Endobronchial ultrasound-guided transbronchial needle aspiration in the diagnosis of mediastinal metastases of clear cell renal cell carcinoma

Abstract

Evaluation of mediastinal lymphadenopathy in patients with a previous diagnosis of renal cell carcinoma (RCC) is critical for the determination of further treatment. A minimally invasive method of cytology sampling of mediastinal lymph nodes using endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) has emerged as a useful tool in diagnosis. Between January 2010 and April 2018, we performed 1744 EBUS-TBNA studies of mediastinal and hilar lymph nodes for a variety of clinical indications including mediastinal malignancy. Sixteen patients (93.7% males, mean age 59.1 years, range 44?81 years) were diagnosed by cytological and cell block study to have metastatic clear cell RCC. Twelve patients had been diagnosed with clear cell RCC in the past (mean 39 months, range 4?89 months) while in four, the tumor was primarily diagnosed in the staging phase on the basis of EBUS-TBNA. The EBUS features of the mediastinal nodal masses included increase of size (mean 2.5?cm, range 1.6?3.8?cm), irregular, inhomogeneous, hypervascular, and hyperechoic echotexture. EBUS-TBNA is a procedure safe and effective for evaluating mediastinal lymphadenopathy in patients with clear cell RCC. Immunohistochemistry in the cell block is decisive for proper diagnosis. The cytologist plays a key role in the diagnosis of metastatic clear cell RCC due to the treatment implications that this neoplasm encompasses.