Bit of a dark question. Those of us with Hashi's - or "borderline Hashi's" as my GP likes to call it - have chronic lymphocytic thyroditis, right? And there is an association, not huge, with non-Hodgkins lymphoma. My brother has chronic lymphocytic leukaemia. Both of our ailments are probably genetic, and I would think an autosomal dominant gene. My aunt also has CLL (or SLL, the World Health Org says these are the same disease.) CLL is also associated with non Hodgkins. Women dominate Hashi's, and I think men dominate CLL.
Maybe there will be few answers, because in the UK CLL is picked up very late. It is found much earlier in the USA because of private medical annual screenings. I can't find a study which has looked for an association, and it could be disguised by the male/female ratios in these diseases. But.... anyone got a relative with CLL?
I don't think that my situation is likely to be a coincidence.