A case of splenic myelolipoma in a German Shepherd dog

An older neutered female German Shepherd dog was referred to our Department for necropsic evaluation after euthanasia for chronic renal insufficiency. Apart from chronic renal lesions and gastrointestinal ulcerations, the macroscopic examination showed multiple off-white multifocal splenic nodules. Histologic examination revealed multiple, well-demarcated, unencapsulated masses of hematopoietic elements admixed with mature adipose tissue, consistent with a diagnosis of myelolipoma. This benign tumor is rarely reported in dogs in the literature and is more often observed in the form of a single encapsulated nodule. The other possible sites where these tumors can be seen are adrenal glands and organs retaining hematopoietic activity. Although several hypotheses have been proposed, the exact origin of myelolipoma still remain unknown