Abstract
Case summary
A 13-year-old spayed female domestic shorthair cat presented with jaundice, showing increased levels of serum liver enzymes and total bilirubin. Abdominal ultrasound revealed a tortuous, dilated common bile duct and a 5–6 mm isoechoic mass near the greater papilla in the duodenum. A CT scan revealed the presence of a duodenal mass that disrupted mucosal continuity and obstructed the common bile and pancreatic ducts. The cat underwent an excisional biopsy of the affected mucosa near the major duodenal papilla. Histopathological examination revealed adenocarcinoma, which was completely removed through duodenal resection. The pancreaticobiliary junction was then anastomosed to the afferent duodenal loop, followed by a gastrojejunostomy procedure. The postoperative total serum bilirubin and pancreatic enzyme levels were within the reference interval. The patient showed no signs of recurrence on postoperative day 408.
Relevance and novel information
This study reports the first case of duodenal peripapillary adenocarcinoma in a cat with long-term postoperative survival. After the complete peripapillary adenocarcinoma resection, a successful surgical digestive system reconstruction was conducted through gastrojejunostomy and pancreaticobiliary junction anastomosis to the duodenum. This approach shows potential as a treatment for duodenal lesions involving the major papilla in cats.
Keywords: Gastrojejunostomy, pancreaticobiliary junction, peripapillary adenocarcinoma, reconstruction
Case description
A 13-year-old spayed female domestic shorthair cat was brought to our hospital as a result of anorexia that had persisted for 18 days. The cat experienced loss of appetite, lethargy, vomiting and weight loss over 3 months. Physical examination indicated mild jaundice. Complete blood cell count showed no abnormalities. Alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP) and total bilirubin (TBIL) serum levels were elevated (Table 1).
Table 1.
Perioperative blood examination of the present case
| Variable | Day 1 | Day 8 | POD 10 | POD 24 | POD 104 | RI |
|---|---|---|---|---|---|---|
| HCT (%) | 32.5 | 30.1 | 27.3 | 25.5 | 40.6 | 24–45 |
| RBC (×104/μl) | 674 | 612 | 560 | 528 | 852 | 550–1000 |
| HGB (g/dl) | 11.1 | 10.3 | 9.1 | 8.8 | 14.2 | 8–14 |
| WBC (/μl) | 11,700 | 15,300 | 34,500 | 19,300 | 13,200 | 6000–18,000 |
| PLT (×104/μl) | 36.2 | 37.8 | 59.4 | 59.1 | 55.5 | 30–80 |
| TBIL (mg/dl) | 2.1 | 10.1 | 0.5 | 0.1 | 0.1 | 0.1–0.4 |
| ALT (U/l) | 954 | NE | NE | 97 | 56 | 22–84 |
| AST (U/l) | 344 | NE | NE | 40 | 52 | 18–51 |
| ALP (U/l) | 225 | NE | NE | 49 | 24 | 0–58 |
| ALB (g/dl) | 2.8 | NE | NE | 2.4 | 2.1 | 2.3–3.5 |
| SAA (μg/ml) | <3.75 | NE | NE | 19.76 | NE | 0–5.49 |
ALB = albumin; ALP = alkaline phosphatase; ALT = alanine aminotransferase; AST = aspartate aminotransferase; HCT = haematocrit; HGB = haemoglobin; NE = not evaluated; PLT = platelet count; POD = postoperative day; RBC = red blood cell count; RI = reference interval; SAA = serum amyloid A; TBIL = total bilirubin; WBC = white blood cell count
An abdominal ultrasound detected a 5–6 mm spher-ical mass near the major duodenal papilla, leading to a tortuous, dilated common bile duct (CBD) with a diameter of 6–7 mm. An abdominal CT scan (Supria; Hitachi Medical Systems) showed a duodenal mass lesion that disrupted mucosal continuity and obstructed the CBD, resulting in the dilation of the extra- and intrahepatic bile ducts (Figure 1). The CT scan revealed no metastatic lesions in distant organs. Cholecystocentesis was conducted under anaesthesia after the CT scan, yielding viscous bile, which was submitted for bacterial culture, yielding negative results. Mass lesion biopsy was conducted on day 2 after the initial evaluation.
Figure 1.
(a) Transverse contrast-enhanced CT image. Mass lesion (white arrows). (b) Contrast-enhanced dorsal reconstructed image presenting mucosal continuity loss over the duodenal mass lesion (white arrowheads), which obstructed the common bile duct and caused extra- and intrahepatic bile duct dilation
Midline celiotomy was conducted, revealing extensive CBD and pancreatic duct (PD) dilation (Figure 2). An incision was made on the antimesenteric side of the duodenum, near the major papilla, to biopsy the tumour. A 4 Fr feeding catheter (Atom Pink Catheter; Atom Medical) was inserted through the major papilla to minimise the risk of damaging the duodenal papilla during biopsy. Punch and excision biopsies of the mass were conducted. After biopsy, the incision was closed using a 4-0 polydioxanone suture (PDS Plus; Johnson & Johnson) in a simple interrupted pattern, and the abdominal wall was also closed.
Figure 2.
(a) Dorsal view. After laparotomy, the common bile duct (white arrow) and pancreatic ducts (white arrowhead) were dilated. The extension within the duodenum (asterisk) could also be observed. The upper right and lower left sides of the image show the cranial and caudal aspects, respectively. (b) Duodenal papillary region
Histopathological examination revealed tumour tissue of atypical glandular epithelial origin in the mucosal layer. There was a diagnosis of adenocarcin-oma and increased TBIL levels (10.1 mg/dl) (Table 1). Consequently, surgical resection of the mass and digestive tract reconstruction were required 11 days after the initial evaluation.
Atropine sulphate (0.5 mg/kg IV; Nipro ES Pharma) was administered, followed by anaesthesia induction with propofol (6 mg/kg IV, PropoFlo 28; Zoetis). After intubation, general anaesthesia was maintained using isoflurane (0.8–1.0%) under oxygen therapy during mechanical ventilation, ensuring an end-tidal CO2 of 30–40 mmHg. Lactated Ringer’s solution (5 ml/kg/h; Terumo) was administered intraoperatively. Intraoperative analgesia was provided through a continuous rate infusion (CRI) of fentanyl (2.5–7.5 μg/kg/h; Daiichi Sankyo). Ampicillin sodium (10 mg/kg IV, Viccillin; Meiji Seika Pharma) was administered 30 mins preoperatively and every 90 mins thereafter. Noradrenaline (0.25–0.5 μg/kg/min; Alfresa Pharma) was administered intraoperatively. Rocuronium bromide (0.5 mg/kg/h, Eslax; MSD) was used as a muscle relaxant to reduce isoflurane requirement.
A midline celiotomy was conducted from the xiphoid process to the umbilicus with the cat in dorsal recumbency. CBD and PD were dilated; however, the PD diameter had decreased since the previous surgery. Tumour areas in the duodenum and pancreas were carefully dissected using electrocautery, and no accessory PD was detected. The duodenum was resected with a 2 cm margin on both sides of the tumour. A margin of approximately 3 mm was left, and the tumour-connected CBD and PD were cut. The tumour at the major papilla was resected en bloc (Figure 3a). Each resected pyloric antrum and duodenum stump was closed with a 4-0 polydioxanone suture using a simple interrupted pattern. A longitudinal incision of approximately 1 cm was made in the duodenum approximately 1 cm distal to the closed duodenal stump. The dilated CBD was then anastomosed to the proximal portion of the incised duodenal orifice using a 5-0 polydioxanone suture. The transected PD was catheterised and tem-porarily secured with a 3 Fr feeding catheter using a purse-string suture with 7-0 polydioxanone suture. The other end of the catheter was inserted into the distal duodenum. The resected stump of the PD and adjacent pancreatic tissues were buried in the incised duodenal opening and sutured using a 6-0 polydioxanone suture (Figure 3b,c). Upon CBD and PD reconstruction, the Billroth II 1 procedure with antiperistaltic side-to-side gastrojejunostomy was conducted using a simple continuous pattern with a 4-0 polydioxanone suture. A Braun anastomosis 2 was created through side-to-side enteroenterostomy as follows: occluding with finger pressure, 3 cm full-thickness incisions were made in the afferent and efferent jejunal loops approximately 20 cm distal to the gastrojejunostomy site. The anastomosis was conducted using a simple continuous pattern with a 4-0 polydioxanone suture. A 6.5 Fr transgastric enteral tube (outer diameter 2.3 mm) (Kangaroo; Covidien) was placed, with its tip positioned 5 cm beyond the Braun anastomosis (Figure 4). In addition, an abdom-inal drainage tube was inserted and the abdominal wall was subsequently closed.
Figure 3.
(a) Pancreas detachment from the duodenum through electrocautery (white dotted line). A 2 cm margin was established, and tumour resection was achieved by common bile duct (CBD) and pancreatic duct (PD) (red dotted line) transections. The dotted line box highlights the tumour. (b) A new longitudinal incision was made on the antimesenteric aspect of the duodenum remnant. The dilated CBD was end-to-side anastomosed to the proximal segment of the new opening using a 5-0 polydioxanone suture. The yellow arrow indicates the choledochoduodenostomy. The transected PD was catheterised and temporarily secured with a 3 Fr multipurpose catheter with purse-string suture using a 7-0 polydioxanone suture (blue arrow, as shown in the illustration in panel c). The catheter was inserted into the distal portion of the duodenum. The catheterised PD and adjacent pancreatic tissue were buried into the remaining distal duodenal incision and sutured with a 6-0 polydioxanone suture (black arrow, as shown in the illustration in panel c). (c) Choledochoduodenostomy (yellow arrow) and invagination pancreaticoduodenostomy (black arrow). The blue arrow indicates the PD secured with a catheter with purse-string suture
Figure 4.
(a) After biliary and pancreatic duct reconstruction, Billroth II surgery was conducted using peristaltic-side gastrojejunostomy (white arrow). An additional Braun anastomosis was conducted 20 cm downstream between the jejunal limbs (white arrowhead). (b) Surgical procedure. The tip of the transgastric enteral tube was advanced 5 cm beyond the anastomosis site
The cat recovered uneventfully from the anaesthesia. The operative time from skin incision to closure was 368 mins. Postoperatively, the cat received a CRI of fentanyl (2.5 μg/kg/h) and noradrenaline (0.1–0.5 μg/kg/min) for 8 and 48 h, respectively, then ampicillin sodium and famotidine (Gaster; LTL Pharma) intravenously as well as the antiemetic maropitant (Cerenia; Zoetis) subcutaneously for 5 days.
Histopathological examination revealed tumour infiltration extending into the intestinal mucosa, submucosa, muscularis interstitium, papillary interstitium and bile duct mucosal layer of the affected area. A complete resection was achieved (Figure 5). Postoperatively, the cat was placed on a liquid diet through an enteral tube at a rate of 4–6 ml/h using a syringe pump, providing 25% of the daily caloric requirement to help prevent afferent loop and dumping syndromes. Ultrasound examinations were conducted daily.
Figure 5.
(a) Resected mass sent for histopathological examination. (b) Histopathological examination revealed duodenal adenocarcinoma with clear and complete margins
On postoperative day (POD) 6, almost no drainage was observed from the abdominal tube, prompting its removal. Gastrointestinal imaging was conducted using iopamidol (2 ml/kg; Fuji Pharma) to assess bowel motility and contrast flow on POD 10. Gastric emptying was delayed; nevertheless, no leakage was found at the anastomotic site. The contrast medium reached the rectum 7 h after administration (Figure 6). The serum TBIL level was nearly normal, but there was an increase in the white blood cell (WBC) count (Table 1). An ultrasound examination revealed no abnormalities. On POD 15, despite the ultrasound results being normal, the cat experienced delayed gastric emptying episodes with vomiting and fever. Subcutaneous maropitant and continuous intravenous metoclopramide hydrochloride (0.04 mg/kg/h CRI, Primperan; Nichi-Iko Pharma) were administered. Vomiting and fever subsided on POD 18, and appetite improved on POD 19. By POD 24, serum TBIL, AST and ALP levels returned to normal (Table 1). A CT scan on POD 24 revealed a mildly thickened gallbladder and slightly dilated CBD. The pancreatic tube remained in place. To enable medication and nutrition-al supplement administration, the enteral tube was replaced with a percutaneous endoscopic gastrostomy tube (PEG-20; Mila International) after CT under anaesthesia. The cat was discharged on POD 30.
Figure 6.
Despite delayed gastric emptying, no anastomotic leak was observed on gastrointestinal contrast radiography. The contrast medium reached the rectum 7 h after administration
Three months postoperatively, the cat showed no signs of adenocarcinoma. A CT scan revealed no recurrence or metastasis of adenocarcinoma and the pancreatic tube was invisible (Figure 7). The liver panel results were normal (Table 1). The gastrostomy tube was removed since the cat was eating adequately and medications could be administered orally. At 14 months postoperatively, the cat remained healthy.
Figure 7.
CT was conducted on postoperative day 24. (a) A slightly thickened gallbladder and mildly dilated common bile duct were observed. Nonetheless, the pancreatic duct was invisible. A pancreatic tube was observed. (b) A CT scan was performed 3 months postoperatively and showed no signs of recurrence, metastasis or carcinomatosis. The pancreatic tube was no longer visible
Discussion
Adenocarcinoma in the duodenal papilla has been previously reported in cats;3,4 however, its optimal treatment remains unclear. This study is the first to describe the surgical treatment and clinical course of duodenal papillary adenocarcinoma in cats. The en bloc duodenal papilla tumour resection requires biliary tract and PD reconstruction. Cholecystoenterostomy is associated with poor prognosis in cats, with a 50% overall mortality rate and almost 100% mortality when neoplasia is present. 5 Only 50% of patients survive beyond 2 weeks, with 23% surviving longer than 6 months. 6 Postoperative intermittent vomiting and loss of appetite are likely due to cholangiohepatitis caused by the reflux of intestinal content into the gallbladder. 7 In addition, although pancreatic reconstruction is necessary, limited data are available on this challenging procedure in small animals. 8
In humans, pathologies in the periampullary region are usually treated using the Whipple procedure, 9 which involves the removal and reconstruction of the upper gastrointestinal tract. Referencing the Whipple procedure, we chose to conduct direct PD and CBD anastomosis to the duodenum. CBD anastomosis was feasible because of the dilated CBD. Invagination, a technique applied in the Whipple procedure, was used during PD reconstruction to minimise the risk of pancreatic leakage and fistula formation.8,10 Furthermore, using Billroth II instead of directly connecting the resected duodenal segments could reduce intestinal debris within the biliary–enteric anastomosis, thereby minimising the risk of ascending cholangiohepatitis caused by enterobiliary reflux. 7 After resecting the duodenal papillary tumour, Roux-en-Y anastomosis was also an option. The Billroth II procedure facilitates digestive secretion mixing with food in the stomach. Conversely, the Roux-en-Y technique interposes a jejunal loop between the stomach and proximal jejunum, allowing mixing to occur distal to the stomach. 11 In humans, the Roux-en-Y procedure is often used as a substitute for Billroth II to reduce the risk of afferent loop syndrome and bile reflux into the stomach. 12 Nonetheless, future studies should conduct a comparative analysis of Roux-en-Y with Billroth II. Braun anastomosis is often used to reduce Billroth II surgery-associated complications, such as afferent loop syndrome and alkaline reflux gastritis; nevertheless, 13 further studies are needed on this procedure in small animals.
Dumping syndrome is a complication often linked with Billroth II surgery in humans. 14 Transiently elevated WBC count, vomiting and fever during hospitalisation were attributed to gastrointestinal inflammation caused by the surgical procedure (as ultrasound revealed no abnormalities); however, it is possible that the vomiting could be partially associated with dumping syndrome. However, its occurrence in dogs and cats has not been proven.
A limitation of this study is that the postoperative antibiotics used were not evidence-based. 15 In addition, local anaesthesia blocks were not used for this invasive surgery, 5 presenting a consideration for future studies. However, these studies are limited by the rarity of this tumour in cats. Despite the small number of clinical cases and published surgical techniques, this case report indicates that this approach should be considered as a treatment option for duodenal adenocarcinoma.
Conclusions
This study reports the first case of duodenal peripapillary adenocarcinoma in a cat with long-term postoperative survival. The surgical reconstruction, involving gastrojejunostomy and pancreaticobiliary junction anastomosis to the duodenum, was feasible after the complete resection of the peripapillary adenocarcinoma. This approach is a viable option for treating major papilla-involving duodenal lesions in cats.
Acknowledgments
We would like to thank Noriko Nagata DVM, medical illustrator of LAIMAN Corporation, for medical illustration and Kazuko Hirayama DVM, PhD, DJCVP, for providing advice on histopathology. We would also like to thank Editage for the English language review.
Footnotes
Accepted: 17 September 2025
Author note: This case report was presented at the 11th Annual Congress of the Asian Society of Veterinary Surgery in Nagoya, Japan in 2023.
The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Funding: The authors received no financial support for the research, authorship, and/or publication of this article.
Ethical approval: The work described in this manuscript involved the use of non-experimental (owned or unowned) animals. Established internationally recognised high standards (‘best practice’) of veterinary clinical care for the individual patient were always followed and/or this work involved the use of cadavers. Ethical approval from a committee was therefore not specifically required for publication in JFMS Open Reports. Although not required, where ethical approval was still obtained it is stated in the manuscript.
Informed consent: Informed consent (verbal or written) was obtained from the owner or legal custodian of all animal(s) described in this work (experimental or non-experimental animals, including cadavers, tissues and samples) for all procedure(s) undertaken (prospective or retrospective studies). No animals or people are identifiable within this publication, and therefore additional informed consent for publication was not required.
ORCID iD: Fumiya Osaka
https://orcid.org/0009-0007-2926-3305
Chieh-Jen (John) Cheng
https://orcid.org/0000-0003-3376-5440
Kazushi Asano
https://orcid.org/0000-0003-0099-7974
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