Hi @akita - I'm very sorry you're dealing with such a difficult and worrying situation. Sometimes doctors aren't the best at explaining what they are doing. If they told you it's a rare adenocarcinoma, that means they genetically sequenced the biopsy samples to check what specific type of cancer it is. They do this to best match the treatment options. You can ask to see those results (they usually send the samples to a special lab for this analysis - and that lab will provide a report.) My advice would be to talk to an oncologist at a NCI designated cancer center in your area, if that is possible. (I have a rare adenocarcinoma myself.) I hope you have a friend or family member that can help support you through all of this.
https://www.cancer.gov/research/infrastructure/cancer-centers/find