Environmental Health Perspectives
VoL 9, pp. 317-318, 1974
Commentary
Peritoneal Mesothelioma
by Jacob Churg*
The data that I want to present deals with
peritoneal mesothelioma or at least with tumors
that might be class.ified as peritoneal
mesothelioma. We have collected about 120
cases in this category. Cases of obvious car-
cinoma, such as mucous-cell carcinoma were
rejected, and all other cases that could possibly
be m'esothelioma were consldered. We have
studied in detail 82 of these cases. About half of
the material came from our Environmental
Science Laboratory where there
is great
predominance-about 90%-of people who have
asbestos exposure. The other half came from
other sources submitted to the Mesothelioma
Panel and there the rate of asbestos exposure
was about 50%. Histologically, 75% of tumors
were classified as epithelial type, 21% as
biphasic, and 4% as mesenchymal or sar-
comatous. However our certainty of diagnosis
was not of that order.
I am not going to go into the histologic
patterns of mesothelioma; they are of interest
mainly to pathologists. Some patterns are
acceptable to most pathologists as typical
mesothelioma, and we saw such patterns in 32
cases, about 1/3 of the cases. In a further 28
cases, the pattern was suggestive but not
typical, and in the remaining 22 cases it was
quite atypical and very often non-specific or
anaplastic. Because of that we had to divide our
cases into definite, probable, and possible. On
taking all available data into account, including
gross findings and histochemistry, about 1/4
turned out to be definite, about 1/2 were
*Mount Sinai School of Medicine, New York, New York
10029.
probable, and the remaining 1/4 were possible.
This includes all cases, autopsy and biopsy
material, and there is much more difficulty with
the biopsies. In the autopsy material (37
patients), we could classify 50% as definite, 33%
as probable, and 17% as possible. Even after the
autopsy, about half the cases could not definite-
ly be established as mesothelioma. I think this is
of imp