@steiner
Hello. I had not heard of your Primary Cutaneous Marginal Zone diagnosis, and does present the question of it's cause.
To answer your questions, I don't know what caused it. I had a certain amount of stress, but think everybody probably has stress in their life and how they deal with it. I retired in 2018 which ended the work stress. Nutrition....Have always ate fairly healthy but suppose I could have done better. For 5 years now, I do take a multiple vitamin, plus C, D, Zinc and Omega-3. Just hoping those supplements might help me and my immune system a bit. No problems with swollen lymph nodes or itching. PET ( not for SMZL) a couple times and get a CT every 6 months
In wondering about what caused this and my other medical problems, (My situation is a bit more complicated because since my SMZL diagnosis, I've also had two lung cancers and two skin cancers. ) I consulted with the the Clinic's genetic department and reviewed family medical history and in 2023 had genetic testing for all known cancer genes. None were identified. So I do not have any answers. Everything outside of a sterile bubble, could be suspect.... in my opinion !

In another posting, there is a reference made about Epigenetics by mrgreentea and I found that to be interesting.