Objective—To determine prevalence of pituitary
tumors, detectable by means of computed tomography
or magnetic resonance imaging, in cats with
insulin resistance suspected to have acromegaly or
hyperadrenocorticism versus cats with well-controlled
Animals—16 cats with insulin resistance that were
also suspected to have acromegaly (n = 12) or pituitary-dependent hyperadrenocorticism (4) and 8 cats
with well-controlled diabetes mellitus.
Procedure—Computed tomography was performed
on all 16 cats with insulin resistance and 2 cats in
which diabetes mellitus was well-controlled. The
remaining 6 cats in which diabetes mellitus was wellcontrolled
underwent magnetic resonance imaging.
Images were obtained before and immediately after
IV administration of contrast medium.
Results—Computed tomography revealed a mass in
the region of the pituitary gland in all 16 cats with
insulin resistance. Maximum width of the masses
ranged from 4.4 to 12.7 mm; maximum height ranged
from 3.1 to 12.6 mm. Results of computed tomography
performed on 2 cats with well-controlled diabetes
and magnetic resonance imaging performed on the
remaining 6 cats were considered normal.
Conclusions and Clinical Relevance—Results suggest
that cats with insulin resistance suspected to
have acromegaly or pituitary-dependent hyperadrenocorticism
are likely to have a pituitary mass detectable
by means of computed tomography or magnetic resonance
imaging. (J Am Vet Med Assoc 2000;216: