The diagnostic value of tissue button technique for specimen accusation during endobronchial ultrasound-guided transbronchial fine-needle aspiration.

Introduction: The quality of tissue acquisition during endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is a major determinant of the diagnostic yield of the procedure. In the tissue button (TB) technique, the retrieved cellular specimen is fixed in ethanol and subsequently scraped from slide using surgical blade into formaldehyde and processed like ordinary tissue biopsy thus potentially increasing its diagnostic value.

Objectives: To retrospectively evaluate the diagnostic yield of a TB technique in patients undergoing EBUS-TBNA for various malignant and benign conditions.

Methods: The diagnostic yield of specimen obtained by two methods (TB and traditional cell-block technique) performed during the same procedure are outlined in 46 patients who underwent EBUS-TBNA (median age = 65, range 19-85 years).

Results: Overall, in both malignant and benign conditions, TB resulted in clear diagnostic material in 43/46 (93.4%) patients. Specifically, TB provided clear histological diagnosis of malignancy (either primary lung cancer or metastases from extra-thoracic cancer) in 30/46 (65.2%) patients and granulomatous inflammation in 11/46 (23.9%) of patients. Only in two patients TB did not provide diagnostic material.

Conclusions: The newly introduced TB technique provides valuable histological diagnostic material during EBUS-TBNA both malignant and benign conditions. Given its simplicity and its high diagnostic yield, TB should be considered to be used as one of the preferred specimen acquisition modalities during EBUS-TBNA specimen processing. Direct comparison to alternative tissue processing techniques during EBUS-TBNA should be explored in further randomized prospective studies.