Utilidad de la PAAF guiada por TC en el diagnóstico de lesiones mediastínicas

Objective

To evaluate the diagnostic accuracy of the percutaneous fine needle aspiration cytology (FNAC) for mediastinal lesions by using histology or follow-up clinical diagnosis as gold standard.

Patients and Methods

CT-guided percutaneous FNAC was performed on 131 patients with mediastinal lesions. Helical CT was used with 3–10 mm image thickness range and low radiation dose (40 mAs, 120 kV). Samples were immediately examined by a cytologist to determine if they were representative. Histological samples were obtained by means of biopsy or resection specimens in 73 patients and clinical follow-up in 50.

Results

The material was satisfactory for diagnosis in 126 patients (95.2 %), in whom 103 lesions (78.6%) were considered malignant (62 primary tumours and 41 metastases) and 23 (17.6%) benign. In the 123 patients with clinical monitoring or pathological diagnosis, using FNAC led to the identification of malignancy with a sensitivity of 95.2 % (95%CI: 89.2–97.9%), specificity 84.2% (95%CI: 62.4–94.5%), positive predictive value 97.1% (95%-CI: 91.7–99.0%), negative predictive value 76.2% (95%CI: 54.9–89.4%), likelihood-ratio positive 6.03 (95%CI: 2.13–17.05) and accuracy 93.5% (95%CI: 87.7–96.7%). Pneumothorax was the most frequent complication (3 cases). There was good agreement between the cytological findings and the histological findings, not only for malignant lesions (kappa coefficient: 0.641) but also for benign (kappa 0.607).

Conclusions

CT-guided percutaneous FNAC is a safe and effective technique for the diagnosis of the mediastinal masses, with a high diagnostic yield for malignancy depicting.