Mixed Malignant Pancreatic Tumour in a Rhesus Macaque (Macaca mullata).

Pancreatic islet cell tumours are rare in non-human primates. The majority of reported cases are benign islet cell adenomas in rhesus macaques (Macaca mullata). Here we describe a pancreatic tumour composed of both exocrine and endocrine cells known as a mixed acinar-neuroendocrine carcinoma in a captive rhesus macaque. A diagnosis of a mixed tumour requires intermingling of neoplastic exocrine and neuroendocrine cells and must be differentiated from ductal adenocarcinomas in which only the ductal component is neoplastic with interspersed normal neuroendocrine cells. Immunohistochemistry, including antibodies against cytokeratin 7 and chromogranin A, was used to demonstrate that both exocrine and endocrine neoplastic cells exhibited cellular atypia, invasion into the adjacent parenchyma and intraparenchymal metastasis consistent with a mixed malignant tumour. Expression of multiple hormones such as gastrin, insulin, pancreatic polypeptide and somatostatin was also observed throughout the neoplastic cell population, while the endocrine component of the neoplasm was predominantly positive for glucagon.

Primary Myxoid Liposarcoma of the Greater Omentum in a Rhesus Macaque (Macaca mulatta).

We here report a spontaneous case of primary myxoid liposarcoma of the greater omentum with subsequent transperitoneal recurrence. The primary mass was incidentally found during an exploratory laparotomy for a presumed diagnosis of trichobezoar or phytobezoar and was removed surgically. Histopathologic examination of the mass revealed the presence of a myxoid liposarcoma. Eleven months later, recurrence with severe transperitoneal sarcomatosis of the myxoid liposarcoma was noted and confirmed by necropsy and histopathology. A review of the literature revealed that liposarcoma in NHP conforms to the behavior and prognosis of this neoplasm in humans.

Pneumatosis intestinalis in an SIV-infected rhesus macaque (Macaca mulatta).

Pneumatosis intestinalis (PI) has been described as an incidental finding in domestic animals and humans where it is associated with human immunodeficiency virus infection among other comorbidities. This report describes emphysematous changes consistent with PI in a simian immunodeficiency virus (SIV)-infected rhesus macaque (Macaca mulatta).

Meeting report: Emerging respiratory viral infections and nonhuman primate case reports.

A workshop on Emerging Respiratory Viral Infections and Spontaneous Diseases in nonhuman primates was sponsored by the concurrent Annual Meetings of the American College of Veterinary Pathologists and the American Society for Veterinary Clinical Pathology, held December 1-5, 2012, in Seattle, Washington. The session had platform presentations from Drs Karen Terio, Thijs Kuiken, Guy Boivin, and Robert Palermo that focused on naturally occurring influenza, human respiratory syncytial virus, and metapneumovirus in wild and zoo-housed great apes; the molecular biology and pathology of these viral respiratory diseases in nonhuman primate (NHP) models; and the therapeutic and vaccine approaches to prevention and control of these emerging respiratory viral infections. These formal presentations were followed by presentations of 14 unique case studies of rare or newly observed spontaneous lesions in NHPs (see online files for access to digital whole-slide images corresponding to each case report at http://scanscope.com/ACVP%20Slide%20Seminars/2012/Primate%20Pathology/view.apml). The session was attended by meeting participants that included students, pathology trainees, and experienced pathologists from academia and industry with an interest in respiratory and spontaneous diseases of NHPs.