Have you tried supplemental iodine? From my understanding, hyperparathyroidism can be caused by iodine deficiency. For help with that, I suggest going to the Iodine Supplementation forum.
If there is a tumor present, the combination of oleander extract, Budwig's flaxseed/cottage cheese (small curd cottage cheese or quark, if available) and Essiac tea has been a good one. I like Pau d'arco a lot too.
If you determine that there is definitely a tumor present and it is or is suspected to be cancerous, then I suggest looking at:
A Natural Anti-Cancer Protocol
and also suggest looking at using a topical cream made of concentrated oleander, concentrated colloidal silver and a bit of DMSO. See:
The Recipe for Oleander Soup Part 1
The Recipe for Oleander Soup Part 2 - Tips and Advice
Inositol/IP6 has proven very effective against many tumors and it may also help chelate out some of the excess calcium.