No abstract

Intravascular lymphoma is characterized by being a malignant neoplasm of extranodal T or B lymphocytes with exclusive proliferation within the vascular lumen, particularly of small vessels. The clinical signs vary due to the involvement of several organs, mainly the central nervous system. The diagnosis is difficult because many of the tests performed are not conclusive and, therefore, necropsy is the most efficient way to identify this tumor. This case report aims to describe the anatomopathological findings of a case of intravascular lymphoma in a mixed breed, 8 years old dog who presented neurological signs and was submitted to a necroscopic examination with clinical suspicion of granulomatous meningoencephalitis. The necropsy findings were not specific, but the presence of intravascular neoplastic lymphocytes in the brain, spleen, adrenal gland and stomach was verified by microscopy. These cells were positive for the CD3 antibody by immunohistochemistry, confirming the T lymphocyte phenotype. This neoplasm should be considered in the diagnosis of encephalopathies in dogs.

Lipid-rich carcinoma of the mammary gland is a rare variant of cancer and extremely uncommon in dogs. This case report describes the clinical and histopathological aspects of lipid-rich carcinoma in a female dog. A four-year-old spaeyd German Shepherd dog with enlarged volume adhered to the caudal and inguinal abdominal mammary region was examined. The impossibility of surgical ressection led to euthanasia during the surgical procedure. At necropsy, analysis of the abdominal cavity revealed the presence of an irregularly shaped mass, whitish with red areas, in the intrapelvic region. Also, metastases in axillary and mediastinal lymph nodes and right lung were observed. Histopathological analysis of the tumor in the mammary glands and intrapelvic mass showed malignant neoplastic proliferation of epithelial cells. The cells had a distinct shape and boundary, a well-defined cytoplasm, and the presence of intracytoplasmic macro and micro vacuoles, which sometimes pushed the nuclei to the periphery. The lymph nodes had lost the histological architecture due to metastasis. Marked and diffuse immunostaining of tumor cells in the cytoplasm by pancytokeratin, GATA 3 and 35BH11 confirmed the epithelial origin of the tumor. This very aggressive and uncommon neoplasm should be considered as a possible metastasi in the differential diagnosis of tumors of the abdominal cavity.

This study aims to verify survival in female dogs with breast tumor by analyzing the expression of target proteins PIK3CA, ZEB1, and ZEB2 belonging to the PI3K/AKT/mTOR pathway through immunohistochemistry (IHC) test in a retrospective study. The samples were obtained from dogs with breast cancer, previously identified by standard histopathological analysis, from which tissue microarray (TMA) blocks were made, and then immunohistochemical analyzes (IHC) were carried out using the development kit “REVEAL Polyvalent HRP-DAB Detection System,” for the proteins previously mentioned. For the purpose of prognostic analysis, these dogs were monitored for 540 days after surgical resection and survival was related to protein expression using the histoscore (HS) method. The HS is a measure to convert the IHC into quantitative values, and it is based on the intensity of the staining and the percentage of stained cells, ranging from 0 to 300. Individually through the analysis of the IHC, it was observed in the PIK3CA protein that from the HS = 164 the survival was on average 189 days, for ZEB1, the HS = 100 the survival was on average 438 days, and on the protein ZEB2 with the HS = 157, the survival was on average 178 days. Thus, the high expression of PIK3CA and ZEB2 proteins was correlated with lower survival in the dogs. In all studied proteins, it was observed that HS > 100 was correlated with a significant reduction in overall survival (p>0.05). The lower survival in female dogs with breast cancer after surgical resection was related to low rates of expression of PIK3CA and ZEB2 and, therefore, these can be considered as prognostic markers reserved for breast cancer in female dogs.