Diagnostic Criteria
Following an initial duodenal slide review, it was determined
that potential treatment-related non-neoplastic findings in
the duodenum of mice and rats were limited to the following
5 histopathologic diagnoses: (1) villus, histiocytic cellular infiltrates;
(2) villus, atrophy/blunting; (3) villus, enterocyte vacuolation;
(4) villus, single-cell necrosis; and (5) crypt, epithelial
hyperplasia. With rare exceptions, such findings were not present
in control animals, and the prevalence and/or severity of
these findings often increased in a dose-responsive manner in
SDD-treated animals.
Histiocytic infiltration occurred primarily in the lamina propria
of the villus tips and was characterized by small nodular
aggregations of histiocytic macrophages with abundant, faintly