Sunday, July 10, 2016
My thyroid nodule
Since I have a portable ultrasound, I looked at my thyroid nodule and found it to be about 1.8 cm, with some internal calcifications and a bright capsule. It was slightly darker than the surrounding thyroid tissue and had a few visible blood vessels.
I read about thyroid nodules and found that:
1. They are being noticed much more frequently because of increased use of CT scanning and ultrasound imaging.
2. They are very common. Nearly half of people will have significant, greater than 1 cm, thyroid nodules at autopsy.
3. About 5% of thyroid nodules are cancer, and cancer is more common in younger people, people with a family history of thyroid cancer, history of radiation to the head and neck, rapid growth of a nodule and larger nodules.
4. Experts generally recommend biopsy (taking a thin needle sample) of nodules over 1 cm in size.
5. Thyroid cancer is being overdiagnosed due to biopsies, because a needle can pick up a little bitty thyroid cancer which would never have been any problem over a person's life.
6. Some thyroid cancers will kill people. Most will not. It's hard to tell which will do what even after evaluating the tissue taken at a biopsy.
So I decided that if mine were a cancer which would cause trouble, it would almost certainly grow. I decided to follow it on ultrasound, measuring its size and watching what it looked like, and maybe get a biopsy if it grew.
It didn't seem to grow, at least not much. I was aware that it existed. I could feel it, though it didn't hurt. I was happy with my decision. Then I went to a talk about thyroid cancer at a major medical meeting. The speaker said that some thyroid cancers could grow very slowly over years and could still metastasize (spread to other areas.) Shucks. What if I got metastatic thyroid cancer? I could just imagine my family's displeasure. "It's a fool who has herself for a doctor." Also the expense, the plans forsaken. I decided to have it biopsied.
I went to a radiologist friend who said she had done many and assured me it would be painless. I scheduled it a week after my decision. I found that I needed a preoperative physical exam, which was a problem because I didn't have a doctor and hesitated to fill out my own paperwork because I figured I couldn't get away with it. So I had a physical exam which wasn't bad at all. I shuttled the paper copy to the radiology department. They still lost it, but eventually found it, and all was as it should be.
The radiology department is very familiar to me. I knew the smell and sound and paint color of the room in which I donned my hospital gown. The radiology technician gooped my neck with ultrasound gel and took about a million pictures of my nodule, measuring its length, width, height, observing its color doppler signal, looking for other nodules that might have hidden from my examining hand. My radiologist friend came in. We discussed things we agreed upon. We argued about the utility of mammography. That was probably not a good move, since she would then stick my neck with a variety of needles.
She numbed the left side of my neck with a lidocaine injection. I asked her if she knew that the nodule was on the opposite side and she reassured me that she hadn't been born yesterday and had performed this procedure before and knew exactly where my nodule was. She introduced a long needle from the wrong side of my neck into the nodule on the other side so as to avoid poking my carotid artery which was really quite close to my nodule. The bright shiny capsule turned out to be incredibly tough, requiring rather vigorous stabbing to get a sample. She then informed me that she recommended we do a core biopsy as well, since the pathologist appreciated a larger piece for evaluation. This was done through a type of coaxial cable. The core was taken with a gun which made a disconcerting thump as it removed tiny pieces of my thyroid. She showed me the little bottles with chunks of tissue it them. The hardware came out of my neck. Blood was mopped up.
It didn't hurt very much. Maybe a little like being strangled without the can't breathe part. Maybe not that bad, since I've never actually been strangled and wouldn't know. There isn't much numbing, just at the place where the needle goes into the skin because the thyroid itself has only dull pressure sensation. Swallowing is rather sore for a few days, however, because the thyroid moves up and down with every swallow.
Weeks later the bills began to arrive. I have medical insurance these days, through the hospital where I work. The total charges were $2,361. About half of this was for the ultrasound, about $300 was for the pathologist to read the slides. Another approximately $300 was to the radiologist, with free update on the utility of 3-D mammography and $500 was for supplies such as needles and coaxial cable. "Adjustments" due to using the hospital, which provides the insurance, for the whole procedure reduced the cost by a bit over $1000. So insurance paid $820 and I paid about $500.
The results came back "non-diagnostic." There was not enough thyroid tissue to be sure it's not cancer. Up to 20% of thyroid biopsies are non-diagnostic.
My initial reaction was that I was looking for cancer cells and they didn't find cancer cells and so I'm fine. It turns out that this is about right. There is a study from 2014 in which patients with non-diagnostic results on fine needle aspirate had a repeat biopsy (which I would not do because ouch, in so many ways). These patients almost never had cancer diagnosed, and almost all of those who did have abnormal repeat biopsies turned out to have false positive results. This means that they had a significant surgery removing a part of the thyroid and there was no cancer.
What I learned from my thyroid biopsy:
1. They are very expensive and the cost to even a well insured consumer is not small.
2. A thyroid biopsy is not painless. It is also not horribly painful. I do not want another one.
In the big picture, there is not a lot of value in routinely evaluating thyroid nodules with biopsy. There are 240 million adults in the US. About half of them probably have thyroid nodules greater than 1 cm. Performing an uncomplicated biopsy on all of them would cost about 240 billion dollars, assuming no repeat biopsies, diagnosing 6 million of them with cancer. Thyroidectomy and further treatment and followup of these diagnosed patients could easily cost that much again, adding up to nearly half of the US's yearly healthcare spending. A not insignificant number of people would suffer damage to their recurrent laryngeal nerve, limiting their ability to speak and sing, or lose the function of their parathyroid glands which regulate calcium balance. Of the cancers discovered, quite a few (hard to know the number) would never cause harm if untreated. Only about 1900 people die of thyroid cancer each year in the US and some of these are due to very aggressive cancers that will be fatal regardless of when or whether surgery is done. Despite an increase in detection and surgery for thyroid cancer in the last decade, there has been no change in death rates for this disease.
In the smaller picture, specifically the picture of an individual person with a lump in the thyroid, it is difficult to know what to do. Thyroid cancers can metastasize and kill a person. They just don't do that very often. Reassurance is valuable. Being diagnosed with cancer that would have caused no harm could be devastating. Being diagnosed early and avoiding death is priceless but extremely unlikely. As a doctor my practical approach should probably be to avoid searching for thyroid lumps in patients with no symptoms and to try to help those patients whose lumps come to light navigate the dangerous waters of further medical evaluation.