Immediate assessment of fine needle aspiration cytology of lung

To assess the value of immediate assessment of cytology in percutaneous fine needle aspiration (FNA) cytology of lung.

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.

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.

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.