Convex probe EBUS for centrally located parenchymal lesions without a bronchus sign

Abstract

Background: Convex probe endobronchial ultrasound (CP-EBUS) has proven safe and accurate for identifying malignancy and granulomatous disease affecting the mediastinum and hilum. For the diagnosis of parenchymal lung lesions, conventional techniques such as transbronchial biopsy, brush and lavage are useful, particularly when an airway leads directly to the lesion. For centrally located intraparenchymal lesions, CP-EBUS has been shown to be efficacious.

Objective: To expand on the existing literature in an effort to highlight the important diagnostic role of CP-EBUS in centrally located lesions, particularly those without a bronchus sign.

Methods: In our cohort of 430 patients undergoing CP-EBUS between 03/2009-03/2012, we retrospectively identified 32 who underwent transbronchial needle aspiration (TBNA) of a centrally located parenchymal lung lesion. All lesions were completely surrounded by lung parenchyma and not visualized during white light bronchoscopy. Diagnostic yield was determined and compared to conventional bronchoscopic biopsy techniques, when performed.

Results: The mean lesion size was 25.6 mm and 24/32 (75%) lesions were located in the lower lobes. A definitive diagnosis was obtained in 27/32 (84.4%) of parenchymal lesions without a bronchus sign biopsied using CP-EBUS. CP-EBUS provided the exclusive method of diagnosis in 15/32 (46.9%) patients in this cohort. Most lesions (26/32) were diagnosed as non-small cell carcinoma. There were no procedural complications.

Conclusion: CP-EBUS is useful for diagnosing parenchymal lung abnormalities without a bronchus sign, extending its scope beyond mediastinal and hilar lymph nodes. It is imperative that physicians performing EBUS maintain this tool as a complement to conventional bronchoscopic techniques.

Keywords: Endobronchial ultrasound (EBUS); Lung cancer; Parenchymal lesions.