Fine needle biopsy provides a highly accurate diagnostic method which can be performed rapidly with minimal risk. It provides a definitive diagnosis in most patients at low cost with minimal trauma. Patients at poor surgical risk are saved a thoracotomy in many instances. Patients who are clinically inoperable can receive appropriate chemotherapy and radiotherapy without major surgery done solely for diagnostic purposes. In comparative studies, this technique has generally been reported to be superior to bronchoscopic biopsy and sputum cytology in the diagnosis of radiologically evident lung lesions. In screening patients, sputum cytology remains the method of choice and is essentially the only method of diagnosing early lesions not seen radiologically. Bronchial brush biopsy, another technique of great value, is particularly useful in the diagnosis of central bronchial lesions. Appropriate utilization of these three cytologic sampling procedures provides for the highest degree of accuracy in the diagnosis of pulmonary disease with minimum risk to the patient.

Fine needle aspiration cytology of lung lesions: a clinicopathological and cytopathological review of 150 cases with emphasis on the relation between the number of passes and the incidence of pneumothorax.
Cytopathology. 2007 Feb;18(1):44-51.

OBJECTIVE: The aim of this study was to review the lung fine needle aspirations (FNA) that were done in our hospital between January 1998 and April 2004. Interobserver agreement, sample adequacy and the relation between the number of passes and the occurrence of pneumothorax are presented. STUDY DESIGN: One hundred fifty cases of lung FNA from the department of pathology files were identified and the available specimens and patient charts were reviewed. The interobserver agreement was calculated. The relation between the number of passes and the subsequent development of pneumothorax was tested using Mann-Whitney U-test. RESULTS: The material of 132 patients (88%) out of 150 were retrieved and reviewed. There were 85 cases of non-small cell lung cancer (NSCLC) (64.4%), nine cases of small cell lung cancer (6.8%), five cases of metastatic cancer (3.8%) and 33 cases were reported negative for cancer (25%). The NSCLC included 36 cases of adenocarcinoma (27.3%), 32 cases of squamous cell carcinoma (24.2%), and 17 cases of large cell undifferentiated carcinoma (12.9%). The interobserver agreement k was 0.93, (95% CI 0.87-0.98). The majority of cases (95.5%) were considered adequate for interpretation. The charts of 138 patients (92%) were reviewed for postprocedure radiologically confirmed pneumothorax. Sixteen patients (11.6%) developed pneumothorax only three of whom (2%) required a chest tube for treatment. The number of passes was identified in 118 patients (85.5%). The number of passes did not have a statistically significant association with the development of a pneumothorax (P = 0.747). CONCLUSION: Fine needle aspirations to diagnose lung lesions is a safe procedure with a low incidence of pneumothorax. Its findings are reproducible with high interobserver agreement. Immediate adequacy evaluation and triage by a pathologist guarantees adequate sample in most instances. The number of passes was not associated with an increased incidence of pneumothorax.

Fine needle aspiration cytology of pulmonary lesions: a reliable diagnostic test.Pathology. 2001 Feb;33(1):13-6.

The objective of this study was to determine the accuracy of image-guided fine needle aspiration cytology (FNAC) in the diagnosis of pulmonary lesions. A retrospective study was undertaken of 286 patients with 288 lesions, who underwent a total of 302 procedures. The FNAC diagnoses were reported as malignant, suspicious, atypical, benign or non-diagnostic. Subsequently the FNAC diagnoses were correlated with either the histological or clinical diagnoses. Of the 288 lesions, 64.6% were reported on FNAC as malignant, 2.1% suspicious, 2.4% atypical, 20.8% benign and 10.1% nondiagnostic. On review of the suspicious, atypical, selected benign cases and non-diagnostic FNAC by an independent pathologist there was agreement with the original FNAC diagnosis in all cases. All of 186 malignant FNAC diagnoses were confirmed malignant either clinically or on subsequent histology. Four of the six suspicious FNAC diagnoses had a malignant outcome, one patient had organising pneumonia on excision biopsy and one was lost to follow up. Six of the seven atypical FNAC diagnoses were confirmed on histology as malignant, while one lesion resolved spontaneously. Fifty-two of 60 benign FNAC diagnoses were confirmed benign either clinically or on histology. Seven of the lesions diagnosed as benign on FNAC were proven to be malignant. One patient with a benign FNAC diagnosis was lost to follow-up. Ten of the 29 non-diagnostic FNAC group were later shown on clinical or histological follow up to be malignant. This study shows that image guided FNAC for the diagnosis of malignant pulmonary lesions has a sensitivity of at least 92% and a specificity of at least 96%. It is a reliable diagnostic test although its accuracy is limited by technical difficulties in obtaining an adequate sample.

Fine needle aspiration biopsy cytology of pulmonary tumors.Rocz Akad Med Bialymst. 1997;42 Suppl 1:309-13.  

Transthoracic fine needle aspiration specimens of the pulmonary tumors were obtained from 144 patients. Fine needle aspiration biopsy were performed using local anaesthesia and ultrasonographic or scopie control. The 20-gauge needles were used to obtain the specimens. 93 of patients have been diagnosed as squamous cell carcinomas, 28 as adenoid carcinomas, 18 as anaplastic carcinomas and 5 as a non neoplastic lesions (tuberculoma and abscessus). The tumors were typed according to the second WHO histological classification. Analysis of the date indicated that malignant neoplasms were identified correctly with an accuracy of 92.0%. There were not false positive diagnoses. There were two false negative diagnoses (squamous cell carcinoma) and in three cases the diagnosis were as suspected for malignancy. The results confirmed the value of fine needle aspiration cytopathology for the diagnosis of pulmonary tumors.

Immediate assessment of fine needle aspiration cytology of lung.J Clin Pathol. 1996 Oct;49(10):839-43.

AIMS: To assess the value of immediate assessment of cytology in percutaneous fine needle aspiration (FNA) cytology of lung. METHODS: FNA specimens from 75 consecutive patients with suspected pulmonary neoplasms were subjected to immediate cytology assessment. Direct smears were prepared in the radiology department and stained using the Diff Quik method. The cellular content was assessed and, if possible, a provisional diagnosis offered. A second FNA was requested if the initial aspirate seemed of doubtful adequacy. The diagnostic accuracy was examined by review of clinical and radiological data in all patients, and by correlation with other histological or cytological material in 25 patients. Complications of the procedure were identified during the clinical review. RESULTS: Two of 75 specimens were inadequate for diagnosis. Satisfactory diagnostic material was obtained in 51 patients on a single aspirate and following a second FNA in 22 patients. Of the 73 satisfactory aspirates, 58 were malignant, one highly suspicious of malignancy and 14 reported as negative for malignancy. All malignant diagnoses were confirmed on clinical or pathological review. FNA accurately distinguished primary small cell and large cell carcinomas in those patients with pathological follow up. There were two false negative reports, one due to sampling error and the other due to misinterpretation of aspirate material. The diagnostic specificity was 100% and sensitivity 96.6%. Complications were recorded in seven (9.3%) patients, five of whom developed pneumothorax; a chest drain was required in one patient. CONCLUSIONS: Percutaneous FNA cytology provides safe and accurate diagnosis in the investigation of pulmonary lesions. Immediate cytology assessment ensures that aspirate material is handled optimally, and those patients requiring further sampling or ancillary investigation identified rapidly. The number of unsatisfactory and false negative lung FNA are therefore reduced. The complication rate is minimised by decreasing the number of pleural punctures.