Inconclusive Result from CT Guided Transthoracic Needle Aspiration and Biopsy: Affecting Factors and Final Outcome

ABSTRACT

PURPOSE: Inconclusive results from computed tomography (CT)-guided transthoracic needle aspiration and biopsy (TNAB) performed for lung lesions presents a clinical dilemma. The purpose of this study was to determine the factors affecting an inconclusive result from a CT guided TNAB, and to evaluate the final outcomes of these inconclusive results. MATERIALS AND METHODS: The medical records and radiologic features of 331 patients with lung lesion who received CT guided TNAB were analyzed retrospectively. The results of the TNAB were classified as conclusive (malignancy or specific benign diagnosis) or inconclusive (nonspecific benign or nondiagnostic). RESULTS: Of the 331 cases, 269 (81.3%) were diagnosed as a malignancy (210) or a specific benign lesion (59) after the first TNAB. The remaining 62 (18.7%) were inconclusive. Benign disease, a lesion size < or =15 mm, and morphology of the consolidation type were features significantly correlated with inconclusive results. Of these 62 inconclusive cases a second TNAB was performed in 23, and conclusive diagnoses were obtained in 19 (82.6%). Surgery or radiographic follow up was done in other cases. Finally, among the 62 inconclusive results on the first CT guided TNAB, 16 lesions were diagnosed as malignant, 26 were classified as specific benign disease, and the remaining 20 were defined as nonspecific inflammation. Age over 50 and morphology of a nodule or a mass type were significantly correlated with a malignancy in these 62 cases with inconclusive results on the first TNAB. CONCLUSION: A final diagnosis of benign disease was significantly higher after the CT guided TNAB was inconclusive for lesions < or =15 mm that had consolidation type morphology. Despite the application of core biopsy procedures, there continue to be appreciable numbers of inconclusive results after the first CT guided TNAB. A repeat CT guided TNAB had a high diagnostic yield in these cases and therefore should be considered for cases with inconclusive results.