<s>[INST] I am 25 year old female. I recently got done with chemotherapy and radiation treatments for hodgkins lymphoma located in my neck. I have what appears to be a blood blister in between my inner thigh and groin. Ever since cancer, I am now on the very cautious side of everything. What could it be? [/INST] Hi, dear. I have gone through your question. I can understand your concern. You may have low platelet count which leads to blister.  Or some other cause.  You should go for complete blood count and coagulation profile.  Then you should take treatment accordingly. Hope I have answered your question, if you have doubt then I will be happy to answer. Thanks for using Chat Doctor. Wish you a very good health. </s>