Prevalence of pituitary tumors among diabetic cats with insulin resistance

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 diabetes mellitus. Design-Case series. Animals-16 cats with insulin resistance that were also suspected to have ac romegaly (n = 12) or pituitary-dependent hyperadrenocorticism (4) and 8 cat s with well-controlled diabetes mellitus. Procedure-Computed tomography was performed on all 16 cats with insulin res istance and 2 cats in which diabetes mellitus was well-controlled. The rema ining 6 cats in which diabetes mellitus was well-controlled underwent magne tic 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 r anged from 4.4 to 12.7 mm; maximum height ranged from 3.1 to 12.6 mm. Resul ts of computed tomography performed on 2 cats with well-controlled diabetes and magnetic resonance imaging performed on the remaining 6 cats were cons idered normal. Conclusions and Clinical Relevance-Results suggest that cars with insulin r esistance suspected to have acromegaly or pituitary-dependent hyperadrenoco rticism are likely to have a pituitary mass detectable by means of computed tomography or magnetic resonance imaging.