The contribution of the Study of the Marsnz”"sse in our Laforatory
The Marsha*lese materials are of great importance to the study
er this contrac?
The fresh tissue when removed here by us is studied sremptly by meth@ds in use under
this contract.
Although most of the neoplasms found in the Marshallfse have been
benign, it is important to note that a total of 6 carcinomas have begén
of these had metastasized tc the regional cervical 1j;=>h nodes.
found.
Two
Thefradiated Marshals.
thyreids ofter. ave many minute solid cellular or mixe< papillary
ang follicular lesic?:
in addition to = much larger lesion which had drawn srimary attentioh. Many of the
tiny lesions are occupying an area no larger than a icren normal follicles just as is
seen in the raccated rat thyreids.
At the time of the last annual report we descrite= a 21 year olf Marshallese who
we had Just operated for mitiple benign adenomas.
mother was exposed to fallout.
= was 6 months fin
utero when his
The special studies c= that thyroid Fissue showed the
bizarre nuclear forms recognized as evidence of radciezion effect.
the time of
preparation of this report, we have just operated arn< removed several benign but
atypical adencras from the thyroid of his mother wnc =ad developed masses in the last
year.
The facter of long delay in the development of =eoplasms is
animals and me...
Our experience has shown that the rets do not deve
Dhasized in both
they are radiated when very young and 1/2 to 2/3 of <he life span ps
Marshallese lesion did not develop for 9 years. Mar; of the early Jesions~came from
the atoll with the highest fallout (Rongelap).
It was quite some
lesions began appearing in people who were on the nex= nearest ato
the dose had been somewhat less. While lesions were appearing on
ydars later that
no lesions, buc in the most recent years, 8 individueis have been ope ated and 3 car
cinomas found.
These observations seem to emphasize =he risk of th
low dose range.
Further support for the concern for the low dose and long latest period is illustrated by the very considerable number of individuais coming to megical attention
for neoplasms of the thyroid after irradiation to tie head and neck}
Relatively small
doses to shrinx lymphoid tissue and even smaller doses for acne seem implicated in our
experience amé that of others. We are screening a very considerable number of persons
referred because” of such known exposure.
The Part Played by TSH in Neoplasm Formatic. Following131y Radiation
Although each rat experiment has required almos= 2 ers laps
succeeded in cStaining neoplasms in rat thyroids usinz
_ frequency.
1t alane
The yields have become (60%) sufficient. good so that
be used to test inhibiting and stimulating effects =. the inductiar
lesions.
time, we have
With increasing
[the model may now
and growth of sucr
For. many years thyroid stimilating hormone (iS&5 has theorectjcally been implicated in the cevelopment of thyroid tumers. First =. the chronic dpplication of an
iodine deficient diet; then ry the chronic use of gexicrogenic subs#ances and finally
in recent years by radioiodine. Simply stated, the Lack of iodine[to make hormone,
the block of the synthesis of hormone or the damage => the cell
mechanism for hormone producticn may lead to a deficiency of thyroi¢ normone and a
gompensatory increas: