Cytologic examination of exfoliative specimens obtained during endoscopy for diagnosis of gastrointestinal tract disease in dogs and cats

Abstract

Objective - To determine whether cytologic examination of exfoliative specimens obtained during endoscopy was as useful as histologic examination of mucosal biopsy specimens for the diagnosis of gastrointestinal tract disease in dogs and cats and to compare the diagnostic accuracy of 2 techniques (brush or touch) in preparing specimens for cytologic examination. Design - Prospective case series. Animals - 85 dogs and 23 cats. Procedure - Specimens for cytologic and histologic examination were obtained during routine endoscopic examination of the stomach, small intestine, and colon. A diagnosis was made on the basis of cytologic findings (graded objectively) and compared with the diagnosis on the basis of histologic findings. Results - The diagnostic accuracy of cytologic examination was high for all 3 organs. Sensitivities, specificities, and predictive values of positive and negative results were > 90% in most instances. The diagnostic accuracy of the brush technique was equal or superior to that of the touch technique for 84% of specimens. The brush technique was most useful in detecting cellular infiltrates in the lamina propria, whereas the touch technique was more likely to detect acute mucosal inflammation. Percentages of false-positive (3.2%) and false-negative (6.9%) cytologic interpretations were low. Clinical Implications - Endoscopy is safe and requires little time to procure specimens for cytologic examination, which can be obtained concurrently with mucosal biopsy specimens. Cytologic examination of exfoliative specimens obtained during endoscopy is a useful and reliable adjunct to histologic examination of biopsy specimens in the diagnosis of gastrointestinal tract disease in dogs and cats.