Claudin-7-positive synchronous spontaneous intrahepatic cholangiocarcinoma, adenocarcinoma and adenomas of the gallbladder in a Bearded dragon (Pogona vitticeps)

Evaluation of Neoplasia, Treatments, and Survival in Lizard Species

Neoplasia has been reported in lizards, but more research is needed to accurately document the prevalence and prognosis of the various known neoplasms that affect lizards. This study reviewed medical records from an online database, the Exotic Species Cancer Research Alliance (ESCRA), and reviewed published literature to determine the prevalence of neoplasia, malignancy, metastasis, treatment strategies, and outcomes by species and sex. Records from 55 individual lizards, 20 different species, and 37 different tumors were identified. In the literature, 219 lizards, 59 species, and 86 unique tumors were identified from 72 published case reports. Potential signalment factors such as age, sex, and species were evaluated to see if they affected case outcome. Additional factors including neoplasia type, presence of metastasis, and types of pursued treatments were also evaluated. Statistical analysis was performed to determine whether a factor was significantly associated with animal death due to the identified neoplasia or with animal survival or death due to other causes (non-neoplastic outcomes). Komodo dragons and savannah monitors were more likely to die from neoplasia compared to other lizard species. Cases where the status of metastasis was unknown were significantly associated with death due to neoplasia. Having an unknown status of male versus female was significantly associated with non-neoplastic outcomes of death. Leukemia and islet cell carcinoma were significantly associated with death due to neoplastic causes. Chondrosarcoma, myxosarcoma, osteosarcoma, and squamous cell carcinoma were significantly associated with non-neoplastic outcomes of death. Surgery alone and radiation therapy alone each were significantly associated with non-neoplastic outcomes of death, while lizards not receiving treatment were significantly associated with death due to neoplasia. Benign neoplasia was significantly associated with non-neoplastic outcomes of death. These results will aid in the improved diagnosis and management of neoplasia in lizard species, as well as expanding our understanding of prognostic indicators of neoplasia in lizards.

Diagnostic Clinical Pathology of the Bearded Dragon (Pogona vitticeps)

The bearded dragon (Pogona vitticeps), an omnivorous Agamid lizard native to inland Australia, is one of the most popular reptile pets due to their sociable behavior, tame demeanor, low-maintenance care, and relative ease of breeding. Because they are generally stoic animals, thorough physical examination in conjunction with routine clinicopathologic data can prove invaluable in identifying disease and implementing appropriate therapy in a timely manner. The goal of this article is to assist the practicing clinician, based on literature review, on how to approach the diagnostic challenge encountered in everyday practice when working up various conditions in bearded dragons.

Use of computed tomography to determine a species-specific formula for body surface area in bearded dragons (Pogona vitticeps)

OBJECTIVE

To use CT-derived measurements to calculate a shape constant (K constant) and create a formula to calculate body surface area (BSA) on the basis of body weight in bearded dragons (Pogona vitticeps).

ANIMALS

12 adult client-owned bearded dragons that underwent CT between December 4, 2019, and April 2, 2020.

PROCEDURES

Each bearded dragon in this prospective cohort study underwent physical examination, body weight measurement, and CT. A 3-D surface model was then reconstructed from CT data with available software and used for BSA calculations. Animals were considered collectively and grouped by sex and age. Nonlinear regression analysis of BSA versus body weight was performed, and a species-specific formula was derived for calculating BSA in bearded dragons.

RESULTS

Mean age, body weight, and CT-derived BSA were 2.1 years, 356 g, and 580 cm². The calculated K constant was 11.6 (R² = 0.994; SE = 0.275) for the 12 bearded dragons, and the CT-derived BSA formula was as follows: BSA in cm² = 11.6 × (body weight in g)^2/3. The K constant differed substantially for bearded dragons grouped by age (12.1 for younger [between 1 and ≤ 2 years of age; n = 8] vs 10.9 for older [> 2 years of age; 4] animals) but did not differ on the basis of sex.

CONCLUSIONS AND CLINICAL RELEVANCE

Results indicated that because the K constant for bearded dragons in the present study was larger than the preexisting K constant of 10 used for reptiles or the various K constants established for some companion mammals, doses of chemotherapeutic drugs needed to treat affected bearded dragons may be higher than previously thought.

Gross, histologic, and immunohistochemical characteristics of cutaneous chromatophoromas in captive bearded dragons

Chromatophoromas are neoplasms that develop from the dermal pigment-bearing and light-reflecting cells (chromatophores) in the skin of reptiles, fish, and amphibians. Seventeen cutaneous chromatophoromas were identified from 851 bearded dragon submissions (2%) to a private diagnostic laboratory in a 15-y period. No sex predilection was found. Ages ranged from 9 mo to 11 y. Chromatophoromas most commonly were single, raised, variably pigmented masses or pigmented scales on the trunk, and less commonly the extremities or head. Microscopically, iridophoromas, melanophoromas, mixed chromatophoromas, and nonpigmented chromatophoromas were identified. Neoplasms were often ulcerated and invaded deep into the subcutis and muscle. Most commonly, nuclear atypia was mild-to-moderate, and mitotic count was low. Six neoplasms had abundant, periodic acid-Schiff-positive, mucinous stroma. Histologic examination was often adequate to diagnose chromatophoromas in bearded dragons given that 11 of 17 had some degree of pigmentation, although it was often scant. IHC for S100 and PNL2 could be helpful to diagnose poorly pigmented neoplasms. No lymphatic invasion or metastases at the time of excision were noted in any of the cases. Follow-up data were available for 6 cases, with no reports of recurrence or neoplasia-related death. Two cases had elevated mitotic counts and nuclear pleomorphism, which has been associated with metastasis in other reports of bearded dragon chromatophoromas. In general, it appears that aggressive surgical excision is often curative, but monitoring may be warranted for cases in which tumors had high mitotic count and nuclear pleomorphism.

Lymphoid leukemia in five bearded dragons (Pogona vitticeps)

CASE DESCRIPTION

2 male and 3 female adult bearded dragons (Pogona vitticeps) were evaluated at the North Carolina State University College of Veterinary Medicine's Exotic Animal Medicine Service between September 2018 and October 2019 because of severe lymphocytosis.

CLINICAL FINDINGS

All 5 bearded dragons had nonspecific clinical signs, including lethargy, poor appetite, ocular discharge, and weight loss. Clinicopathologic testing revealed extremely high lymphocyte counts with morphological findings consistent with lymphocytic leukemia.

TREATMENT AND OUTCOME

All 5 patients were treated with lomustine, prednisolone, and antimicrobials. In addition, 1 or 2 doses of L-asparaginase were administered when the drug was available. Partial remission was achieved in all 5 patients. One patient, after disease progression was documented, was treated with cyclophosphamide and achieved a second partial remission. One of the 5 patients was still alive and continuing to receive chemotherapy at the time of final follow-up 244 days after the initial diagnosis. Survival times (ie, times from initial diagnosis to euthanasia) for the other 4 patients were 57, 157, 330, and 416 days.

CLINICAL RELEVANCE

The present report represented the first description of lomustine as a primary chemotherapeutic agent for the treatment of lymphocytic leukemia in bearded dragons and provided information on response to treatment, adverse effects, and survival times.

Evaluation of a ventral and a left lateral approach to coelioscopy in bearded dragons (Pogona vitticeps)

OBJECTIVE

To compare a ventral and a left lateral endoscopic approach to coelioscopy in bearded dragons (Pogona vitticeps).

ANIMALS

18 adult bearded dragons.

PROCEDURES

In a randomized crossover design involving 2 surgical approaches, anesthetized bearded dragons first underwent coelioscopy with a ventral approach (left lateral of midline next to the umbilicus; animal positioned in dorsal recumbency) or left lateral approach (intercostal; animal positioned in right lateral recumbency) and then with the alternate approach. A 2.7-mm × 18-cm, 30° oblique telescope with a 4.8-mm operating sheath and CO₂ insufflation at 2 to 5 mm Hg were used. Ease of entry into the coelom and ease of visual examination of visceral structures were scored.

RESULTS

Both approaches were straightforward, with the left lateral approach requiring significantly more time than the ventral approach. Scores for ease of visual examination for the heart, lungs, liver, stomach, intestines, pancreas, gallbladder, left kidney, gonads, and fat body were good to excellent. Visual examination of the spleen and adrenal glands was difficult in most animals via either approach. The left kidney, testis, and vas deferens were easier to see with the left lateral approach, whereas the pancreas in females and gallbladder in both sexes were easier to see with the ventral approach. All bearded dragons recovered without complications from the procedures, except for one with nephritis, renal gout, and hepatic necrosis.

CONCLUSIONS AND CLINICAL RELEVANCE

Both coelioscopy approaches could be safely and effectively used in bearded dragons. Choice of approach should be based on the coelomic structures requiring evaluation.

Metastatic Cholangiocarcinoma in a Bearded Dragon (Pogona vitticeps)

A 6.5-year-old female bearded dragon (Pogona vitticeps) was presented with a swollen right pelvic limb. A tissue core biopsy from the swollen area was performed and a presumptive histopathological diagnosis of adenocarcinoma was made. This diagnosis was confirmed after limb amputation. Two months after amputation a sudden deterioration in the overall health of the patient occurred. Ultrasound examination of the coelomic cavity revealed hypoechoic lesions in the liver. The patient was euthanized and submitted for necropsy which revealed a severely enlarged liver with multiple coalescing yellowish nodules. Cholangiocarcinoma of the liver with metastases to the spleen, left mesovarium and right pelvic limb was diagnosed after histopathological examination.

Retrospective review of neoplasms of captive lizards in the United Kingdom

BACKGROUND

Neoplasia has historically been regarded as an unusual occurrence in reptiles. The aim of the present study was to evaluate the prevalence of neoplasms in routine diagnostic samples submitted to a specialist exotic animal laboratory.

METHODS

Over a 10-year period, 690 lizard samples were submitted for histopathological or cytopathological examination by Royal College of Veterinary Surgeons specialists in Veterinary Pathology (Zoo and Wildlife). Records were reviewed retrospectively and non-neoplastic diagnoses excluded from further analysis.

RESULTS

158 neoplasms were diagnosed in 149 lizards, with 22.9% of submissions resulting in a diagnosis of neoplasia. The skin was the most commonly affected organ, and squamous cell carcinomas were the most common neoplasms identified (17.7% of all neoplastic diagnoses).Bearded dragons and panther chameleons had a statistically significant higher proportion of neoplasia diagnosis than the lizard population as a whole, and geckos had a statistically significantly lower proportion.Several neoplasms identified in this study have not been previously reported in lizards, including a testicular Sertoli cell tumour, testicular granulosa cell tumour, splenic haemangiosarcoma, gastric adenocarcinoma and basal cell carcinoma.

CONCLUSION

The results suggest that the prevalence of neoplasia in captive lizards may be higher than previously reported, and that there is variation in prevalence between different lizard species and families. It is unclear whether these differences relate to genetic or management factors.

Synchronous cancers of gallbladder carcinoma and combined hepatocellular cholangiocarcinoma: an unusual case and literature review

Background

Synchronous primary cancers in gallbladder and liver are rarely reported. Here we report an unusual case of synchronous cancers of gallbladder carcinoma and combined hepatocellular cholangiocarcinoma.

Case presentation

Several lesions in the gallbladder and in adjacent parenchyma of liver were discovered in a 65-years-old woman by imaging examination. Surgical resection was performed following a diagnosis of primary gallbladder carcinoma with local hepatic metastasis. Histological examination confirmed the diagnosis of primary gallbladder carcinoma, and the lesions in the liver consisted of hepatocellular carcinoma simultaneously with cholangiocarcinoma. Adjuvant chemoradiation therapy was not performed due to the patient’s refusal of the treatment. Unfortunately, the patient died of widespread metastasis 8 months after the operation.

Conclusions

The disease needed to be differentially diagnosed from gallbladder carcinoma with hepatic metastasis. Aggressive surgical approach should be based on a balance between the risk of surgery (morbidity and mortality) and the outcome.

Oncology of Reptiles: Diseases, Diagnosis, and Treatment

Based on necropsy review, neoplasia in reptiles has a comparable frequency to that of mammals and birds. Reptile neoplasia is now more frequently diagnosed in clinical practice based on increased use of advanced diagnostic techniques and improvements in reptilian husbandry allowing greater longevity of these species. This article reviews the current literature on neoplasia in reptiles, and focuses on advanced diagnostics and therapeutic options for reptilian patientssuffering neoplastic disease. Although most applied clinical reptile oncology is translated from dog and cat oncology, considerations specific to reptilian patients commonly encountered in clinical practice (turtles, tortoises, snakes, and lizards) are presented.

Cholecystic adenocarcinoma and pancreatic insulinomas in a goat

A 13-year-old female Boer goat with a history of chronic arthritis and recurrent episodes of recumbency, increased serum gamma-glutamyl transferase, and complete inability to stand was submitted for necropsy. Gross changes included the presence of a white, firm, smooth, 6 cm × 4 cm × 3 cm mass that diffusely expanded and partially effaced the gall bladder and infiltrated the adjacent hepatic parenchyma. On cut surface, the mass was pale yellow and had small, irregular, dark yellow areas. Scattered through the pancreas were 2 gray, well-demarcated, soft, homogeneous, 1 cm in diameter nodules that bulged out from the capsular surface. The right femoral head had a locally extensive area of cartilage erosion. Histological and immunohistochemical evaluation of the gall bladder and pancreatic nodules revealed a primary cholecystic adenocarcinoma and multifocal insulinomas, respectively. A metastatic focus from the gall bladder neoplasm was observed infiltrating the right adrenal gland medulla. The goat also had mild pulmonary infestation by Muellerius capillaris. Primary hepatobiliary and pancreatic neoplasia is rare in goats, and to the authors' knowledge, neither cholecystic adenocarcinoma nor pancreatic insulinomas have been previously reported in this species.