Canine vascular neoplasia - a population-based clinicopathologic study of 439 tumours and tumour-like lesions in 420 dogs

[Lameness and swelling of the metatarsus in a Saluki - Could it be an arteriovenous fistula?]

A 12-year-old Saluki was presented with acute lameness and plantar swelling of the right metatarsus following an episode of free running. Radiographs showed soft tissue swelling only, the involved bone and joint structures were unremarkable. The lesion recurred several months later. Ultrasonographic imaging of the lesion revealed a well-vascularized cavernous structure. Subsequent surgical removal and histopathological examination of the structure raised the initial suspicion of an arteriovenous fistula, which was then confirmed histologically following a second surgical removal of another recurrence. The purpose of this case report is to illustrate the potential complexity of what initially appears to be a simple lameness. At the same time, attention is focused on the possibility that arteriovenous fistulas may tend to recur.

Retrospective Study of Clinicopathological Changes and Prediction Model for Canine Vascular Neoplasms

Vascular neoplasms, including hemangiosarcoma (HSA) and hemangioma (HMA), are more common in dogs than other domestic animal species; however, comprehensive laboratory screening tests for early diagnosis are currently limited. The aims of this study were to investigate general signalments, anatomic locations, and clinicopathological abnormalities of dogs diagnosed with vascular neoplasms and to determine the diagnostic significance of these abnormalities. Retrospective data of dogs with HMA, HSA, and healthy dogs were analyzed. Dogs with HMA and HSA were seniors, with mixed breeds being most affected. HMA affected predominantly non-visceral sites, while HSA was more common in visceral sites, particularly the spleen. In multivariate model analyses, the odds of HMA diagnosis were 5.5 times higher in anemic dogs and 33.0 times higher in lymphopenic dogs compared to dogs without the abnormalities. The odds of HSA diagnosis were 42.5 times higher in anemic dogs, 343 times higher in lymphopenic dogs and 92.7 times higher in dogs with hyperfibrinogenemia compared to dogs without the abnormalities. The study suggested that these identified abnormalities were nonspecific and commonly observed in various chronic diseases, and hence their combination with clinical information, such as diagnostic imaging and histopathology, is important to facilitate a more precise diagnosis of canine vascular neoplasms.

Intravascular papillary endothelial hyperplasia in the lungs of a wild Korean raccoon dog

A male Korean raccoon dog of unknown age was rescued and placed at the Daejeon Wildlife Rescue Center, Korea. Physical examination revealed severe emaciation and dehydration, as well as thick crusts and alopecia over most of the body. During medical care, the animal died and was submitted for postmortem examination. Firm, brown-red lesions of various sizes were observed on the surface of the lungs. In cross-sections of the lungs, pulmonary vessels were thickened and dilated, with white irregular papillary luminal projections. Histologically, pulmonary blood vessels were severely hyperplastic, characterized by thickened dilated walls and fibrous papillary projections covered with a single layer of endothelial cells (ECs). Hyperplastic fibrous connective tissue was confirmed by Masson trichrome staining. The ECs expressed CD31. We diagnosed the lesion as intravascular papillary endothelial hyperplasia, a unique non-neoplastic reactive process that has not been reported previously in pulmonary vessels of canids, equids, or felids, to our knowledge.

Tumor-associated macrophages in canine visceral hemangiosarcoma

Canine hemangiosarcoma (HSA) is a highly malignant tumor derived from hematopoietic stem cells and commonly occurs in visceral organs or skin. Visceral HSAs are particularly aggressive and progress rapidly despite multimodal treatment. Tumor-associated macrophages (TAMs) play a central role in carcinogenesis, tumor progression, and metastasis in humans and murine models. In this retrospective study, we investigated the prevalence and phenotype of TAMs in privately owned, treatment-naïve dogs with naturally occurring HSA. We used CD204 as a general macrophage marker and CD206 as a marker for M2-polarized macrophages. Formalin-fixed paraffin-embedded tissues from HSAs in the spleen (n = 9), heart (n = 6), and other locations (n = 12) from 17 dogs were sectioned and immunohistochemically labeled with CD204 and CD206 antibodies. The mean number of log(CD204)- and log(CD206)-positive cells and the ratio of log(CD206/CD204)-positive cells were compared with normal surrounding tissues and between tumor locations. There were significantly more macrophages and M2 macrophages, and a higher ratio of M2 macrophages to total macrophages in tumor hot spots (P = .0002, P < .0001, and P = .0002, respectively) and in tumor tissues outside of hot spots (P = .009, P = .002, and P = .007, respectively) than in normal surrounding tissues. There were no significant differences between tumor locations, but there was a trend toward higher numbers of CD204-positive macrophages within the splenic tumors. There was no association between histological parameters or clinical stage and TAM numbers or phenotype. As in humans, TAMs in dogs with HSA have a predominantly M2-skewed phenotype. Dogs with HSA could serve as excellent models to evaluate new TAM-reprogramming therapies.

Hemangiosarcoma in dogs as a potential non-rodent animal model for drug discovery research of angiosarcoma in humans

Since the domestication of dogs 10,000 years ago, they have shared their living environment with humans and have co-evolved. The breeding process that dogs have undergone in only a few centuries has led to a significant accumulation of specific genetic alterations that could induce particular diseases in certain breeds. These canine diseases are similar to what is found in humans with several differences; therefore, comparing such diseases occurring in humans and dogs can help discover novel disease mechanisms, pathways, and causal genetic factors. Human angiosarcoma (AS) and canine hemangiosarcoma (HSA), which are sarcomas originating from endothelium, are examples of diseases shared between humans and dogs. They exhibit similar characteristics and clinical behaviors, although with some critical differences resulting from evolution. In this review, we will describe the similarities and differences in terms of clinical and molecular characteristics between human AS and canine HSA, and discuss how these similarities and differences can be applied to advance the treatment of these diseases.

Progressive angiomatosis, resembling human skeletal-extraskeletal angiomatosis, arising in multiple digits in two dogs

Two dogs presented with progressive, expansile and invasive lesions on a hind paw. Case 1, a 10-year-old female Shetland sheepdog had diffusive and aggressive-looking lesions on the middle digits of the left hind paw. Radiographic examination showed invasion into and destruction of the underlying bone. A malignant tumour was suspected initially; however, histological features of atypical vascular proliferations without mitotic activity were consistent with progressive angiomatosis. Case 2, an 11-year-old female English springer spaniel presented with similar lesions in the same toes, also involving bone. Progressive angiomatosis was suspected clinically, as tumour cells were not detected by cytology and screening did not detect metastatic disease. Histopathology confirmed the diagnosis. Progressive angiomatosis is an uncommon non-malignant condition which should be considered as a differential diagnosis for radiographically lytic digital lesions.

Histopathological Grading, Clinical Staging and CD 31 Expression of Canine Splenic Hemangiosarcoma

Canine hemangiosarcoma is a common, highly fatal tumor of older dogs, and predictors of survivability may provide clinically useful information. The objectives of this case series were to determine if a previously published tumor histological grading scheme, the level of tumor cellular atypia, clinical staging, or the level of CD 31 expression were useful for predicting the survival time in dogs with splenic hemangiosarcoma. Canine splenic hemangiosarcomas from 16 dogs were histologically graded, clinically staged, and assessed for CD 31 expression. Medical records were reviewed, the date of death was obtained, and survival data were analyzed statistically. Histopathological grading and clinical staging of canine splenic hemangiosarcomas, and the expression of CD 31 by the tumor cells were not significantly associated with the median survival time of the dogs in this study. However, strong expression of CD 31 by canine splenic hemangiosarcoma tumor cells was observed in dogs with short survival times, which warrants further studies to evaluate the potential prognostic value of CD 31 expression for the survival of dogs with splenic hemangiosarcoma.

Granulation tissue-type hemangioma in a 6-week-old puppy - a case report

BACKGROUND

Hemangioma is a well-known neoplasia in veterinary and human medicine. Several subtypes have been described and are distinguished based on their histologic appearance. The classification schemes of hemangiomas in human and veterinary medicine are different, and various purpose-based schemes can be found in the literature.

CASE PRESENTATION

A six-week-old puppy was presented that suffered from a neoplasia that extended to the musculature of the hind limb. After surgical excision, the mass was submitted for pathohistological examination. The mass was composed of endothelial cells forming vascular slits admixed with a fibrous stroma and spindle cells. Immunohistological examination was positive for factor VIII-related antigen and smooth muscle actin, supporting the diagnosis of hemangioma.

CONCLUSION

The final diagnosis of granulation tissue-type hemangioma was given due to the histological appearance of the neoplasia. Granulation tissue-type hemangioma is a rare subtype of hemangioma. In this case an uncommonly young dog was affected.

Gene expression profiles of beta-adrenergic receptors in canine vascular tumors: a preliminary study

Beta adrenergic receptors (β-AR) play a key role in regulating several hallmark pathways of both benign and malignant human and canine tumors. There is scarce information on the expression of β-AR in canine vascular tumors. Therefore, the purpose of the present research work was to study the mRNA expression levels of the three subtypes of the β-AR genes (ADRB1, ADRB2, ADRB3) in hemangiosarcoma (HSA) and hemangioma (HA), as well as in vascular hamartomas (VH) from dogs.Fifty samples (n = 50) were obtained from 38 dogs. Twenty-three animals had HSA, eight animals HA and seven animals VH. HSA were auricular (n = 8), splenic (n = 5), cutaneous (n = 6), auricular and splenic (n = 2), cutaneous-muscular (n = 1) and disseminated (n = 1). There were seven cases of HSA that were divided into primary tumor and secondary (metastatic) tumor. Skin and muscle samples with a normal histological study were used as control group. ADRB gene expression was determinate in all samples by real-time quantitative PCR. Results showed that ADRB1, ADRB2 and ADRB3 were overexpressed in HSA when compared to the control group. ADRB2 was overexpressed in HA when compared to the control group. HSA express higher values of ADBR1 (p = 0.0178) compared to VH. There was a high inter-individual variability in the expression of the three subtypes of ADBR. No statistically significant difference in the expression of ADBR genes were observed between HSA primary when compared to metastatic or in different anatomical locations. In conclusion, canine HSA overexpress the three β-AR subtypes and canine HA β2-AR. High variability was observed in β-AR mRNA levels amongst HSA cases.

International Harmonization of Nomenclature and Diagnostic Criteria (INHAND): Nonproliferative and Proliferative Lesions of the Dog

The INHAND (International Harmonization of Nomenclature and Diagnostic Criteria for Lesions) Project (www.toxpath.org/inhand.asp) is a joint initiative of the societies of toxicologic Pathology from Europe (ESTP), Great Britain (BSTP), Japan (JSTP), and North America (STP) to develop an internationally accepted nomenclature for proliferative and nonproliferative lesions in laboratory animals. The purpose of this publication is to provide a standardized nomenclature for classifying lesions observed in most tissues and organs from the dog used in nonclinical safety studies. Some of the lesions are illustrated by color photomicrographs. The standardized nomenclature presented in this document is also available electronically on the internet (http://www.goreni.org/). Sources of material included histopathology databases from government, academia, and industrial laboratories throughout the world. Content includes spontaneous lesions, lesions induced by exposure to test materials, and relevant infectious and parasitic lesions. A widely accepted and utilized international harmonization of nomenclature for lesions in laboratory animals will provide a common language among regulatory and scientific research organizations in different countries and increase and enrich international exchanges of information among toxicologists and pathologists.

Canine and feline haemangiosarcoma

INTRODUCTION

Haemangiosarcoma (HSA) is a malignant neoplasm of dogs and cats that is suspected to originate from a pluripotent bone marrow progenitor with a complex and multifactorial pathogenesis.

APPROACH

Pertinent literature was identified, reviewed, and summarized for inclusion in the manuscript.

RESULTS/INTERPRETATION

Dogs are more frequently diagnosed with HSA than cats, and primary sites of this disease include dermal, subcutaneous/intramuscular, and visceral (most commonly the spleen). Dogs and cats with HSA generally have a poor prognosis owing to the rapid and widespread metastasis typically associated with this disease. However, some forms such as cutaneous HSA behave in a less aggressive fashion with improved outcomes. Surgical excision and anthracycline-based chemotherapy remain the mainstays of treatment, although novel treatment modalities are currently under investigation for potential roles in treatment of this disease.

CONCLUSION

This review aims to describe the clinical presentation and progression of the various forms of HSA in dogs and cats as well as to provide a systematic review of the veterinary literature with a focus on the various published treatment options and associated outcomes.

Primary Cystic Lymphangioma of the Spleen in an Adult Dog

Proliferative disorders of lymphatic origin in animals are mostly congenital or occur within the first few months of life. Involvement of internal organs is extremely infrequent. A seven-year-old entire female mixed-breed dog was presented with apathy and poor appetite. Abdominal ultrasonography revealed a focally enlarged spleen with an anechoic round lesion. Splenectomy was performed and pathological examination demonstrated a sponge-like, compressible tumour composed of endothelium-lined vascular cystic spaces filled with eosinophilic proteinaceous material lacking erythrocytes. Immunohistochemical stains showed that cyst-lining cells were strongly positive for CD31 and factor VIII and focally positive for lymphatic vessel endothelial hyaluronan receptor 1 (LYVE-1). Based on these findings, the lesion was identified as splenic cystic lymphangioma. To the best of our knowledge, this is the first description of solitary lymphangioma of the spleen in animals.

Immunohistochemical detection of p53 and pp53 Ser392 in canine hemangiomas and hemangiosarcomas located in the skin

Background

p53 protein is essential for the regulation of cell proliferation. Aberrant accumulation of it usually occurs in cutaneous malignancies. Mutant p53 is detected by immunohistochemistry because it is more stable than the wild-type p53. However, post-translational modifications of p53 in response to ultraviolet radiation are important mechanisms of wild-type p53 stabilization, leading to positive staining in the absence of mutation. The aims were: 1) to analyze the immunohistochemical expression of p53 and phospho-p53 Serine³⁹² in canine skin endothelial tumours; and 2) to determine if any relationship exists between p53 and phospho-p53 Serine³⁹² overexpression and cell proliferation.

Results

p53 and phospho-p53 Serine³⁹² immunolabeling was examined in 40 canine cutaneous endothelial tumours (13 hemangiomas and 27 hemangiosarcomas). Their expression was associated with tumour size, hemangiosarcoma stage (dermal versus hypodermal), histological diagnosis and proliferative activity (mitotic count and Ki-67 index). Statistical analysis revealed a significant increase of p53 immunoreactivity in hemangiosarcomas (median, 74.61%; interquartile range [IQR], 66.97–82.98%) versus hemangiomas (median, 0%; IQR, 0–20.91%) (p < .001) and in well-differentiated hemangiosarcomas (median, 82.40%; IQR, 66.49–83.17%) versus hemangiomas (p = .002). Phospho-p53 Serine³⁹² immunoreactivity was significantly higher in hemangiosarcomas (median, 53.80%; IQR, 0–69.50%) than in hemangiomas (median, 0%; IQR, 0.0%) (p < .001). Positive correlation of the overexpression of p53 and phospho-p53 Serine³⁹² with mitotic count and Ki-67 index was found in the cutaneous vascular tumours (p < .001). The Ki-67 index of the hemangiomas (median, 0.50%; IQR, 0–2.80%) was significantly lower than that of the hemangiosarcomas (median, 34.85%; IQR, 23.88–42.33%) (p < .001), and that specifically of well-differentiated hemangiosarcomas (median, 24.60%; IQR, 15.45–39.35%) (p = .001). Immunolabeling of 18 visceral hemangiosarcomas showed that the p53 (median, 41.59%; IQR, 26.89–64.87%) and phospho-p53 Serine392 (median, 0%; IQR, 0–22.53%) indexes were significantly lower than those of skin (p = .001; p = .006, respectively).

Conclusions

The p53 and phospho-p53 Serine³⁹²overexpression together with high proliferative activity in hemangiosarcomas versus hemangiomas indicated that p53 might play a role in the acquisition of malignant phenotypes in cutaneous endothelial neoplasms in dogs. The Ki-67 index may be useful in distinguishing canine well-differentiated hemangiosarcomas from hemangiomas.

Refining the "double two-thirds" rule: Genotype-based breed grouping and clinical presentation help predict the diagnosis of canine splenic mass lesions in 288 dogs

Prediction of the likely histopathological diagnosis of canine splenic masses can guide appropriate decision-making. This study explores the predictive effect of breed and clinical presentation on the diagnosis of a canine splenic mass. Records from the Royal Veterinary College, United Kingdom (2007-2017) were reviewed. Dogs with a histopathologic or cytologic diagnosis from a splenic mass, or imaging findings consistent with disseminated metastatic disease, were included. Signalment, physical examination, haematology results, imaging findings and pathology reports were recorded. Breeds were grouped according to several permutations of their phenotype and then by clustering of breeds based on single nucleotide polymorphism analysis. Binary logistic regression was performed to identify predictors of malignancy and haemangiosarcoma. Two hundred and eighty-eight dogs were identified: 27% female and 63% male, 21% entire and 79% neutered; German Shepherd was the most common breed (11%). Median age was 10 years and median bodyweight 25 kg. Thirty-eight percent of dogs presented with haemoabdomen; a splenic mass was found incidentally in 28%. Sixty percent had a malignant tumour of which haemangiosarcoma comprised 66%. On multivariable analysis, genotype-based breed group (P = .004), haemoabdomen (P < .001) and neutrophil count (P = .025) predicted malignancy, and genotype-based breed group (P < .001) and haemoabdomen (P < .001) predicted haemangiosarcoma. Genotype-based breed group and occurrence of haemoabdomen may have predictive value to diagnose malignant splenic masses and more specifically haemangiosarcoma. The effect of genotype-based breed grouping was a superior predictor of the diagnosis of a canine splenic mass lesion compared with all phenotype-based groupings tested.

Prevalence, distribution, and clinical characteristics of hemangiosarcoma-associated skeletal muscle metastases in 61 dogs: A whole body computed tomographic study

BACKGROUND

Skeletal muscle metastases (SMMs) have been described sporadically in canine oncology.

HYPOTHESIS/OBJECTIVES

To determine the prevalence, localization, and clinical signs of SMMs associated with hemangiosarcoma (HSA) in a population of dogs presented for whole body computed tomography (CT).

ANIMALS

Dogs with a histologically confirmed HSA and a tissue core specimen or fine needle aspirate of suspected metastatic lesions were included in the study.

METHODS

Retrospective study. Dogs with a final diagnosis of visceral or muscular HSA that underwent whole body CT scan were enrolled in the study. Final diagnosis of primary tumor and SMMs was reached by histology, cytology, or both. Signalment, clinical signs, localization of the primary lesion, and metastases characteristics were reviewed.

RESULTS

Sixty-one dogs met the inclusion criteria. Skeletal muscle metastases were detected in 15 dogs (24.6%) and all of these dogs had also metastases in ≥1 sites. Presence of SMMs was significantly higher in males but was not significantly related to age, neuter status, breed, localization, and dimensions of the primary tumor. Nine of 15 (60.0%) dogs with SMMs showed lameness or reluctance to move whereas these signs were not recorded in any of the 42 dogs without SMMs (P < .001).

CONCLUSION AND CLINICAL IMPORTANCE

Prevalence of SMMs in our population of dogs with HSA was higher in comparison to previous studies in the human and veterinary medical literature. Whole body CT is recommended for staging of dogs with HSA, because SMMs could be missed by clinical examination and traditional diagnostic imaging modalities.

Adjuvant Doxorubicin with or without Metronomic Cyclophosphamide for Canine Splenic Hemangiosarcoma

This retrospective study investigated the outcome of 33 dogs with splenic hemangiosarcoma treated with surgery followed by adjuvant dose-intensified doxorubicin (DOX) with or without low-dose metronomic cyclophosphamide (LDM-C) maintenance therapy. Among the 33 dogs, 18 dogs received LDM-C. Clinical stage was available for all dogs (5 stage I, 18 stage II, and 10 stage III). Nine dogs had macroscopic, and 24 dogs had microscopic disease at the start of DOX treatment. Median progression-free survival (PFS) and overall survival were 125 and 133 days, respectively. Clinical stage and tumor burden (microscopic versus macroscopic) at the start of chemotherapy was prognostic for PFS. No significant difference was observed in PFS or overall survival for the addition of LDM-C after a completed DOX protocol (P = .563 and P = .148, respectively). Based on the results of this retrospective study, the addition of LDM-C therapy as a maintenance regimen following a completed protocol of DOX adjuvant treatment of canine hemangiosarcoma may not improve outcome.

MicroRNA-214 Promotes Apoptosis in Canine Hemangiosarcoma by Targeting the COP1-p53 Axis

MicroRNA-214 regulates both angiogenic function in endothelial cells and apoptosis in various cancers. However, the regulation and function of miR-214 is unclear in canine hemangiosarcoma, which is a spontaneous model of human angiosarcoma. The expression and functional roles of miR-214 in canine hemangiosarcoma were presently explored by performing miRNA TaqMan qRT-PCR and transfecting cells with synthetic microRNA. Here, we report that miR-214 was significantly down-regulated in the cell lines used and in clinical samples of canine hemangiosarcoma. Restoration of miR-214 expression reduced cell growth and induced apoptosis in canine hemangiosarcoma cell lines through transcriptional activation of p53-regulated genes although miR-214 had a slight effect of growth inhibition on normal endothelial cells. We identified COP1, which is a critical negative regulator of p53, as a novel direct target of miR-214. COP1 was overexpressed and the specific COP1 knockdown induced apoptosis through transcriptional activation of p53-regulated genes as well as did miR-214-transfection in HSA cell lines. Furthermore, p53 knockdown abolished the miR-214-COP1-mediated apoptosis; thus, miR-214 and COP1 regulated apoptosis through controlling p53 in HSA. In conclusion, miR-214 functioned as a tumor suppressor in canine hemangiosarcoma by inducing apoptosis through recovering the function of p53. miR-214 down-regulation and COP1 overexpression is likely to contribute to tumorigenesis of HSA. Therefore, targeting miR-214-COP1-p53 axis would possibly be a novel effective strategy for treatment of canine hemangiosarcoma and capable of being applied to the development of novel therapeutics for human angiosarcoma.

Massive haematoma formation associated with proximal popliteal artery haemangioendothelioma in a dog

A mixed breed dog presented with diffuse unilateral hind limb swelling, which ultrasound and cytology confirmed to be caused by severe haematoma formation. Multi-detector computed tomography (MDCT) angiography allowed distinct visualisation of an anomalous segment of the proximal popliteal artery, the presumed origin of the self-sustaining haematoma. Histopathology classified the malformed vessel as a haemangioendothelioma, a neoplasia of intermediate malignancy. Considering this as differential diagnosis to a neoplastic vascular alteration of high malignancy (such as haemangiosarcoma) might alter choice of treatment in future cases with similar clinical and imaging findings.

Integrating databases for research on health and performance in small animals and horses in the Nordic countries

In a world of limited resources, using existing databases in research is a potentially cost-effective way to increase knowledge, given that correct and meaningful results are gained.Nordic examples of the use of secondary small animal and equine databases include studies based on data from tumour registries, breeding registries, young horse quality contest results, competition data, insurance databases, clinic data, prescription data and hunting ability tests. In spite of this extensive use of secondary databases, integration between databases is less common. The aim of this presentation is to briefly review key papers that exemplify different ways of utilizing data from multiple sources, to highlight the benefits and limitations of the approaches, to discuss key issues/challenges that must be addressed when integrating data and to suggest future directions. Data from pedigree databases have been individually merged with competition data and young horse quality contest data, and true integration has also been done with canine insurance data and with equine clinical data. Data have also been merged on postal code level; i.e. insurance data were merged to a digitized map of Sweden and additional meteorological information added. In addition to all the data quality and validity issues inherent in the use of a single database, additional obstacles arise when combining information from several databases. Loss of individuals due to incorrect or mismatched identifying information can be considerable. If there are any possible biases affecting whether or not individuals can be properly linked, misinformation may result in a further reduction in power. Issues of confidentiality may be more difficult to address across multiple databases. For example, human identity information must be protected, but may be required to ensure valid merging of data. There is a great potential to better address complex issues of health and disease in companion animals and horses by integrating information across existing databases. The challenges outlined in this article should not preclude the ongoing pursuit of this approach.

Elevated serum thymidine kinase activity in canine splenic hemangiosarcoma*

Thymidine kinase 1 (TK1) is a soluble biomarker associated with DNA synthesis. This prospective study evaluated serum TK1 activity in dogs presenting with hemoabdomen and a splenic mass. An ELISA using azidothymidine as a substrate was used to evaluate TK1 activity. Sixty-two dogs with hemoabdomen and 15 normal controls were studied. Serum TK1 activity was significantly higher in dogs with hemangiosarcoma (HSA) than in normal dogs (mean ± SEM = 17.0 ± 5.0 and 2.01 ± 0.6, respectively), but not dogs with benign disease (mean ± SEM = 10.0 ± 3.3). Using a cut-off of 6.55 U/L, TK activity demonstrated a sensitivity of 0.52, specificity of 0.93, positive predictive value of 0.94 and negative predictive value of 0.48 for distinguishing HSA versus normal. When interval thresholds of <1.55 and >7.95 U/L were used together, diagnostic utility was increased. Serum TK1 evaluation may help to discriminate between benign disease and HSA in dogs with hemoabdomen and a splenic mass.

Breed differences in the proportional morbidity of testicular tumours and distribution of histopathologic types in a population-based canine cancer registry

Histologically verified tumours submitted to the Norwegian Canine Cancer Register from 1990 to 1998 were studied (n=14,401). The proportion of testicular tumours (n=345) was 2.4%, and the breakdown of histological tumour diagnoses is presented. The frequency of the most common histopathological types was 33% interstitial (Leydig), 26.4% Sertoli and 33.9% seminomas/germ cell tumours. The average age at diagnosis was 10 years, but was significantly lower for Sertoli cell tumours (8.6 years) than for the other tumour types. Following a histopathological re-evaluation, 22.5% of the original tumor diagnoses were modified. Proportional morbidity ratios were calculated and individuals from the breeds Shetland sheepdog and Collie were five times more likely to have testicular tumours than the overall average for the registry. Breed differences in the distribution of histopathologic types were observed. Shetland sheepdog and Collie were most commonly diagnosed with Sertoli cell tumours, while all tumours from Norwegian elkhound in this material were seminomas.

Skeletal-extraskeletal angiomatosis in a dog

An 8-year-old castrated male mixed-breed dog had an ill-defined hemorrhagic and painful lesion in the base of the claw of the second digit of the right forelimb. Radiographically, the expansile and lytic lesion affected the distal phalanx. The digit was amputated and submitted for histologic examination. Histologically, the distal phalanx was largely replaced by a mass composed of variably sized cavernous vascular spaces lined by a single layer of flattened endothelial cells. A similar mass was in the subcutis adjacent to the distal phalanx. The benign vascular proliferation involving the medulla of bone and a second tissue type in this dog is consistent with skeletal-extraskeletal angiomatosis as described in humans. To the authors' knowledge, this is the first report of skeletal-extraskeletal angiomatosis in the veterinary literature.

Canine neoplasia--introductory paper

The paper gives a brief introduction to canine oncology, including its comparative aspects as basis for recording tumours in the animal kingdom. In an abbreviated presentation of the Norwegian Canine Cancer Project for the years 1990-1998, the data (n=14,401) were divided into age groups, each of two years, into different categories of tumours, and into age and gender. As expected, cutaneous histiocytoma was the dominant tumour type in both sexes during the two first years of life. In the age group 2-3.99 years histiocytoma was still the largest group in males, but was surpassed by benign epithelial skin tumours in females. After the age of 4 years, benign epithelial skin tumours constituted the greatest circumscribed group in males, and mammary tumours in females, although the summated other tumours, not explained in this survey, dominated overall in males. Maligancies (cancer) were shown in the same way, by corresponding groups of gender and age. While mastocytoma was the most common tumour and non-Hodgkin's lymphoma the second most common during the two first years of life in females, the situation was reversed in males. Later, mammary tumours dominated in females, while different tumour types not further specified in this summarized report dominated in males, until the end of the age registration (above 14 years). Number, sex and location of most common tumours are shown in a tabular outline. Comparative aspects between human and dog tumours are considered: mammary and testicular neoplasia seemed more frequent in dogs than in humans in Norway, while intestinal, pulmonary and prostatic malignancies were less common in dogs. In our study, vascular tumours and tumour-like lesions constituted about 3% of the total data. As benign vascular tumours are incompletely reported to the human Cancer Registry, no dependable comparison may be made, but malignant vascular tumours have been on the rise during the last decades in the Norwegian human population, more so in men then in women. Finally, the article deals briefly with the development of endothelial cells, and the sparse information on causal factors of vascular tumours.

Canine vascular neoplasia--histologic classification and inmunohistochemical analysis of 221 tumours and tumour-like lesions

A light microscopic evaluation of 221 canine vascular tumours and tumour-like lesions, supplemented by immunohistochemistry (von Willebrand Factor, CD31, vimentin), revealed a high degree of conformity with similar conditions in humans. Four main categories of tumours are reported, i.e. benign types: haemangiomas (n=127) and lymphangioma (n=1); tumour-like lesions: papillary endothelial hyperplasia (n=8) and vascular ectasias (n=2); neoplasms of intermediate malignancy: haemangioendotheliomas (n=27), and the obvious malignant form: angiosarcomas (n=57). Further classification showed that all subtypes had their human counterparts. Papillary endothelial hyperplasia and arteriovenous and venous haemangiomas are described for the first time in dogs. The combination of conventional histopathologic methods and immunohistochemistry was in many cases very useful diagnostically, the latter technique being in some cases indispensable for establishing a definite diagnosis. In general CD31 was the most useful marker for tumours originating from endothelial cells, especially for poorly differentiated haemangiosarcomas.