Yield of transbronchial needle aspiration in diagnosis of mediastinal lesions

To determine the transbronchial needle aspiration (TBNA) yield for procedures performed by fellows in training, and the predictors of positive TBNA yield at our center.

Retrospective chart review.

A tertiary teaching hospital.

One hundred seventy patients who underwent fiberoptic bronchoscopy with TBNA of mediastinal lesions from January 1991 to July 1999.

Final diagnoses were available for 166 patients. TBNA was diagnostic in 104 patients (61%) and nondiagnostic in 66 patients (39%). Of 170 cases, 123 patients (72%) had malignancies, 30 patients (18%) had benign disease, and 13 patients (8%) were normal. Of 123 malignancies, 85 patients (69%) had a positive result by TBNA. Of 30 cases with benign disease, 11 patients (37%) had positive TBNA findings. Eight of 13 patients (62%) with a normal diagnosis had diagnostic TBNA (normal lymphoid tissue). There were statistically significant correlations between TBNA result and cell type of the lesion (p < 0.001), size of the lesion (p < 0.05), and type of malignancy (small cell carcinoma more than non-small cell carcinoma more than lymphoma, p < 0.05). We did not find any significant difference for aspiration yield between carinal and tracheal sites (p > 0.05). Logistic regression analysis indicated that the presence of malignancy is the major determinant of TBNA yield (p = 0.009). In addition, lesion size does affect yield after being adjusted for diagnosis (one-sided p = 0.04).

TBNA is a minimally invasive diagnostic technique with a high yield, even in hands of less experienced operators. Malignancy, lesion size, and type of malignancy are major determinants of TBNA yield.