Disseminated sclerosing peritoneal mesothelioma in a dog

Abstract

A 7-year-old female German Shepherd Dog was presented with multiple petechiae and ecchymoses along the ventral abdomen, flank, and on the vaginal mucosa. The clinical diagnosis was severe hemoperitoneum and presumed disseminated intravascular coagulopathy. Postmortem examination revealed a 22 cm × 15 cm × 6 cm, firm, and convoluted peritoneal mass along with hemoperitoneum, and multifocal, ill-defined, 0.5-1.5 cm in diameter, white to tan nodules in the pulmonary parenchyma. Histologically, the peritoneal mass was composed of large anaplastic cells consistent with malignant mesothelioma interspersed in abundant fibrous connective tissue. Metastasis of the neoplastic cells occurred to the brain, adrenal glands, lymph nodes, and lungs. On immunohistochemical evaluation, neoplastic cells coexpressed cytokeratin and vimentin, and were negative for cluster of differentiation (CD)18. Electron microscopy revealed numerous surface microvilli around the entire circumference of the neoplastic cells, as well as tight junctions, and desmosome-like structures. Based on test findings, a disseminated sclerosing peritoneal mesothelioma was diagnosed.

Using of immunocytochemistry in differential diagnosis of neoplasms of serosal cavities in dogs

“…In numerous researches conducted on both canine and human cases, immunohistochemistry performed on tissue samples and immunocytochemistry performed on cellular samples of mesotheliomas have revealed constant expression of intermediate filaments typical for both epithelial and mesenchymal cells (Hurlimann 1994, Höinghaus et al 2008, Espino et al 2010, Gumber et al 2011, Vascellari et al 2011. However, simple co-expression of these two intermediate filaments cannot be used as a marker of neoplastic mesothelial cells, since co-expression of cytokeratin and vimentin in the same cells has been detected also in other types of tumors, for example synovial sarcomas, haemangiosarcomas, mammary gland carcinomas (Desnoyers et al 1990, Rabanal andElse 1994).…”

Rapid multiple immunofluorescent staining for the simultaneous detection of cytokeratin and vimentin in the cytology of canine tumors

“…Malignant cells from mesothelioma and those from carcinoma are usually difficult to distinguish based on cytomorphologic appearances alone . Theoretically, mesothelial cells exhibit dual expression of cytokeratin and vimentin, and the present RMIF method could help distinguish epithelial cells, mesenchymal cells (including macrophages), and mesothelial cells on a single slide, and provide clinical pathologists a tool to identify and classify suspected neoplastic cells in body cavity effusions.…”

Cytomorphometry of serosal effusion in dogs

“…According to the results of numerous studies, differentiation between mesotheliomas, epithelial malignant tumours, and some sarcomas could be difficult or even impossible. It concerns not only cellular samples but also microscopic examination of tissue samples collected during more or less invasive medical procedures (Smith and Hill 1989, Baker and Lumsden 2000, Brisson et al 2006, Ordonez 2006, Gumber et al 2011, Bertazollo et al 2012, Przeździecki and Sapierzyński 2014. Due to moderate to severe pleomorphism of benign hyperplastic mesothelium this reactive process could be confused with some cancers.…”