Hepatic Hemangiosarcoma in a Cynomolgus Macaque (Macaca fascicularis).

An experimentally naïve, 9-y-old, intact male cynomolgus macaque was reported for bleeding from an unidentified site. Sedated physical examination indicated mild gingival separation from the lingual aspect of the upper right canine tooth as the source of the hemorrhage. Physical exam revealed a firm mass adhered to the left zygomatic arch, 2 subcutaneous nodules on the chest, and a large mass in the cranial abdomen. Radiographs revealed a large soft-tissue mass in the cranial abdomen and multifocal nodules in the caudal lung fields. On ultrasonography, the liver was grossly enlarged and contained a cavi- tated mass. Hematology and serum chemistry results demonstrated severe regenerative anemia with normal clotting times and adequate platelet count. For humane reasons, euthanasia was elected. On gross examination, the liver was markedly enlarged by an expansile mass primarily affecting the median lobe, with multiple, smaller nodules throughout the remaining lobes. Multifocal round, firm nodules were observed on the surface of all lung lobes and throughout the omentum. Histologic examination of the hepatic, cutaneous, osseous, and pulmonary lesions demonstrated well-defined, endothelium-lined vascular channels arranged in cords with abundant hemorrhage; endothelial-cell immunomarkers confirmed these results. On the basis of these findings, hepatic hemangiosarcoma, with metastases to the lungs, omentum, subcutis, and bone, was diagnosed. This case study is the first report of spontaneous hepatic hemangiosarcoma in a cynomolgus macaque and the first case with metastasis to bone in a NHP.

Longitudinal MRI Evaluation of Ischemic Stroke in the Basal Ganglia of a Rhesus Macaque (Macaca mulatta) with Seizures.

An adult rhesus macaque developed seizures after the induction of ischemic stroke. Initially, on the day of surgery, a focal ischemic lesion was present exclusively in the right caudate nucleus. By 48 h after stroke induction, the lesion had extended into the putamen, when a seizure was observed. Our report highlights the temporal changes in infarction of unilateral basal ganglia after acute stroke and the accompanying clinical symptoms. This unusual case may provide additional information regarding the involvement of the basal ganglia in seizures, given that prior case reports and studies usually have not described the temporal and spatial evolution of the lesion before clinical symptoms emerge.

Acute Abdominal Distension Due to Disseminated Peritoneal Neoplasia in a Rhesus Macaque (Macaca mulatta).

This report describes the clinical, radiographic, and pathologic findings in a female rhesus macaque that presented with acute abdominal distension and tympany. The macaque was euthanized after evidence of severe colonic distension on radiography and observation of widespread peritoneal adhesions on exploratory laparotomy. Gross and histopathologic evaluation revealed extensive entrapment of gastrointestinal and reproductive tracts by serosal fibrovascular proliferative tissue containing foci of endometriosis. The diagnosis of endometrial stromal sarcoma was supported by expression of CD10, Wilm tumor 1, estrogen receptor, and progesterone receptor and failure to express immunohistochemical markers characteristic of a range of differential diagnoses. In humans, this relatively uncommon neoplasm can arise from sites of endometriosis and often presents clinically as intestinal obstruction, similar to the presentation in this macaque.

Lung Lobe Torsion in an Adult Male Common Marmoset (Callithrix jacchus).

A 6-y-old, intact, pair-housed male common marmoset (Callithrix jacchus) presented with acute onset dyspnea and tachypnea immediately after sedation with alfaxalone; a history of gradual weight loss initiated the examination under sedation. Thoracic radiographs revealed significant right-lung consolidation, with a vesicular gas pattern in the right caudodorsal lung field, pleural effusion, and dorsal displacement of the heart. The marmoset was euthanized due to his unstable condition and poor prognosis. At necropsy, the cranial and middle lobes of the right lung were homogenously dark red-brown, enlarged, edematous, and twisted around the longitudinal axis at the hilus. The left lung lobes were pale pink and slightly edematous. In light of the clinical and gross necropsy findings, acute torsion of the right cranial and middle lung lobes was diagnosed. Predisposing conditions for lung lobe torsion include trauma, neoplasia, pulmonary disease, previous thoracic surgery, and diaphragmatic hernia, but none of these applied to this case. Initial therapy for lung lobe torsion is to stabilize the patient and treat for underlying conditions, with prompt surgical resection as the treatment of choice. To our knowledge, this report is the first description of lung lobe torsion in an experimentally unmanipulated New World NHP.

Hepatocellular carcinoma in two captive golden-headed lion tamarins (Leontopithecus chrysomelas).

Two cases of hepatocellular carcinoma (HCC) in 2 female captive golden-headed lion tamarins (Leontopithecus chrysomelas) are described. HCC was diagnosed in both, with pulmonary metastasis in one of them. Neoplastic cells were positive for hepatocyte-specific antigen (HSA) by immunohistochemistry, confirming the diagnosis.

Uterus-like Masses in a Rhesus Macaque (Macaca mulatta).

Endometriosis is a relatively common condition in women and some populations of adult female rhesus macaques. However, endometriosis with extensive smooth muscle proliferation, as occurs in endomyometrioma and uterus-like mass (ULM), is rare in women. This report describes a case of endometriosis with extensive smooth muscle metaplasia resembling multiple ULM in a 20-y-old female rhesus macaque. During a protocol-related procedure, a large, smooth, globoid, freely moveable mass was palpated in the midabdomen. Ultrasonography revealed a cystic structure from which dark brown fluid was aspirated. During exploratory laparotomy, an 8-cm spherical mass in the greater omentum and 3 additional masses (diameter, 2 to 5 cm) attached to the omentum were excised. Microscopic examination of the masses revealed numerous foci of ectopic endometrial glands and stroma frequently surrounded by bundles of smooth muscle and fibrous connective tissue. The gross and histologic lesions in this macaque bore many similarities to ULM in women. To our knowledge, this case represents the first report of endometriosis resembling a uteruslike mass in a NHP.

Hepatocellular carcinoma with intracranial metastasis in a Japanese macaque (Macaca fuscata).

BACKGROUND: A 23-year-old male Japanese macaque (Macaca fuscata) showed left ptosis, which progressed to exophthalmos. METHODS: The macaque underwent a clinical examination, CT and MRI, and was euthanized. Necropsy and histopathological examination were performed after euthanasia. RESULTS: The CT revealed and MRI confirmed an intracranial mass at the skull base with orbital extension. At necropsy, there were a large hepatic mass and an intracranial mass compressing the left temporal lobe of the brain. Histopathological and immunohistological examinations revealed that the masses were hepatocellular carcinoma (HCC) and a metastatic lesion. In both the primary and metastatic lesions, neoplastic hepatocytes were arranged mainly in a trabecular pattern. Immunohistochemically, the tumor cells were positive for cytokeratin (AE1/AE3 and CAM5.2) and hepatocyte paraffin 1 and negative for cytokeratin 7 and 20 and vimentin. CONCLUSION: To our knowledge, this is the first case report of HCC with intracranial metastasis in a macaque.

Spontaneous telangiectatic osteosarcoma in a rhesus macaque (Macaca mulatta).

Osteosarcoma (OS) is the most common type of bone cancer, especially in young. Telangiectatic osteosarcoma (TO) is a rare variant of OS, and hence, its occurrence, presentation, and prognosis are poorly understood. A 4-year-old female rhesus monkey presenting lameness and swelling was examined for a mass on the right humerus. Radiography revealed fracture and disorganized structure of bone tissue. Histopathological examination revealed malignant neoplasm composed of anaplastic osteoblasts, which invaded the bone marrow and surrounded blood-filled cysts in the epiphysis and diaphysis forming septa. Cytogenetic analysis showed aneuploid cells, supernumerary AgNORs, and a marker fragment. The neoplasm was diagnosed as TO. To our knowledge, the occurrence of TO and its cytogenetic analysis were reported for the first time in non-human primates.

Use of ultrasound imaging for the diagnosis of abnormal uterine bleeding in the bonnet macaque ( Macaca radiata).

Ultrasound is a powerful, low-cost, non-invasive medical tool used by laboratory animal veterinarians for diagnostic imaging. Sonohysterography and transvaginal ultrasound are frequently used to assess uterine anomalies in women presenting with abnormal uterine bleeding (AUB). In the present study, we have evaluated the abdominal ultrasound of bonnet monkeys ( n = 8) showing spontaneous ovulatory ( n = 5) and anovulatory ( n = 3) AUB. The ovulatory ( n = 5) macaques showed cyclic AUB for 7-8 days. The anovulatory ( n = 3) macaques had irregular AUB with menstrual cycles of 40-45 days. The B-mode abdominal, colour Doppler and 3D ultrasound scans were performed during the proliferative phase of the menstrual cycle. Ultrasound examination revealed endometrial polyps in five macaques and endometrial hyperplasia in three animals. The width and length of endometrial polyps was around 0.5-1 cm (average 0.51 ± 0.23 cm × 0.96 ± 0.16 cm) with significant increase in endometrial thickness ( P < 0.0002). 3D ultrasound also showed a homogeneous mass in the uterine cavity and colour Doppler ultrasound showed increased vascularity in the endometrial polyps. Endometrial hyperplasia characteristically appeared as a thickened echogenic endometrium ( P < 0.0002). This study demonstrates the use of non-invasive ultrasound techniques in the diagnosis of AUB in macaques.

Uterine angioleiomyoma in an African green monkey (Chlorocebus aethiops sabaeus).

BACKGROUND: A uterine neoplasm was observed, as an incidental finding, during post-mortem examination of a 26-year-old female multiparous African green monkey (Chlorocebus aethiops sabaeus). The intramural, expansile, 2 to 3 cm well-demarcated, dark-red, nodular neoplasm was located on the anterior uterine body (corpus) wall. METHODS: The mass was examined by light microscopy and by immunohistochemistry. RESULTS: The mass was confirmed as a cavernous uterine angioleiomyoma (syn. vascular leiomyoma) characterized by abundant intratumoural vasculature lined by Factor VIII-positive endothelial cells and surrounded by smooth muscle actin-positive cell proliferations. CONCLUSION: Angioleiomyoma sharing the characteristics of intramural human cavernous uterine angioleiomyoma should be considered in the differential diagnosis of uterine tumours in non-human primates.

Osteosarcoma in Baboons (Papio spp).

Bone neoplasms in baboons (Papio spp) are rare, with only one confirmed case of osteosarcoma previously described in the literature. Over a 12-y period, 6 baboons at a national primate research center presented with naturally occurring osteosarcoma; 3 lesions affected the appendicular skeleton, and the remaining 3 were in the head (skull and mandible). The 6 cases presented were identified in members of a large outdoor-housed breeding colony. The subjects were not genetically related or exposed to the same research conditions. Diagnoses were made based on the presentation and radiographic findings, with histologic confirmation.

Efficacy of antibiotic-impregnated polymethylmethacrylate beads in a rhesus macaque (Macaca mulatta) with osteomyelitis.

Here we describe the successful surgical implementation of antibiotic-impregnated polymethylmethacrylate beads in a rhesus macaque (Macaca mulatta) with marked osteomyelitis. The macaque presented to the veterinary clinic with grossly contaminated bite wounds in the left ankle secondary to conspecific trauma. Radiographic findings were highly suggestive of osteomyelitis. Additional differential diagnoses included bony infarct, fracture, and cellulitis. In light of the location of the lesion and extensive tissue trauma, the animal had a poor prognosis. Systemic, broad-spectrum antibiotics were instituted. After 2 wk of care, lesions did not respond to empirical therapies. On consultation, a veterinary orthopedic surgeon at another facility recommended placement of antibiotic-impregnated polymethylmethacrylate beads at the sites of osteomyelitis. The animal underwent minor surgery in which beads were introduced into the wound. The monkey had a positive response to therapy. The animal regained full function and was returned to outdoor social housing. Veterinarians are encouraged to consider using antibiotic-impregnated polymethylmethacrylate beads when treating osteomyelitis in other nonhuman primates and in other traditional laboratory animal species.

Locally infiltrative ameloblastic fibroma in a rhesus macaque (Macaca mulatta) with characterizations of its proliferating activity and biological behavior.

An 8-year-old male rhesus macaque (Macaca mulatta) presented with unilateral enlargement of the left mandible. Radiographs revealed a marked expansion of the left mandible with a multilocular radiolucent mass with abundant osteolysis. The mass was grossly firm, fleshy, and gelatinous on the cut surface. Histologically, the mass was locally infiltrative and composed of neoplastic epithelial and mesenchymal components that stained positive for cytokeratin and vimentin, respectively. Occasional densely spherical condensations of fibroblasts resembling the cap stage of odontogenesis were present in the mesenchyma. Immunohistochemical staining with Ki-67, S-100, and CD34 indicated that both epithelial and mesenchymal components of the neoplasm had low proliferation. Alcian blue, periodic acid-Schiff, and trichrome stains showed an immature stromal component with no collagen formation. Based on the clinical, histologic, and immunophenotypic features, the tumor was identified as a locally infiltrative ameloblastic fibroma.

Peripheral ossifying fibroma and juxtacortical chondrosarcoma in cynomolgus monkeys (Macaca fascicularis).

Literature on spontaneous primary bone tumors in nonhuman primates is sparse. This case report describes 2 different neoplastic bone lesions in 2 adult cynomolgus monkeys (Macaca fascicularis), including macroscopic, radiographic, histologic, and immunohistochemical findings. In one monkey, a firm mass located at the palatogingival junction of the left rostral maxilla was confirmed to be a peripheral ossifying fibroma in light of its histologic and immunohistochemical characteristics. In another monkey, a lobulated tumor at the right distal femur that radiographically showed moderate radiopacity with splotchy areas of mineralization was confirmed to be a juxtacortical chondrosarcoma on histologic examination. The 2 neoplastic bone lesions revealed rare histologic and immunohistochemical characteristics and contribute to the known tumor spectrum of cynomolgus monkeys.

Multicystic bone disease (Gorham-Stout syndrome) in a spider monkey (Ateles geoffroyi ).

BACKGROUND: In April 2000, a 2.5-year-old pet female Geoffroyi's spider monkey presented for reduced activity, a subdued demeanor, and boney enlargement involving both radii. METHODS: On further examination, polyostotic bone cysts were identified involving many of the tubular bones and were identified radiographically. Microscopic examination of a bone biopsy revealed hemorrhage and other characteristics typical of an aneurysmal bone cyst. In addition, excessive osteoclasia was noted, in association with fibrotic areas rather than with Howship's lacunae as expected from a growing animal. RESULTS: These findings were consistent with Gorham-Stout syndrome, a rare condition reported previously in ∼175 human cases and in a dog at necropsy. The diet history and further testing suggested a negative calcium balance. Treatment included the administration of bis-phosphonates, which appeared to bring about marked improvement. Almost 8 years later (November 2008), radiographs were again taken and suggested some resolution of bone cysts, primarily those in the legs. CONCLUSIONS: This represents the first reported case and a potential therapy for this rare condition in a non-human primate.

Dioctophyma renale (Goeze, 1782) in the abdominal cavity of a capuchin monkey (Cebus apella), Brazil.

This study reports a case of parasitism by Dioctophyma renale (Goeze, 1762) encysted in the abdominal cavity of a capuchin monkey (Cebus apella) coming from the Centro Nacional de Primatas, Brazil. The animal was sent to the Veterinary Clinic sector with an increase in abdominal volume and no occurrence of any other clinical signs. Upon palpation, a movable circular mass with a diameter of approximately 10 cm was found. Urinalysis, complete blood count and serum biochemistry were performed without revealing any alterations. The animal was then submitted to an abdominal ultrasound exam. The cyst was punctured and a surgical removal procedure was performed, revealing a brownish-colored cylindrical structure that was already deteriorated, making it impossible to perform morphological analysis and classification. In the sediment of the liquid found, eggs were encountered that had morphological characteristics compatible with D. renale. The objective of this paper is to report the first case of parasitism by D. renale in C. apella (Linnaeus, 1758).

Camptomelia in a rhesus macaque (Macaca mulatta).

An 8.5-mo-old female rhesus macaque was examined for an apparent lump on the right arm, below the elbow. The macaque showed no signs of pain or discomfort. Examination revealed that the lump was actually a bend in the forearm. Radiography demonstrated that some of the long bones of the animal were bowed. Differential diagnoses included rickets, hyperparathyroidism, pseudohyperparathyroidism, and a growth dysplasia. No other similar abnormalities in animals from that cage or any other enclosure in our large colony were observed. Blood chemistries and a complete hemogram were within normal limits for a macaque of this age. Serum was submitted for a vitamin D profile that included assays for parathyroid hormone, 25-hydroxyvitamin D, and ionized calcium. Serum samples from sex- and age-matched normal controls were sent for comparison and to establish a baseline profile. The affected animal had vitamin D levels comparable to unaffected controls. Bone biopsies appeared normal for a macaque of this age. Fluorine levels in the drinking water supply were within acceptable limits. Consistent with the information available, a diagnosis of idiopathic camptomelia, or bowing of the long bones, was made. In humans, developmental camptomelia is associated with several bone dysplasias in infants and children. These conditions are thought to be caused by genetic mutations in enzymes or transcription factors that control development of the epiphyses and are almost always associated with other lethal and nonlethal developmental abnormalities.

Significance of imaging features of alveolar echinococcosis in studies on nonhuman primates.

In this study, we report the imaging findings in two Japanese monkeys (Macaca fuscata) diagnosed with alveolar echinococcosis. Both monkeys were treated with albendazole for 10 years, without surgery. Radiography, computed tomography, and contrast-enhanced ultrasonography were performed under general anesthesia. This is the first report on contrast-enhanced ultrasonographic imaging for alveolar echinococcosis wherein perflubutane was used as the contrast medium. The findings of the imaging analyses were similar to those reported for alveolar echinococcosis in humans, such as snowflake sign and worm-eaten sign. In addition, the serology correlated well with the imaging data in these two monkeys. Therefore, we propose that the imaging findings of alveolar echinococcosis in nonhuman primates may be used to accumulate data on this condition in human alveolar echinococcosis.

Calcinosis circumscripta in a common marmoset (Callithrix jacchus jacchus).

A 2.5-y-old, male common marmoset (Callithrix jacchus jacchus) developed a 2-cm, interscapular, subcutaneous mass with variably firm and cystic areas. Radiographs demonstrated a radiodense mass in close proximity to a previously implanted microchip. Fine-needle aspiration yielded a chalky liquid that, on cytologic examination, contained amorphous debris. Aerobic and anaerobic cultures were negative. Surgical excision required extensive dissection, with the mass infiltrating deep to the scapula and extending to the mammary gland. The mass weighed 30 g and comprised 10% of the animal's body weight. Microscopic examination demonstrated multifocal, variably sized, amorphous aggregates of granular, basophilic material (mineral) in the subcutis and extending to skeletal muscle. Mineral deposits were surrounded by macrophages, giant cells, and fibrous connective tissue. A focal area of ectopic bone production was present. Crystallographic analysis and x-ray diffractometry determined the material to be comprised of 100% hydroxyapatite. These findings were consistent with a diagnosis of calcinosis circumscripta. Systemic metabolic abnormalities were excluded based on examination of complete blood count, serum chemistry, and ionized calcium. Calcinosis circumscripta in the common marmoset has not previously been reported, although the lesion has been reported to occur in rhesus macaques and is well described in man and dogs. Accumulation of calcium deposits and production of ectopic bone in a marmoset is interesting in light of this species's unique calcium and vitamin D metabolism.