Primary Gallbladder Adenocarcinoma in a Cat

Abstract

Background: Biliary tumors have low incidence in cats and are more common in elderly animals. Hepatobiliary tumors have different classifications and their etiology is difficult to interpret. In most cases, the diagnosis is only possible in advanced stages, which clouds the precursor factors. The late diagnosis is explained by the absence or specificity of clinical manifestations and laboratory changes. The majority of hepatobiliary neoplasms in cats are incidental findings in surgeries or necropsies. This study aimed to report clinical, laboratory, pathological and immunohistochemical results in a feline case of gall bladder adenocarcinoma.Case: A cat, male, neutered, mixed breed, 4 years, was admitted at a veterinary clinic with a history of polyuria / polydipsia, anorexia, apathy, jaundice and emesis for 60 days. The animal had been treated in another clinic with silymarin, famotidine and cyanocobalamin, and fed by esophageal tube based on the presumptive clinical diagnosis of cholangitis. The clinical examination revealed jaundice, abdominal pain, weight loss, enlargement of the liver and gallbladder and the presence of a structure in the epigastric region. Based on clinical signs, blood tests (complete blood count and liver enzymes), abdominal ultrasound and thoracic radiography were requested. In the exam results, eosinophilia, bilirubinemia and increased alkaline phosphatase, glutamic pyruvic transaminase and gamma glutamyl transferase were observed, in addition to the presence of icteric and hemolyzed serum. Ultrasound exam revealed thickened and dilated cystic and common ducts, large and thick gallbladder, bile with bile mud, hypoechogenic liver, thickening in the duodenal papilla and enlarged pancreatic and duodenal lymph nodes. There were no alterations in thoracic radiography. Based on the findings, the diagnosis of extrahepatic biliary obstruction was suggested. In celiotomy, dilated gallbladder with a thick blackened wall was observed. Bile puncture was performed for analysis, and total cholecystectomy and removal of obstructive content was performed. The patient suffered cardiorespiratory arrest after the procedure. A fragment of gallbladder and liver were sent to evaluation with histopathology and immunohistochemistry, and results were compatible with gallbladder adenocarcinoma.Discussion: Hepatobiliary neoplasms in cats are uncommon, apart from lymphoma. The incidence is higher in elderly cats and in males, which did not match the animal in this case. The clinical presentation of the condition is quite nonspecific, corroborating with other reports, in which changes are often only evident in advanced stages of the disease. Laboratory and imaging findings pointed to a biliary tree disorder, and cholangitis was suggested. However, the lack of clinical improvement and examination findings of exams lead to an exploratory laparotomy for better inspection of the organs and identification of possible causes. One of the differential diagnoses that should be considered in cats with extrahepatic biliary obstruction is gallbladder adenocarcinoma, especially in animals with an unsatisfactory response in clinical treatment. Tests such as histopathology and immunohistochemistry are essential for the definitive diagnosis of this neoplasm. Surgical resection is indicated in cases of malignant masses, providing longevity and better quality of life. Hypotension is a common complication in hepatobiliary surgeries, which can result in death.

Full text

Acta Scientiae Veterinariae, 2020. 48(Suppl 1): 540.
CASE REPORT
Pub. 540
ISSN 1679-9216
1
DOI: 10.22456/1679-9216.101267
Received: 24 March 2020 Accepted: 26 September 2020 Published: 25 October 2020
1Equalis, Programa de Pós-Graduação, Natal, RN, Brazil. 2 Hospital Veterinário Jerônimo Dix-Suit Rosado Maia, Universidade Federal Rural do Semi-
Árido (UFERSA), Mossoró, RN. 3Departamento de Medicina Veterinária, Universidade Federal Rural de Pernambuco (UFRPE), Recife, PE, Brazil.
4Centro de Ciências da Saúde, Universidade de Fortaleza (UNIFOR), Fortaleza, CE, Brazil. 5Faculdade de Medicina Veterinária, Universidade Estadual
do Ceará (UECE), Fortaleza. CORRESPONDENCE: T.T. Diogenes [taianitorquato@gmail.com] & M.A. Rocha [mariana4981@hotmail.com]. Faculdade
de Medicina Veterinária, UECE. Av. Dr. Silas Munguba n. 1700. Campus Itaperi. CEP 60.740-903 Fortaleza, CE, Brazil.
Primary Gallbladder Adenocarcinoma in a Cat
Taiani Torquato Diogenes1, Mariana Araújo Rocha2, Keytyanne de Oliveira Sampaio3, Robério Gomes Olinda4,
Diana Celia Sousa Nunes Pinheiro5 & Reginaldo Pereira de Sousa-Filho5
ABSTRACT
Background: Biliary tumors have low incidence in cats and are more common in elderly animals. Hepatobiliary tumors
have different classifications and their etiology is difficult to interpret. In most cases, the diagnosis is only possible in ad-
vanced stages, which clouds the precursor factors. The late diagnosis is explained by the absence or specificity of clinical
manifestations and laboratory changes. The majority of hepatobiliary neoplasms in cats are incidental findings in surgeries
or necropsies. This study aimed to report clinical, laboratory, pathological and immunohistochemical results in a feline
case of gallbladder adenocarcinoma.
Case: 4-year-old male castrated mix breed cat was admitted at a veterinary clinic with a history of polyuria / polydipsia,
anorexia, apathy, jaundice and emesis for 60 days. The animal had been treated in another clinic with silymarin, famotidine
and cyanocobalamin, and fed by esophageal tube based on the presumptive clinical diagnosis of cholangitis. The clinical
examination revealed jaundice, abdominal pain, weight loss, enlargement of the liver and gallbladder and the presence of a
structure in the epigastric region. Based on clinical signs, blood tests (complete blood count and liver enzymes), abdominal
ultrasound and thoracic radiography were requested. In the exam results, eosinophilia, bilirubinemia and increased alkaline
phosphatase, glutamic pyruvic transaminase and gamma glutamyl transferase were observed, in addition to the presence
of icteric and hemolyzed serum. Ultrasound exam revealed thickened and dilated cystic and common ducts, large and
thick gallbladder, bile with bile mud, hypoechogenic liver, thickening in the duodenal papilla and enlarged pancreatic and
duodenal lymph nodes. There were no alterations in thoracic radiography. Based on the findings, the diagnosis of extrahe-
patic biliary obstruction was suggested. In celiotomy, dilated gallbladder with a thick blackened wall was observed. Bile
puncture was performed for analysis, and total cholecystectomy and removal of obstructive content was performed. The
patient suffered cardiorespiratory arrest after the procedure. A fragment of gallbladder and liver were sent to evaluation
with histopathology and immunohistochemistry, and results were compatible with gallbladder adenocarcinoma.
Discussion: Hepatobiliary neoplasms in cats are uncommon, apart from lymphoma. The incidence is higher in elderly cats
and in males, which did not match the animal in this case. The clinical presentation of the condition is quite nonspecific,
corroborating with other reports, in which changes are often only evident in advanced stages of the disease. Laboratory
and imaging findings pointed to a biliary tree disorder, and cholangitis was suggested. However, the lack of clinical im-
provement and examination findings of exams lead to an exploratory laparotomy for better inspection of the organs and
identification of possible causes. One of the differential diagnoses that should be considered in cats with extrahepatic
biliary obstruction is gallbladder adenocarcinoma, especially in animals with an unsatisfactory response in clinical treat-
ment. Tests such as histopathology and immunohistochemistry are essential for the definitive diagnosis of this neoplasm.
Surgical resection is indicated in cases of malignant masses, providing longevity and better quality of life. Hypotension
is a common complication in hepatobiliary surgeries, which can result in death.
Keywords: feline, immunohistochemical, liver, neoplasm, surgery.

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T.T. Diogenes, M.A. Rocha, K.O. Sampaio, et al. 2020. Primary Gallbladder Adenocarcinoma in a Cat.
Acta Scientiae Veterinariae. 48(Suppl 1): 540.
INTRODUCTION
Primary gallbladder neoplasms are rare in cats,
in which incidence values vary from 1 to 3% among di-
fferent types [11]. These conditions are more common
in elderly animals and breed-related predispositions
have not been reported [1].
Hepatobiliary neoplasms are classified as
hepatocellular adenomas, hepatocellular adenocarci-
nomas, cholangiocellular adenomas, cholangiocellular
adenocarcinomas or mesenchymal tumors. The cho-
langiocellular adenocarcinomas include intrahepatic
bile duct adenocarcinomas, extrahepatic bile duct
adenocarcinomas and gallbladder carcinomas [3].
The etiologies of gallbladder tumors are hard to
interpret. In most cases, diagnosis is confirmed only in
advance stages of the disease, which hinders the identi-
fication of precursor lesions [7]. Late diagnosis may be
explained by the clinical presentation that is absent in
50% of cases and is composed by nonspecific signs, such
as inappetence, weight loss, lethargy and emesis [6].
Laboratory alterations, such as the increased
levels of serum liver enzymes are also unspecific [1].
Hence, half the cases of hepatobiliary tumors in cats
are incidental findings of surgeries or necropsies [4].
This study aimed to report clinical, laborato-
rial, pathological and immunohistochemical findings
in a case of gallbladder adenocarcinoma in a cat.
CASE
A 4-year-old male castrated mix breed cat was
admitted at a veterinary clinic for consultation. Accor-
ding to the owner, the individual presented a history
of apathy, polyuria/polydipsia, anorexia, emesis and
jaundice for 60 days. Based on a previous diagnosis of
cholangitis in another clinic, the individual was being
treated orally for 40 days with Silymarin1 [40 mg/kg,
twice a day BID], Famotidine2 [1 mg/kg, once a day
- SID], and with Cyanocobalamin3 [250 µg, via sub-
cutaneous injections every 7 days]. Patient was being
fed through an esophageal tube with hypercaloric pasty
feed for 30 days. In the clinical examination, emacia-
tion was observed with a body score of 4 (1-9 scale).
In addition, the individual presented jaundice in skin
and mucosa, hepatomegaly, abdominal pain and a mass
was identified in the epigastric region. In view of the
situation, some tests were requested, such as complete
blood count, biochemical enzyme activity (direct-
-bilirubin, free-bilirubin, indirect-bilirubin, Alkaline
Phosphatase - AP, Glutamic Pyruvic Transaminase
- GPT and Gamma-Glutamyl Transferase - GGT),
total abdominal ultrasound and thoracic radiography.
Leukogram results demonstrated intense eo-
sinophilia (2.624 cells/µL - reference: 0-1,500 cells/
µL/L). Serum biochemical profile presented elevated
levels of bilirubin (Direct bilirubin 11.4 mg/dL - re-
ference: 0.30 mg/dL; Indirect bilirubin 4.6 mg/dL
- reference: 0.0-0.5 mg/dL) liver enzymes (FA 255
mg/dL - reference: 25.0-93.0 mg/dL; TGP 527 mg/dL
- reference: 6.0-83.00 mg/dL; GGT 40.00 mg/dL - refe-
rence: 1.3-5.10 mg/dL), icteric and hemolyzed serum.
In abdominal ultrasonography, the liver pre-
sented reduced and gross echogenicity with no eviden-
ce of nodules or cysts. Gallbladder presented severely
thick echogenic walls (0.35 cm), anechoic bile with
hypoechoic content in the lowest part (biliary mud).
Cystic and common ducts were dilated (0.46 cm and
0.29 cm in diameter, respectively) and thick (0.09 cm
in both). Duodenum was also thick in the duodenal
papilla (0.30 cm) and pancreatic parenchyma was sli-
ghtly hypoechoic. Lymphadenomegaly was observed
in pancreatic and duodenal lymph nodes. Thoracic
radiography did not present alterations.
Considering the case and the unsatisfactory the-
rapeutic response, a possible diagnosis of extrahepatic
biliary obstruction was considered. Hence, a surgical
approach was suggested to perform a bilioenteric bypass.
Maintenance fluid therapy was recommended, and pain
was managed using Meloxicam4 [0.05 mg/kg, SC, SID]
for 3 days. The animal was submitted to surgery, in
which pre-anesthesia consisted of Methadone5 [0.3 mg/
kg, SC] and Dexmedetomidine6 (3 m/kg, SC). Isoflurane
was used for induction via mask and in maintenance at
2%. In the celiotomy, gallbladder was severely dilated
(Figure 1) and manual decompression was not possible.
In addition, the left liver duct, cystic duct and common
bile duct were ingurgitated. Gallbladder walls were
thick and dark. Hyperemia was observed in proximal
duodenal walls, omentum and peripancreatic fat, in
addition to lymphadenomegaly. Based on these findin-
gs, total cholecystectomy was performed. At the end of
surgery, a severe hypotension occurred, which resulted
in cardiorespiratory arrest. Resuscitation protocol was
performed with no success. A bile sample was collected
for cytology and bacterial culture. The excised gallblad-
der and a liver fragment were sent for histopathological
analysis. Bacterial culture was negative and cytology

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T.T. Diogenes, M.A. Rocha, K.O. Sampaio, et al. 2020. Primary Gallbladder Adenocarcinoma in a Cat.
Acta Scientiae Veterinariae. 48(Suppl 1): 540.
results demonstrated squamous epithelial cells, neutro-
phils, macrophages and amorphous acellular material
with no evidence of bacteria or parasite eggs.
In histopathological examination, marked
proliferation of unencapsulated carcinoma epithelial
cells which infiltrated the mucosa and submucosa of
the gallbladder was observed. Neoplastic cells formed
irregular acini and papillary structures, which were
sustained by abundant fibrovascular stroma (marked
desmoplasia) [Figure 2A] . Multifocal intramural in-
flammatory infiltrate of neutrophils and eosinophils
was observed. Tumoral clots were seen in lymph and
blood vessels, in addition to necrotizing vasculitis
and fibrin thrombi in submucosal vessels. In the liver
fragment adjacent to the gallbladder, discrete fibrosis
and marked proliferation of periportal biliary ducts
was observed. In addition, a fine diffuse hepatocellular
vacuolization was identified.
According to the histopathological findings,
gallbladder adenocarcinoma was diagnosed. Samples
from these tissues were submitted to immunohistoche-
mical analysis, in which four biomarkers were used
in the peroxidase streptavidin-biotin technique with
the monoclonal antibodies Anti-Hepatocyte Specific
Antigen (Clone OCH1E5)7, Anti-CK Pan (Clone AE-
1AE3)8, Anti-CK7 (Clone OV-TL12/30)9 and CK20
(Clone Ks20.8)9. Immune expressions for CK Pan and
CK7 were observed, which confirmed the diagnosis
(Figure 2B,D) [Figure 2C].
DISCUSSION
Hepatobiliary neoplasia in cats is relatively un-
common with the exception of lymphomas [9]. A study
conducted by Patnaik [10], demonstrated that among
hepatobiliary tumors in cats, those of epithelial origin
and biliary system were most frequent, unlike humans
and dogs, in which liver neoplasia are more common.
Primary hepatobiliary tumors occur more fre-
quently in older and male individuals with average age
between nine and ten years [12]. However, the animal
in this case was much younger (4-year-old).
Clinical presentation presented by the cat in
this report consisted of apathy, anorexia and emesis,
which are unspecific. This finding corroborates with
[9] that reported these signs in hepatobiliary cases. Ac-
cording to Liptak et al. [6], only 50% of hepatobiliary
neoplasia cases in cats present clinical manifestations,
which are nonspecific and mostly identified in advan-
ced stages of the disease. Other clinical manifestations
include weight loss, jaundice, hepatomegaly, polyuria
and polydipsia [4,12].
The main biochemical alterations that were
identified in this case are unspecific for the tumor and
could occur in several conditions affecting liver and
biliary tree, including increased liver transaminases
and bilirubin [9]. Other expected laboratory findings
include neutrophilia and chronic anemia, which were
not observed in this report [1].
Clinical and laboratory alterations suggested
the initial diagnosis of cholangitis. However, the lack
of improvement after the clinical treatment and the
ultrasonographic findings suggestive of obstructive
condition, especially due to the dilation of common
and cystic ducts led to the extrahepatic biliary duct
obstruction diagnosis [2]. In addition, the presence of
biliary mud suggests cholestasis, which is considered
a significant finding in cats [4].
This condition may occur as a consequence of
chronic cholangitis, pancreatitis, gallstones, parasite
infestation and neoplasms [9]. Hence, all of these
conditions are considered as differential diagnoses of
gallbladder adenocarcinoma. Surgical exploration for
biliary decompression and inspection of liver and other
organs is recommended when the cause is not iden-
tified or in the absence of clinical improvement after
the treatment is initiated [2], which was the procedure
adopted in this case.
Neoplasm was demonstrated by the malignant
epithelial cell infiltrate in mucosa and submucosa of the
gallbladder. These cells presented immune expression
by CK7, which marks ductal, glandular, superficial
squamous and transition epitheliums, and by CK Pan,
which is a specific antigen marker of filaments of
epithelial cells that characterizes adenocarcinoma [5].
Surgical resection is indicated to provide
better duration and quality of life for the animal [12].
Chemotherapy does not present adequate results in the
treatment of primary hepatobiliary tumors [1]. During
surgery, the occurrence of hypotension is common in
cat anesthesia during procedures involving gallbladder
and biliary tree, which can result in death [8] as occur-
red in this case. A mechanism that may affect muscle
tonus in these patients is the presence of increased
bilirubin concentrations in blood. In addition, a possi-
ble increased liberation of nitric oxide associated with
obstructive jaundice have been reported in dogs [8].

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T.T. Diogenes, M.A. Rocha, K.O. Sampaio, et al. 2020. Primary Gallbladder Adenocarcinoma in a Cat.
Acta Scientiae Veterinariae. 48(Suppl 1): 540.
Prognosis for malignant hepatobiliary neopla-
sia is unfavorable with elevated metastasis rates [3],
which were not observed in this case. However, the
possibility was clear, considering the tumoral clots
identified in histopathological analysis.
The gallbladder adenocarcinoma should be
considered as a differential diagnosis for extrahepatic
biliary obstruction in cats, especially in cases that are
unresponsive to clinical treatment. Histopathology and
immunohistochemistry are key tests to confirm the
presence of this neoplasia. Despite the risk of death
during surgery, the indicated treatment is surgical
resection with the aim to promote better quality of life
for the animal.
MANUFACTURERS
1Takeda Pharma Ltda. Jaguariúna, SP, Brazil.
2Aché Laboratórios Farmacêuticos S.A. Guarulhos, SP, Brazil.
3Laboratório Bravet Ltda. Rio de Janeiro, RJ, Brazil.
4Ouro Fino Saúde Animal Ltda. Cravinhos, SP, Brazil.
5Cristália Produtos Químicos Farmacêuticos Ltda. Itapira, SP, Brazil.
6Zoetis Inc. Parsippany, NJ, USA.
Figure 1. Gallbladder carcinoma in a cat. Marked dilation and thickening
of gallbladder walls.
Figure 2. Gallbladder carcinoma in a cat. A- Marked proliferation of carcinoma cells with acini-like structures. Cell morphology range from polygonal
to cuboidal with scarce to moderate eosinophilic cytoplasm. Nuclei are round to oval with vacuolated chromatin and evident nucleoli [H.E.; Obj. 20x].
B- Intense cytoplasmatic immune marking of epithelial cells for CK Pan [Obj. 10x]. C- Moderate cytoplasmatic immune marking of epithelial cells for
CK7 [Obj. 40x]. D- Intense cytoplasmatic immune marking of epithelial cells for CK Pan [Obj. 20x].

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T.T. Diogenes, M.A. Rocha, K.O. Sampaio, et al. 2020. Primary Gallbladder Adenocarcinoma in a Cat.
Acta Scientiae Veterinariae. 48(Suppl 1): 540.
CR540
http://seer.ufrgs.br/ActaScientiaeVeterinariae
7Abcam Plc. Cambridge, RU, UK.
8Thermo Fisher Scientific Inc. Carlsbad, CA, USA.
9Dako North America Inc. Carpinteria, CA, USA.
Declaration of interest. The authors report no conflicts of
interest. The authors alone are responsible for the content and
writing of paper.
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