1. Dissection of the parathyroid glands post mortem is
greatly facilitated by the recognition of their opacity
to transmitted light. The location of these glands
before or at operation is being attempted by the use of
radio -isotopes. On the principle that all radiation is
harmful, it is suggested that the possibility of
employing transillumination be investigated. It should
be possible to illuminate them with an intra-oesophageal
light source, either primary or secondary, suitably
collimated and cooled.
2. A proper appreciation of their cytology requires thi
sections; these may be attained by simple variation of
standard methods.
3. A staining method has been evolved for the ready
identification of the oxyphil cells. It is reasonably
reliable on necropsy material, even if somewhat demanding
technically. Its evolution was guided by histochemical
theory and in practice it fulfils the criteria of
maximum tinctorial density and considerable selectivity
on thin sections. Its colour also lies in the region of
the spectrum to which the eye is most sensitive, a highly
desirable feature in a stain to' be used for the study of
cytological granules for prolonged periods.
4. The previously reported great variation in the total
weights of the glands is confirmed; there is also a great
variation in area as between the glands of an individual.
5. On the evidence of the overlap of v ghts and numbers
of glands, it is suggested that on occasion one may
accept fewer than the conventional 3 or 14 glands as the
normal number. On a number of occasions two glands will
be as large as a set of four nearby.
6. Adipose tissue may be present or absent in any decade.
7. Glands devoid of fat are commoner in the first decade
than subsequently.
8. The commonest level of adipose tissue in a gland is
below 10%.
Assuming that anything above this should be regarded
as a fatty gland, such cases were reviewed regarding their
nutritional status as recorded on the necropsy report.
There is only a slight correlation with bodily obesity,
almost half being from the normally nourished. A number
were from the emaciated.
9. The distribution of fatty glands within Table
is not systematic enough to be able to say more from it
than that large glands tend to contain more fat. A
diposity does not equate with atrophy under normal
c ircumtances.
10. The average gland contains relatively little fat
but individuals may show great variation between their
glands. The assessment of atrophy on the evidence of
such estimations must be difficult in the extreme.
11. The greatest amounts of fat lie in the 50 - 70%
range and may occur at any point along the table of:mean
parenchyma volumes.
12. Oxyphil cells are probably always present.
13. The oxyphil cell counts show, tentatively, the same
type of distribution as has been reported by others, i.e
up to a normal level of some 8% in the female and 5% in
the male in the 9th. decade.
14. These figures are rather lower perhaps because of
my separate treatment of the oxyphil cell islets. These
rarely amount to more than a few percent of the parench
area and although large areas do tend to occur against
the background of a high oxyphil cell count this is by
no means invariable.
15. Inspection of the post mortem diagnoses of those
showing either high counts, islets or both was quite
unrewarding. My own material tended to associate them
with senile dementia or intracranial aneurysms while
from general hospital practice the association was more
with atherosclerosis, hypertension and myocardial
infarction; these "associations" are purely a reflection
of the types of work done in different hospitals. The
suggested correlation of oxyphil cell population with the
latter group of conditions is, I believe, spurious; it
would certainly require a very rigorous investigation to
confirm its validity.
16. No general correlation between oxyphil counts and
obesity can be demonstrated.
17. No light is cast upon the problem of the oxyphils
by this study. An insignificant fraction of a tiny organ
we know nothing of the total amount of "oncocytes"
present in an individual's other organs; it may be that
these cells form a system of unknown function.
18. Enlightenment may perhaps come from repetition of
the work demonstrating their hyperplasia following the
administration of thiourea.
