Invasive Tracheal and Cranial Mediastinal Aspergillosis in a Young Otherwise Healthy Cat

A 3.5-year-old castrated male domestic medium hair cat was evaluated for dry cough and labored breathing. A cranial mediastinal mass was seen on thoracic radiographs. On computed tomography, the mass displaced the cranial vena cava and dorsally displaced and compressed the intrathoracic trachea. The patient was taken to surgery for attempted mass removal. Intraoperatively, the mass was adhered to the cranial vena cava, aortic arch, left subclavian artery, and had partially engulfed the brachiocephalic trunk. The cat was euthanized and on necropsy the mass was found to invade the lumen of the vena cava and the tracheal lumen. An Aspergillus lentulus fungal granuloma was diagnosed histologically and by fungal culture and PCR. We highlight the difficulty in determining the extent of invasion with invasive aspergillosis and provide evidence that invasive aspergillosis can occur in otherwise healthy, young cats with no concurrent immunosuppressive treatments or comorbidities.