Diagnosis: Alpaca: C2, Gastric squamous cell carcinoma & rupture with liver metastases and carcinomatosis
History: 15-years-old, female, alpaca, Lama pacos
Diagnosis: C2, Gastric squamous cell carcinoma with liver metastases and carcinomatosis
Description: At necropsy, in C2, there was a 30x20x15 cm, not encapsulated, infiltrative growing, and relatively well demarcated mass which on the cut surface contained abundant necrotic material, pus and fibrosis. The mucosa was focally extensive severe ulcerated and covered by a thick layer of necrotic material and pus. In the mesenterium and intestinal serosa there were multiple white nodules of firm consistency, approximately 1x1cm size. White nodules were also seen within the liver capsule and parenchyma, approximately 1.5x1cm size. In the colon and C3 mucosa multifocal chronic ulcerations were present. The abdomen and thorax contained approximately 500 ml of red, transparent fluid.
Comments: This was an interesting case of a rare presentation of gastric squamous cell carcinoma with carcinomatosis and metastases to the liver, mesenteric lymph nodes in an alpaca. The patient presented with a history of 2 weeks loss of appetite, apathy and weight loss. An intraabdominal neoplasia was suspected at ultrasound examination. At necropsy, the alpaca was in a poor body condition. In histology, the wall of compartment 2 (C2) is severely disrupted by an ulcerated, multilobular, infiltrative growing, non-encapsulated, pooorly demarcated, densely cellular,neoplasia, projecting from the mucosa and extending to the serosa consisting of islands, nests and anastomosing cords of neoplastic polygonal epithelial cells separated by moderate to large amount of fibrovascular stroma. Many submucosal and subserosal vessels contain clusters of neoplastic cells (tumor emboli) as well as fibrin thrombi. The same neoplastic cells were present within the liver and mesenterial tissue. Immunohistochemically the neoplastic cells were positive for cytokeratin. The neoplastic cells most commonly originate from squamous mucosal epithelium of compartments 1 and 2, but it could arise also from the glandular mucosa of compartment 3.
Picture by: Francesca Popescu
Author: Francesca Popescu, Vanessa Schumacher
Institute of Animal Pathology, University of Bern, Vetsuisse Faculty, Switzerland