Thanks for asking! There are a couple of aspects to your question.

First, how common is it to have recurrent parathyroid disease? It’s hard to get firm numbers on exactly how many people end up having more than one parathyroid operation, because patients often follow up with different providers, and a recurrence can take many years to present (like in your situation). So I can’t give an exact number or percentage, but I can say your situation is fairly uncommon, but not rare.

There are a few reasons why someone might need a second parathyroid operation:

1. They had multiple parathyroid tumors or even hyperplasia (enlargement of all four parathyroids), but only one was removed during the first operation. In this case, the patient will not be cured after the first operation, so labs will still indicate primary hyperparathyroidism (high calcium and inappropriate PTH levels). This scenario usually occurs because the surgeon only went after the parathyroid tumor seen on a scan, and did not examine the remaining parathyroid glands. Scans for parathyroid disease are often misleading, and will only show one parathyroid tumor (or none) even if there are multiple tumors. The risk of this happening is greatly reduced if your surgeon looks at all four parathyroid glands during the operation.

2. There was just one parathyroid adenoma, but it was not completely removed during the operation. When you take out a parathyroid tumor, you have to remove the entire parathyroid gland. The tumor essentially obliterates the normal gland, so you can’t leave any part of the gland behind or you risk the tumor growing back. Sometimes, part of the tumor may be in a difficult location, and the surgeon may inadvertently leave behind a small piece of the tumor. If the piece left is large, then the person will not be cured and labs will still show primary hyperparathyroidism. If the piece is tiny, the patient will be cured… temporarily. It can take years, but eventually the little piece remaining will grow larger and become a problem again.

3. A second parathyroid tumor developed years after surgery. This is less common than the above scenarios, but it does happen. In this case, the patient may have had just one parathyroid adenoma and three normal parathyroid glands during their first operation. And then later one of those normal glands grew a tumor. You can also see cases of hyperplasia that present like this. In hyperplasia, all four glands are diseased. But they do not become enlarged and abnormal at the same time. You could have one gland that looks like a tumor and three glands that look normal. Over time, the others will develop disease as well, but this can take years.

If your first parathyroid operation was successful, and you had normal calcium and PTH levels until recently, then the most likely scenario is the third one.

Most doctors should be aware that parathyroid disease can reoccur. That doesn’t mean that they are all looking out for it or will diagnose it when it happens.

When you have your second parathyroid operation, it is important to have an experienced surgeon doing it, since reoperations can be more challenging than first-time operations.