Sclerosing Peritoneal Mesothelioma in a Dog Evaluated by Electron Microscopy and Immunoperoxidase Techniques

Abstract

intracytoplasmic membrane-bound electron-dense neurosecretory granules further suggests the presence of chief cells. In the present study, the tumor cells have the histologic and special staining pattern, immunohistochemical staining properties, and ultrastructural features characteristic of neoplasms of the chemodectoma group. The unusual location of this tumor may be due to the widespread distribution of chemoreceptor cells associated with the extra-adrenal tissue of the paraganglionic system. This cow’s tumor may have originated from the myocardial components of the intravagal paraganglia or the visceral autonomic paraganglionic cell groups associated with the myocardial vasculature and atria1 septum of the heart. Acknowledgments. We thank Dr. B. G. Wiersma (Dairyland Veterinary Service, Fond du Lac, WI) for submitting this case and Ms. Anne Slattery for performing the immunohistochemical stains. We are grateful for the cooperation and histotechnologic support provided by Ms. Susan Samuelsen and Ms. Beth Byrne and for the photographic assistance provided by Mr. Craig Radi.