Pulmonary adenocarcinoma in an aged mare : a case report

Aim of the present paper is to report a case of pulmonary carcinoma in a 23 years old Appaloosa mare with a hystory of progressive weight loss, coughing and serosanguineous nasal discharge of one week duration. On physical examination, depression, poor body condition, tachypnoea, bilateral serosanguineous nasal discharge and a wide area of decreased lung sounds on auscultation of the right side, were detected. Laboratory evaluation showed hypochromic anaemia, leukocytosis with neutrophilia and leukopaenia, hyperfibrinogenaemia, hyperprotidaemia, hypoalbinaemia, increased beta 2 and gamma globulin fractions, hypoxaemia and normocapnia. Thoracic ultrasound showed a large rounded mass extended from the 9th to 14th right intercostal space of homogeneous echogenicity, in which neither brochial or vascular structures were detectable. Endoscopy showed a large amount of serosanguineous discharge within the tracheal lumen and a mass of reddish soft tissue completely obliterating the right caudal lobar bronchus. Hystopathology of the endobronchial mass and of the trans-thoracic ultrasound guided biopsies revealed the presence of columnar to cuboidal epithelial cells arranged in cords or forming acini with moderately high nuclear to cytoplasmic ratio, hyperchromatic nuclei variable in size, and a high mitotic rate. According to these findings a pulmonary adenocarcinoma was diagnosed. Due to worsening of the clinical conditions, the mare was humanely destroyed. Necroscopy confirmed the presence of a 30 cm in diameter, tan, moderately firm, solitary mass in the right caudal pulmonary lobe, characterized by acinar-like structures lined by moderately pleomorphic flat to cubic brhonchiolar and alveolar epithelial cells with a high mitotic rate, consistent with adenocarcinoma.