS: The results confirm that FNA cytology is a useful tool in the initial evaluation of thyroid nodules. Intraoperative frozen section is a valuable procedure to confirm the cytological diagnosis and identify malignancy in patients with indeterminate or unsatisfactory cytological diagnosis. With reliance on frozen sections as an intraoperative guide of thyroid surgery, the possibility of unnecessary extensive surgery and the need for the second operation are considerably lower.     

Utility of fine-needle aspiration cytology and frozen-section examination in the operative management of thyroid nodules

Fine-needle aspiration cytology has a high sensitivity for the diagnosis of solitary thyroid nodules. Certain diagnoses involving follicular histologies often cannot be made with needle biopsy alone. The utility of frozen-section examination of thyroid nodules, with particular regard to those lesions with follicular histologies, is also limited. We examined the correlation of fine-needle aspiration cytology and frozen-section examination in solitary thyroid nodules to determine the contribution of frozen-section examination to the operation. We reviewed the fine-needle aspiration cytology, frozen-section examination, and final pathology of 100 consecutive patients undergoing thyroidectomy for a solitary solid thyroid nodule in an 4-year period. The diagnoses were classified as indeterminant, benign, or malignant. The utility and impact of the diagnosis from fine-needle aspiration or frozen section on the operative procedure performed was analyzed. Fine-needle aspiration cytology as a diagnostic test for thyroid nodules demonstrated an indeterminant rate of 23 per cent, with a diagnostic accuracy of 77 and 92 per cent for benign and malignant disease, respectively. In all patients with inaccurate benign diagnosis on fine-needle aspiration cytology, follicular neoplasm was misinterpreted for follicular adenoma or multinodular goiter. In comparing frozen-section results, the indeterminant, benign, and malignant rates were 7, 96, and 64 per cent, respectively. Of the 23 patients with indeterminant results on fine-needle aspiration cytology, the intraoperative frozen-section diagnosis on 4 patients was deferred to permanent section; 18 received accurate cytological diagnosis; and in 1 patient, carcinoma was missed. Overall, the decision about the extent of surgical thyroid resection was changed in only 2 patients based on the frozen-section results. Preoperative evaluation with fine-needle aspiration cytology can accurately and appropriately define the extent of thyroid surgery in most patients with a diagnosis of malignant neoplasm or benign disease. Intraoperative frozen-section examination may be helpful if fine-needle aspiration cytology results are inderminant and in cases of follicular histology as an adjunct for evaluation of the thyroid nodule, but overall, frozen section does not contribute to the management of the thyroid lesion at the time of surgery.     

The use of fine needle aspiration biopsy in the management of thyroid disease

Fine needle aspiration biopsy is now a first line investigation in thyroid disease. The purpose of this study was to evaluate the results of this technique in comparison with routine histopathology. A total of 593 aspirations over a four year period were included. There were 390 (65.7%) solitary nodules, 124 (20.9%) multinodular goiters, 66 (11.1%) diffuse goitres and 13 (2.2%) recurrent post thyroidectomy nodules. Radioisotope scanning in 386 cases showed 325 (84.2%) cold nodules, 54 (14.0%) warm nodules and 7 (1.8%) hot nodules. There were 458 (77.2%) colloid goitres and cysts, 14 cases of thyroiditis (2.2%) and 30 malignancies diagnosed on fine needle aspiration biopsy. In 19 cases (3.2%) a diagnosis of follicular neoplasm and in 29 cases (4.9%) a diagnosis of suspicious aspirate was made. Histological results were available in 176 cases. In 108 cases findings of histology and FNAB were compared with radioisotope scanning. A sensitivity of 92.8% and 42.8%, a specificity of 90.1% and 98.7% and accuracy index of 90.3% and 94.3% was found, when considering suspicious cases alternatively as positives and negatives. Surgery was recommended in all suspicious cases to prevent reduction in sensitivity of the technique. Fine needle aspiration biopsy was found to be a highly effective procedure which can obviate a lot of unnecessary surgery in thyroid lesions.     

Severe occlusive carotid artery disease: hemodynamic assessment by MR perfusion imaging in symptomatic patients

BACKGROUND: The purpose of this study was to assess the capability of magnetic resonance imaging (MRI) and cytology and flow cytometric (FCM) deoxyribonucleic acid (DNA) analysis in fine-needle aspiration biopsy (FNAB)-derived materials for diagnosing malignancy of the parotid lesions and the efficacy of FCM analysis in FNAB. METHODS: Magnetic resonance imaging findings and FCM results (ploidy and S + G2 + M phases [S + G2M] fraction) and cytology in FNAB-derived materials in 26 patients with 26 parotid lesions (12 benign lesions, 14 malignancies) were assessed for predicting malignancy. Flow cytometric results in aspirates were compared with those in surgically resected tissues. RESULTS: When a single predictor was used, cytology (92% accuracy) was most accurate for malignancy, followed by ill-defined margin (88% accuracy) and aneuploidy (88% accuracy). The combination of FCM and cytology raised the rate of sufficient materials from 92% to 100% and accuracy from 92% to 96% compared with cytology alone. The same highest accuracy (96%) was obtained with the combination of the ill-defined margin or other findings such as cytology, aneuploidy, or a high (S + G2M) fraction (6% <). Deoxyribonucleic acid ploidy in the FNAB showed full agreement with that in the surgical specimens. Receiver operating characteristic curves showed that the diagnosis of malignancy with (S + G2M) fraction in FNAB was superior to that in surgical specimens, but no significant difference was noted. CONCLUSIONS: A combination of MRI findings, cytology, and FCM results is optimal for diagnosing malignancies of the parotid lesions, and FNAB may replace the surgical specimens in FCM analysis.     

Pediatric thyroid nodules: management in the era of fine needle aspiration

BACKGROUND/PURPOSE: Thyroid nodules are rare in children. The need to uncover malignancy is the most challenging dilemma in management. The aim of this report was to determine whether management of pediatric thyroid nodules has changed in the era of fine-needle aspiration (FNA) cytology. METHODS: Twenty-four children with thyroid nodules comprised the study group. Demographic characteristics, clinical manifestations, imaging results, FNA cytology results, surgical therapy, complications, and pathological reports were reviewed retrospectively. FNA cytology results were categorized as either benign, malignant, suspicious, or insufficient. RESULTS: Girls outnumbered boys (five to one) with a mean age of 14.9 years. Nineteen nodules were benign and five malignant. Malignancy was characterized by localized tenderness, multiglandular appearance, and fixation to adjacent tissues. Ultrasound scans and nuclear scans gave no clue toward management because cystic, hot, and warm nodules figured among malignant cases. FNA in 18 children achieved 80% accuracy, 60% sensitivity, 90% specificity, 75% positive, and 81% negative predictive value. Physical examination findings, persistence of the nodule, and progressive growth decided for surgery in most children. CONCLUSIONS: FNA is a safe adjunctive test that plays a minor role in the decision to withhold surgery. Its greatest strength is to resolve, in case of suspicious or malignant cytology, that a more radical procedure will be needed. Clinical judgement as determined by serial physical findings continues to be the most important factor in the management of thyroid nodules in children.     

Solitary thyroid nodules. Separating benign from malignant conditions

Although features found on history taking, physical examination, thyroid function tests, and imaging studies help categorize solitary thyroid nodules as benign or malignant, fine-needle aspiration biopsy is the diagnostic test of choice. Nodules found to be malignant on cytologic examination should be treated with surgery. Benign nodules may be followed clinically or treated with levothyroxine to suppress their growth. Intermediate nodules should be excised if there is clinical suspicion of malignancy. In suspect nodules, levothyroxine therapy with follow-up ultrasound assessment for size is appropriate. Nodules that do not shrink significantly within 6 months should be excised.     

Isolated thyroid nodule. Comparative value of cyto-puncture and scintigraphy

OBJECTIVES: Nodular thyroid disease, indicated by the presence of single or multiple nodules within the thyroid gland is a common clinical problem, the main question remains the malignancy. Radionuclide scanning, ultrasonography and fine needle aspiration biopsy have been helpful to distinguish benign from malignant nodules and to select patients for surgery. METHODS: We performed a prospective study to assess the comparative value of fine needle nonaspiration biopsy and thyroid scinti scan in the management of 412 patients operated for solitary thyroid nodule. RESULTS: Sensitivity and negative predictive values were the same for both methods, but specificity of cytology was greater than that of thyroid scinti scan (80.53% vs. 10.47%, p < 0.001). DISCUSSION: Thyroid radionuclide scanning remains valuable in the evaluation of a cytological benign solitary thyroid nodule when TSH value is low, in order to distinguish toxic adenoma from cold nodule in Graves' disease.     

Fenfluramine challenge test in obsessive-compulsive disorder--first results

BACKGROUND: The aim of this study is to evaluate the additional diagnostic significance of immunocytochemical staining of thyreoglobulin (TG) in Fine Needle Aspiration Biopsy (FNAB) of neck lymph-nodes, in patients with a previous history of thyroid carcinoma. METHODS: Twenty-five smears performed by ultrasound-guided FNAB on laterocervical nodes with a 21-23 gauge needle were evaluates. All smears were stained according to Papanicolaou and microscopically examined. RESULTS: Of these 25 smears, 15 were diagnostic and 10 were non diagnostic. Of the 15 diagnostic cases, 10 were positive for metastatic lesions from thyroid neoplasm and the other 4 were classified as reactive lymphoadenitis. One smear for each case was selected for the immunohistochemical stain. All the 10 non-diagnostic cases showed no reaction to thyreoglobulin. Neoplastic cells, from 9 out of 11 cytologically positive smears, expressed thyreoglobulin in the cytoplasm. In one case no reaction was evident and the other one was discarded for technical reasons. In 3 of the 4 cases cytologically classified as lymphoadenitis, immunoreactive thyreoglobulin was not found. In the fourth case, blastic-like cells showed a scanty cytoplasmic rime which was immunoreactive for TG and thus was classified as a metastatic tumour. On this basis, it is suggested that FNAB should be performed routinelly in the diagnostic evaluation of neck masses of unknown origin in patients with a previous history of thyroid neoplasm. CONCLUSIONS: If the FNAB is inconclusive, a second aspiration should be performed while immunoperoxidase stain to evidentiate TG may be an adjuntive diagnostic tool in cytologically negative cases.     

Management of thyroid nodules

Clinically apparent thyroid nodules occur in about 5 percent of the population. Because most patients with thyroid nodules present initially to their primary care physician, family physicians should have a thorough understanding of the diagnosis and treatment of thyroid nodules. The history and physical examination may be helpful in detecting thyroid nodules but are not useful in predicting malignancy. Furthermore, laboratory studies, ultrasonography and nuclear medicine scans do not reliably differentiate between benign and malignant thyroid nodules. In most cases, fine-needle aspiration biopsy can accurately identify malignant thyroid nodules. Fine-needle aspiration biopsy is safe and can be performed in an office setting.     

Meta-analysis of the efficacy of extradural clonidine to relieve postoperative pain: an impossible task

PURPOSE: The diagnostic accuracy and rate of complications of CT-guided core biopsies (CB) from suspected tumors of the chest were compared to the accuracy a complications of fine-needle aspiration biopsies (FNAB). METHODS: The accuracy in the diagnosis of a benign or malignant lesion of 79 FNAB (19.5 G self-aspirating cutting needle) and of 83 CB (18 G automated core biopsy) and the rates of pneumothorax, pleural drainage and hemoptysis were retrospectively evaluated. RESULTS: With FNAB, the sensitivity for malignant lesions was 62.1% and the accuracy 68.4%. With CB the sensitivity amounted to 85.9% and accuracy to 86.7%. The rate of pneumothorax was 25.3% following FNAB, with a drainage rate of 5.1% compared to 19.3% and 6.0%, respectively, following CB. The rate of pneumothorax and drainage increased with increasing path length through aerated lung. In advanced emphysema, the pneumothorax rate did not increase; however, in pneumothoraces, pleural drainage was mandatory in 20% of FNAB and in 100% of CB. Hemoptysis without any therapeutic consequences occurred in 3.8% following FNAB and in 6.0% following CB. CONCLUSIONS: With CB diagnostic accuracy can be clearly increased without an obvious increase in the complication rate. However, in patients with obvious emphysema, the pleural drainage rate of pneumothorax may be higher following CB.     

Amino acids and vitamins prevent culture-induced metabolic perturbations and associated loss of viability of mouse blastocysts

BACKGROUND: Subsequent to the publication of a report in 1984 entitled "Poorly Differentiated ("Insular") Carcinoma: A Reinterpretation of Langhans "wuchernde Struma," poorly differentiated insular thyroid carcinoma (PDITC) has become recognized as a distinct thyroid neoplasm. It is classified morphologically and biologically as an intermediate entity between well-differentiated (papillary and follicular) and undifferentiated (anaplastic) thyroid carcinomas. Only a few publications have addressed the findings with fine needle aspiration biopsy (FNAB). CASE: A 67-year-old female presented for evaluation of a massively enlarged thyroid gland. Fine needle aspiration biopsy of the thyroid with a 22-gauge needle showed many large, multilayered, round to oval nests of tumor cells, 0.2-0.4 mm in diameter. Rosettelike configurations of 8-15 cells, 0.025-0.050 mm in diameter, were also observed. Nests of neoplastic cells in the histologic sections were virtually identical to those in the fine needle aspiration biopsy specimens. When the patient developed metastatic cervical adenopathy one year later, a microfollicular pattern was seen on both the FNAB and histologic sections. CONCLUSION: When nests of tumor cells, 0.2-0.4 mm in diameter, are identified in a thyroid FNAB specimen, PDITC should be included in the differential diagnosis. A microfollicular pattern in a metastatic lymph node does not exclude the possibility that the primary tumor is a PDITC.     

The diagnostic imaging of complex breast nodules]

This study was aimed at determining the role of high-frequency (7.5 MHz) US combined with cytology in the diagnosis of complex breast nodules (complex cysts--cystic tumors). The study population included 60 patients presenting with complex breast nodules selected on the basis of US patterns among 3,000 cases. All patients were also submitted to US-guided fine-needle aspiration biopsy (FNAB). Cytology of nipple discharge was always performed when discharge was present (15 cases), mammography was performed in 50 cases and pneumocystography in 10. US allowed the identification of the lesion in all patients and the diagnosis of nature in 73%; with FNAB the figure reached 96.7%. Mammography identified the lesion in 95% of patients, but failed to reveal the complex nature of the nodule. In a small number of cases mammography proved to be a useful complementary tool demonstrating malignant features not recognizable on US images. On the contrary, pneumocystography yielded no further information with respect to US. Diagnostic control was obtained by means of surgery in 30 patients and of clinical-US follow-up in the extant 30 cases. On the basis of their US features the lesions were classified into two groups: I) nodules having a mainly liquid component--i.e., hemorrhagic, septic, multilocular cysts, papillary cystadenoma; II) nodules having a mainly solid component--i.e., solitary intraductal papilloma, intracystic carcinoma, mixed carcinoma, phylloid adenoma, sarcoma. As to the former group, US proved reliable in making a diagnosis in the cases with typical hemorrhagic, septic and multilocular cysts. In the atypical cases, FNAB of the solid component of the nodule was necessary to differentiate irregular clots, thick septa or inflammatory thickening from different conditions. As to the latter group, FNAB of the solid component and/or mammography proved useful in making a diagnosis, even though to this aim US revealed peculiar patterns which were highly suggestive. In our experience, combined US and FNAB are of basic importance in the diagnosis of breast lesions, thus replacing pneumocystography which has been widely employed so far. As regards mammography, its role seems limited to pointing out the peculiar characters of malignancy which could not be demonstrated otherwise.     

CT-guided transthoracic needle biopsy: a comparison between automated biopsy gun and fine needle aspiration

AIMS: We retrospectively investigated the diagnostic accuracy and complication rate of transthoracic core biopsy using an automated biopsy gun and compared the findings with those of aspiration needle biopsy. PATIENTS AND METHODS: Seventy-three patients underwent 74 core biopsy procedures and 50 patients underwent 52 aspiration biopsy procedures. Of these, a final diagnosis was obtained in 107 lesions with surgery or clinical course. Fifteen patients in which a final diagnosis was not obtained were excluded from the study on diagnostic accuracy. Thus, in the study of diagnostic accuracy, 63 core biopsy procedures for 62 lesions are included. Core biopsy was performed with an 18 G cutting needle using an automated biopsy gun. Aspiration biopsy was performed with a 20 G aspiration needle. RESULTS: Core biopsy yielded sufficient material in 57/63 procedures (90.5%). A correct diagnosis was obtained in 36 procedures (85.7%) for malignant leisons and a specific benign diagnosis was obtained in 11 procedures (52.4%). Aspiration biopsy yielded a correct diagnosis in 26 procedures (81.3%) for malignant leisons and in seven (46.7%) for benign lesions. The overall correct diagnosis were 75.8% and 71.7% with core biopsy and aspiration biopsy, respectively. Core biopsy gave a higher predictive rate than that of aspiration biopsy for both benign and malignant lessons (P < 0.02). Pneumothorax occurred in 18/74 (24.3%) patients with core biopsy and in 18/45 (40.0%) patients with aspiration biopsy. Of these, three with core biopsy and two with aspiration biopsy needed tube drainage. The other complication was haemoptysis, which occurred in six patients following core biopsy and in three after aspiration biopsy. All nine cases subsided spontaneously. There were no fatal complications. CONCLUSIONS: Core biopsy with a biopsy gun increase the diagnostic accuracy with a higher histologic predictive rate and no obvious additional risk of complications.