I have a swollen lymph node (unilateral) above the collar bone (size of a blueberry). i just got over having pneumonia. they found bilateral perihilar fullness with peribronchial thickening. does this sound like a case of lymphoma? no other symptoms?

All of this can be due to a strong immune response to what could have been a bout of viral or atypical pneumonia. Nevertheless a follow-up is needed. Did the radiologist recommend a chest CT scan as is most often the case with hilar prominence? I think this test is superior to an ultrasound. Discuss this with your physician. You could also consult a pulmonologist for evaluation&further advice