You may find this case report interesting concerning a case of Hamburger Thyrotoxicosis.
The woman in question had recurring episodes of hyperthyroidism.
A 61-year-old woman with a history of
recurrent episodes of transient
thyrotoxicosis presented in November
2001 with a 3-week history of weight
loss of 4 kg, palpitations and
increased sweating. She had mild
tachycardia (112 beats/minute) and
fine tremor of the hands. She had no
thyroid enlargement, thyroid bruits,
eye signs or pretibial myxedema. A
clinical diagnosis of hyperthyroidism
was confirmed by elevated free
thyroxine (T4) (46 [normally 9 to 23]
pmol/L) and suppressed
thyroid-stimulating hormone (TSH)
(0.02 [normally 0.35 to 5.0] μIU/L).
Her symptoms resolved spontaneously
and her free T4 returned to normal (12
pmol/L) within 8 weeks.
The probable cause was identified as their raising their own livestock and having it butchered locally.
Further questioning into the patient's
dietary history revealed that she
lived on a farm with her husband and
that every couple of years they
slaughtered a cow from their herd,
which was their main source of meat.
Inquiries to the couple's local
butcher revealed that he was unaware
of the prohibition against gullet
trimming (a procedure whereby muscles
from the bovine larynx are harvested)
and had inadvertently been
contaminating edible meat with thyroid
tissue. He used meat from the neck of
the patient's cows to make patties,
which were usually consumed by the
patient within a couple of months of
butchering. Her husband, who was not
affected by any thyroid problems, did
not consume these patties, preferring
other cuts of meat.
Apparently this is not an unknown cause of temporary hyperthyroidism and is the reason thyroid glands are kept out of the food supply.
Community-wide outbreaks of
thyrotoxicosis caused by the
consumption of bovine thyroid gland in
ground beef in Minnesota, South Dakota
and Iowa10,11 in 1984 and 1985
resulted in the prohibition of gullet
trimming in all plants that slaughter
cattle and pigs. This case emphasizes
that sporadic cases of recurrent
thyrotoxicosis caused by consumption
of thyroid-contaminated beef may still
occur and may be diagnosed as silent
thyroiditis. For patients with
features suggestive of silent
thyroiditis, health care providers
should consider this cause of
hyperthyroidism, especially for anyone
who may be slaughtering farm animals
for their own use and for hunters who
may be gullet trimming game.
Eating more than tiny amounts of thyroid gland may not be a good idea.