Expression of tumour transcription factor GLI1 in canine mammary tumours tissue.

BACKGROUND: Mammary tumor is one of the most common diseases of canine in pet clinics. OBJECTIVES: This study investigates the distribution and expression of the tumor transcription factor GLI1 and the downstream proteins, Bmi1 and Sox2, in canine mammary tumors and paracancerous tissues. METHODS: Cancerous and paracancerous normal mammary tissues were detected using western blotting (WB), and immunohistochemistry. RESULTS: The results showed that the histopathology of different types in mammary tumors by microscopic observation. GLI1/Bmi1/Sox2 expression was significantly higher in canine mammary invasive carcinoma than in ductal carcinoma and adjacent normal mammary tissues (p < 0.01). The expression of GLI1 in invasive carcinoma tissues was significantly higher than Bmi1 and Sox2, while Sox2 expression in ductal carcinoma tissues was significantly higher than GLI1 and Bmi1 (p < 0.01). GLI1/Bmi1/Sox2 all showed positive reactions in both mammary tumor and adjacent normal mammary tissues with immunohistochemistry. GLI1 and Sox2 showed strong positive staining in the cytoplasm of invasive mammary carcinoma and ductal carcinoma cells, and weak positive staining in the nuclei. The positive Bmi1 reaction was mainly concentrated in the cytoplasm of invasive carcinoma and ductal carcinoma cells, while the positive reaction on the cell membrane was weak. CONCLUSIONS: We speculate that GLI1 and related proteins play an important role in regulating the proliferation and differentiation of tumors. Therefore, it provides important reference for the pathogenesis and pathogenicity of canine mammary tumor.

Partial parotid sialoadenectomy in a horse with parotid ductal carcinoma: Surgical description and case report.

OBJECTIVES: To describe the surgical findings, histopathological features, and long-term outcome for a horse with parotid salivary carcinoma. STUDY DESIGN: Case report ANIMALS: Twelve year old American Quarter Horse gelding. METHODS: The gelding was presented for a 10 × 10 cm swelling below the base of the right ear. Ultrasonographic examination revealed a mass involving the right parotid salivary gland. Incisional biopsy was consistent with parotid carcinoma. The tumor was marginally excised. The lateral wall of the guttural pouch was excised with the mass and was reconstructed with a porcine small intestinal submucosal (SIS) sheet. Cisplatin beads were implanted in the wound bed prior to closure. Firocoxib (0.1 mg/kg orally, daily, every 24 h) treatment was initiated. RESULTS: Postoperative complications included right-sided facial nerve paralysis, difficulty with deglutition of fibrous feeds, and surgical site dehiscence. Wound healing was achieved by second intention. Partial improvement in nerve function was observed within the first 6 months. At 12 months postparotidectomy, no sign of tumor reoccurrence or metastatic disease was present, and the gelding returned to work. CONCLUSION: Partial parotid sialoadenectomy was performed with a favorable long-term outcome. Regional anatomic knowledge is crucial.

Biphasic Feline Mammary Carcinomas Including Carcinoma and Malignant Myoepithelioma.

Feline mammary tumors are usually malignant and aggressive carcinomas. Most cases are simple monophasic carcinomas (1 epithelial population), and additional phenotyping is usually not needed. In this study, we describe 10 malignant mammary tumors from 9 female cats that had unusual histomorphology: they appeared biphasic, with 2 distinct cell populations. Initially, they were morphologically diagnosed as either carcinosarcoma (1/10) or malignant pleomorphic tumor (9/10) of the mammary gland, as the latter did not match any previously described histological subtype. Immunohistochemistry (IHC) was performed for pancytokeratin, cytokeratins 8 and 18, cytokeratin 14, cytokeratins 5 and 6, vimentin, p63, calponin, alpha-smooth muscle actin, Ki-67, ERBB2, estrogen receptor alpha, and progesterone receptor. In 7 of 10 cases, the biphasic nature was confirmed and, on the basis of the IHC results, they were classified as carcinoma and malignant myoepithelioma (4/10), ductal carcinoma (1/10), and carcinosarcoma (2/10). The other 3 of 10 cases were monophasic based on IHC. In the cases of carcinoma and malignant myoepithelioma, the malignant myoepithelial cells were 100% positive for vimentin (4/4) and variably positive for p63, calponin, and cytokeratins (4/4). These findings show that, although rare, biphasic mammary carcinomas do occur in cats. In dogs and humans, tumors composed of malignant epithelial and myoepithelial cells have a less aggressive behavior than certain simple carcinomas, and therefore, their identification might also be clinically significant in the cat.

Hormone Receptor Expression Analyses in Neoplastic and Non-Neoplastic Canine Mammary Tissue by a Bead Based Multiplex Branched DNA Assay: A Gene Expression Study in Fresh Frozen and Formalin-Fixed, Paraffin-Embedded Samples.

Immunohistochemistry (IHC) is currently considered the method of choice for steroid hormone receptor status evaluation in human breast cancer and, therefore, it is commonly utilized for assessing canine mammary tumors. In case of low hormone receptor expression, IHC is limited and thus is complemented by molecular analyses. In the present study, a multiplex bDNA assay was evaluated as a method for hormone receptor gene expression detection in canine mammary tissues. Estrogen receptor (ESR1), progesterone receptor (PGR), prolactin receptor (PRLR) and growth hormone receptor (GHR) gene expressions were evaluated in neoplastic and non-neoplastic canine mammary tissues. A set of 119 fresh frozen and 180 formalin-fixed, paraffin-embedded (FFPE) was comparatively analyzed and used for assay evaluation. Furthermore, a possible association between the hormone receptor expression in different histological subtypes of canine malignant mammary tumors and the castration status, breed and invasive growth of the tumor were analyzed. The multiplex bDNA assay proved to be more sensitive for fresh frozen specimens. Hormone receptor expression found was significantly decreased in malignant mammary tumors in comparison to non-neoplastic tissue and benign mammary tumors. Among the histological subtypes the lowest gene expression levels of ESR1, PGR and PRLR were found in solid, anaplastic and ductal carcinomas. In summary, the evaluation showed that the measurement of hormone receptors with the multiplex bDNA assay represents a practicable method for obtaining detailed quantitative information about gene expression in canine mammary tissue for future studies. Still, comparison with IHC or quantitative real-time PCR is needed for further validation of the present method.

Proposed classification of the feline "complex" mammary tumors as ductal and intraductal papillary mammary tumors.

When compared with the canine species, feline mammary tumors (FMTs) are much less heterogeneous, with a predominance of simple malignant neoplasm. Benign FMTs are rare, and it is unclear if complex and mixed tumors exist in the feline. In this study, we selected for immunohistochemical analyses 12 FMTs that had unusual histologic features. A group of 8 (2 benign and 6 malignant) FMTs showed a biphasic epithelial/myoepithelial population and a very regular cord-like distribution in a "Chinese lettering" pattern, within ectatic ducts. A second group (2 benign and 2 malignant) had an intraductal epithelial papillary growth pattern with a basally located monolayer of myoepithelial cells and a supporting fibrovascular stroma. The myoepithelial component always produced a standard immunohistochemical signature. All malignancies were grade I, and the subjects were all alive at 1 year postdiagnosis. On the basis of their morphology, we propose that they be classified as feline ductal adenoma/carcinoma and feline intraductal papillary adenoma/carcinoma, respectively. They overlap with their canine counterparts and lack the typical myoepithelial differentiation patterns seen in canine complex neoplasms, and therefore, the term complex should be avoided in felines. This study will add new information on FMT classification and be useful for prognostic studies.

Studies on argyrophilic nucleolar organizer regions (AgNORs) in a spontaneous mammary gland ductal carcinoma of a captive rhesus monkey.

A spontaneous mammary gland ductal carcinoma was diagnosed in a 13-year-old female captive rhesus monkey (Macaca mulatta). The expression of argyrophilic nucleolar organizer regions (AgNORs) was studied to investigate the correlation between the histologic invasiveness and cell proliferation activity assay for predicting the biologic behavior of this tumor type. The results of this study show that the AgNOR size in tumor cells reflect the degree of malignancy when compared with the pattern of peripheral blood lymphocytes of the same individual. This is the first study showing a significant AgNOR feature of a malignant breast tumor in a rhesus monkey and it longs to provide additional diagnostic tool in tumor pathology.

Hyperplastic and neoplastic lesions of the mammary gland in macaques.

Macaques provide an important animal model for the study of hormonal agents and their effects on risk biomarkers for breast cancer. A common criticism of this model is that spontaneous breast cancer has rarely been described in these animals. In this report, we characterize 35 mammary gland lesions ranging from ductal hyperplasia to carcinoma in situ and invasive ductal carcinoma in cynomolgus and rhesus macaques. Based on a retrospective analysis, we estimated the lifetime incidence of mammary gland neoplasia in aged female macaques to be about 6%. Hyperplastic lesions (n = 19) occurred segmentally along ducts and included such features as columnar alteration, micropapillary atypia, and fibroadenomatous change. In situ carcinomas (n = 8) included solid, comedo, cribriform, and micropapillary elements, encompassing 4 of the major architectural patterns seen in human lesions. Invasive ductal carcinomas (n = 8) were generally solid, with prominent central necrosis and mineralization, often on a background of micropapillary ductal hyperplasia and in situ carcinoma. Cytologic changes of invasive lesions included increased mitoses, nuclear pleomorphism, extensive microinvasion, and stromal desmoplasia. Axillary lymph-node metastases were confirmed in 5 of the 8 invasive carcinomas. On immunohistochemistry, intraductal and invasive carcinomas had increased Ki67/MIB1 and HER2 expression and selective loss of estrogen and progesterone receptors. These findings suggest that breast cancer is an underreported lesion in macaques and highlight unique morphologic and molecular similarities in breast cancer between human and macaque species.