GIZZARD ADENOCARCINOMA IN AN AGED HUMBOLDT PENGUIN (SPHENISCUS-HUMBOLDTI)

Spontaneous gizzard adenocarcinoma was found in a 15-year-old male Hum boldt penguin (Spheniscus humboldti). The lesser curvature of the gizz ard wall was extensively and markedly thickened with a hard white tumo ur mass. Histopathologically, the tumour in the gizzard consisted of t wo structures: small to large acini lined by cuboidal or flattened cel ls with poor stroma in the mucosa, and undifferentiated tumour cells a rranged singly or in cords with acinar structures separated by dense f ibrous tissue in the muscular layer. Small white metastatic tumours of the intestine and the pancreas had a similar histological appearance to that in the muscular layer of the gizzard. From the location of tum our in the gizzard and the stainability with combined alcian blue pH 2 .5-periodic acid Schiff, it was considered that this tumour might orig inate from the lining cells of the tip of the gizzard mucosal folds.