Mediastinal Masses Radiology — Practice

A 45-year-old male chronic smoker presents with haemoptysis, weight loss of 6 kg over 3 months, and a persistent cough. Chest X-ray reveals a 3 cm spiculated opacity in the right upper lobe with hilar enlargement. CT chest confirms a heterogeneous mass with irregular margins and ipsilateral mediastinal lymphadenopathy. What is the MOST appropriate next investigation to obtain tissue diagnosis?