On off fevers of up to 38.3 c (orally)for last 4 months. no swollen lymph node. all bloodwork ok. 2 abd. us, chest, neck xray ok. lymphoma ruled out ?

Afraid not: It's very difficult to "totally" exclude the possibility of having lymphoma (or most cancers). This is because they can start off being very small, and could be anywhere. In your case I would say that CT scanning of the abdomen, chest, neck would give a much more thorough and detailed look at those areas.. that said, there are many more common causes of fever than lymphoma, so still unlikely.