Stromal neoplasm

Hi everyone,  well today After a few weeks of tests on a lump on the right hand side of neck I've been diagnosed with stromal neoplasm. I'm told that this is a rare cancer that probably originated in my gut and has worked its way through my lymphatic system and has revealed itself in a tumor in my neck. Everyone at the hospital have been fantastic and I am booked in for an operation next week to remove my lymph node and then investigations will be carried out to find out where the cells came from, the extent of them in my system and from then the best approach to treatment. I was just wondering if anyone else has experienced this form of cancer as it appears that it is quite rare and there are no indications on its causes other than genetic? Many thanks1