31st May 2023

A 27-year-old male presents to ED with a 2-week history of chest pain and a cough

A 27-year-old male presents to ED with a 2-week history of chest pain and a cough. His CXR shows an enlarged mediastinum. He goes on to have a PET CT which confirms a localised PET avid mass with no distant areas of increased uptake. A CT guided biopsy is performed which shows giant multinuclear cells surrounded by an inflammatory infiltrate.

What is the most likely diagnosis based on the above findings?