Q. Are there side effects from the biopsy which involves a full general anaesthetic?
My answer: If they only take the SN and a couple of close nodes, there will most likely be some discomfort and reduced mobility while the wound heals. There may be some mild but quite managable lymphodema afterwards.
Q. If something is positive then I believe they take out all the lymph glands.
My answer: Maybe, depending on what they find (how many, macro or micro invasion..) but they will most like take out more as the goal is to remove the cancer with “clean margins” and that includes the lymph nodes.
Q. That procedure can be quite debilitating cant it? ie quality of life is compromised with no guarantee of prolonged survival?
My answer: Yes, it can be if extensive lymphodema develops afterwards. If you are fit, especially if you work out now, it tends to be less severe. But it is usually manageable though you will have to respect your limitations. There are no guarantees but consider this: If nothing is found, EXCELLENT, the surgery is relatively minor and you’re basically done but in the watch and monitor mode with regular visits to the derm. If they do find something, the cancer will be removed again. It’s always best to remove the cancer if you can. The data I’ve seen clearly says resection of the known cancer always improves survival. If you decide to do nothing and, in fact, there is cancer in the lymph nodes, you can almost bet, in time, it will spread.
Q. Lastly with very large or thick nodular melanomas from what I read there is not a lot of statistical advantage in the procedure?
My answer: I’m unaware of this, but proper staging is very important from treatment and insurance points of view.
Could you please post your pathology report results? There are many experts here who can help you make sense of it. Also, do not be shy about getting more medical opinions and finding a derm and/or clinic that specializes in melanoma.
Another thing to consider. The goal is to never, ever, get to stage IV. You ALWAYS have to stay ahead of this disease. That does not mean life stops and focuses on this disease but here an ounce of prevention is worth a ton of cure.
IMO, you would be very wise to proceed with the SNB.