Lung adenocarcinoma as a cause of spontaneous pneumothorax in a cat

A 15-year-old indoor/outdoor female, neutered, domestic European short haired cat was presented to our clinic with a history of neck-elongation and wheezing during inspiration/expiration. The first signs of respiratory disease occurred two weeks before the clinical presentation. After taking of clinical history, clinical examination and basic laboratory tests (complete blood count, blood smear, snap Feline Immunodeficiency Virus / Feline Leukemia Virus Combo test), a lung x-ray was performed showing the presence of left lung atelectasis and pneumothorax. The primary causes of lung atelectasis were not determined. Given that the general condition of the cat was very bad, she was put in an oxygen cage, thoracocentesis was performed, but the animal?s condition did not improve, and 24 hours after clinical presentation, the cat died. Autopsy revealed the presence of a tumor mass on the caudal lobe of the right lung, tumor formation in the area of trachea bifurcation and changes in the liver in the form of four round structures of different sizes. Histopathologically, the existence of primary undifferentiated lung adenocarcinoma with metastases on the liver and trachea was determined.