Immunohistochemistry of mesothelioma mesothelioma

could resemble lung carcinoma, particularly adenocarcinoma.
whereas in a few cases, the clinical, radiographic,
and histologic features purpose to the correct diagnosis, in
several cases, mesothelioma can not be distinguished from
carcinoma on purely morphological grounds. the foremost
common diagnostic problem during this regard is distinguishing
mesothelioma from epithelial tumors, particularly
adenocarcinoma. many studies testing massive numbers of
cases with panels of antibodies against candidate markers
to distinguish mesothelioma from carcinoma are reported.
during a study by ordonez, 373 nineteen candidate immunohistochemical
biomarkers were evaluated on a collection of 110
lung tumors together with sixty mesotheliomas and 50 adenocarcinomas.
antibodies that proved most sensitive in identifying
mesothelioma were those against calretinin (100%
sensitivity, 92% specificity), ck5/6 (100% sensitivity, 98%
specificity), and wt1 (93% sensitivity, 100% specificity).
antibodies most correct for identifying adenocarcinoma
were ttf-1 (74% sensitivity, 100% specificity), tag72
(88% sensitivity, 100% specificity), cea (88% sensitivity,
100% specificity), and cd15 (72% sensitivity, 100%
specificity). another candidate marker recently added to
this list is podoplanin, that is recognized by monoclonal
antibody d2-40. 374 this marker has nearly 90% sensitivity
for epithelioid mesothelioma 375–377 however has low sensitivity
for sarcomatoid mesothelioma and cross-reacts with metastatic
65% of serous carcinomas 375 and approximately 15%
of squamous carcinomas. 378
so, a substantial list of antibodies is currently out there with
reasonable sensitivity and specificity for distinguishing mesothelioma
from alternative tumors in tissue sections (table 22. 3).
it's probably that no single panel can distinguish all mesotheliomas
and alittle range of poorly differentiated tumors
can not be identifiable through ihc. optimal panels for distinguishing
mesothelioma from adenocarcinoma are
advised 379–381 and most embrace a limited range of antibodies.
that antibodies are employed within these panels will
ultimately depend not just on sensitivity and specificity but
too on clinical context and native resources out there for addressing
this problem also.
electron microscopy will too be helpful within the diagnosis
of mesothelioma. by electron microscopy, tumor cells have
microvilli, that are longer and thinner than those seen in
adenocarcinomas, and also the length/diameter ratio will be used to
favor one tumor versus the opposite. of note, electron microscopy
is less useful in poorly differentiated epithelial tumors and that in
sarcomatous tumors