Kazushi Asano

Background: Differentiation of catecholamine-producing tumours from other adrenal tumours remains difficult. Chromogranin A (CgA) is a marker for catecholamine secretion in the body. An assay for quantification of the CgA epitopes vasostatin and catestatin has been validated for use in dogs but not yet evaluated in dogs with catecholamine-producing tumours. The aims were to evaluate the assays foranalysis of plasma concentrations of the CgA epitopes vasostatin and catestatin in dogs with adrenal tumours and to compare concentrations between catecholamine-producing tumours and adrenocortical tumours in dogs that were subjected to adrenalectomy. Twelve dogs with histopathologically confirmed catecholamine-secreting tumours (eleven pheochromocytomas (PCCs), one extra-adrenal sympathetic paraganglioma (PGL)) and twelve with adrenocortical tumours were included in the study. Plasma concentrations of the CgA epitopes vasostatin and catestatin were determined byradioimmunoassay (RIA), before adrenalectomy in 23 out of 24 dogs and after adrenalectomy in six of the dogs with catecholamine-secreting tumours (five PCC, one PGL). Tumour diagnosis was made by histopathology in all cases. Results: Overall, median plasma concentration of the CgA epitopevasostatin in dogs with catecholamine-secreting tumours was 0.82 nmol/L (interquartile range (IQR) 0.52 to 1.60 nmol/L), which was significantly higher(Wilcoxon rank sum exact test, P= 0.0374) than the vasostatin concentration in adrenocortical tumours (median 0.50; IQR 0.34 to 0.59 nmol/L). A subsetof dogs (5/12) with catecholamine-secreting tumours had elevated plasma vasostatin concentrations preoperatively. After successful surgery, thepreoperatively elevated plasma vasostatin concentrations decreased numerically, however without reaching statistical significance. Catestatin concentrationdid not differ between tumour types. Conclusions: Elevated plasma concentration of the CgA epitope vasostatin showed potential as a biomarker for asubset of catecholamine-secreting tumours.

Liver lobe torsion (LLT) is a rare, potentially life‐threatening condition in dogs and is reported most often in medium‐ to large‐breed dogs. Neoplasia‐associated LLT is unusual, and detailed descriptions of LLT associated with hepatocellular carcinoma (HCC) are scarce. A 12‐year‐old spayed female Pembroke Welsh Corgi (9.5 kg) presented with acute collapse after several months of progressive lethargy and inappetence. Laboratory abnormalities included increased alanine aminotransferase and aspartate aminotransferase activities and C‐reactive protein concentration. Computed tomography (CT) identified a 7.2 × 6.7 × 6.5 cm mass arising from the left medial liver lobe, a whirl sign at the base of the mass and a non‐enhancing hypoattenuating region consistent with necrosis. Midline celiotomy and left medial liver lobectomy were performed without detorsion. Cytology of abdominal effusion was consistent with a culture‐negative inflammatory exudate. Histopathology confirmed HCC with extensive necrosis, and the examined surgical margin was free of neoplastic cells. The dog recovered uneventfully, was discharged on postoperative Day 4 and had no recurrence of clinical abnormalities at 1‐year follow‐up. This case highlights the apparent association between HCC and LLT and the unusual location of the torsion axis at the base of the mass rather than at the hepatic hilus, although causality cannot be established from a single case. CT visualisation of the whirl sign at this atypical site was instrumental in establishing the preoperative diagnosis and guiding surgical planning.

Objective: To characterize CT perfusion (CTP)-derived time to highest observed adrenal tissue enhancement (T-peak) and arterial blood flow (AF), evaluate associations with triple-phase CT findings, and assess the diagnostic performance of T-peak, AF, and the tumor-to-contralateral adrenal AF ratio for differentiating pheochromocytomas from adrenocortical tumors. Methods: Historical CTP data from 5 healthy Beagles served as controls. Client-owned dogs evaluated from November 21, 2024, through May 31, 2026, underwent triple-phase CT, CTP, adrenalectomy, and histopathology. Time to highest observed adrenal tissue enhancement was the interval from contrast administration to the greatest sampled adrenal attenuation; AF was calculated with a single-input maximum-slope model. Results: 20 dogs with 22 tumors (8 adrenocortical adenomas, 7 adrenocortical carcinomas, and 7 pheochromocytomas [PHEOs]) were included. Time to highest observed adrenal tissue enhancement was longer in both adrenocortical tumor groups than in PHEOs; a post hoc cutoff < 36.0 seconds yielded apparent 100% sensitivity and specificity. Arterial blood flow was lower in both adrenocortical tumor groups than in controls and higher in PHEOs than in adrenocortical carcinomas. Arterial blood flow had an area under the curve of 0.923; a cutoff > 100.60 mL/min/100 mL yielded apparent 85.7% sensitivity and 100% specificity. Among 17 dogs with unilateral tumors, the tumor-to-contralateral AF ratio completely separated PHEOs from adrenocortical tumors. Arterial blood flow correlated positively with CT wash-in and washout indices, whereas T-peak correlated negatively with arterial- and venous-phase percentage enhancement washout. Conclusions: Time to highest observed adrenal tissue enhancement and AF differed among adrenal tumor types and were associated with CT enhancement characteristics. Clinical Relevance: Computed tomography perfusion may provide adjunctive information for preoperative adrenal tumor characterization, but the proposed thresholds require validation in larger independent cohorts.

Objective: To describe staged pre‐renal caudal vena cava (CVC) occlusion before en bloc right divisional hepatectomy with segmental caval resection in two dogs with right divisional hepatocellular carcinoma (HCC) involving the CVC. Animals: Two client‐owned, 11‐year‐old neutered male dogs (Siberian Husky and Shih Tzu). Study design: Short case series. Methods: Dog 1 (Siberian Husky) had prior hemoperitoneum and biopsy‐confirmed HCC; dog 2 (Shih Tzu) had persistent liver enzyme elevations and a suspected hepatic tumor. Computed tomography (CT) showed right divisional masses (91.8 × 122.3 × 101.4 mm; 77.0 × 94.8 × 70.2 mm) with CVC compression or involvement and no pre‐existing collateral venous return. A percutaneously controlled hydraulic occluder was placed around the pre‐renal CVC. Gradual outpatient occlusion was performed over 79 and 44 days while monitoring saphenous venous pressure, renal values, and hindlimb edema. Complete CVC occlusion and collateralization were confirmed by CT before en bloc right divisional hepatectomy with segmental CVC resection. Results: Macroscopically complete resection was achieved in both dogs. Complete HCC resection was confirmed histopathologically. Morbidity was limited to transient wound exudation in dog 1 and transient ascites in dog 2. No recurrence or metastasis was identified in dog 1 during follow‐up. In dog 2, no clinical signs suggestive of recurrence or metastasis were reported. Survival after hepatectomy was 352 and 2467 days. Conclusion: Staged pre‐renal CVC occlusion may establish collateral venous return and permit planned en bloc right divisional hepatectomy with segmental CVC resection in carefully selected dogs with right divisional HCC involving the CVC.

Objective: To characterize CT perfusion (CTP) in canine massive hepatocellular carcinoma (HCC) and explore associations with descriptive histomorphologic differentiation categories. Methods: This retrospective study included 20 client-owned dogs with surgically excised, histopathologically confirmed HCC of the massive gross phenotype and interpretable preoperative CTP datasets. Hepatic arterial flow (HAF), portal venous flow (PVF), and hepatic perfusion index (HPI) were calculated with a dual-input maximum-slope method. Freehand tumor regions of interest were drawn as large as possible along tumor margins while excluding visible vessels and necrotic or cystic regions. The CTP metrics were compared between tumor and nontumorous liver and among differentiation groups. Results: Tumors had lower PVF than nontumorous liver (23.40 vs 127.15 mL/min/100 mL; P < .001) and higher HPI (65.81% vs 29.66%; P < .001), whereas HAF did not differ (52.98 vs 50.29 mL/min/100 mL; P = .154). Among differentiation groups, HAF differed (global P = .011; well > moderate; adjusted P = .042), PVF differed (global P = .025; poor < well; adjusted P = .031), and HPI did not differ (global P = .664). Conclusions: Canine HCC showed relative arterial dominance on CTP driven mainly by reduced PVF. Although HAF and PVF differed among differentiation categories, these findings should be interpreted cautiously because only 3 tumors were poorly differentiated. Clinical Relevance: CTP may provide quantitative arterial and portal perfusion information but should not replace morphologic imaging, surgical assessment, or other established diagnostic and prognostic approaches; it cannot define histologic type or differentiation or predict metastasis, resectability, or prognosis.

Background: Noninvasive biomarkers for canine prostatic adenocarcinoma (PAC) are lacking. Serum multi-element profiling by inductively coupled plasma-mass spectrometry (ICP-MS) may provide diagnostic information. Objectives: To derive preliminary reference intervals (PRIs) for 18 serum elements in clinically healthy male dogs, assess a Metallobalance index (MBI) for distinguishing PAC from controls, and explore associations with lymph node metastasis, surgical margin status, and postoperative change. Animals: The study included 115 dogs: clinically healthy males ( n = 65), dogs with benign prostatic hyperplasia (BPH; n = 25), one dog with a prostatic cyst, and dogs with histopathologically confirmed PAC ( n = 24). The diagnostic control group comprised 91 dogs. Methods: Serum concentrations of 18 elements were measured by ICP-MS, and central 95% PRIs were derived. An 18-element linear discriminant analysis (LDA) model generated the MBI. Cutoffs maximized Youden’s index; apparent performance was summarized by sensitivity, specificity, accuracy, and area under the receiver operating characteristic curve (AUC). Post hoc analyses restricted controls to dogs aged ≥7 years and compared BPH with PAC using the Study 1 MBI equation without refitting. Element-specific and clinicopathological subgroup analyses were exploratory. Results: PRIs were derived for all elements. The MBI showed high apparent discrimination between PAC and controls (AUC, 0.983). At a cutoff of 0.8030, sensitivity, specificity, and accuracy were 100.0, 92.3, and 93.9%, respectively. Apparent AUCs were 0.984 with age-restricted controls and 0.998 for BPH versus PAC. As these were unvalidated training-set estimates, they should not be interpreted as clinical performance. In dogs with PAC, preoperative MBI was higher with lymph node metastasis, but did not differ by surgical margin status or clearly change 2 weeks postoperatively. Conclusions and clinical relevance: ICP-MS-based multi-element profiling with LDA showed high apparent training-set discrimination of canine PAC from controls, including benign prostatic disease. The association with lymph node metastasis warrants further study, whereas findings did not support short-term postoperative monitoring or a validated prognostic role. Independent validation in a larger prospective cohort is required before clinical application.

Objective: To describe the perioperative and long‐term outcomes of dogs with massive hepatocellular carcinoma (HCC) in the right hepatic division causing compression or involvement of the caudal vena cava (CVC) treated with right divisional hepatectomy using temporary caval occlusion (TCO). Study design: Retrospective case series. Animals: Nineteen client‐owned dogs. Methods: Medical records were reviewed. Data collected included signalment, preoperative imaging findings, operative details, adjunct procedures, transfusion requirements, histopathological diagnosis and surgical margin status, perioperative complications, and survival to discharge. Long‐term outcome information was obtained from recheck examinations when available and from telephone interviews with referring veterinarians and/or owners. Results: Right divisional hepatectomy with TCO was completed in all dogs; a Pringle maneuver was used in two of 19 dogs. Median TCO duration was 17.6 min (range, 7.0–25.7) and median operative time was 82 min (range, 69–127). Primary suture repair of the CVC was required in six of 19 dogs. R0 resection was achieved in 14 of 19 dogs. One dog died on postoperative day 2; 18/19 dogs were discharged. Of these dogs, seven were alive without reported recurrence or intrahepatic metastasis at the last follow up, 95–1355 days after surgery, whereas 11 had died at a median of postoperative day 729 (range, 204–1154). Postoperative intrahepatic metastasis was suspected in two dogs. Conclusion: Temporary caval occlusion‐assisted right divisional hepatectomy provided venous control in selected dogs with massive right‐sided HCC and compression or involvement of the CVC, with no intraoperative mortality, one in‐hospital death, and postoperative complications in six of the 18 discharged dogs. Clinical significance: Temporary caval occlusion facilitates controlled dissection of the right hepatic veins and repair of small caval defects when present.

Background: Granulosa cell tumour (GCT) is the most common primary ovarian neoplasm in cats and may arise from residual ovarian tissue following incomplete spay procedures. Objectives: To describe the surgical management of a GCT identified in the setting of Ovarian Remnant Syndrome (ORS) in a spayed cat with hyperestrogenaemia without estrus signs, and to assess the potential utility of serum estradiol as an adjunct for diagnosis and postoperative monitoring. Methods: A 6‐year‐old female domestic shorthair cat, reportedly spayed, presented with a 2‐week history of weight gain and abdominal distension. Diagnostic imaging and cytology suggested a large neuroendocrine tumour occupying the abdominal cavity. Exploratory laparotomy was performed, and the abdominal mass along with one hepatic nodule was resected. Results: Histopathology confirmed GCT in the abdominal mass with hepatic metastasis. A preoperative serum sample collected at initial presentation and assayed after receipt of the histopathology report showed markedly increased estradiol. Although clinical signs improved after surgery, the cat re‐presented 4 weeks later with abdominal distension and severe anaemia; imaging revealed progression of hepatic lesions, and the patient died 5 weeks after surgery. Conclusions: This case highlights that GCT can occur in the setting of ORS without estrus signs, despite marked hyperestrogenaemia. Ovarian remnants may undergo neoplastic transformation and cause life‐threatening disease, even in the absence of estrus signs. Serum estradiol may be a valuable marker for diagnosis, treatment response, and recurrence monitoring in feline GCT.

Objective: To assess clinical presentation, treatment, and outcomes of dogs with two or three congenital extrahepatic portosystemic shunts (M‐EHPSS). Study design: Multi‐institutional retrospective study. Sample population: A total of 15 dogs with M‐EHPSS. Methods: Medical records were reviewed, and data was collected on dogs with M‐EHPSS diagnosed via computed tomography (CT) between 2008 and 2024. Signalment, clinical signs, bloodwork values, postoperative complications, long‐term clinical outcome, survival, and owner reported quality of life were recorded. Results: Approximately half of the dogs (7/15; 47%) were Miniature Schnauzers. Clinical signs and hematologic indicators at presentation were comparable to EHPSS. The mean dog age at diagnosis via CT imaging was 1451 days, and all dogs underwent surgical attenuation (SA) except for one that was ultimately lost to follow up examination. A total of 12 dogs had two shunts, and three dogs had three shunts. Seven dogs did not undergo attenuation of one shunt; these other shunts were either not initially suspected (5/7), the attenuation device was misplaced (1/7) or surgeon preference to not place attenuation device (1/7). Left gastro‐phrenic EHPSS were the only EHPSS not suspected initially. At the time of last follow‐up (median: 1253 days), 10/15 dogs were alive. Clinical outcomes were good or excellent in most dogs (12/14; 86%). Conclusion: These findings suggest that M‐EHPSS dogs have a similar prognosis to dogs with standard EHPSS dogs when all EHPSS are identified and treated with appropriate attenuation placement. A potential breed predisposition towards Miniature Schnauzers was identified. Clinical significance: This information provides guidance for treatment and prognosis of dogs with M‐EHPSS.

Objective: To describe the clinical application and outcome of the double‐flap technique (DFT) for oesophagogastric reconstruction following distal oesophagectomy and proximal gastrectomy in a cat with extensive oesophagogastric leiomyosarcoma. Study Design: Case report. Patient: A 10‐year‐old neutered male domestic shorthair cat. Case Description: Computed tomography revealed a large mass at the oesophagogastric junction in a cat with vomiting and regurgitation. Distal oesophagectomy and proximal gastrectomy were performed, followed by oesophagogastric reconstruction using the DFT, a valve‐forming technique involving two seromuscular flaps designed to reduce gastroesophageal reflux. Intraoperative oesophagogastric endoscopy was used to assess anastomotic patency and integrity. Outcome: The reconstruction using the DFT was feasible without intraoperative complications after the complete resection of the mass. The operation time was 134 min. The resected mass was histopathologically diagnosed as a leiomyosarcoma. Oral feeding resumed on postoperative Day (POD) 13. Although the cat required frequent small meals due to reduced gastric capacity, vomiting did not occur. No evidence of anastomotic leakage or reflux oesophagitis was observed. After a period of clinical stability, the cat presented on POD 53 with lethargy and anorexia. Metastatic disease was suspected, and the cat succumbed to cancer‐associated cachexia on POD 66. Conclusions: This is the first reported case of oesophagogastric reconstruction using the DFT following extensive resection of the oesophagogastric junction in a cat. The procedure was technically feasible and resulted in functionally effective reconstruction without evidence of reflux or anastomotic complications. The DFT may represent a viable surgical option for feline patients undergoing gastrectomy for oesophagogastric neoplasia.