Retrospective study of canine cutaneous tumors in Japan, 2008-2017

A retrospective Italian Society of Veterinary Oncology (SIONCOV) study of 56 cats with appendicular osteosarcoma

Osteosarcoma is the most common malignant primary bone cancer, but it is infrequently reported in cats. Feline appendicular osteosarcoma typically exhibits good prognosis when treated with surgery alone. A retrospective multi-institutional study was conducted to identify possible prognostic factors. Cats diagnosed with appendicular osteosarcoma were included if initial staging and follow-up information were available. Data including signalment, tumour characteristics, treatment modalities, and survival outcomes were collected and analysed. Fifty-six cats were included; the femur was the most frequently affected bone. Eight cats had distant metastasis at admission and an additional 9 developed metastatic disease during follow-up, resulting in an overall metastatic rate of 30%. Forty-nine (87.5%) cats underwent surgery, and 4 also received adjuvant chemotherapy. Among operated cats, median time to local progression (TTLP), time to distant progression and tumour-specific survival (TSS) were not reached. One- and 2-year survival rates were 66% and 55%, respectively. Seven (12.5%) cats received no treatment; 1- and 2-year survival rates were 25% and 0%, respectively. Operated cats had significantly longer TTLP (P < .001) and TSS (P = .001) compared with non-operated cats. Among operated cats, young age negatively impacted local tumour progression, while the presence of distant metastasis at diagnosis was associated with a higher risk of tumour-related death. This study reaffirms the good prognosis for cats with appendicular osteosarcoma undergoing surgery, but sheds light on some additional factors to consider. Accurate initial staging is recommended, as the metastatic rate may exceed many previous estimations. Surgery substantially extends survival time, whereas the role of chemotherapy remains uncertain.

Incidence rates of the most common canine tumors based on data from the Swiss Canine Cancer Registry (2008 to 2020)

Monitoring neoplasms in standardized registries facilitates epidemiologic studies of risk factors for tumor development and predisposition. In an observational study, we determined incidence rates (IR) and malignant tumor incidence rate ratios (IRR) by age, sex, and breed in Swiss dogs using demographic data from the official Swiss dog registration database Amicus. The dataset analyzed included 54'986 tumors diagnosed by histology and cytology in four Swiss veterinary pathology laboratories between 2008 and 2020. Diagnoses were coded according to the Vet-ICD-O-canine-1 system. Most tumors occurred in the skin (n = 19'045; 34.64%), soft tissues (n = 11'092; 20.17%), and mammary glands (n = 7'974; 14.50%). The IRs for all and for malignant tumors were 775/100'000 dog-years at risk (95%CI 764-777) and 338/100'000 dog-years at risk (95%CI 333-342), respectively. Females (850; 95%CI 834-853) had a higher overall tumor IR than males (679; 95%CI 666-684). The highest tumor IR was found at 11 years of age (1'857; 95%CI 1'780-1'867). Potential novel breed-specific predispositions were uncovered, with high IRs for several benign and malignant tumors in Polski Owczarek Nizinnys (overall IR: 3'303; 95%CI 2'502-3'864) and high IRs for malignant tumors in Russian Black Terriers (melanomas: 345; 95%CI 138-708), Field Spaniels (adenocarcinomas: 376; CI95% 138-817), Dogo Argentinos (mast cell tumors: 844; CI95% 591-1'169), King Charles Spaniels and Manchester Terriers (lymphomas: 319; CI95% 137-627 and 302; CI95% 98-704, respectively), Landseers (osteosarcomas: 74; CI95% 15-216), Bouvier des Flandres (hemangiosarcomas: 127; CI95% 26-371), and Bearded Collies and Cane Corso Italianos (gliomas: 91; CI95% 45-162 and 34; CI95% 7-99, respectively). Nordic hunting dogs had the highest (8.08; CI95% 3.55-16.7) and Chihuahueno the lowest cancer IRRs (0.42; 95%CI 0.31-0.57) compared to mixed breeds. In conclusion, the calculated IRs and IRRs revealed previously unknown predisposing factors, including novel breed-specific susceptibilities. The results may have implications for cancer screening, diagnostic work-up, breeding management and oncologic and translational research.

Fascial plane mapping for superficial tumor resection in dogs. Part III: Hindlimb and pelvis

OBJECTIVES

To categorize the fascial planes and the intersections of these fascial planes in the hindlimb of the dog to facilitate preoperative planning for superficial cancers.

STUDY DESIGN

Qualitative anatomical study.

SAMPLE POPULATION

Four male and five female mixed breed dogs, weighing ~15-35 kg.

METHODS

Skin and subcutaneous fat were removed, and fascial planes were explored to determine borders and quality. Fascia was categorized as type I (discrete sheets), type II (adhered to thin muscles), type III (adhered to thick muscles), or type IV (associated with periosteum). Digital modification of specimen photographs was performed to map tissues.

RESULTS

Differences in dogs were noted due to either size or sex but were sufficiently minor to allow mapping. Fasciae of the hindlimb were predominantly type II or III, with type I fascia primarily at the lateral gluteal region, fascia lata, and lateral crus. Type IV fascia was seen at the iliac wing, ischium, patella, tibial tuberosity, medial tibia, distal crus, and pes. Fascia for surgical use was thin or absent at the ischiorectal fossa, femoral triangle, extensor mechanism, medial and distal crus, and pes. Intersections and tissues at the ventral perineum may also pose challenges for maintenance of a deep margin.

CONCLUSION

Fascial types and integrity of the hindlimb varied with location, with the perineum, cranial stifle, and distal limb presenting the greatest challenges.

CLINICAL SIGNIFICANCE

These images may be used to guide both therapeutic decision-making and intraoperative excision of superficial tumors of the hindlimb and pelvis.

Cutaneous Plasmacytoma with Systemic Metastases in a Cape Serotine Bat (Laephotis capensis)

Despite their relatively long life-spans, reports of neoplasia in bats are rare and are limited to a handful of cases. In this report, we describe a 2-year-old female wild Cape serotine bat (Laephotis capensis) that had been caught by a domestic cat and presented with a skin mass over the chest area. Histopathological analysis of a subsequent biopsy revealed proliferating sheets of neoplastic round cells, occasionally appearing to form packets, supported by a fine, fibrovascular stroma. Marked nuclear pleomorphism was seen, as well as a high mitotic count. Immunohistochemistry displayed positive labelling for MUM1 in the neoplastic cells. The diagnosis was extramedullary plasmacytoma (EMP); a neoplasm consisting of plasma cells derived from B lymphocytes. Due to a deteriorating condition, the bat was anaesthetised, and the mass was surgically removed two weeks later. However, the bat succumbed under the anaesthetic. Histopathological examination of the mass showed the same neoplastic cell population as observed in the biopsy; in addition, there was a locally extensive infiltration of neoplastic cells in the spleen and a mild presence of neoplastic cells in circulation. This is the first report of an EMP in a bat, and we compare the findings with that seen in dogs and cats.

Pathological, histochemical, and immune-histochemical studies on some canine-skin neoplasm at Sharkia province, Egypt

Background

Cutaneous neoplastic disorders are often observed in small mammal pets, such as dogs, regardless of their gender.

Aim

An important objective of this work was to give a full account of the clinical, pathological, and immune-histochemical features of several skin tumors in dogs.

Methods

This study was a case series in the hospital clinic, Faculty of Veterinary Medicine, Zagazig University, Egypt. Twenty-five dogs (14 males and 11 females) were examined clinically during the period from March 2022 to October 2023. The skin swelling was collected from affected animals and then subjected to a detailed histopathological study to record the different gross and microscopic findings and confirm the diagnosis by immunohistochemistry.

Results

Skin neoplasia in dogs was exposed to various clinical signs, and the dogs' ages ranged between 3 and 11 years. Concerning tumor features, the majority of neoplasms were malignant (65.52%) more than benign (34.48%). The study revealed the presence of 29 cases of dogs showed neoplasia with different prevalence rates including squamous cell carcinoma (13.79%), mast cell tumor (6.89%), basal cell tumors (10.34%), histiocytoma (6.89%), trichoepithelioma (10.34%), transmissible venereal tumor (10.34%), trichilemmoma (3.44%), scalp paraganglioma (3.44%), pilomatricoma (10.34%), malignant melanomas (17.24%), and miscellaneous cases as fat necrosis (6.89%), in males and females dogs with different histopathological lesions and immunohistochemistry expressions for pan-cytokeratin (CK), melanocyte-differentiation antigens (S100 protein), and synaptophysin.

Conclusion

Malignant melanomas (17.24%) are the extremely common cutaneous tumors diagnosed in this study. Meanwhile, benign tumors such as trichilemmoma, trichoepithelioma, pilomatricoma, and paraganglioma are less frequent in dogs.

Automated diagnosis of 7 canine skin tumors using machine learning on H&E-stained whole slide images

Microscopic evaluation of hematoxylin and eosin-stained slides is still the diagnostic gold standard for a variety of diseases, including neoplasms. Nevertheless, intra- and interrater variability are well documented among pathologists. So far, computer assistance via automated image analysis has shown potential to support pathologists in improving accuracy and reproducibility of quantitative tasks. In this proof of principle study, we describe a machine-learning-based algorithm for the automated diagnosis of 7 of the most common canine skin tumors: trichoblastoma, squamous cell carcinoma, peripheral nerve sheath tumor, melanoma, histiocytoma, mast cell tumor, and plasmacytoma. We selected, digitized, and annotated 350 hematoxylin and eosin-stained slides (50 per tumor type) to create a database divided into training, n = 245 whole-slide images (WSIs), validation (n = 35 WSIs), and test sets (n = 70 WSIs). Full annotations included the 7 tumor classes and 6 normal skin structures. The data set was used to train a convolutional neural network (CNN) for the automatic segmentation of tumor and nontumor classes. Subsequently, the detected tumor regions were classified patch-wise into 1 of the 7 tumor classes. A majority of patches-approach led to a tumor classification accuracy of the network on the slide-level of 95% (133/140 WSIs), with a patch-level precision of 85%. The same 140 WSIs were provided to 6 experienced pathologists for diagnosis, who achieved a similar slide-level accuracy of 98% (137/140 correct majority votes). Our results highlight the feasibility of artificial intelligence-based methods as a support tool in diagnostic oncologic pathology with future applications in other species and tumor types.

Epidemiology of canine cutaneous round cell tumours on the canary archipelago in Spain

In this study we undertook a comprehensive analysis of a Pet Tumour Registry of the Canary Archipelago (PTR-CA) in Spain to investigate the epidemiology of canine cutaneous round cell tumours. From a database of 2526 tumours collected from 2003 to 2020, we conducted a longitudinal analysis of the main trends in diagnosis, age, multiplicity and anatomical distribution as well as a case-control study comparing these cases with the contemporaneous canine population of the Canary Archipelago to analyse breed distribution. In line with former studies, we found histiocytomas mostly affect young dogs (2, IQR 1-5) and mast cell tumours affect middle-to-old dogs (8, IQR 6-10) with grade 1 affecting at younger ages (6.5, IQR 6-8) than both grade 2 (8, IQR 6-10 years) and grade 3 (9, IQR 7-11). Histiocytomas and plasmacytomas showed a similar anatomical distribution appearing mainly on the face, head and neck regions while mast cell tumours occur mainly on limbs and trunk. Higher risk for mast cell tumours and histiocytomas were found for Bulldog-related breeds such as Boxer (ORMCT  = 23.61, CI95%: 19.12-29.15, ORHCT  = 10.17, CI95%: 6.60-15.67), Boston Terrier (ORMCT 19.47, CI95%: 7.73-49.05, ORHCT 32.61, CI95%: 11.81-90.07) and Pug (ORMCT 8.10, CI95%: 5.92-11.07, ORHCT 7.87, CI95%: 4.66-13.28) while Chihuahua dogs showed significantly less risk (ORMCT 0.18, CI95%: 0.09-0.33, ORHCT 0.41, CI95%: 0.21-0.78). Notably, the Canarian Mastiff, a local breed, had a low risk of suffering from a mast cell tumour which raises the question of whether this relates to a genetic peculiarity of this breed or some husbandry and environmental factor.

Incidence and the risk of occurrence of benign and malignant canine skin tumours in Poland - a five-year retrospective study

Introduction

The aim of the study was to compile data on the frequency and distribution of canine skin tumours and determine the risk of these being malignant as opposed to benign. This determination proceeded from tumour histogenesis and gave consideration to the dog's breed, sex, age and the anatomical location of tumours.

Material and Methods

This retrospective five-year epidemiological study included 3,139 canine skin tumours collected in Poland. A univariable logistic regression analysis was performed to determine the odds ratios (ORs) with 95% confidence intervals (CIs).

Results

Microscopic analysis showed a significant predominance of benign tumours (65.02%) as well as mesenchymal and melanocytic tumours (59.57%). The most frequently diagnosed were mast cell tumours, accounting for 13.79% of all skin tumours, and other common tumour types were lipomas (6.40%), haemangiopericytomas (5.96%) and malignant melanomas (4.65%). The risk of malignant versus benign tumours was 1.212 times higher in the female than in the male dogs. A higher risk of development of malignant epithelial tumours was found in boxers (OR 4.091), German shepherds (OR 4.085) and flat-coated retrievers (OR 43.596). A higher risk of development of malignant mesenchymal tumours was found in golden retrievers (OR 4.693), boxers (OR 2.342), bulldogs (OR 3.469) and Maltese (OR 2.757).

Conclusion

The results may serve as a reference point for further studies of the complex biology of canine skin tumours.

Treatment of multiple synchronous canine mast cell tumours using intratumoural tigilanol tiglate

Mast cell tumours (MCTs) are common canine skin neoplasia. While they generally occur as single tumours, multiple synchronous MCTs (msMCTs) of de novo/non-metastatic origin are reported in a proportion of the patient population. Where there is no evidence of metastasis or lymphatic spread, MCTs are effectively controlled by surgery and other local therapies. However, treatment of de novo msMCTs can be more challenging, especially when they occur in surgically difficult locations. Here, we report the use of tigilanol tiglate, a novel small molecule registered as a veterinary pharmaceutical for the local treatment of non-metastatic MCTs, in the treatment of patients with msMCTs presenting at three Australian specialist referral centres. We also present a meta-analysis of the literature to provide a better understanding of the prevalence of canine msMCTs. Notably, nine patients with a total of 32 MCTs were treated during the study. A complete response was recorded in 26 (81%) of the individual MCTs on Day 28 after a single tigilanol tiglate injection. Of the 6 initially non-responsive MCTs, one achieved a complete response after a further tigilanol tiglate treatment. A complete response was reported at 6 months in all 22 of the tumours that were evaluable and that had recorded a complete response at Day 84. For the literature meta-analysis, 22 studies were found with prevalence estimates of msMCTs ranging from 3 to 40%; when combined, these studies yielded 3,745 patients with a prevalence of 13% (95% CI 10; 16). Overall, the results demonstrate the utility of intratumoural tigilanol tiglate as an option for the treatment of multiple MCTs where multiple surgical resections would have been required.

Tumour Incidence in Dogs in Germany: a Retrospective Analysis of 109,616 Histopathological Diagnoses (2014-2019)

Characterization of a tumour entity is based on the precise histopathological diagnosis taking into account the signalment of the diseased animal. The present study is a comprehensive, up-to-date statistical investigation on the type, frequency and breed distribution of neoplasia in dogs in Germany. The histopathological datasets of 109,616 German canine tissue samples (2014-2019) were processed and statistically examined in retrospect. Non-neoplastic diseases were found in 38,650 samples (35.3%) and 70,966 neoplasms (64.7%) were diagnosed. The most common neoplasms were mammary tumours (21.9%), benign epithelial skin tumours (15.4%), mast cell tumour (9.7%), histiocytoma (7.0%), soft tissue sarcoma (5.8%), lipoma (5.8%), melanocytic tumours (5.2%) and odontogenic tumours (4.7%). In general, Beagles, Magyar Vizslas, Boxers, Schnauzers, Spaniels, French Bulldogs and Golden Retrievers had an increased risk of neoplasia (odds ratio 1.17-1.46; all: P ≤0.001) compared with crossbreed dogs. In particular, Boxers, Golden Retrievers, Rottweilers and Schnauzers were often affected by malignant neoplasms, whereas some breeds (eg, West Highland White Terrier, Magyar Vizsla, Chihuahua, Dachshund and Yorkshire Terrier) were frequently affected by numerous benign tumour types. Despite the known risk of haemangiosarcoma in German Shepherd Dogs, other malignant tumours were rare in this breed. Depending on the type of tumour, some purebred dog breeds can have an increased, reduced or identical risk for certain neoplasms compared with crossbreeds. Discussion of breed predispositions to tumour diseases must therefore be conducted critically and with a view to clinical relevance.

Retrospective study of canine cutaneous tumors submitted to a diagnostic pathology laboratory in Northern Portugal (2014-2020)

Background

Cutaneous neoplastic diseases are the most and second-most frequently reported tumors in male and female dogs, respectively. The aims of this study were to report the occurrence of canine cutaneous tumors in a pathology laboratory located in Northern Portugal between 2014 and 2020, and to characterize and categorize the anatomical locations, breed, age, and sex of the animals affected with different types of neoplasms.

Results

Throughout the 7-year study, 1,185 cases were diagnosed as cutaneous tumors, with 62.9% being classified as benign, and 37.1% as malignant. Mast cell tumors (22.7%) were the most frequently diagnosed tumor type, followed by benign soft tissue tumors (9.7%), sebaceous gland tumors (8.1%), vascular tumors (7.9%) and soft tissue sarcomas (7.6%). Cutaneous tumors commonly exhibited multicentric occurrence (14.6%) followed by single occurrence in hindlimb (12.1%), forelimb (8.6%), buttock (7.1%), abdominal (6.5%) and costal (5.2%) areas. The odds of developing cutaneous neoplasia were higher with increasing age (p < 0.001). Females had an increased odds of developing skin tumors compared to males (crude OR = 2.99, 95% (2.51, 3.55); adj OR = 2.93, 95% (2.46, 3.49). Purebred dogs, as a group, showed a reduced odds of developing cutaneous tumors when compared to mixed-breed dogs (crude OR = 0.63, 95% (0.53, 0.74); adj OR = 0.75, 95% (0.62, 0.89).

Conclusions

Mast cell tumors, benign soft tissue tumors and sebaceous tumors were the most common histotypes encountered. The epidemiological survey achieved with this study demonstrates the relative frequency of different types of tumors in this particular population. Furthermore, the results herein achieved can act as a basis or a beneficial reference for local veterinarians helping in the establishment of a preliminary and presumptive diagnosis of canine cutaneous tumors histotypes.

Plain English summary

Skin tumors are the most and second-most frequently reported tumors in male and female dogs, respectively. The aim of this study was to report the occurrence of canine skin tumors in a diagnostic pathology laboratory located in Northern Portugal, between 2014–2020 and to characterize the anatomical distributions, breed, age, and sex of the animals affected by different skin tumors.

During this period, 1,185 cases were diagnosed as skin tumors; 62.9% were diagnosed as benign, while 37.1% were malignant. Mast cell tumors (22.7%) were the most frequently diagnosed neoplasia, followed by benign soft tissue tumors (9.7%), sebaceous gland tumors (8.1%), vascular tumors (7.9%) and soft tissue sarcomas (7.6%). Skin tumors commonly developed in more than one location (14.6%) followed by solitary development in hindlimb (12.1%), forelimb (8.6%), buttock (7.1%), abdominal (6.5%) and costal (5.2%) areas. An increased odds of developing skin neoplasms as the patient’s age increase was detected. Females showed an increased odds in comparison to male dogs. Purebred dogs presented decreased odds for developing skin tumors in comparison to mixed-breed dogs.

The information relevance achieved with this study demonstrates the relative frequency of different types of tumors in this particular population, acting as a basis or a beneficial reference for regional veterinarians when providing an initial diagnosis of canine skin tumors.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40575-022-00113-w.

Diagnosis, Prognosis and Treatment of Canine Cutaneous and Subcutaneous Mast Cell Tumors

Mast cell tumors (MCTs) are hematopoietic neoplasms composed of mast cells. It is highly common in dogs and is extremely important in the veterinary oncology field. It represents the third most common tumor subtype, and is the most common malignant skin tumor in dogs, corresponding to 11% of skin cancer cases. The objective of this critical review was to present the report of the 2nd Consensus meeting on the Diagnosis, Prognosis, and Treatment of Canine Cutaneous and Subcutaneous Mast Cell Tumors, which was organized by the Brazilian Association of Veterinary Oncology (ABROVET) in August 2021. The most recent information on cutaneous and subcutaneous mast cell tumors in dogs is presented and discussed.

Prevalence and distribution of canine neoplastic and non-neoplastic cutaneous lesions in Serbia: a retrospective study of 2432 Cases (2011 – Mid 2021)

Cutaneous lesions, especially skin tumors in dogs, are among the most common lesions in this animal species. The aim of this study was to identify the most common types of canine cutaneous lesions, to determine the absolute and relative frequency of each type of cutaneous lesion, anatomical locations, mean age, as well as gender and breed distribution. The examination included all samples of cutaneous lesions in dogs obtained by surgical biopsy in veterinary clinics and examined at the Laboratory of the Department of Pathology at the Faculty of Veterinary Medicine, University of Belgrade from the 1st January 2011 to the 1st July 2021. In this period (126 months), a total of 2432 samples of cutaneous lesions were examined, of which 1984 (81.58%) were tumors (1037/1984, 52.27% benign and 947/1984, 47.73% malignant) and 448 (18.42%) non-neoplastic cutaneous lesions. The most commonly found cutaneous tumors were: mast cell tumor (17.34% of all tumors), histiocytoma (9.78%), papilloma (7.91%), lipoma (7.81%), squamous cell carcinoma (7.36%), trichoblastoma (4.44%), hepatoid adenoma (4.39%) and malignant melanoma (4.18%). The most common non-neoplastic cutaneous lesions were: follicular cyst(s) (35.04% of all non-neoplastic lesions), pyogranulomatous chronic dermatitis (23.88%), lymphocytic dermatitis (7.37%), hyperkeratosis (4.24%), and granulomatous dermatitis (3.79%). Our results substantially confirm previously reported data regarding cutaneous neoplastic and nonneoplastic lesions in dogs, and provide updated information on their frequency, animal age, anatomic location and breed distributions.

Long-term assessment of risk factors for canine tumors registered in Xi’an, China

Tumors are one of the leading causes to death in pet dogs among diseases. The tumor incidence of pet dogs has been increasing, raising widespread concern. In this study, retrospective analysis was performed with 246 tumor cases registered in Xi’an Animal Hospital, Northwest A&F University from 2009 to 2018. Correlations of sex, age and breed with tumor incidences were evaluated. The results showed that reproductive system tumors occupied the highest proportion (39.84%), followed by cutaneous tumors (28.05%), digestive tumors (18.70%) and ocular tumor (4.47%). Among the reproductive system tumors, breast tumors are the most common tumor in female pet dogs, especially for Pekingese (11.43%). Female dogs with high susceptibility to breast tumors were at the ages of 6–18 years old. As far as cutaneous tumors were concerned, the male pet dogs at all ages, particularly Golden Retrievers (17.39%), showed a high incidence. By contrast, male Samoyed aged from 4 to 13 years had the highest incidence (15.22%) of digestive tumors. In addition, pet dogs with ocular tumors mainly happened at the ages of 0–1 years and 6–13 years. Collectively, our findings are significant to develop effective measures of medical surveillance for pet dogs’ health and will provide insights for comparative oncology.

Diagnostic Value and Application of Infrared Thermography in the Analysis of Circumanal Gland Tumors

In dogs, circumanal tumors are the third most common skin neoplasm. Circumanal gland adenomas (CAGAs) have a good prognosis. Contrastingly, circumanal gland adenocarcinomas (CAGAC) have high relapse rates and may be metastatic. This study aimed to investigate the utility of thermal imaging as an ancillary modality for the diagnosis of canine CAGA and CAGAC. We analyzed the following parameters: SpT, temperature measured at the tumor center; SpNT, temperature measured at a healthy sphincter skin spot distant from the tumor; TA, temperature measured at a tumor-encompassing ellipse-shaped area; and NTA, temperature measured at an ellipse-shaped area of the healthy sphincter skin distant from the tumor. In CAGAs, the mean SpT and SpNT temperature values differed by −1.45°C (p < 0.01) while the mean TA and NTA temperature values differed by −0.96°C (p < 0.05). In CAGACs, mean SpT and SpNT temperatures differed by −1.71°C (p < 0.01) while the mean TA and NTA temperatures differed by −1.69°C (p < 0.01). The mean SpT and TA temperature values measured in CAGAs and CAGACs differed by −0.10°C (p = 0.87) and 0.52°C (p = 0.38), respectively. Both tumors were colder than healthy sphincter skin. However, a substantial number of CAGACs were colder than CAGAs. Temperature differences ≥ 1°C between tumors and healthy sphincter skin increased the probability of CAGAC diagnosis by 17.45%. Thermal imaging allowed discrimination between healthy and tumoral tissues; therefore, it could be a good ancillary diagnostic modality.

Fascial plane mapping for superficial tumor resection in dogs. Part II: Forelimb

OBJECTIVE

To detail the qualitative fascial categories and fascial intersections of the forelimb of the dog to facilitate preoperative planning for superficial cancers.

STUDY DESIGN

Qualitative anatomical study.

SAMPLE POPULATION

Three male and four female mixed breed canine cadavers weighing approximately 20-35 kg.

METHODS

The skin and subcutaneous fat were excised. Fascial planes were incised and elevated to allow exploration of their quality and borders. Fascia was categorized as type I (discrete sheets), type II (tightly adhered to thin muscles), type III (tightly adhered to thick muscles), or type IV (associated with periosteum). Photographs of specimens were digitally modified with overlays to map tissue types.

RESULTS

Differences between the cadavers used were largely based on muscle mass and sex, with minimal other subjective differences affecting fascial mapping. The fasciae of the forelimb were largely type II or type III, with type I fascia at the antebrachium and type IV fascia at the olecranon, scapular spine, and accessory carpal bone. Fascial integrity was often questionable or lacking distal to the distal quarter of the antebrachium.

CONCLUSION

The fascial types and integrity of the forelimb varied with anatomic location with thin or absent fascia for surgical use at the elbow, carpus, and manus.

CLINICAL SIGNIFICANCE

This study provides information for preoperative planning and excision of superficial tumors of the forelimb. Knowledge of the potential limitations of fascia to provide a deep margin may influence selection of treatment modalities.

Digital Lesions in Dogs: A Statistical Breed Analysis of 2912 Cases

Breed predispositions to canine digital neoplasms are well known. However, there is currently no statistical analysis identifying the least affected breeds. To this end, 2912 canine amputated digits submitted from 2014–2019 to the Laboklin GmbH & Co. KG for routine diagnostics were statistically analyzed. The study population consisted of 155 different breeds (most common: 634 Mongrels, 411 Schnauzers, 197 Labrador Retrievers, 93 Golden Retrievers). Non-neoplastic processes were present in 1246 (43%), tumor-like lesions in 138 (5%), and neoplasms in 1528 cases (52%). Benign tumors (n = 335) were characterized by 217 subungual keratoacanthomas, 36 histiocytomas, 35 plasmacytomas, 16 papillomas, 12 melanocytomas, 9 sebaceous gland tumors, 6 lipomas, and 4 bone tumors. Malignant neoplasms (n = 1193) included 758 squamous cell carcinomas (SCC), 196 malignant melanomas (MM), 76 soft tissue sarcomas, 52 mast cell tumors, 37 non-specified sarcomas, 29 anaplastic neoplasms, 24 carcinomas, 20 bone tumors, and 1 histiocytic sarcoma. Predisposed breeds for SCC included the Schnauzer (log OR = 2.61), Briard (log OR = 1.78), Rottweiler (log OR = 1.54), Poodle (log OR = 1.40), and Dachshund (log OR = 1.30). Jack Russell Terriers (log OR = −2.95) were significantly less affected by SCC than Mongrels. Acral MM were significantly more frequent in Rottweilers (log OR = 1.88) and Labrador Retrievers (log OR = 1.09). In contrast, Dachshunds (log OR = −2.17), Jack Russell Terriers (log OR = −1.88), and Rhodesian Ridgebacks (log OR = −1.88) were rarely affected. This contrasted with the well-known predisposition of Dachshunds and Rhodesian Ridgebacks to oral and cutaneous melanocytic neoplasms. Further studies are needed to explain the underlying reasons for breed predisposition or “resistance” to the development of specific acral tumors and/or other sites.

Histologic features of hair follicle neoplasms and cysts in dogs and cats: a diagnostic guide

Hair follicle neoplasms occur in many different species, including humans. In domestic animals, they are most common in dogs. Most hair follicle tumors are benign, but malignant neoplasms can also occur. To diagnose hair follicle neoplasms, a thorough knowledge of follicular anatomy is important, given that follicular tumors are classified according to the differentiation pattern seen in the corresponding part of the normal hair follicle. This review focuses on the key diagnostic features of hair follicle tumors and follicular cysts in dogs and cats.

Comparative In Vitro and In Vivo Studies on Feline, Canine, and Human Merkel Cell Carcinoma

Merkel cell carcinoma (MCC) is an aggressive cutaneous neuroendocrine tumor, and most human MCC cases are infected by Merkel cell polyomavirus (MCPyV). However, the underlying pathogeneses of MCC in animals remain unclear. In the present study, newly established cell lines from feline and canine MCC, a MCPyV-positive human MCC cell line, and MCC tissues from 25 cats and 1 dog were examined and compared pathologically. Feline and canine MCCs were composed of tumor cells arranged in trabeculae and solid packets. Twenty out of 25 feline MCC cases (80%) had other proliferative cutaneous lesions, such as carcinoma in situ and squamous cell carcinoma. Among the 25 feline MCC cases, tumor cells were immunopositive for cytokeratins (CKs), including CK5/6 (4/25 cases, 16%), CK7 (5, 20%), CK18 (25, 100%), CK19 (20, 80%), and CK20 (20, 80%). The tumor cells of feline MCC were also immunopositive for synaptophysin (24/25, 96%) and CD56 (22/25, 88%). The tumor cells of canine MCC were immunopositive for CK18, CK19, CK20, and synaptophysin. Cultured feline and canine MCC cells grew in adherent monolayers and exhibited diffuse cytoplasmic immunoreactivity for CKs, whereas human MCC cells grew in suspension and exhibited dot-like cytoplasmic immunoreactivity for CKs. Differences in the distribution of CKs between human and animal MCC may be attributed to cell adhesion propensities. MCPyV genes and antigen were not detected in feline or canine MCC, suggesting a different etiology from human MCC.

Histological and Immunohistochemical Features of Trichoblastoma in a Sarda Breed Sheep

Simple Summary

Skin tumors in ruminants are occasionally reported and are mostly associated with the presence of oncogenic viruses, such as papillomavirus, or to direct skin exposure to solar radiation. Spontaneous tumors with adnexal differentiation, originating from the hair follicle or its associated glands, are even more rarely reported in these species. Investigation of the histological and immunohistochemical features of a trichoblastoma (tumor arising from the hair follicle) detected in the ear of a Sarda breed sheep, allowed for the study of comparative aspects of this tumor with other domestic species in which this neoplasm is commonly reported, such as in dogs and cats, and in human beings. This work contributed to the deepening of the knowledge of ovine spontaneous tumors unrelated to the presence of papillomaviruses.

Abstract

Skin tumors with adnexal differentiation are commonly reported in dogs and cats, while only anecdotal evidence is available in sheep. Here we illustrate the macroscopic, histologic, and immunohistochemical features of a cutaneous lesion with adnexal differentiation in a 6-year-old female Sarda breed sheep, surgically treated for a horn-like mass located in the left pinna. Additionally, we investigate a possible contribution of Ovine Papillomaviruses (OaPVs). Histologically, the dermis was expanded by an expansive and unencapsulated multilobulated nodule composed of cuboidal to spindle basaloid cells arranged in variably-sized cytokeratins (CK) AE1-AE3, CK 5/6 and CK 34 beta E12, p63—positive winding cords with a characteristic palisade arrangement of neoplastic cells in the periphery of the tumor. Based on these results, the cutaneous neoplasm was diagnosed as a trabecular trichoblastoma with spindle cells and rare structures resembling papillary mesenchymal bodies. Additionally, multiple enlarged sebaceous lobules clustered around dilated ducts suggestive of sebaceous gland hyperplasia were detected near the trichoblastoma. No PV DNA was found in the examined tissues, suggesting that ovine PVs are not involved in the pathogenesis of the present skin tumors with adnexal differentiation. Further investigations and efforts are required to elucidate the prevalence of skin tumors with adnexal differentiation in this species.