Pemphigus erythematosus and cutaneous epitheliotropic lymphoma in a Labrador Retriever dog.

BACKGROUND: Paraneoplastic pemphigus is an autoimmune blistering skin disease associated with concurrent neoplasia that is rarely observed in veterinary medicine. CASE DESCRIPTION: This case report presents a ten-year-old female Labrador Retriever dog with generalized seborrhea and alopecic, crusting and ulcerative lesions in the periocular and perioral regions, the lips and the groins. FINDINGS/TREATMENT AND OUTCOME: Hematology analysis showed a marked increase in the number of lymphocytes, while the rest of the values were normal. Skin biopsies were collected and the histological findings were consistent with pemphigus in association with an epitheliotropic lymphoma. Immunohistochemical analysis was performed. There was deposition of immunoglobulin G (IgG) in the basement membrane and in the intercellular space that corresponded with an immunostaining pattern characteristic of pemphigus erythematosus (PE). The lymphoma was positive to CD3 cells and was classified as a T-cell epitheliotropic lymphoma. CONCLUSION: To our knowledge, this is the first case of PE and cutaneous lymphoma coexisting in a dog, expanding the list of associations between immune-mediated diseases and cancer in dogs, and providing support to the eventual connection between autoimmunity and neoplasia in this species.

N-cadherin expression in feline mammary tumors is associated with a reduced E-cadherin expression and the presence of regional metastasis.

The cadherin family of adhesion molecules regulates cell-cell interactions. N-cadherin is expressed by neural and fibroblast cells but not by normal epithelial cells. In human medicine, the role of N-cadherin in breast cancer remains controversial, but some studies have described the switch from E-cadherin to N-cadherin as a critical step in the malignant progression of neoplastic cells. The present study was carried out on 160 feline mammary tumors (21 adenomas and 139 carcinomas). The relationship between the immunohistochemical expression of N-cadherin in neoplastic epithelial cells and 2 established prognostic factors such as regional metastasis and tumor grade was examined. The results of the study showed a statistically significant relation between the expression of N-cadherin and the 2 prognostic factors, and also a reduced expression of E-cadherin in tumors that expressed N-cadherin.

Naturally acquired visceral leishmaniosis in a captive Bennett's wallaby (Macropus rufogriseus rufogriseus).

A high prevalence of leishmaniosis has been reported from an increasing number of domestic and wild mammals around the world. In Australian macropods, Leishmania spp infection has been occasionally described in its cutaneous form only. The purpose of this report is to present a case of fatal visceral leishmaniosis in a captive Bennett's wallaby in Madrid, Spain, which was investigated by detailed macroscopic, histologic, and immunohistochemical examinations.

Reduced expression of E-cadherin and ß-catenin and high expression of basal cytokeratins in feline mammary carcinomas with regional metastasis.

Feline mammary carcinomas are highly aggressive neoplasms. Several mechanisms are thought to be involved in their progression, including the loss of epithelial adhesion molecules. The present study was carried out on 21 adenomas and 139 mammary carcinomas. Of the carcinomas, 66 were not reported to have metastasized, while the remaining 73 had evidence of regional lymph node metastasis at the moment of diagnosis. The relationship was examined between the expression of the E-cadherin-ß-catenin complex and basal (CK5/6, CK14) and luminal (CK8/18) cytokeratin expression. In the medical literature, carcinomas expressing basal cytokeratins are reported as having a poor prognosis in human breast cancer. Results revealed that preservation of the expression of E-cadherin and ß-catenin is a significant feature of carcinomas without metastasis, whereas carcinomas with metastasis reveal the loss of one or both adhesion molecules. Additionally, basal cytokeratin expression was statistically associated with the presence of regional metastasis. Furthermore, the expression of E-cadherin-ß-catenin was significantly correlated with the high expression of CK18 and low expression of CK5/6.

Cyclooxygenase-2 expression is related with localization, proliferation, and overall survival in canine melanocytic neoplasms.

A direct relationship has been firmly established between cyclooxygenase-2 (COX-2) expression and malignant behavior in human melanoma. This report examines the relationship between COX-2 expression and tumor location, mitotic and proliferative indices, degree of T CD3(+) lymphocyte infiltration, overall survival, and frequency of recurrence and metastasis of 57 melanocytic tumors (25 oral and 32 cutaneous). COX-2 was highly or moderately expressed in 88% of oral neoplasms (22 of 25), whereas for their cutaneous counterparts, COX-2 expression was low or insignificant in 75% of cases (24 of 32). High and moderate COX-2 expression levels were observed in 73% of melanocytic tumors with a mitotic index ≥ 3 per 10 high-power fields (26 of 36), whereas in 81% of tumors with a mitotic index < 3 (17 of 21), expression was mild or absent. There were 41 cases with known clinical outcomes; of those showing high, moderate, and mild COX-2 expression, 83.3% (10 of 12), 37.5% (3 of 8), and 25% (2 of 8) died, respectively, whereas 100% of animals showing no COX-2 expression (13 of 13) were still alive at the last follow-up. COX-2 expression was statistically correlated with tumor location, mitotic and percentage Ki-67 proliferative indices, and overall survival, frequency of neoplastic recurrence and metastasis. Regression analysis also showed disease-specific predictive value for COX-2 expression for subjects with melanocytic neoplasms. Additionally, only high COX-2 expression showed significant differences in overall survival, in comparison with moderate, mild, or absent expression. These results suggest that high COX-2 expression may be considered a prognostic biomarker and potentially as a target for therapeutic and preventive strategies in canine melanocytic neoplasms.

Histopathological lesions in 15 cats with leishmaniosis.

Recent research into the prevalence of Leishmania infantum infection in the Mediterranean basin points to the involvement of cats as a reservoir host, but only sporadic cases of feline leishmaniosis have been reported. Feline leishmaniosis presents primarily as cutaneous disease and diagnosis is based on the demonstration of the parasite by skin biopsy. The present report describes the microscopical changes in tissue biopsies from 15 cats with leishmaniosis. The biopsies were derived from the skin, ocular tissue and mucocutaneous junctions. The most common histopathological feature was diffuse granulomatous inflammation with macrophages containing numerous amastigotes. Other patterns included granulomatous perifolliculitis and lichenoid interface dermatitis, where there were fewer parasitized macrophages. The presence of amastigotes was confirmed by immunohistochemistry in each case. The results of the study confirm the value of histopathological and immunohistochemical techniques for the diagnosis of feline leishmaniosis.