Comparative Evaluation of the Cytological, Histopathological and Immunohistochemical Findings of Canine Cutaneous and Subcutaneous Masses

Abstract

In this study, we compared the cytological, histopathological, and immunohistochemical diagnoses of 71 canine cutaneous and subcutaneous masses. Cytological diagnoses included 56 tumors (21 mesenchymal, 15 epithelial, 16 round cell, four melanocytic), 13 infl ammatory reactions, and two cysts. Of the 21 cytologically diagnosed mesenchymal tumors, three were later confi rmed non-tumoral (hematoma, granulation tissue, fi broepithelial polyp). Thirteen out of 15 epithelial tumors were correctly diagnosed cytologically, whereas two cases were confi rmed to be non-tumoral (fi broepithelial polyp, granulation tissue) after histopathological examination. One mast cell tumor was later confi rmed as fi brous hyperplasia; diagnoses were correct in other round cell tumors. Cytological diagnoses were correct for all melanocytic tumors and cystic lesions. Five cases which had been cytologically diagnosed as infl ammatory reactions were diagnosed as tumors (lymphoma, papilloma, sebaceous adenoma, and squamous cell carcinoma) after histopathological examination. Immunohistochemistry confi rmed the histopathological diagnoses of all epithelial and round cell tumors, while the diagnoses of six mesenchymal tumors were changed after the immunohistochemical examination. The total accuracy of cytology in the diagnosis of tumoral/non-tumoral masses was 84.5%, and the accuracy in the determination of benign/malignant behavior was 83%. Diagnostic accordance between histopathology and immunohistochemistry was 86.6%. High success rates obtained with cytological diagnoses prove that cytology is a reliable diagnostic tool. The main diagnostic challenge remains with mesenchymal tumors and tumors accompanied by infl ammatory reactions. The results suggest that immunohistochemistry is fundamental for diagnoses of most mesenchymal tumors.

U studiji je urađena uporedna analiza citoloških, histopatoloških i imunohistohemijskih dijagnostičkih metoda ispitivanja kutanih i supkutanih masa kod 71 pasa. Citološka dijagnoza je obuhvatala 56 tumora (21 mezenhimskog porekla, 15 epitelnih, 16 tumora okruglih ćelija i četiri melanocitna tumora), 13 infl amatornih promena i dve ciste. Od dvadesetjednog mezenhimskog tumora, tri su kasnije potvrđena kao neneoplastične lezije, (hematomi, granulomatozno tkivo, fi broepitelijalni polip). Posle histopatoloških ispitivanja, trinaest od ukupno 15 epitelnih tumora, citološki su bili pravilno dijagnostikovani pri čemu su dva potvrđena kao neneoplastične tvorevine (fi broepitelni polip, granulaciono tkivo). Jedan mastocitom je kasnije potvrđen kao fi brozna hiperplazija. Dijagnoza je bila tačna u slučajevima tumora okruglih ćelija. Citološka dijagnoza je bila tačna u svim slučajevima melanotičnih tumora i cista. Pet slučajeva kod kojih je citološki nalaz ukazivao na zapaljenske reakcije, posle histopatološkog ispitivanja dijagnostikovani su kao tumori (limfom, papilom, sebaceozni adenom i skvamozni karcinom). Primenom imunohistohemijskih metoda, potvrđene su histopatološke dijagnoze svih epitelnih i tumora okruglih ćelija dok je dijagnoza šest mezenhimskih tumora promenjena posle ispitivanja imunohistohemijskim metodama. Tačnost citoloških ispitivanja u dijagnostici tumora i netumorskih tvorevina bila je 84,5%, pri čemu je tačnost u određivanju benignog/malignog ponašanja tkiva bila 83%. Usklađenost između histopatološkog i imunohistohemijskog rezultata bila je 86,6%. Visok nivo tačnosti koji je dobijen na osnovu citoloških ispitivanja, dokazuje da je citološka metoda ispitivanja dobra početna dijagnostiča tehnika. Međutim i dalje je glavni izazov u dijagnostičkom smislu, ispitivanje mezenhimskih tumora kao i tumora praćenih infl amacijom. Rezultati ukazuju da imunohistohemijsko ispitivanje predstavlja osnovu dijagnoze većine mezenhimskih tumora.