Hi, I am not too familiary with para conditions but the word adenoma is overgrowth of thyroid tissue I do believe and is benign as my nodules were when biopsied .. they were follicular adeonomas. I am not sure about the other term -- hyperplasia ... maybe some others will jump in. The parathyroid issue may be resp. for some of your results in the calcium dept on your bloodwork but I am NOT a Dr at all ..just a patient like you and really cannot be sure or diagnose ..
You can repost on Dr. Lupo's community, too.
http://www.medhelp.org/forums/Thyroid/show/120
The other nodules found in the thyroid are pretty small and probably unable to biopsy due to their size. They typically monitor small ones like that ev; 6mos - yr.
C~