Multiple swollen lymph nodes, non tender, armpits, neck, clavicle, tiny lung nodules, progressive in number last 6 months, none big enough for biopsy (just under cm), if was low grade lymphoma how quickly would they grow? well otherwise?

There are multiple causes of lymph node enlargement. For info: https://my.clevelandclinic.org/health/diseases/15219-swollen-lymph-nodes You may feel the nodes every couple of weeks, if any of the lymph glands doubles in size, becomes painful, ulcerates, or other nodes become enlarged, or you develop fever, or lose weight, you should see a doctor. Wish you good health!