Material and Method: All TNB diagnoses considered to have benign non-specific features at the Radiology Department between January 2007 and December 2011 were retrospectively reviewed for definitive diagnosis based on clinical impressions and for CT imaging characteristics.

Results: Sixty-seven cases with TNB were given a benign non-specific diagnosis and had complete pathologic or radiologic follow-ups. Of these 67 cases, 16 (23.9%) were malignant and 51 were benign. Two main definitive diagnoses of benign cases were pulmonary tuberculosis (32.8%) and pneumonia/lung abscess (23.9%). On the CT images, most of lesions in the group of pulmonary tuberculosis (14/22, 63.6%) were not enhanced after contrast administration (p<0.005), and necrotic mediastinal lymph nodes were significantly found more in final malignancy diagnoses (p<0.005).

Conclusion: The definitive diagnoses of benign non-specific diagnoses based on TNB in this tuberculosis-endemic area had a high rate of both malignancy and pulmonary tuberculosis. Hence, repeated biopsies or radiological follow-ups are advised.

Keywords: Benign non-specific diagnosis, Transthoracic needle biopsy (TNB), Pulmonary lesions