Those counts do look like a good sign! I can see both sides of the coin - removing the thymoma now in the hopes that it won't spread and could help with recovering, and waiting until your husband has 50k platelets because it will limit platelet transfusions so that he hopefully won't develop antibodies to donated platelets (in case he needs them again later.) I think any tumor can cause faulty info to the immune system like you say or, on the flip side, having a tumor means there is a dysfunction in the immune system to begin with. This is going to sound completely goofy but my son has had two plantars warts for 3 years, prior to having AA. When he was on Acyclovir just after ATG for a week (for a virus), the warts started going away nicely, then they took him off of it they came back. Oddly while on acyclovir his red blood cell morphology showed up as normal on his CDC and reverted to abnormal when he went off of it. They are stubborn things, I've tried attacking them for the last year - we've used the salicylic acid pads, freezing them off, Vicks even (since my older's son wart went away with Vick's). It sounds completely silly but what are warts? They're benign tumors. And what do tumors do? They hijack your red blood cells through angiogenisis to feed blood into the tumor, and also highjack platelets and mononuclear lymphocytes and cause them to aggregate around the tumor to keep it alive. The main reason I'm typing all this is to explain that I've read alot about it recently and found this fascinating article among many: "Platelets: Guardians of Tumor Vasculature:
http://cancerres.aacrjournals.org/co...9/14/5623.long. An interesting line I caught in it was, "Clinical and experimental evidence indicates that platelets play a role in the spread of cancer. Both thrombocytopenia and antiplatelet treatments reduce the number of experimental metastases." Which makes me wonder if AA is the body reacting (in a highly over-reactive way) to what it sees as a cancer or tumor, in an effort to shut down the process that is feeding it. So, enough with the philosophizing :-p, but I do think your hypothesis about the tumor causing faulty info to the immune system is correct, and that there's good reason to believe that removing the thymoma will help. However, your husbands results to ATG look very encouraging so far, so waiting for 50k platelets looks like it is in the realm of close possibility!
BTW my son hit 34k platelets about 8 weeks out from ATG It took him a few months more to go over 50K. We're 1 yr and 4 mo out and he is hovering around 100k platelets (he hit 140k once but they went back down).