21st February 2025

A 40-year-old man presents with 2 weeks of chest discomfort and dysphagia on a background of 1 month of fatigue and weight loss.

A 40-year-old man presents with 2 weeks of chest discomfort and dysphagia on a background of 1 month of fatigue and weight loss. He has no significant medical history but does report a 20-pack-year smoking history. Investigations are as follows:

CT chest: large anterior mediastinal mass

Blood results:


Haemoglobin: 135 g/L (130 – 180 g/L) White cell count: 6.2 x10⁹/L (3.6 – 11.0×10⁹/L) Platelet count: 450 x10⁹/L (40 – 400 x10⁹/L) beta-HCG: 4,500 IU/L (0-3 IU/L) Alpha fetoprotein: 2,500 ng/mL (10-20ng/mL)	Sodium: 132 mmol/L (133–146 mmol/L) Potassium: 3.8 mmol/L (3.5–5.3 mmol/L) Creatinine: 54 μmol/L (59–104 μmol/L) eGFR: >90 mmL/min/1.73 m² LDH: 650 U/L (<250U/L)

Haemoglobin: 135 g/L (130 – 180 g/L)

White cell count: 6.2 x10⁹/L (3.6 – 11.0×10⁹/L)

Platelet count: 450 x10⁹/L (40 – 400 x10⁹/L)

beta-HCG: 4,500 IU/L (0-3 IU/L)

Alpha fetoprotein: 2,500 ng/mL (10-20ng/mL)

Sodium: 132 mmol/L (133–146 mmol/L)

Potassium: 3.8 mmol/L (3.5–5.3 mmol/L)

Creatinine: 54 μmol/L (59–104 μmol/L)

eGFR: >90 mmL/min/1.73 m²

LDH: 650 U/L (<250U/L)

What is the most appropriate next investigation?

Select the SINGLE most appropriate option from the list below. Select ONE option only.