"Migrating tissue," or Another Possibly Gross Thread

So, I went to my doctor because of pain under my jaw that was getting worse. After diagnosing it as “something infected” and putting me on antibiotics and anti-inflammatories, with orders to have another doctor’s appointment plus a dentist appointment in a week, we sat back to chat. He listed some of the less likely, though infinitely more interesting, causes of the pain. These included dental abscess, bronchial cleft cyst, and migrated thyroid tissue.

Pause the playback. Migrated thyroid tissue? What on earth is that? What on earth would cause it? I have autoimmune thyroiditis… could it be so bad that chunks of my thyroid fall off? Can all tissues “migrate”? Do they do it seasonally? Do they leave trails that can be counted like the rings of a tree? Help! None of this is in the Merck Manual!

Giving this my one allowed bump. My but I do have a knack for asking questions that go unanswered…

This is one of those bodily phenomena that are really weird. There is apparently a theory on the possible cause of endometriosis (when the uterus’ lining migrates and grows on other organs, like the ovary, intestines or bladder), that the tissue migrates through the fallopian tubes. So maybe several types of body tissue have a habit of “migrating”, particularly those tissues that are implicated in autoimmune disease. IANAD so don’t quote me on this!

Apparently the thyroid migrates through the neck during gestation, and can leave bits of itself behind in odd places.
This search might help get you started: thyroid migration. Also look up ectopic thyroid.
Not being an embryologist or an endocrinologist, I’d probably screw things up if I said much more.

While doing Squink’s search for “ectopic thyroid,” I came across this painting by Sir Frederic Leighton, the guy who did Flaming June. It is of a woman with a marked goiter:

http://www.metmuseum.org/Works_Of_Art/viewOnezoom.asp?dep=11&zoomFlag=0&viewmode=1&item=87.15.79

Shall she be our mascot?

All of the developmental stuff about the thyroid is enormously interesting. I wonder how likely one is to know if one has thyroid tissue where it shouldn’t be?

The thyroid starts life (in the foetus) up at the base of the tongue, and during development moves down the neck to where it’s generally found. Sometimes it doesn’t quite get there, and a bit is left higher up the neck.

Similar to the way testicles are formed in the abdomen and move down through the inguinal canal to the scrotum, only sometimes they don’t and thus you have undescended testicles.

It’s not that your thyroid suddenly takes a fancy to wander around the place!