Cancer morbidity in Croatian cats: Retrospective study on spontaneously arising tumors (2009-2019)

One of the current leading causes of death in pet cats is neoplasia. The scarcity of data on tumor prevalence in cats from south-eastern Europe led to this retrospective study which reports an abundant collection of tumors diagnosed in cats living in Croatia. Archived histopathology findings (diagnosis, cell origin, and biological behavior), and epidemiological data (breed, sex, age, and anatomical site of the tumor) of the cats diagnosed with at least one tumor were collected and statistically analyzed. For the research, 2338 archived feline samples, obtained from 2009-2019, have been reviewed. In 659 samples (28.1%) one or more tumors were diagnosed. Tumors have most often affected non-pedigree cats, cats between 7 and 15 years of age, and female cats. Most tumors showed malignant behavior (85.7%). The most frequent diagnoses were mammary adenocarcinoma, lymphoma, and squamous cell carcinoma. Regarding origin, most samples were epithelial (46.9%), but mesenchymal (28.7%) and lymphoid tumors (17.0%) were also frequently found. Tumors most often occurred in the skin and subcutis, mammary gland (in females), digestive system, and hemolymphatic system (in males). Statistical analysis did not reveal breed, sex, and age predisposition, but female animals and non-pedigree cats were significantly more likely to develop malignant tumors. This detailed study gives insight into the most frequent tumors that occur in cats from Croatia, and the data reported here is likely applicable to other countries. This data will contribute to clinical veterinary oncology, as it presents the most extensive tumor index of cats in south-eastern Europe.

Clinical and histopathological investigation of symmetrical alopecia with associated chronic pruritus in tufted capuchin monkeys (Sapajus apella apella)

BACKGROUND

Symmetrical alopecia is a common symptom of endocrine and autoimmune diseases, which are rarely manifested with pruritus. Increased levels of stress in primates have been presented with increased levels of pruritus and alopecia appearance.

METHODS

A pruritic and alopecic disease was investigated in a group of tufted capuchin monkeys (N = 12), but due to ethical reasons, four random animals were further investigated by numerous diagnostic methods. The impact of food and enclosure enrichment was assessed and observed over a 2-year period.

RESULTS

Histopathology of four random tufted capuchin monkeys revealed lymphocytic perifolliculitis, with an appearance of a "swarm of bees" which was suggestive of alopecia areata. Etiological classification of pruritus excluded dermatological, systemic, and neurological causes, making it behavioral. Enclosure and food enrichment had a beneficial impact on pruritus (12/12) and alopecia (10/12).

CONCLUSION

The findings were suggestive of alopecia areata, while the pruritus was considered behavioral in origin. Alopecia and pruritus improved upon enclosure and food enrichment.

Granular cell tumor in the central nervous system of a ferret (Mustela putorius furo) - a case report

A granular cell tumor (GCT) in the central nervous system (CNS) of a ferret is a rare finding. In this case a cerebral GCT is described in a 5-year-old castrated female ferret. The animal developed lameness in right hind leg which progreseed to total ataxia. The animal died and a necropsy revealed the mass in the medial to caudal part of the left frontal lobe of the brain. Based on histological and imunohistochemical findings, tumor was diagnosed as granular cell tumor. Immunohistochemically, granular cells were diffusely positive for vimentin and neuron-specific enolase (NSE) and weakly focal reactivity for S-100 protein was seen. Neoplastic cells did not express cytokeratins and glial fibrillary acidic protein (GFAP). Although immunohistochemistry was performed, histogenesis of this tumor remains unsolved and controversial.

Mast Cells in the Mammalian Testis and Epididymis-Animal Models and Detection Methods

Mast cells (MCs) are an evolutionary well-conserved type of cells, mediating and modulating allergic responses in innate immunity and tissue remodeling after chronic inflammation. Among other tissues, they inhabit both the testis and epididymis. In the testis, MCs usually appear in the interstitial compartment in humans, but not in other standard experimental models, like rats and mice. MCs seem to be responsible for testicular tissue fibrosis in different causes of infertility. Although experimental animal models follow the effect on MC activation or penetration to the interstitial tissue like in humans to some extent, there is an inconsistency in the available literature regarding experimental design, animal strain, and detection methods used. This comprehensive review offers an insight into the literature on MCs in mammalian testes and epididymides. We aimed to find the most suitable model for research on MC and offer recommendations for future experimental designs. When using in vivo animal models, tunica albuginea incorporation and standard histological assessment need to be included. Domesticated boar strains kept in modified controlled conditions exhibit the highest similarity to the MC distribution in the human testis. 3D testicular models are promising but need further fine-tuning to become a valid model for MC investigation.

The clinical correlation of findings obtained by fine needle fenestration biopsy of the canine spleen with visible ultrasound changes

The medical records databases (March 2016 to March 2021) of the Faculty of Veterinary Medicine, University of Zagreb, were examined to determine the frequency and clinical relevance of cytological diagnoses from fine-needle fenestration biopsy (FNFB) of the spleen in dogs with visible ultrasound changes. Seventy-five dogs were divided into clinically relevant and irrelevant groups, according to the clinical relevance of the diagnosis. The incidence of clinically relevant diagnoses was 28/75 (37.3%). Malignant diagnoses were over-represented (23/28; 82.1%), followed by hemorrhages/hematomas (3/28; 10.7%) and suppurative inflammation (2/28; 7.1%). The most common malignancy was lymphoma (12/28; 42.9%). There was no correlation between the ultrasound lesions examined and the relevant cytological diagnoses, except in cases of patchy echo texture (P = 0.010). Lesion size greater than 1.74 cm had the highest sensitivity/specificity values (91.3%; 42.1%) with a significant area under the curve (AUC) of 0.68 (P = 0.029) for predicting clinically relevant findings. The complication rate due to bleeding was 2/130 (1.5%). In conclusion, splenic FNFB can be safely performed in dogs as it carries a low risk of development of complications. Specific ultrasonographic findings, such as patchy echo texture pattern, may increase the suspicion of the presence of neoplastic disease in the form of lymphoma. According to ROC analysis, lesion size greater than 1.74 increases the possibility of predicting clinically relevant findings.

Prevalence of pathological lesions diagnosed by cytology in cats, with association of diagnosis to age, breed and gender

Cytology is the diagnostic procedure of the microscopic evaluation of cells. It is becoming increasingly important and more frequently used in veterinary diagnostics, having many advantages including simplicity, speed and low cost. To determine the pathological changes diagnosed by cytology in cats, as well as the distribution of age, breed and gender in the diagnosed changes, we performed a retrospective study on slides submitted to the Department of Veterinary Pathology for routine cytological examination. The archive was searched for all feline cytology slides submitted from 2009 to 2018. All the slides were re-evaluated and classified into one of the four pathological processes: ‘neoplasia’, ‘inflammation’, ‘other condition’ or ‘non-diagnostic sample’. Breed, age, gender and the tissue from which the lesion was sampled were noted from the submission form, and statistically analyzed. The most frequent type of pathological process diagnosed was neoplasia, which reflects the high prevalence of neoplastic diseases in cats reported in literature data. Pathological changes were mostly diagnosed in domestic shorthaired cats of both sexes, with an average age of 8.4 years, but no breed, age or gender predisposition was found. The most evaluated tissue was skin, probably due to its accessibility and the ease of obtaining a sample from skin lesions. The most frequent neoplasia were malignant and the most frequent diagnosis was round cell neoplasia. Cats affected with round cell neoplasia had a significantly lower average age (7.3 years) than cats diagnosed with epithelial and mesenchymal neoplasia (9.9 and 10.3 years, respectively), probably reflecting the common retroviral infection in Croatian cats.

Pathomorphological features and mast cell count in canine visceral hemangiosarcomas

Visceral hemangiosarcoma were analyzed at the Department of Veterinary Pathology of the Faculty of Veterinary Medicine, University of Zagreb, over a 5-year period. From a total of 52 tumor masses in a total of 31 dogs, histological growth patterns (cavernous, capillary or solid) and the amount of tumor supporting stroma were evaluated. Additionally, sections were stained with toluidine blue for the purpose of mast cell detection and their number was determined in the tumor parenchyma, tumor stroma and edges. The average age of the affected animals was 10 years, males predominated, and the tumors occurred most frequently in cross breeds, German Shepherd dogs and Labrador Retrievers. The highest number of visceral hemangiosarcoma was found in the spleen (27/52). The most common growth pattern of visceral hemangiosarcoma was solely cavernous with a mixture of cavernous and solid patterns in different proportions. Mast cells were found in 44/52 (84.6%) of the visceral hemangiosarcomas. A smaller number of mast cells were found in the tumor parenchyma, and higher number were found in the stroma and tumor edges. The number of mast cells in tumors was not significantly associated with the tumor growth pattern, but there was a positive correlation between MCC - tumor parenchyma and stroma (rs = 0.28, P<0.05), MCC - tumor stroma + edges (rs = 0.74, P<0.05) and MCC - tumor parenchyma and MCC- tumor stroma+edges (rs = 0.30, P<0.05) in all the examined tumors. In splenic tumors, there was only a significant positive correlation between MCC - stroma+edges (rs P = 0.68 P<0.05). These results suggest a higher mast cell count in tumors with more developed stromal components in canine visceral hemangiosarcomas, and certainly indicate the need for further research on their role and the factors they release in the development and progression of hemangiosarcomas.

Expression of E-cadherin and Ki-67 in canine apocrine and sebaceous gland tumors

A histopathological analysis of 13 apocrine gland tumors and 22 sebaceous gland tumors in dogs was performed, which were submitted to the Department of Veterinary Pathology from 1 January 2010 to 31 December 2012. An association between the immunohistochemical expression of E-cadherin and Ki-67, the type, and the biological behavior of the tumors was investigated. The mean age of dogs with apocrine gland tumors was 10.15 years, and 10.91 years for sebaceous gland tumors. According to the histopathological analysis, 53.8% carcinomas and 46.2% adenomas of the apocrine glands were found. In the sebaceous gland tumors, epitheliomas were dominant (50.0%), followed by adenomas (36.4%) and carcinomas (13.6%). Survival time in dogs with sebaceous gland tumors was shortest in patients with diagnosed epitheliomas, intermediate in adenomas, and longest in carcinomas. The incidence of metastases was low in the groups with sebaceous adenomas and epitheliomas, and recurrence was most common in carcinomas. The average survival time was about the same for apocrine gland adenomas and carcinomas, with a higher incidence of metastases and recurrence for carcinomas. Immunohistochemical analysis of E-cadherin and Ki-67 expression confirmed the efficiency of this method for the accurate histological classification of apocrine and especially sebaceous gland tumors. The analyzes performed showed that the location and intensity of E-cadherin expression can be helpful in predicting the biological behavior of sebaceous gland tumors. In contrast to sebaceous gland tumors, the analysis of apocrine gland tumors showed that there was no correlation between E-cadherin expression and the biological behavior of apocrine gland tumors.

Quantification of morphology of canine circumanal gland tumors: a fractal based study

Circumanal gland tumors are very common neoplasms of dogs. Their classification relies on microscopic examination and is further supported by a few immunohistochemical markers that help indicate their prognosis. However, new additional tests would be highly useful. The purpose of this study was to develop such a test using fractal analysis which is increasingly being applied in science, especially in the field of biomedicine. A total of 53 circumanal gland tumors were chosen from our department archives. After a precise histological classification according to the World Health Organization classification, the number of de novo classified samples was as follows: 15 adenomas, 11 epitheliomas, 21 well differentiated carcinomas, 6 poorly differentiated carcinomas. Ten samples of normal circumanal gland were also included as control. All samples were immunohistochemicaly stained with vimentin. All immunohistochemical reactions were photographed at two different magnifications -100X and 400X- and converted to 1 bit in black and white (bitmap) images, thus enhancing the positive vimentin reactions. These images were used for the assessment of fractal dimension applying the box counting method and computer software Fractalyse. To determine the significance of results, conventional statistics were performed using Statistica software.

The overall vimentin stain score was significantly higher in epitheliomas and carcinomas than in normal circumanal glands (CG) or adenomas. Mean values of fractal dimension estimated at magnification 100X and 400X were as follows: normal CG 1.318 and 1.372, CG adenomas 1.384 and 1.408, CG epitheliomas 1.547 and 1.597, CG well differentiated carcinomas 1.569 and 1.607, CG poorly differentiated carcinomas 1.679 and 1.723. Significant differences (at level of 5%) of these values were observed between individual groups of CG adenomas or normal CG, and epitheliomas or carcinomas.

The above results indicate vimentin immunohistochemistry staining and assessment of fractal dimension as an ancillary diagnostic method of choice when discerning between benign and malignant tumors of circumanal glands. Additional development of the method of fractal dimension assessment may yield a possibility for this tool to successfully discern between all of the types of CG tumors.

Canine testicular tumors: two types of seminomas can be differentiated by immunohistochemistry

Background

Testicular tumors are the most common genital neoplasms in male dogs, with Leydig cell tumors (LCT), seminomas (SEM), and Sertoli cell tumors (SCT) the most common forms. Human SEM are classified as classical (CSEM) or spermatocytic (SSEM). Intratubular germ cell neoplasia of undifferentiated origin (IGCNU) is another form of human testicular tumor. The aim of this study was to verify that CSEM/SSEM classification is valid in dogs and confirm the existence of canine IGCNU.

Results

Testicular tumors were found in 46% of dogs at necropsy and accounted for 7% of tumors biopsied. The median age of dogs with tumors at necropsy was 10.16 years; median age at positive biopsy was 10.24 years. The most common tumors, in decreasing order, were LCT, mixed tumors, SEM and SCT at necropsy, and SEM, SCT, mixed tumors, LCT, peripheral nerve sheath tumor, and teratoma in the biopsy group. IGCNU was found in 3% of testicles at necropsy and in 3% of biopsy samples. Two dogs had testicular tumor metastasis. Expression of c-KIT was most common in SEM and seminomatous components of mixed tumors. PLAP was mostly expressed in IGCNU, SEM, teratoma, and some mixed tumors. Cytokeratin was mainly expressed in SCT. CD30 expression was low in both groups.

Conclusions

The high tumor incidence at necropsy can be attributed to older age. Tumor incidence in biopsy samples, dog age, and histological classification were consistent with previous studies. The higher incidence of SEM and SCT in the biopsy group probably resulted from the obvious clinical expression of these tumor types. The low incidence of metastasis confirmed the predominance of benign tumors. Low CD30 expression confirmed the low incidence of testicular embryonal carcinoma. Cytokeratin helps differentiate stromal tumors, especially SCT, from germ cell tumors. Histology and c-KIT and PLAP expression indicate that IGCNU exists in dogs. Expression of c-KIT and PLAP confirmed that CSEM and SSEM classification is valid in dogs.

Complex mammary adenoma with sebaceous differentiation in a dog

Sebaceous metaplasia arising within a complex adenoma of the left fourth mammary gland is described in a 9-year-old miniature pinscher bitch. Microscopically, the tumour was composed of tubular and ductular structures admixed with clusters of spindle-shaped, myoepithelial-like cells and units formed of well-differentiated sebocytes surrounded by basaloid cells. Abundant lipid droplets were identified within the latter population by Sudan III staining. Immunohistochemical expression of cytokeratin AE1/AE3 was detected in epithelial cells and in the cells with sebaceous differentiation.