Gallbladder lymphoma in a miniature dachshund

Abstract

A 7-year-old, miniature dachshund was referred for examination and treatment of persistent anorexia, deep yellow-coloured urine and leucocytosis. The clinical sign of jaundice, results from a serum biochemistry profile and ultrasonographic images suggested a biliary tract obstruction. A cholecystectomy was performed to remove the obstruction. Histopathological assessment of the resected gallbladder and partial common bile duct indicated diffuse large B-cell lymphoma. Twelve days after the initial operation, a second procedure was performed due to bile leakage into the abdominal cavity. Chemotherapy was administered twice after the second operation but discontinued, because the dog showed adverse effects. The dog is still alive 24 months after the surgery. To the authors' knowledge, this is the first description of canine gallbladder lymphoma.

Fig. 1.

Abdominal ultrasonography of the gallbladder. Abdominal ultrasonography of the gallbladder showing a hyperechoic wall (arrow) and hyperechoic sludgy content (arrowhead).

Fig. 2.

Intraoperative abdominal cavity findings (A) and Mucous membrane in the gallbladder (B). The enlarged gallbladder and the yellow and mildly distended liver lobes are apparent (A). Mildly yellowed gallbladder wall lumina and several gallstones are observed in the gallbladder during surgery (B).

Fig. 3.

Overview (A) and detail (B) of the histopathological aspects of the gallbladder. The gallbladder and proliferating tissue of the common bile duct comprise diffuse large lymphoid neoplastic cells with large vesicular nuclei with coarse chromatin and one or several prominent nucleoli. Several mitotic figures are observed throughout the neoplastic tissues (arrowhead). Hematoxylin and Eosin stain. Bar=200 µm (A) and 20 µm (B).

Fig. 4.

Immunohistochemical staining of the dissected gallbladder. (A) Neoplastic lymphoid cells are positive for CD20 in the cytoplasmic membrane. Immunolabeling with anti-CD20, Hematoxylin counterstain. (B) The nuclei of neoplastic lymphoid cells are positive for Pax5. Immunolabeling with anti-Pax5, Hematoxylin counterstain. (C) The majority of neoplastic lymphoid cells are negative for CD3. Small mature lymphocytes infiltrating into the neoplastic tissue are positive for CD3. Immunolabeling with anti-CD3, Hematoxylin counterstain. All bars=50 µm.