A Carcinoid Tumor in the Gallbladder of a Dog

Abstract

Abstract.A cholecystectomy was performed on a 10-year-old spayed female mixed-breed dog with chronic weight loss, persistently increased liver enzyme activities, and cholecystomegaly identified by ultrasonographic examination. A subsequent diagnosis of a biliary carcinoid was made based on a neuroendocrine-type histologic pattern, cytoplasmic argyrophilia by Grimelius staining, immunopositivity for chromogranin A, and the ultrastructural finding of cytoplasmic secretory granules in neoplastic cells. Extrahepatic biliary carcinoid tumors are rare tumors of humans and have not been documented in domestic animals.Key words: Dogs; gallbladder; biliary; carcinoid. In humans and animals, carcinoid tumors are uncommon neoplasms that arise from dispersed cells of the neuoroendocrine system in the gastrointestinal tract, biliary system, pancreas, and lung. These cells belong to one of two functional groups: 1) the amine precursor uptake and decarboxylation cells that produce serotonin and adrenocorticotrophic hormone, or 2) those cells capable of synthesizing low molecular weight polypeptide or protein hormones such as chromogranin, cholecystokinin and secretin. Definitive diagnosis of carcinoid tumors is based on histologic features, immunostaining for secretory products such as chromogranin, and ultrastructural identification of neuroendocrine secretory granules. 2 In dogs, hepatic, gastrointestinal, and pulmonary carcinoids have been reported. [5][6][7] Intestinal carcinoids have also been documented in a horse and a cow. 2 In horses, three cases of maxillary sinus carcinoid tumors have been reported as well. 8 In humans, carcinoid tumors are frequently found in the gastrointestinal system (74%) and the bronchopulmonary system (25%). Within the gastrointestinal tract, the most common sites include the small bowel (29%), appendix (19%), and rectum (13%). 3 In this case, a 10-year-old spayed female mixed-breed dog initially presented for weight loss and persistent vomition. No abnormalities were noted on physical examination. Serum biochemistry abnormalities included increased liver enzyme activities, including aspartate aminotransferase (625 U/ L; reference range 10-60 U/L), alanine aminotransferase (2,225 U/L; reference range 8-57 U/L), lactate dehydrogenase (531 U/L; reference range (0-250 U/L), and alkaline phosphatase (4,460 U/L; reference range 10-140 U/L) as well as hyperbilirubinemia (Total bilirubin 5.6 mg/dL; reference range 0-0.6 mg/dL) consistent with hepatocellular damage and cholestasis. During the next 8 weeks, progres-

Primary neuroendocrine carcinoma of the gallbladder in a dog

“…This case, to our knowledge, is the third report of primitive neuroendocrine tumors of the gallbladder (Willard et al 1988;Morrell et al 2002). At this moment we assume this tumor to be putatively primitive of the gallbladder, but no other mass was identified by physical and collateral examinations nor during the laparotomy.…”

Hepatobiliary Neuroendocrine Carcinoma in Cats: A Clinicopathologic, Immunohistochemical, and Ultrastructural Study of 17 Cases

“…39 Subsequently, a few reports, mostly single cases, of hepatic and gallbladder neuroendocrine carcinoma in dogs have been published. 10,27,28,34 Neuroendocrine carcinoma arises from the dispersed neuroendocrine system. 4,9,21 Although uncommon, neuroendocrine carcinoma has been described in a wide range of organs in humans.…”

Adenoma of the gallbladder in a mongoose (Mungos mungo)

“…Epithelial neoplasms are common (PONOMARK & MACKEY, 1976;JONES et al, 1997); whereas, mesenchymal neoplasms are extremely rare (SANT'ANA et al, 2000). Primary neoplasms of the gallbladder in domestic animals include adenomas (CULEN & POPP, 2002), leiomyomas (SANT'ANA et al, 2000), carcinomas (CULEN & POPP, 2002;SAKAI et al, 2003), and carcinoid tumors (MORREL et al, 2002). The only reports of gallbladder neoplasms in wild animals in the literature are as follows: an adenoma in a chimpanzee (STAROST & MARTINO, 2002) and a bearded dragon (JAKAB et al, 2011), an adenocarcinoma in two African lions in captivity (SAKAI et al, 2003), and biliary tumors (two adenomas and five carcinomas) in prosimian primates in a retrospective study (REMICK et al, 2009).…”