Is elevated pth but normal calcium most likely a parathyroid tumor?

That's 1 possibility: Besides a parathyroid tumor, it could also be due to low vitamin d levels, or kidney failure.

No, something else.: A parathyroid tumor (adenoma) would have elevated PTH with an elevated calcium level (known as primary hyperparathyroidism). When the PTH level is high but the calcium level is normal, it is referred to as secondary hyperparathyroidism. Causes for secondary include kidney disease, vitamin d deficiency, and a few other much rarer conditions. It can also occur naturally in some african americans.

Not necessarily: Your doctor will likely investigate your vitamin d levels relative to pth, calcium, magnesium, and phosphorus. Elevations in PTH could be the result of vitamin d deficiency also, as well as other things. You may need to see an endocrinologist or possibly even a nephrologist. Please discuss this with your primary care provider to plan a course of action.

Depends on calcium: If the calcium is elevated or high normal and PTH is significantly elevated, primary hyperparathyroidism is most likely cause and would most likely be treated with surgery. If the calcium is low the most likely cause is vitamin d deficiency.