23 year-old British Caucasian university student felt some gland swelling at her neck. Upon further questioning, she reports on and off fever with overnight sweating, and noticed 7 kg weight loss. She travelled to Malaysia, Thailand and Hong Kong 6 months previously. BCG vaccination has been obtained. On examination, there is palpable rubbery cervical lymphadenopathy. Subsequent chest X ray uncovers increased mediastinal opacity and enlargement.
What is the differential diagnosis and course of action?