CELOMATIC MESOTHELIOMA IN A BLACK GROUSE (Lyrurus tetrix, Linnaeus 1758): MORPHOLOGICAL STUDY AND POSSIBLE AETIOPATHOGENESIS

Mesothelioma is a rapidly fatal neoplasm in humans and animals, rarely described in birds. Also in this case, exposure to asbestos played a decisive role in the disease. A 8-yr-old male Black grouse (Lyrurus tetrix), kept as part of a reintroduction project of the species, had been reared for years in an enclosure with a small shelter, built with Eternit panels (cement and asbestos). The canopy, even as a result of the action of atmospheric agents, was very worn and damaged. In the last year of life, the bird had progressively lost weight, while maintaining normal physical activity and appetite, except for the last period in which severe dyspnea was reported. The bird died spontaneously. At the opening of the coelomatic cavity, an impressive ascitis, and a proliferative yellowish tissue, with a villous-papillary appearance, which extended from the pulmonary area to the cardiac base, up to infiltrate the air sacs and a large part of the liver, were noticed. Upon the overturning of the sternal plastron, it was observed that the serosa covering the internal face of the sternal bone was also totally transformed by these nodular formations. Organs and the abnormal tissue were fixed in formalin for histomorphological analysis. The examination of the tissue, taken in several points, permitted the diagnosis of epithelioid mesothelioma, the most frequent observable form. It is now clear that the intense and long exposure to asbestos, increase the risk of contracting mesothelioma, for its carcinogenic action.