From how long he had this lump/
Any recent infection?
Does he had fever in recent past?
Lymph node infection is called Lymphadenitis.It is a common complication of certain bacterial infections such as streptococcus or staphylococcus. Fine needle aspiration cytology (FNAC) may be done.In this technique, a thin, hollow needle is inserted into the mass/lump to extract cells that will be examined under a microscope. based on this the exact diagnosis can be made.X-ray chest & some blood tests may be required.
The exact diagnosis can only be made after physical examination & tests.So I advice for your boyfriend to make an appointment with doctor.
Please click green ACCEPT BUTTON so I can be paid for assisting you. BONUS and Positive Feedback are always greatly appreciated.