Peripheral nerve sheath tumours (PNSTs) are rare in the mammary glands of dogs. Here, we report a case of a schwannoma, composed of two parts, of the mammary gland of a dog. The first part consists of clusters of uncircumscribed, alternating, more concentrated and looser regions. In the more concentrated parts, typical fascicularly arranged schwannoma intermingle in plexiform arrangement, more subtle in appearance than in neuronal tumour areas. The second part undergoes regression consisting predominantly of residual shorter rosettes of cells with the presence of a peculiar variably sized swirling of target-like formations consisting of compact, thicker, pinkish lamellae also with occasional adjacent cells. Immunohistochemically, the tumour cells are positive for evidence of vimentin and neuro-specific enolase. They exhibit the variable expression of the S-100 protein, show mild CD56 positivity, and focally mildly accentuated proliferative activity as assessed by Ki-67. The tumour elements are negative for evidence of cytokeratin 7, cytokeratin 20, and oestrogen receptors. Hybrid tumours may change their morphology in combination with atypical localisation and may be underdiagnosed in veterinary biopsy practice. They differ from epithelial tumours prognostically, as well as in their development and behaviour, therefore it is essential to clearly differentiate them.

• Klíčová slova
• Schwann cells, histopathology, hybrid tumours, mammary gland, perineural cells, peripheral nerve cells, veterinary oncology,
• Publikační typ
• časopisecké články MeSH
• kazuistiky MeSH

The aim of this study is to investigate the correlation between the incidence of spontaneous tumours of various origins and the localisation in dogs with sex, breed, and age factors. A total of 360 tumours with various localisation were studied pathomorphologically. Histopathologic data sets from 360 dog tissue samples were processed and statistically examined. A chi-square test of independence was conducted to examine the relationships among the various levels of the specified variables. Logistic regression models were employed for dichotomous outcomes to ascertain the influence of certain explanatory variables on the tumour types. Characteristic pathomorphological changes observed during examination of dogs with oncologic diseases were determined. The most common neoplasms were mammary tumours, accounting for 43% of the cases. The mammary gland tumours were most common in mongrel dogs (25%), with German Shepherds (17.3%), Poodles, Dachshunds, Central Asian Shepherds (6.7% each), and Rottweilers (5.7%) following. The highest frequency of these tumours appeared at 8 years of age, predominantly originating from the ductal epithelium, which represented 46.4% of all the malignant cases.

• Klíčová slova
• clinical study, dogs, histopathology, localisation, tumours,
• Publikační typ
• časopisecké články MeSH

With the increase in the life expectancy of domestic animals and their increasingly affectionate relationship with their owners, it is possible to observe an increase in cases of neoplasms in these animals. Mammary neoplasia mainly affects older females who have not been castrated, due to hormonal dependence for the development of the tumour. The main form of treatment is surgery. This study aims to carry out an updated review on mammary neoplasms in female dogs covering the anatomy, physiology, prevalence, causes, diagnoses, treatments, prevention and prognosis, based on scientific articles by renowned researchers.

• Klíčová slova
• dogs, mammary carcinoma, mammary lump, mammary tumour, manual,
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

Here, we report a rare case of concurrent primary splenic lymphoma and mammary gland tumour (MGT) with polycystic ovaries in a 10-year-old, intact female Jindo dog. The dog was presented with multiple masses in the fourth left mammary gland, the largest of which measured 6 cm in diameter, along with enlargement of the left inguinal lymph node on physical examination. Ultrasonography, radiography, and computed tomography scans revealed polycystic ovaries and a mass in the tail of the spleen, after total splenectomy and mastectomy with ovariohysterectomy, histopathological examination identified splenic diffuse large B cell lymphoma and malignant myoepithelioma of the mammary gland was found. To our knowledge, this is the first report of the concurrent occurrence of splenic lymphoma, MGT, and polycystic ovaries in a dog.

• Klíčová slova
• lymphoma, mammary gland tumors, myoepithelium, polycystic ovaries, surgical resection,
• Publikační typ
• časopisecké články MeSH
• kazuistiky MeSH