Document Type : Original Articles
Authors
1
Department of Clinical Sciences, Faculty of Veterinary Medicine, Ur.C., Islamic Azad University, Urmia, Iran.
2
Department of Pathology, Faculty of Veterinary Medicine, Ur.C., Islamic Azad University, Urmia, Iran.
10.32598/ARI.81.4.3701
Abstract
Introduction: Primary lung tumors (PLTs) are rare in dogs, and benign pulmonary adenomas of connective tissue origin and primary pulmonary neoplasms are infrequently reported in the genera Canis and Felis. This study aimed to examine the pathological and immunohistochemical features of canine pulmonary adenomas diagnosed over a 10-year period.
Materials & Methods: Dogs with lung adenoma (n=6) underwent necropsy and were investigated for hematological changes, histopathology (hematoxylin and eosin [H&E], Masson’s trichrome, and Perl’s Prussian blue staining), and immunohistochemistry.
Results: Out of 882 dogs of various breeds with clinical respiratory signs, pulmonary adenomas were detected in six (0.68%), mostly in large, 8- to 12-year-old dogs. Hematological assessments revealed remarkable neutrophilia in the tumor-bearing group (P<0.05), and all tumors were identified as papillary adenomas. Interestingly, two tumor-affected dogs had concurrent chronic heart failure manifested by pulmonary hemosiderophages, which is being reported for the first time. The tumors’ immunophenotype was TTF-1-, EGFR-, Napsin-A-, CEA-, EMA-, CK+, Vimentin-, p53-, and Ki-67 negative, indicating the lack of malignant potential. Whilst EGFR expression was not detected in tumorous lungs, positive expression of EGFR, TTF-1, and Napsin-A was observed in approximately 30%, 30%-40%, and 40% of normal pulmonary cells, respectively. The expression profiles for these markers in dogs’ normal pulmonary cells, with variations in TTF-1 and Napsin-A expression, may provide a baseline for comparison with EGFR expression patterns in malignant lung tumors such as adenocarcinomas.
Conclusion: The results suggest that canine pulmonary adenomas are completely benign and have no malignant potential, and immunohistochemical assessments can aid in disease prognosis and inform the development of tailored therapy protocols.
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