Middle lobe shadows can be collapse, consolidation, fissural effusion or mass lesion...all these usually project better in lateral view.I wish you must have talked about your present symptoms.
Next investigation is CT scan of thorax which will outline the lesion clearly and will tell about the lesion...also it will tell about associated lymphadenopathy
usually comes in elderly smokers with symptoms of dry cough occasionally blood tinged, weight loss
, breathlessness, hoarseness
of voice etc
meet your doctor.....
best wishes and thanx for coming to HCM