ABSTRACT:
When detecting a proliferative splenic lesion, veterinarians usually choose splenectomy before a conclusive diagnosis, which can provide a deleterious effect to the dog. The most appropriate would be to perform splenectomy as a therapeutic procedure only in cases with real surgical indication, which can be established after defining microscopic diagnosis and prognosis. The objectives of this study were: to determine the frequency of different types of lesions in spleens of splenectomized dogs in the period of 12 years (2006-2017); determine the representativity of neoplastic lesions (benign and malignant) and non-neoplastic lesions; to evaluate and compare the safety and efficiency of fine needle aspiration biopsy (FNA) and ultrasound-guided Tru-cut needle biopsy for cytological and histopathological diagnosis, respectively, of splenic nodular lesions. In the studied period 224 cases of lesions were found in splenectomized spleens. The frequency of non-neoplastic lesions (50,45%, 113/224) and neoplastic lesions (49,55%, 111/224) was very similar. Among the neoplastic lesions, the malignant ones were more frequent (79,27%, 88/111), and the hemangiosarcoma was the most common (52,25%, 58/111). The possibility of malignant neoplasm was about 74% greater than a benign one. In summary, it was verified that 60.71% (136/224) of the cases corresponded to benign lesions without indication to splenectomy. FNA techniques and Tru-cut biopsy showed a low risk of complications. Regarding the diagnostic efficacy, the FNA obtained 71.43% (15/21) of conclusive diagnoses, 60% (9/15) of which were compatible with the final result of the histopathological evaluation, after splenectomy (gold standard). The Tru-cut biopsy obtained 71.43% (5/7) of conclusive diagnoses and 28.57% (2/7) of inconclusive diagnoses. Among the conclusive one, in 100% of the cases the diagnosis was compatible with the gold standard. Thus, since the possibility of benign splenic lesions in dogs is 1.52 times greater than malignancies, splenectomy should be recommended as a therapeutic procedure only in cases with proven surgical indication, which can be established after definition of microscopic diagnosis and prognosis. The use of FNA and Tru-cut biopsy should be recommended, especially for small and focal splenic lesions, since such techniques are good alternatives for establishing diagnosis previously to splenectomy, which may reduce the number of unnecessary splenectomies. The importance of recommending such techniques is emphasized, especially for dogs with focal splenic lesions smaller than three centimeters.
INDEX TERMS:
Lesions; dogs; evalution; alternative techniques; diagnosis; splenectomy; splenic biopsy; Tru-cut; neoplasms; cytology