Intrapancreatic ectopic splenic tissue in dogs and cats.

Ectopic splenic tissue in the pancreas is a rare incidental finding in man that is often mistaken for pancreatic neoplasia. This condition is documented rarely in animals. This report describes the clinical and pathological features of four cases of intrapancreatic accessory spleens in dogs and cats. This is the first description of this lesion in the dog. The lesions comprised firm, well-demarcated, dark red, spherical masses that were composed microscopically of normal splenic tissue. The possible origin, differential diagnoses and potential practical significance of these lesions are discussed.