The Thymus is a Largely Forgotten Organ
(…at least in primary care…)
The other day I thought of the thymus for the third time in my life. And I’ve been a doctor since 1979 - it just doesn’t come up much!
Some time during my last year of high school in Sweden (I got no credit for my year as an exchange student in Massachusetts, except I was allowed to take my finals in English, as long as I faked a British accent) I had a meal by myself in a modest home cooking sort of restaurant. I had no idea what kalvbräss was, but since I had had delicious wiener schnitzel (made from calve’s meat) in Switzerland many times, I naively thought it was something like that. Well, it wasn’t. It was a pale, soft, almost soggy piece of meat with very bland flavor. There was obviously no Google in those days, so it took me a while to figure out what I had tasted and left largely uneaten.
Kalvbräss is the Swedish word for the thymus. Just about every organ and disease has its own, folksy, name in Sweden. Just one example is the pancreas, which we call bukspottkörteln - the belly spit gland.
Nobody in my family ate thymus. I have lately bothered to figure out, in seconds thanks to google on my iPhone, that the American word for this is sweetbread - neither sweet nor bread!
My second run-in with the thymus was in medical school at Uppsala university in Sweden. During my histology semester, I became involved in diabetes research on athymic mice from the Jackson Laboratory in Bar Harbor, Maine. These rodents are immune compromised, because they don’t have this important part of the normal immune system, and we were hoping to ultimately help making pancreas transplants possible. That project earned me my one and only citation in Index Medicus.
https://link.springer.com/article/10.1007/BF00220518
My Uppsala thymus experience became one of the reasons I ended up living in the beautiful state of Maine, and for a while even coastal Maine, across Mount Desert Narrows from the island where Jackson Lab is located. And, before that, I actually interviewed for the position of company doctor for Jax, as it is called. The position was under the auspices of St Joseph Hospital in Bangor. They said they’d love to have me but couldn’t afford to pay anywhere near what I was used to making.
More than a dozen years later, I have now had reason to think about the thymus again. I have a patient with new onset of cough, worse lying down, unresponsive to steroids and inhalers and with an unremarkable chest X-ray. And, this person has no eosinophils in their blood count. Dr. Google tells me that having zero eosinophil white blood cells can be an indicator of thymoma, a tumor of the thymus. Thymoma can make a person cough. So now I’m only waiting….you guessed it, for the insurance authorization to get a CT scan!