Abstract
Background:
Primary lung neoplasms are, frequently represented by solid, solitary or multiple formations. However, malignant cavitary lesions may be presented as lung adenocarcinomas. Those malignants lesions differ from benignant bullae by the thickness e heterogeinity of its surrounding shape.
Case Description:
The present clinical case reports a 14-year-old female dog, of mixed breed, with an increase in the coughs frequency, fatigue and exercise intolerance. A chest X-ray was taken, a large emphysematous cystic area was found, with thickened and irregular walls located in the left caudal pulmonary lobe, which measured 8cm x 7.5cm x 3cm, and rejected the bronchial branch corresponding to the left caudal pulmonary lobe, in addition to thickening of the bronchial walls, compatible with bronchopathy. The tomographic examination of the cavity showed an air content structure, oval to round in shape, with irregular thick hyperattenuating walls measuring approximately 0.4 cm in thickness, occupying more than 30% of the left hemithorax, and pulmonary lobectomy was chosen. Histopathology confirmed the diagnosis of bronchoalveolar adenocarcinoma, with the presence of sparse areas of necrosis and dystrophic calcification.
Conclusion:
The present case successfully diagnosed a malignant bulae, after a surgical remove. The tomographic finds although not confirmatory, suggest a malignant component by the shape and thickness of its wall. The tomographic exam is of great importance, because only through it, it is possible to evaluate if there is lymph node or pleural involvement or the presence of small metastasis foci. There is indication for surgery and histopathological examination of the piece for a definitive diagnosis.

Key words: Blister, Dog, Computer tomography, Surgery