Özet:
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.
