CYTOLOGIC EVALUATIONS OF CANINE INTESTINAL LYMPHOMA VIA ENDOSCOPIC BIOPSY

Among the intestinal tumours of hematopoietic origin, lymphoma is the most common in the dog The multicentric lymphoma is more common than the intestinal form, while the .alimentary lymphoma usually accounts for 7% of all canine lymphomas and 5-7% of all gastrointestinal neoplasms. Recent studies have shown that canine intestinal lymphomas are to great extent of T-cell origin. Affected dogs most often present with a recent history of non-specific signs, like vomiting, diarrhea, anorexia and lethargy. The dogs involved are most commonly adult or old subjects, with an average age of 6,7 years. The most commonly involved breeds are Boxer, Shar-Pei and Golden Retriever. In light of the clinical and symptomatic overlap between IBD and enteropathy-type lym-phoma, patients are often submitted to endoscopic examination. The endoscopic examination of the small bowel in the lymphoma group showed an aspect referred by gastroenterologists as “clobbedstone appearance” of the intestinal mucosa: the submucosal edema and the ulcerative disease with crisscrossing of the ulcers creates a pattern characterised by multiple, similarly-sized rounded densities that rise above a flattened plane, which has been likened to roads paved by multiple similarly-sized 'cobbled' stones. In dogs with this endoscopic aspect, the cytological examination alone has shown in our study a good diagnostic accuracy in the differential diagnosis between lymphoma and IBD. In fact, we argue that a cytological examination of squash-prep samples is a valuable method for the detection of a infiltrating enter-opahy. In our study, we evaluated the samples using an interpretative algorithm based on a reduced number of some selected cytomorphological clues. These criteria were: 1) presence of lymphoid blast cells, 2) fine structural change of the lymphoid blasts’s membrane, 3) presence of lympho-glandular bodies. The most outstanding result, was the higher diagnostic accuracy of squash-prep cytology compared with endoscopic biopsy histology. Histopathology and immunohistochemistry are generally considered useful in the differential diagnosis between IBD and lymphoma. In our study however, although the evaluation of histopathologic results is not within the aims of the present work, the diagnostic performances of histopathology on endoscopic biopsies didn’t show a better accuracy better than those of cytology alone.