Endobronchial Ultrasound-Guided Transbronchial Needle Aspiration in the Diagnosis of Hilar and Mediastinal Lymph Node Metastases of Melanoma.

Abstract

Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is a minimally invasive technique for investigating hilar and mediastinal lymphadenopathy. This study reports eleven cases in which EBUS-TBNA was used to assess mediastinal and hilar lymph nodes for the presence of metastatic melanoma. A retrospective study was performed of all patients who had a history of melanoma and underwent EBUS-TBNA to assess hilar or mediastinal lymphadenopathy for the presence of metastatic melanoma. In seven cases, molecular analysis to detect mutations in the BRAF gene was also used. Eight patients had been diagnosed with malignant melanoma in the past (mean 54.4 months, range 18 to 115 months) while in the other three this tumor was primarily diagnosed in the staging phase. The male-female ratio was 6:5, and the mean age was 60.3 years (range 42 to 88 years). The mean hilar or mediastinal lymph node size detected with computed tomography was 3.0 cm (range 1.1 to 8.1 cm). Eight (72.7%) cases had metastases to the lung associated with metastases in the mediastinal lymph nodes. In four (50%) of these cases, the lung metastasis was solitary. Three (27.3%) cases had metastases in the mediastinal lymph nodes in absence of lung metastases. Metastatic melanoma was diagnosed by cytology and confirmed by cell block study with immunohistochemistry in all cases. BRAF mutations were detected in two (28.6%) of seven cases studied. Cytology and tissue samples obtained from EBUS-TBNA are adequate to detect metastatic melanoma and permit in some cases the determination of biomarkers and identify the presence or absence of mutations in the BRAF gene. The procedure is safe, fast, and precise for the staging of melanoma.