A thymic carcinoma with glandular differentiation in a dog
Abdi, M.M.; Elliott, H.
Veterinary Record 134(6): 141-142
1994
ISSN/ISBN: 0042-4900 PMID: 8171785 Document Number: 425386
An 11-year-old male Beagle dog with a history of fore limb lameness became dull and lost 5% of its bodyweight. Examination revealed small lumps in the left axillary region and a systolic heart murmur. Radiography showed the left hemithorax to be homogenously opaque and the heart enlarged. No clinical signs of myasthenia gravis were observed, the dog was destroyed. The left lung was collapsed and displaced by a large quantity of brown, cloudy fluid. Smooth ovoid masses were disseminated in the cranial and ventral mediastinal pleura. Microscopically the mass consisted of multiple cysts and ectatic ducts lined by single-layer or stratified, columnar epithelium with basally located palisaded nuclei. Neoplastic epithelial cells formed papillary outgrowths into the lumen, of the cysts and ducts, and rosettes of different sizes with no central lumen. Neoplastic cells were present in the blood and lymphatic vessels and had metastasized into the thoracic aorta and pleural fat. This case strengthens the case for widening the classification of thymic carcinoma to include adenocarinoma.