EPITHELIOTROPIC INTESTINAL T-CELL LYMPHOMA IN A HARBOR SEAL (PHOCA VITULINA)

• Published in: Journal of Zoo and Wildlife Medicine
• Main Authors: Sara Malberg, Henrike Alma Gregersen, Manfred Henrich, Christiane Herden
• Format: Text
• Language: English
• Published: American Association of Zoo Veterinarians 2017
• Subjects: harbor seal; Phoca vitulina
• Online Access: https://doi.org/10.1638/20160221R.1

A 14-yr- old, male harbor seal (Phoca vitulina) presented with depression, anorexia, and weight loss. Clinical examination revealed no specific abnormalities. Diagnostic imaging displayed an enlarged mass in the dorso-cranial abdomen. The animal was euthanized due to progressive worsening of symptoms. Grossly, severe emaciation and a massive enlargement of one mesenteric lymph node were found. Microscopically, a neoplastic round cell population with morphologic characteristics of mature lymphocytes infiltrated the mesenteric lymph node as well as the jejunal mucosa and exhibited a marked invasion of the mucosal epithelial layer. Immunohistochemically, the majority of cells expressed CD3, but not CD79α, indicating a T-cell origin of the tumor cells. Microscopic as well as immunohistochemical findings enabled the diagnosis of an epitheliotropic intestinal T-cell lymphoma, a neoplasm that has yet not been described in a harbor seal.