Immunohistochemical and morphological features of a small bowel leiomyoma in a black crested macaque (Macaca nigra)

Spontaneous Urinary Bladder Leiomyoma in a Rhesus Macaque (Macaca mulatta)

Here we report the case of a urinary bladder leiomyoma in a rhesus macaque. The animal was clinically normal and had a lipoma localized to the stifle. Endovesicular leiomyomas are the most common form of urinary bladder leiomyoma in humans. In contrast, this macaque's tumor exhibited extravesicular localization in the bladder. Urinary bladder leiomyomas account for less than 0.5% of all bladder tumors in humans, with only 250 cases reported in total.

Use of (18)F-fluorodeoxyglucose positron emission tomography-computed tomography to aid in diagnosing intestinal adenocarcinoma in 2 rhesus macaques (Macaca mulatta)

Two aged female rhesus macaques (Macaca mulatta) presented with weight loss and intermittent inappetence. The signalment and constellation of clinical signs led clinicians to suspect the presence of intestinal adenocarcinoma. Because of each animal's advanced age and inconclusive radiographic findings, a noninvasive diagnostic tool was preferred over exploratory laparotomy to assist in determining a diagnosis. Consequently, 2-[(18)F]fluoro-2-deoxy-d-glucose (FDG) positron emission tomography-CT (FDG-PET-CT) was chosen to aid in confirming a suspicion of gastrointestinal adenocarcinoma in both animals. FDG is a glucose analogue labeled with fluorine-18 and is taken up by highly metabolically active cells, as observed in many cancers. Tomography revealed an annular constriction of the small intestine with focal FDG uptake in one animal, and an FDG avid transmural mass in the ascending colon of the second animal. Necropsy later confirmed both sites to be adenocarcinomas. This report supports the use of FDG-PET-CT as an adjunct to conventional radiography in the diagnosis of intestinal adenocarcinoma in nonhuman primates.

Spontaneous leiomyomas of the gastroesophageal junction in a chimpanzee (Pan troglodytes)

A 49-y-old, female chimpanzee presented with a history of cardiac failure. Postmortem examination revealed lesions consistent with congestive heart failure and 2 incidental, round, firm, pale-tan intramural nodules (diameter, 2 cm) in the stomach at the gastroesophageal junction (GEJ). Histologically, the GEJ nodules were diagnosed as benign spindle-cell tumors. Immunohistochemical evaluation revealed neoplastic cells diffusely labeled with α-smooth muscle actin and vimentin, multifocally labeled for desmin, and were negative for c-kit (CD117). Electron microscopy revealed intracytoplasmic bundles of myofilaments with dense bodies, basal lamina, and few pinocytic vesicles in the neoplastic cells. According to these findings, leiomyomas of the GEJ were diagnosed. Gastrointestinal stromal tumors have been documented to occur in chimpanzees, but there are no reports of GEJ leiomyomas. To our knowledge, this report is the first description of spontaneous leiomyomas of the GEJ in a chimpanzee.