Hello and Welcome to ‘Ask A Doctor’ service. I have reviewed your query and here is my advice. I have read your question and understand your concerns. Colloid cysts may result in recurrence often because of the limited possibility of complete removal. These cysts usually don t cause weight gain, only in rare cases when are located near structures such hypothalamus. I think the stress that is causing the presence of the cyst is more likely responsible for the weight gain.I think you should not be worried more than necessary because colloidal cysts are successfully treatable. Hope I have answered your query. Let me know if I can assist you further.