Imaging Case: 33 Year Old Male with Neck Swelling

Case: 33 year old Vietnamese male with a past medical history notable for TB diagnosed 2 years prior to arrival. Patient was treated for 9 months. Patient presents with slowly and progressive swelling on the left side of the neck. There is no aggravating or relieving factors. He denies any recent weight loss, fever, chills or any other constitutional symptoms. He denies shortness of breath or difficulty swallowing.  He denies any back pain or any other lymphadenopathy. He reports that about 9 months ago, the swelling was there but was smaller and has gradually increased in size. Patient is from Vietnam and immigrated more than 10 yrs ago and visited back 5 yrs ago. Patient reports that neck swelling is bothering him but does not interfere with his activity.

Vital Signs:
Temp: 98.3 F
Heart Rate: 81 
Blood Pressure: 109/63
Respiratory Rate: 16
SpO2: 100% RA

Pertinent Physical Exam:
Constitutional: No apparent distress, thin.
Neck: 7 cm x 7 cm firm left mass, no fluctuance, erythema, or tenderness-to-palpation. 

The following CT images of the neck were obtained with contrast:

The follow chest x-ray was also obtained during the ED stay:

What is the most likely origin of this patient's neck swelling?
A) Deep neck abscess
B) Malignancy
C) Lymphadenitis
D) Hematoma