Histological and immunohistochemical features of carcinomas with pulmonary involvement in cattle.

Primary pulmonary neoplasms in cattle are rare. There are few studies on the pathological findings of these neoplasms in this species. This study aimed to describe the histological and immunohistochemical findings of primary and metastatic pulmonary carcinomas in cattle. We conducted a retrospective study of 19 cases of epithelial neoplasms with pulmonary involvement. Histologically, most of the neoplasms were classified as primary pulmonary neoplasms, including different adenocarcinoma subtypes (4/19, 21%) and adenosquamous carcinomas (3/19, 16%), followed by squamous cell carcinoma (6/19, 32%), metastatic uterine adenocarcinoma (4/19, 21%), metastatic hepatocellular carcinoma (1/19, 5%), and metastatic cholangiocarcinoma (1/19, 5%). By immunohistochemistry, all neoplasms were positive for pancytokeratin, and 4/19 (21%) were positive for vimentin. Primary pulmonary neoplasms had immunoreactivity for thyroid transcription factor-1 (6/7), while only 2 of these cases were positive for napsin A. All cases with squamous differentiation (9/9) had immunoreactivity for cytokeratin (CK) 5/6, while only 7 of these cases were positive for p40. CK20, CK7, and CK8/18 showed varied immunoreactivity in the primary and metastatic pulmonary carcinomas but were important markers to confirm the diagnosis of primary mucinous adenocarcinoma and metastatic cholangiocarcinoma. HepPar-1 was only positive in the metastatic hepatocellular carcinoma. The limited number of cases of metastatic uterine adenocarcinomas in this study precluded identification of a specific immunophenotype for this tumor. Immunohistochemistry proved to be an important tool to confirm the proper classification of these neoplasms.

Diabetes Mellitus Following Resection of a Hepatocellular Carcinoma in a Dog Presented with Hypoglycemia.

A 5 yr old male neutered Labradoodle presented for an episode of acute collapse. Point-of-care blood work showed hypoglycemia and abdominal ultrasonography revealed a liver mass arising from the caudate liver lobe. The dog underwent a partial liver lobectomy, and histopathology confirmed a fully resected hepatocellular carcinoma. Blood glucose levels normalized initially after surgery, but 1 wk later, the patient was diagnosed with diabetes mellitus based on the development of polyuria, polydipsia, hyperglycemia, and glucosuria. Appropriate treatment with insulin was initiated, and 1 yr following the diagnosis, the dog was still requiring administration of insulin twice daily. This case describes the uncommon development of diabetes mellitus in a dog following surgical resection of a hepatocellular carcinoma initially associated with hypoglycemia. Although very unusual, this should be considered as a potential complication of surgical treatment of such tumors, and affected patients may require long-term medical management.

Canine primary liver tumors treated with stereotactic body radiation therapy: A case series.

Stereotactic body radiation therapy (SBRT) is an increasingly used alternative treatment option for nonresectable hepatocellular carcinoma (HCC) in people. Comparatively, the publication of SBRT of dogs with HCC is limited. The objective of this retrospective, descriptive case series was to evaluate the clinical outcomes and toxicity data of SBRT in dogs with HCC and imaging-documented primary liver tumors using volumetric-modulated arc therapy delivery at two private institutions. Medical records of 14 dogs treated between 2018 and 2023 were reviewed. All dogs had macroscopic tumors, and 9 of 14 dogs had HCC diagnoses confirmed on cytology or histopathology. The median longest tumor diameter was 5.5 cm. The median percentage of planning target volume relative to liver volume was 27.1%. Most dogs were treated with three daily fractions of 7-7.5 Gy. All dogs completed their radiotherapy protocols. Three of nine HCC dogs experienced partial responses and clinical improvement. Five of nine HCC dogs had stable disease. Overall median survival time was 164 days for nine HCC dogs (range: 93-706 days). One late grade 5 liver and two late grade 3 kidney side effects were reported. One dog received repeated SBRT to the same HCC treatment field, and one dog had two courses of SBRT to bifocal HCC treatment fields, both with no more than grade 2 acute and chronic toxicities.

PRIMARY HEPATIC NEOPLASIA IN THREE ADULT BAMBOO SHARKS (CHILOSCYLLIUM PLAGIOSUM AND CHILOSCYLLIUM PUNCTATUM) IN AN AQUARIUM POPULATION.

Neoplasia in elasmobranchs is uncommonly documented. This report describes primary hepatic neoplasia in three adult female bamboo sharks under managed care: biliary adenocarcinoma in a whitespotted bamboo shark (Case 1; Chiloscyllium plagiosum), biliary adenocarcinoma in a brownbanded bamboo shark (Case 2; Chiloscyllium punctatum), and hepatocellular carcinoma in a whitespotted bamboo shark (Case 3). Case 1 presented with extensive cutaneous papillomas and was electively euthanized. At necropsy, a 4-cm-diameter, pale-tan, firm hepatic mass was identified and diagnosed histologically as a biliary adenocarcinoma. Case 2 presented with decreasing body condition despite normal food intake. Coelomic ultrasound and exploratory surgery revealed several large masses in both hepatic lobes, and the patient was euthanized. At necropsy, nine, 1-6-cm-diameter, black to tan, firm hepatic masses were identified and diagnosed histologically as biliary adenocarcinoma with branchial intravascular neoplastic emboli. Case 3 presented for routine health examination and was euthanized for diagnostic purposes after coelomic ultrasound revealed multiple hepatic masses. At necropsy, two 1-3-cm-diameter, brown- and-black mottled, firm hepatic masses were identified and diagnosed histologically as hepatocellular carcinoma. Immunohistochemistry was performed in two of these cases and was noncontributory, likely because of a lack of cross reactivity between antibodies (antipancytokeratin) and elasmobranch tissues.

CONCURRENT IRON OVERLOAD AND NEOPLASIA IN LESCHENAULT'S ROUSETTES (ROUSETTUS LESCHENAULTII): A CASE SERIES.

This case series investigates a cluster of deaths in a captive colony of Leschenault's rousettes (Rousettus leschenaultii). Six of seven bats that died between March and September 2021 were diagnosed postmortem with both iron overload (IO) and neoplasia, neither of which have previously been reported in this species. Iron status was assessed via hepatic histopathological grading, hepatic iron concentration, and, in two cases, serum iron concentration. On histopathological grading, all cases had hemochromatosis except one, which had hemosiderosis. Hepatic iron concentrations did not correlate with histopathological grading. Neoplasms in these six bats included hepatocellular carcinoma (HCC; 4), bronchioloalveolar adenocarcinoma (1), pancreatic adenocarcinoma (1), and sarcoma of the spleen and stomach (1). One bat had two neoplasms (HCC and sarcoma of the spleen and stomach). One additional case of HCC in 2018 was identified on retrospective case review. Etiology was investigated to the extent possible in a clinical setting. Nutritional analysis and drinking water testing found oral iron intake within acceptable bounds; however, dietary vitamin C was potentially excessive and may have contributed to IO. Panhepadnavirus PCR testing of liver tissue was negative for all bats. A species-associated susceptibility to IO, as seen in Egyptian fruit bats (Rousettus aegyptiacus), is possible. The high incidence of HCC is suspected to be related to IO; other differentials include viral infection. Causes or contributing factors were not definitively identified for the other neoplasms seen but could include age, inherited risk (given a high level of inbreeding), or an oncogenic virus. Pending further research in this species, it is recommended that keepers of Leschenault's rousettes offer conservative amounts of vitamin C and iron (as for Egyptian fruit bats), submit for postmortem examination any euthanized or found dead, and share records of similar cases.

Multifocal Hepatocellular Carcinoma in a Malayan Wreathed Hornbill (Rhyticeros undulatus).

A 30-year-old female intact Malayan wreathed hornbill (Rhyticeros undulatus) was presented for presumed nesting behavior, progressive anorexia, dropping food, and coelomic distension. A complete blood count and plasma biochemistry analysis revealed marked inflammation, severe electrolyte abnormalities, elevated liver enzyme activities and bile acids, and normal plasma iron concentrations. Radiographic images of the patient were consistent with hepatomegaly and loss of serosal detail in the coelomic cavity. A computed tomography study revealed multiple poorly contrast-enhancing hepatic nodules, hepatoperitoneal and intestinal peritoneal fluid and gas, and a contrast-enhancing mass in the ventral coelom. Cytologic samples of the liver were consistent with necrosis, and the coelomic effusion was characterized as an aseptic suppurative exudate. An exploratory coeliotomy was performed and biopsy samples of the liver and a mesenteric mass were histologically interpreted as a tubular carcinoma with metastasis to the liver and secondary portal hepatitis. Euthanasia was elected and multiple liver masses and a peripancreatic mass were identified on necropsy. Histopathological samples collected during the postmortem gross examination showed multiple well-demarcated hepatic masses consisting of neoplastic hepatocytes encapsulated by fibrous tissue and proliferation of dysplastic biliary ductules, as well as a peripancreatic heterophilic granuloma with adjacent pancreatic atrophy and ductular proliferation. Ultimately, the patient was diagnosed with multifocal hepatocellular carcinoma and chronic granulomatous and heterophilic pancreatitis, steatitis, and coelomitis with intralesional bacteria. Malignant hepatobiliary neoplasia has been poorly documented in hornbills despite high anecdotal incidence in this and other avian species predisposed to iron storage disease. This report illustrates clinical and pathological information, including advanced imaging, which could aid in the diagnosis of this condition in hornbills and other avian species.

Fowl adenovirus serotype 4 enters leghorn male hepatocellular cells via the clathrin-mediated endocytosis pathway.

Hepatitis-hydropericardium syndrome (HHS) induced by fowl adenovirus serotype-4 (FAdV-4) has caused large economic losses to the world poultry industry in recent years. HHS is characterized by pericardial effusion and hepatitis, manifesting as a swollen liver with focal necroses and petechial haemorrhage. However, the process of FAdV-4 entry into hepatic cells remains largely unknown. In this paper, we present a comprehensive study on the entry mechanism of FAdV-4 into leghorn male hepatocellular (LMH) cells. We first observed that FAdV-4 internalization was inhibited by chlorpromazine and clathrin heavy chain (CHC) knockdown, suggesting that FAdV-4 entry into LMH cells depended on clathrin. By using the inhibitor dynasore, we showed that dynamin was required for FAdV-4 entry. In addition, we found that FAdV-4 entry was dependent on membrane cholesterol, while neither the knockdown of caveolin nor the inhibition of a tyrosine kinase-based signalling cascade affected FAdV-4 infection. These results suggested that FAdV-4 entry required cholesterol but not caveolae. We also found that macropinocytosis played a role, and phosphatidylinositol 3-kinase (PI3K) was required for FAdV-4 internalization. However, inhibitors of endosomal acidification did not prevent FAdV-4 entry. Taken together, our findings demonstrate that FAdV-4 enters LMH cells through dynamin- and cholesterol-dependent clathrin-mediated endocytosis, accompanied by the involvement of macropinocytosis requiring PI3K. Our work potentially provides insight into the entry mechanisms of other avian adenoviruses.

A 40-YEAR (1980-2019) RETROSPECTIVE REVIEW OF MORBIDITY AND MORTALITY OF FENNEC FOXES (VULPES ZERDA) AT THE BRONX AND PROSPECT PARK ZOOS.

The Wildlife Conservation Society (WCS) has housed fennec foxes (Vulpes zerda) at its facilities since the early 1900s and currently has one of the largest populations managed by the fennec fox Species Survival Plan. Of the 83 foxes held by WCS institutions between 1980 and 2019, 52 medical records and 48 postmortem reports were available for review. Common causes of morbidity included trauma and dermatologic disease, especially atopic dermatitis. Average age at death for animals surviving past 10 wk was 9.76 yr. Common causes of death or euthanasia were neoplasia (15/48, 31%) and infectious disease (14/48, 29%), with neoplastic processes incidentally identified in an additional seven animals. Significant antemortem cardiac changes were identified in 22 animals. Hepatocellular carcinoma (HCC) was diagnosed in nine animals, consistent with previous documentation of HCC as one of the most common neoplasms in this species. Four animals were suspected to have succumbed to vaccine-induced canine distemper virus after receiving a modified live vaccine. No canine distemper infections have been documented after 1981 in this population and since the use of a canarypox-vectored recombinant vaccine. Recommendations for management of this species include routine screening for hepatic neoplasia in adult animals, regular cardiac evaluations including electrocardiogram, echocardiogram, and dermatologic examination as described by the current consensus statement on canine atopic dermatitis. This descriptive morbidity and mortality report is the first for the fennec fox.

Clinical impact of near-infrared fluorescence imaging with indocyanine green on surgical treatment for hepatic masses in dogs.

BACKGROUND: Near-infrared fluorescence imaging using indocyanine green (ICG) is clinically applied to intraoperatively identify hepatic masses in humans. In addition, it is reported to be effective for assessing complete resection in human hepatocellular carcinoma (HCC). However, there is limited information on ICG fluorescence imaging for canine HCC, and its clinical usefulness is still unclear. Therefore, the purpose of this study was to evaluate the intraoperative identification and status of surgical margin for canine hepatic masses using near-infrared ICG fluorescence imaging. This clinical study included 104 dogs with hepatic masses. Between 12 and 24 h prior to surgery, ICG solution was injected intravenously at a dose of 0.5 mg/kg. The fluorescence intensity and pattern of each hepatic mass was investigated using an infrared camera before resection. After resection, the fluorescence intensity of the resection margin was also investigated. The resected masses were histopathologically diagnosed and compared using ICG fluorescence imaging. RESULTS: One hundred and twenty-two masses obtained from 104 dogs included 76 HCCs, 16 hepatocellular adenomas, 12 focal nodular hyperplasias, and 18 other lesions. Of the 122 masses, 106 (94 partial, 9 whole, and 3 ring fluorescence patterns), 7, and 9 masses showed increased, the same, or decreased fluorescence compared to the normal liver tissue, respectively. The fluorescence intensity and pattern were not significantly related to the histopathological diagnosis. The sensitivity and specificity of the margin evaluation in the 47 dogs were 100% and 77.3%, respectively. The median survival times in cases of HCC with complete and incomplete resection were 914 and 254 days, respectively. The median survival time of patients with a complete resection was significantly longer than that of patients with a incomplete resection (p = 0.043). CONCLUSION: ICG fluorescence imaging has potential clinical value for the identification and margin evaluation of canine hepatic masses. Although it is difficult to use fluorescence imaging for the differential diagnosis of liver tumours, it may be useful for assessing complete resection in cases of hepatic masses demonstrating increased fluorescence in dogs, and complete resection of HCC could have a survival benefit.

Hepatocellular carcinomas in captive prosimians.

We performed a retrospective examination of spontaneous hepatocellular carcinomas (HCCs) (primary and metastatic tumors) in 14 captive prosimians brought to the Veterinary Medical Diagnostic Laboratory in North Carolina State University over a period of 11 years (2003 to 2014) to characterize the tumors. These animals are endangered primates; a better understanding of the main fatal neoplasms is crucial. In addition to the histologic evaluation, an immunohistochemical study was also performed, using a hepatocyte marker (hepatocyte paraffin 1 [HepPar-1]) and 2 cholangiocyte markers (keratin 7 [K7] and keratin 19 [K19]), in an attempt to identify a specific profile for HCCs with metastatic behavior. Six of the 14 HCCs had pulmonary metastases. The most frequent histopathological findings were a trabecular pattern (14/14, 100%), presence of multinucleated cells (12/14, 85.7%), and foci of extramedullary hematopoiesis (9/14, 64.3%). The mitotic count was significantly higher in the metastatic HCCs (P < .05). HepPar-1 was detected in all primary and metastatic HCCs, with a strong intensity of staining. Labeling for K7 and K19 was positive in 12 HCCs (85.7%) and 1 HCC (7.1%), respectively. Contrary to the less aggressive HCCs, most of the metastatic HCCs (5/6) expressed K7 in more than 15% of cells. The percentage of K7-positive neoplastic hepatocytes was significantly higher in metastatic HCCs. This study suggests that K7 might be a prognostically relevant marker in HCCs of captive prosimians.

Post-castration prostatic involution: A morphometric and endocrine study of healthy canines and those with benign prostatic hyperplasia.

The objective of this study was to evaluate the effect of castration on dimensions of the prostate by B-mode ultrasound for 90 days, as well as to evaluate changes in serum concentrations of testosterone and oestradiol in clinically healthy canines and those with benign prostatic hyperplasia (BPH). Three groups of animals were used: healthy canines castrated on day 0 (HCC, n = 8), canines with a diagnosis of benign prostatic hyperplasia (BPHC, n = 9) castrated on day 0 and healthy uncastrated canines (IHCC, n = 10). Prostate size was obtained by B-mode ultrasound, while blood samples were collected (days 0, 7, 14, 28, 60 and 90 post-castration) to determine the serum testosterone and oestradiol concentration. Castration did not affect serum oestradiol concentrations. Castration led to a decrease in serum testosterone (reaching values <20 ng/dl in the first week, p < .05), causing a gradual decrease in dimensions of prostate parameters relative to body weight (p < .05). Canines with BPHC had similar prostate dimensions as the IHCC group 2 weeks post-castration. In relation to the prostate's relative parameters, the decrease with time was greater in canines with BPHC than those in the HCC group. When evaluating parameters as a percentage of relative change, the decrease with time was similar in both castrated groups, except for relative length percentage, which presented a more pronounced decline in BPHC canines than HCC canines. In conclusion, castration is an effective, fast and long-lasting treatment for canine patients with BPH, as it causes a rapid decrease in blood testosterone concentrations and a decrease in glandular volume, but does not affect serum oestradiol concentrations. This study did not determine the mechanisms of action, but allowed us to observe (based on morphometric variables) that characteristics of prostate involution after castration differed between canines with BPH and healthy canines.

Hepatocyte ploidy in cats with and without hepatocellular carcinoma.

BACKGROUND: Domestic cats rarely develop hepatocellular carcinoma. The reason for the low prevalence is unknown. Reductions in hepatocellular ploidy have been associated with hepatic carcinogenesis. Recent work in mice has shown that livers with more polyploid hepatocytes are protected against the development of hepatocellular carcinoma. Hepatocyte ploidy in the domestic cat has not been evaluated. We hypothesized that ploidy would be reduced in peri-tumoral and neoplastic hepatocytes compared to normal feline hepatocytes. Using integrated fluorescence microscopy, we quantified the spectra of ploidy in hepatocellular carcinoma and healthy control tissue from paraffin embedded tissue sections. RESULTS: Feline hepatocytes are predominantly mononuclear and the number of nuclei per hepatocyte did not differ significantly between groups. Normal cats have a greater number of tetraploid hepatocytes than cats with hepatocellular carcinoma. CONCLUSIONS: Total hepatocellular polyploidy in normal cat liver is consistent with values reported in humans, yet cellular ploidy (nuclei per cell) is greater in humans than in cats. Tetraploid cat hepatocytes are predominantly mononuclear.

High-Frequency Irreversible Electroporation for Treatment of Primary Liver Cancer: A Proof-of-Principle Study in Canine Hepatocellular Carcinoma.

PURPOSE: To determine the safety and feasibility of percutaneous high-frequency irreversible electroporation (HFIRE) for primary liver cancer and evaluate the HFIRE-induced local immune response. MATERIALS AND METHODS: HFIRE therapy was delivered percutaneously in 3 canine patients with resectable hepatocellular carcinoma (HCC) in the absence of intraoperative paralytic agents or cardiac synchronization. Pre- and post-HFIRE biopsy samples were processed with histopathology and immunohistochemistry for CD3, CD4, CD8, and CD79a. Blood was collected on days 0, 2, and 4 for complete blood count and chemistry. Numeric models were developed to determine the treatment-specific lethal thresholds for malignant canine liver tissue and healthy porcine liver tissue. RESULTS: HFIRE resulted in predictable ablation volumes as assessed by posttreatment CT. No detectable cardiac interference and minimal muscle contraction occurred during HFIRE. No clinically significant adverse events occurred secondary to HFIRE. Microscopically, a well-defined ablation zone surrounded by a reactive zone was evident in the majority of samples. This zone was composed primarily of maturing collagen interspersed with CD3+/CD4-/CD8- lymphocytes in a proinflammatory microenvironment. The average ablation volumes for the canine HCC patients and the healthy porcine tissue were 3.89 cm3 ± 0.74 and 1.56 cm3 ± 0.16, respectively (P = .03), and the respective average lethal thresholds were 710 V/cm ± 28.2 and 957 V/cm ± 24.4 V/cm (P = .0004). CONCLUSIONS: HFIRE can safely and effectively be delivered percutaneously, results in a predictable ablation volume, and is associated with lymphocytic tumor infiltration. This is the first step toward the use of HFIRE for treatment of unresectable liver tumors.

Ovarian teratoma in a woodchuck (Marmota monax) with hepatocellular carcinoma: radiologic and pathologic features.

BACKGROUND: Teratomas are germ cell neoplasms composed of a wide variety of tissues. In the woodchuck, only one testicular teratoma has been described in the literature. The objective of this report was to describe the radiologic and pathologic findings in a female woodchuck (Marmota monax) with an ovarian teratoma consisting of mature tissues originating from all three germ layers. CASE PRESENTATION: A 2-year-old female woodchuck that had been infected at birth with woodchuck hepatitis virus and subsequently developed hepatocellular carcinoma was incidentally discovered to have a mobile 6.6 × 4.8 × 4.7 cm abdominal mass on computed tomography (CT) imaging. The tumor was predominantly solid and heterogenous on CT with soft tissue, fat, and areas of dense calcification. The teratoma did not enhance with intravenous contrast administration. On ultrasound, the tumor was solid with heterogeneous echogenicity, reflecting the fat content and areas of calcification. Sonolucent areas were present that may have represented cysts. There was heterogeneously increased signal on T1-weighted magnetic resonance imaging (MRI) and heterogeneous hyperintensity in T2-weighted imaging. Fat was evident within the tumor. At necropsy, the tumor was attached to the distal end of the right uterine horn. Histopathology showed mature tissue types representing all three germ layers. CONCLUSIONS: Ovarian teratoma should be considered in the differential diagnosis of ovarian or abdominal masses in woodchucks. The tumor displayed mature tissue derived from all three germ layers. CT, ultrasound, and MRI findings were presented in detail and matched the typical imaging appearance of teratomas.

RETROSPECTIVE EVALUATION OF HEPATOCELLULAR NEOPLASMS IN NILE LECHWE (KOBUS MEGACEROS) FROM TWO FLORIDA ZOOLOGICAL INSTITUTIONS.

This case series describes hepatocellular neoplasms in 10 Nile lechwe (Kobus megaceros) at two separate zoological institutions in Florida. Histologically, the neoplasms were classified as hepatocellular carcinoma (n = 7), hepatocellular adenoma (n = 2), and hepatobiliary carcinoma (n = 1). Common clinical signs were nonspecific and included thin body condition (n =7), lethargy (n =6), lameness (n =3), and acute recumbency (n =5). Four males and six females were affected, and the mean age at death was 12.7 yr with a range of 4-18 yr. All cases were diagnosed postmortem, and metastasis to various sites, including lung, lymph nodes, and omentum, was found in 40% of cases (n = 4). A single case of hepatocellular carcinoma in a Nile lechwe was described in 2007; however, this is the first reported series of neoplasms in Reduncinae. The pathogenesis behind the development of hepatocellular neoplasms in Nile lechwe has not yet been identified.

A first case of hepatocellular carcinoma in the baboon (Papio spp.) placenta.

We present a case of hepatocellular carcinoma (HCC) in the placenta of healthy baboon (Papio spp.). Grossly, the fetal, maternal, and placental tissues were unremarkable. Histologically, the placenta contained an unencapsulated, poorly demarcated, infiltrative, solidly cellular neoplasm composed of cells that resembled hepatocytes. The neoplastic cells were diffusely positive for vimentin and focally positive for Ae1/Ae3, Arginase -1, glutamine synthetase, and CD10, and negative for ER, vascular markers (CD31 and D240), S100, glypican, C-reactive protein, FABP, desmin, and beta-catenin; INI1 positivity was similar to non-neoplastic tissues. The case likely represents a unique subtype of HCC.

Hepatic Myoepithelial Carcinoma in a Dog: Immunohistochemical Comparison With Other Canine Hepatic Carcinomas.

An 11-year-old female miniature Dachshund dog presented with a solid, soft, gray mass on the hepatic lateral left lobe. Histologically, the mass consisted of neoplastic proliferation of cells with round nuclei and eosinophilic and vacuolated cytoplasm arranged in alveolar, trabecular, and solid patterns. Immunohistochemically, the neoplastic cells were positive for pancytokeratin (CK AE1/AE3), CK5, CK14, vimentin, Sox9, and myoepithelial markers (α-smooth muscle actin, p63, and calponin). The morphological and immunohistochemical findings indicated a diagnosis of myoepithelial carcinoma. We conducted immunohistochemical studies on other representative canine hepatic tumors. Although the myoepithelial phenotype was not observed in the hepatocellular carcinoma, some tumor cells in cholangiocarcinoma showed immunohistochemical features of myoepithelium, suggesting that some neoplastic cells in cholangiocarcinoma may have the potential to differentiate into myoepithelial cells. To our knowledge, this is the first report in veterinary medicine of a hepatic carcinoma with a myoepithelial phenotype.

Laparoscopic access to the liver and application of laparoscopic microwave ablation in 2 dogs with liver neoplasia.

OBJECTIVE: To determine laparoscopic accessibility of liver lobes and access to the hilus and describe laparoscopic microwave ablation (LMWA) in 2 dogs with hepatic neoplasia. STUDY DESIGN: Experimental/descriptive case series. SAMPLE POPULATION: Six canine cadavers and 2 clinical dogs. METHODS: Cadavers in dorsal recumbency underwent laparoscopic assessment of the liver. A 17 gauge MWA probe was inserted to create an ablation zone at the most proximal aspect of the hilus. The distance from the center of each ablation zone to the most proximal aspect of the corresponding hilus was determined. Two dogs with hepatic neoplasia underwent LMWA. RESULTS: All lobes of the canine liver were accessible via laparoscopy. The median (interquartile range) distances from the ablation zones to the hilus for the caudate process, left lateral, left middle, quadrate, right lateral, and right middle lobes were 2.2 (1.2-2.6), 2.1 (1-4.4), 1.5 (1.4-3.7), 2, 1, 2.5 (1-4.1) cm, respectively. Histopathologic diagnoses treated by LMWA included metastatic hemangiosarcoma and primary hepatocellular carcinoma. Laparoscopic microwave ablation was technically feasible, and no complications from the procedure resulted. CONCLUSION: Laparoscopic access to the hilus of each liver lobe is possible via a ventrodorsal approach provided reverse Trendelenburg and lateral rotation is used, especially for the right lateral lobe. Laparoscopic microwave ablation is feasible in some dogs with hepatic neoplasia. The indications for and efficacy of LMWA for hepatic neoplasia in dogs requires additional investigation. CLINICAL SIGNIFICANCE: Laparoscopic access to all liver lobes and MWA of some neoplastic lesions is feasible in a canine pilot study.

Outcomes and prognostic variables associated with central division hepatic lobectomies: 61 dogs.

OBJECTIVE: To determine the outcome and prognostic variables associated with long-term survival and complications in dogs undergoing hepatic lobectomy of the central division. STUDY DESIGN: Multi-institutional retrospective case series. ANIMALS: Sixty-one client-owned dogs with central division masses. METHODS: Medical records of dogs undergoing hepatic lobectomy of the central division from January 1, 2000 to January 1, 2015 were reviewed for signalment, clinical signs, preoperative staging, preoperative cytology or biopsy results, date of procedure, location of mass, surgical technique, whether cholecystectomy or cholecystopexy was performed, complications, histopathologic diagnosis and margin evaluation, date of local recurrence or detection of metastatic disease, and survival. RESULTS: Hilar resection was associated with increased intraoperative and postoperative complications. Intraoperative complications occurred in 29 dogs, with 20 dogs experiencing intraoperative hemorrhage. Nineteen dogs required transfusions. Immediate postoperative complications occurred in 20 dogs. Perioperative mortality rate was 11%, and 2-week mortality rate was 14.7%. The median survival time for dogs with hepatocellular carcinoma (HCC) was not reached. The 1- and 3-year censored survival rates for dogs with HCC was 82.1% and 82.1%, respectively. Margin status did not impact survival time. CONCLUSION: Hepatic lobectomy of the central division was associated with hemorrhage in approximately 33% of dogs, but there was a relatively low perioperative mortality rate. Hepatic lobectomy for HCC resulted in long-term survival, regardless of margin status. CLINICAL SIGNIFICANCE: Surgeons should anticipate the requirement for blood products in dogs that may require hepatic lobectomy of the central division. Long-term survival can be expected after surgical treatment of HCC, regardless of margin status.

Hepatocellular carcinoma in two captive golden-headed lion tamarins (Leontopithecus chrysomelas).

Two cases of hepatocellular carcinoma (HCC) in 2 female captive golden-headed lion tamarins (Leontopithecus chrysomelas) are described. HCC was diagnosed in both, with pulmonary metastasis in one of them. Neoplastic cells were positive for hepatocyte-specific antigen (HSA) by immunohistochemistry, confirming the diagnosis.