Histopathological Inspection of the Occurrence of Lung Adenocarcinoma in Sheep in Tehran Province

Authors: Nazari A, Avarseji A, Maghsoudlou M and Shahi S*

DOI: 10.23880/oajvsr-16000243

Volume 8, Issue 2

Abstract

Sheep pulmonary adenomatosis is a chronic respiratory disease with a long incubation period that many countries have long recognized. This disease is specific to sheep and most prominent in sheep over three years old. The cause of this disease in sheep is Beta Retroviruses (JSRV) which are transmissible among sheep. Since 1342, there have been reports of clinical cases of the disease in different regions of Iran. So far, histopathology has been one of the best diagnostic methods for this disease. The conducted research inspects the occurrence rate and pathological lesions of this disease in a slaughterhouse located in Tehran. All the studied sheep in this research were bred in the livestock farms of Tehran province and referred to the slaughterhouse. During routine inspections, the lungs that showed different macroscopic signs of pneumonia had been primarily identified and recorded; later, more thorough evaluations of macroscopic and microscopic examinations were performed. One hundred sheep lungs, which showed visible lesions of interstitial pneumonia, were selected for histopathological research. These lungs were generally heavy, edematous, had no signs of collapse, showed rib marks on the lung parenchyma, and appeared waterlogged in some cases. The affected areas were firm and light grey in some lungs. OPA histopathological lesions were observed and documented in 25 out of 300 suspicious lung samples. All twenty-five of the damaged lungs were almost similar in histopathological appearance and showed papillary protrusions consisting of short cuboid to columnar cells inside the ducts of alveoli and bronchioles, respectively. In the atypical form of the disease, which included all cases observed in the present study, infiltration of mononuclear cells and connective tissue was more substantial; large and foamy macrophages were also observed in the alveoli and bronchioles that were present in the vicinity of neoplastic lesions. The classical form of OPA, characterized by the infiltration of macrophages and lymphocytes and the formation of neutrophilic and fibrin molds, was observed in any of the cases.

Keywords: Pulmonary Adenomatosis; Beta Retroviruses; Lung Parenchyma; Macrophages; Lymphocytes

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