Tracheal stenosis and adenocarcinoma in an olive baboon (Papio cynocephalus anubis)

An adult female baboon (Papio cynocephalus anubis) presented for progressive difficulty in endotracheal intubation. Over a 7-y period prior to presentation, she was anesthetized and intubated 67 times for imaging by using single-photon emission computed tomography or positron emission tomography. Laryngoscopic examination revealed tracheal stenosis. Because of increased anesthetic risk and lack of alternative use, she was euthanized, and partial necropsy focusing on the larynx, trachea, and associated structures was performed. Gross examination revealed rigidity and functional fusion of the proximal 5 or 6 tracheal rings and narrowing of the lumen. Histology revealed ossification of tracheal rings and fibrosis of overlying tissue. In addition, a transmural umbilicated mass was present midway down the cervical trachea on its dorsolateral aspect. Histology of the tracheal mass identified a relatively well-circumscribed transmural adenocarcinoma. The combination of overall histologic pattern, evidence of anaplasia, and results of immunohistochemical staining was consistent with a diagnosis of adenoid cystic carcinoma. Anterior tracheal stenosis is a reported complication of intubation in humans and animals. Primary tracheal neoplasms are rare in domestic and research animals and, to our knowledge, have not previously been reported to occur in nonhuman primates.