F. Lonardo et al., MICROADENOCARCINOMA OF THE PANCREAS - MORPHOLOGIC PATTERN OR PATHOLOGICAL ENTITY - A REEVALUATION OF THE ORIGINAL SERIES, The American journal of surgical pathology, 20(11), 1996, pp. 1385-1393
The term microadenocarcinoma was first proposed for a sub-type of panc
reatic carcinoma by Cubilla and Fitzgerald in 1975 based largely on th
e morphological features of 15 cases. Since that time, no independent
studies have appeared in the English literature to address whether mic
roadenocarcinoma represents a distinctive tumor or a pattern of growth
, and some authors have questioned its existence as a definable entity
. Immunohistochemistry is now available to allow the identification of
lines of differentiation in pancreatic neoplasms, on which their clas
sification is largely based. Reasoning that heterogeneity of different
iation between different cases would not justify the separation of mic
roadenocarcinomas from other better defined pancreatic neoplasms, we r
eevaluated 12 cases from the original series using antibodies for acin
ar, endocrine, and ductal differentiation. Two distinctive morphologic
al patterns were identified: microglandular and solid cribriform. The
microglandular cases (n = 6) were not separable from typical ductal ad
enocarcinomas either morphologically or immunophenotypically. Of the s
olid-cribriform cases (n = 6), immunohistochemistry revealed three to
be acinar cell carcinomas, one an endocrine carcinoma, one a mixed end
ocrine-ductal carcinoma, and one a ductal adenocarcinoma. We concluded
that with the benefit of further study, most of these cases could be
reclassified as other types of pancreatic carcinoma. Microadenocarcino
ma is best regarded as a pattern of growth associated with an aggressi
ve clinical course rather than a distinctive entity.