Primary renal tumors in nonhuman primates

Case report: Renal adenoma in a captive ocelot (Leopardus pardalis) in Costa Rica

Reports of renal neoplasia are rare in neotropical wildcats. Ocelots (Leopardus pardalis) are medium-sized wildcats living in America's tropical forests. A 12-year-old captive ocelot was diagnosed with a renal mass occupying approximately 25% of the total right kidney volume. The tissue was stained with routine hematoxylin and eosin (H&E) and periodic acid-Schiff (PAS). Immunohistochemistry with the following markers was performed: cytokeratin (CK) AE1/AE3, CK19, CK 7, CD10, vimentin, Melan A, HMB45, Pax-8, and Wilms' tumor 1 (WT1). Histopathology revealed a well-differentiated epithelial tubular neoplasia with less than one mitotic figure per 2.37mm2 field. Vimentin and Pax-8 were the only positive markers. Immunohistochemically, neoplasia was diagnosed as a renal adenoma. Renal adenomas are seldom reported in neotropical wildcats. Reports on wild species are valuable for properly establishing a clinical prognosis for captive species. To the best of our knowledge, this is the first report that provides detailed microscopic and immunohistochemical descriptions of renal adenoma in a captive ocelot.

Retrospective study of the mortality of the Vieira's titi monkey (Plecturocebus vieirai) at the Sorocaba Zoo, Brazil

BACKGROUND

The Vieira's titi monkey (Plecturocebus vieirai) was recently described and characterized as endemic to Brazil. According to the IUCN red list, this species is classified as critically endangered (CR). At the date of the publication of this manuscript, there are no published data on the health aspects of this species.

METHODS

For this study, the necropsy, and histopathological data of the mortality of P. vieirai at Sorocaba Zoo (São Paulo, Brazil) were collected and analyzed.

RESULTS

Causes of death diagnosed included disorders of the urinary, gastrointestinal, immune, and circulatory systems.

CONCLUSIONS

This study provides information regarding the pathological conditions of P. vieirai and points to urinary and gastrointestinal diseases as the main causes of death in this species at Sorocaba Zoo. These results can help veterinarians who have this species under their care diagnose and deal with it more quickly, increasing the probability of survival.

International Harmonization of Nomenclature and Diagnostic Criteria (INHAND): Non-proliferative and Proliferative Lesions of the Non-human Primate (M. fascicularis)

The INHAND (International Harmonization of Nomenclature and Diagnostic Criteria for Lesions Project (www.toxpath.org/inhand.asp) is a joint initiative of the Societies of Toxicologic Pathology from Europe (ESTP), Great Britain (BSTP), Japan (JSTP) and North America (STP) to develop an internationally accepted nomenclature for proliferative and nonproliferative lesions in laboratory animals. The purpose of this publication is to provide a standardized nomenclature for classifying microscopic lesions observed in most tissues and organs from the nonhuman primate used in nonclinical safety studies. Some of the lesions are illustrated by color photomicrographs. The standardized nomenclature presented in this document is also available electronically on the internet (http://www.goreni.org/). Sources of material included histopathology databases from government, academia, and industrial laboratories throughout the world. Content includes spontaneous lesions as well as lesions induced by exposure to test materials. Relevant infectious and parasitic lesions are included as well. A widely accepted and utilized international harmonization of nomenclature for lesions in laboratory animals will provide a common language among regulatory and scientific research organizations in different countries and increase and enrich international exchanges of information among toxicologists and pathologists.

Inhibitors of TGFβR1/ALK4/JNK3/Flt1 Kinases in Cynomolgus Macaques Lead to the Rapid Induction of Renal Epithelial Tumors

Two young cynomolgus macaques (Macaca fascicularis) given a small molecule kinase inhibitor ((S)-4-((2-(5-chloro-2-fluorophenyl)-5-isopropylpyrimidin-4-yl)amino)-N-(2-hydroxypropyl)nicotinamide [SCIO-120]) via nasogastric intubation gavage, once-daily for 21 days at 400 mg/kg/day, developed an unusual epithelial proliferative process in the renal parenchyma. Morphological and immunohistochemical characterization of the lesions confirmed an invasive malignant epithelial neoplasm (carcinoma). A similar renal neoplasm was seen in a third macaque after a 14-day exposure to a second kinase inhibitor in the same chemical series ((S) 4-((2-(5-chloro-2-fluorophenyl)-5-methoxypyrimidin-4-yl)amino)-N-cyclopropylnicotinamide [SCIO-974]). Despite remarkably short latency periods, exposure to these kinase inhibitors was likely causally associated with the induction of the renal tumors, as renal carcinomas are exceedingly rare spontaneously in macaques. Both SCIO-120 and SCIO-974 were designed as potent TGFβR1 inhibitors (IC50s 37 and 39 nM, respectively). SCIO-120 and SCIO-974 inhibited additional kinases, most notably closely related ALK4 (IC50 = 34  and 20 nM, respectively), c-Jun n-Terminal kinase 3 (JNK3, IC50 = 10 and 20 nM, respectively), and Fms-related tyrosine kinase 1 (29  and 76 nM, respectively). TGFβR1 has been specifically implicated in epithelial proliferative disorders, including neoplasia. Neither SCIO-120 nor SCIO-974 was genotoxic based on bacterial reverse mutation and/or clastogenicity screening assays. The rapid appearance of renal carcinomas in primates following short-term treatment with nongenotoxic kinase inhibitors is remarkable and suggests that the compounds had noteworthy tumor-enhancing effects, hypothetically linked to their TGFβR1 inhibition activity. These observations have implications for mechanisms of carcinogenesis and TGFβR1 biology.

Anaplastic nephroblastoma with peritoneal metastasis in an adult female Sprague Dawley rat

Spontaneous nephroblastomas are uncommon tumors of laboratory rats. This report describes a spontaneous nephroblastoma with peritoneal metastasis in an 11-month-old, female Sprague Dawley rat. The rat was part of a breeding program and presented 15 days post parturition with clinical signs including tachypnea, dyspnea and abdominal distension. At necropsy, the right kidney was markedly enlarged by an expansile pale-tan to white multinodular mass with extension into the retroperitoneal space, with multifocal variably sized nodules involving the mesentery, and surface of pancreas, liver, uterus, and ovarian bursa. The rat also had severe bicavitary effusion. Histologically, the renal parenchyma of the affected kidney was replaced by a moderately cellular, poorly-demarcated, non-encapsulated, multilobulated mass that appeared to compress the adjacent renal outer medulla and cortex. Three distinct neoplastic cell populations were identified in this renal tumor: epithelial cells (convoluted and dilated tubules / rare primitive glomeruloid structures), mesenchymal (neoplastic spindle cells in connective tissue), and blastemal cells (primitive neoplastic cells). The extrarenal nodular masses were predominantly composed of neoplastic mesenchymal and pleomorphic blastemal cells. Immunohistochemically, neoplastic epithelial cells in the renal mass were positive for pancytokeratin, and blastemal cells in both renal and extrarenal masses were positive for Wilms’ tumor 1 protein (WT1) and vimentin. Neoplastic mesenchymal elements in both renal and extrarenal masses were positive for vimentin. The neoplasm was negative for chromogranin A and S100. The tumor was classified as an anaplastic nephroblastoma with metastasis to the mesentery and peritoneal organs.

RADIOGRAPHIC AND ULTRASONOGRAPHIC ABDOMINAL ANATOMY IN CAPTIVE RING-TAILED LEMURS (LEMUR CATTA)

The ring-tailed lemur (Lemur catta) is primarily distributed in south and southwestern Madagascar. It is classified as an endangered species by the International Union for Conservation of Nature. Various abdominal diseases, such as hepatic lipidosis, intestinal ulcers, cystitis, urinary tract obstruction, and neoplasia (e.g., colonic adenocarcinoma and cholangiocarcinoma), have been reported in this species. The aim of this study was to describe the normal radiographic and ultrasonographic abdominal anatomy in captive ring-tailed lemurs to provide guidance for clinical use. Radiography of the abdomen and ultrasonography of the liver, spleen, kidneys, and urinary bladder were performed in 13 and 9 healthy captive ring-tailed lemurs, respectively, during their annual health examinations. Normal radiographic and ultrasonographic reference ranges for abdominal organs were established and ratios were calculated. The majority (12/13) of animals had seven lumbar vertebrae. The sacrum had mainly (12/13) three segments. Abdominal serosal detail was excellent in all animals, and hypaxial muscles were conspicuous in the majority (11/13) of animals. The spleen was frequently (12/13) seen on the ventrodorsal (VD) view and rarely (3/13) on the right lateral (RL) view. The liver was less prominent and well contained within the ribcage. The pylorus was mostly (11/13) located to the right of the midline. The right and left kidneys were visible on the RL and VD views, with the right kidney positioned more cranial and dorsal to the left kidney. On ultrasonography, the kidneys appeared ovoid on transverse and longitudinal views. The medulla was hypoechoic to the renal cortex. The renal cortex was frequently (8/9) isoechoic and rarely (1/9) hyperechoic to the splenic parenchyma. The liver parenchyma was hypoechoic (5/5) to the renal cortex. Knowledge of the normal radiographic and ultrasonographic abdominal anatomy of ring-tailed lemurs may be useful in the diagnosis of diseases and in routine health examinations.

A Mixed Epithelial and Stromal Tumor of the Kidney in a Ringtail Lemur (Lemur catta)

Primary renal tumors are rare neoplasms in nonhuman primates. This report describes a mixed epithelial and stromal tumor of the kidney (MESTK) in a 14.5-year-old female ringtail lemur. The well-demarcated, solid, and cystic mass was located in the pelvis of the left kidney and consisted histologically of both epithelial and mesenchymal components. The mesenchymal cells were arranged in fascicles around cysts lined by a well-differentiated epithelium. Neither the mesenchymal nor the epithelial parts showed significant nuclear atypia or mitotic figures. To our knowledge, only 1 similar case, classified as adenoleiomyofibromatous hamartoma, has been reported in a ringtail lemur. In humans this tumor affects predominantly perimenopausal women and can express estrogen and progesterone receptors. However, neither estrogen nor progesterone receptors could be identified by immunohistochemistry in the tumor of the present ringtail lemur. Therefore, a hormonal mechanism could not be demonstrated in this case.

An Occurrence of Multiple Carcinomas in Both Kidneys of a 5-year-old Female Cynomolgus Monkey (Macaca fascicularis)

An occurrence of multiple carcinoma in both kidneys of a 5-year-old female cynomolgus monkey is described in the present paper. Macroscopically, the kidneys were enlarged with multiple solid and grayish-white masses and cysts mainly in the cortex and outer medulla. Light microscopically, carcinomas showed either tubulopapillary or tubulosolid growth patterns. Carcinoma cells were pleomorphic cuboidal to columnar cells. Cytoplasm was abundant and either granular and eosinophilic or clear, and nuclei were large and vesicular with prominent nucleoli. Electron microscopy revealed the existence of a brush border-like structure on the cell surface of carcinoma cells, suggesting that carcinoma cells arose from proximal tubular epithelial cells. Small foci of tubular epithelial cell hyperplasia and adenomas were also observed independently of carcinomas. There was no evidence of transition from adenoma to carcinoma, and no metastases were detected.

Renal evaluation with B-mode and Doppler ultrasound in captive tufted capuchins (Sapajus apella)

BACKGROUND

This study aimed to evaluate, by B-mode ultrasound and Doppler ultrasound, the kidneys of one Neotropical primate maintained in captivity.

METHODS

Ten adult intact tufted capuchins (Sapajus apella) were evaluated. The morphometric parameters of both kidneys were evaluated and kidney volumes calculated. Color Doppler was used to evaluate renal vascular architecture and to identify arteries of the left kidney. Spectral Doppler was used to measure peak-systolic velocity, end-diastolic velocity, and resistive index (RI).

RESULTS

Both kidneys presented homogeneous cortical echogenicity and homogeneous echotexture with preserved corticomedullary differentiation. There was no statistically significant difference between right and left kidneys for all morphometric parameters. RI of the left renal, interlobar, and arcuate arteries were, respectively, 0.75 (SD, 0.07), 0.70 (SD, 0.08), and 0.70 (SD, 0.06).

CONCLUSIONS

Both kidneys showed similar morphometric parameters by B-mode ultrasound, whereas RI by spectral Doppler decreased progressively from renal artery to interlobar and arcuate arteries.

Spontaneously arising concurrent ileocaecal adenocarcinoma and renal pelvis transitional cell carcinoma in a rhesus macaque (Macaca mulatta)

A 25-year-old, female rhesus macaque (Macaca mulatta) presented with a history of weight loss despite a normal appetite and supportive care. The animal was humanely destroyed due to poor prognosis. Post-mortem examination revealed a focally extensive, firm, white annular constriction at the ileocaecal junction and an incidental finding of a pale white nodule approximately 0.8 cm in diameter in the left renal pelvis. Based on the microscopical findings, ileocaecal adenocarcinoma and renal pelvis transitional cell carcinoma (TCC) were diagnosed. The use of cytokeratin (CK)-7 and -20 and uroplakin III as potential renal TCC markers was evaluated. The neoplastic cells were labelled intensely with antibodies to uroplakin III, but not to CK-7 or -20. Spontaneous intestinal adenocarcinoma has been documented in the rhesus macaque, but concurrent renal pelvis TCC is highly unusual.

Neoplasia in prosimians: case series from a captive prosimian population and literature review

Neoplastic diseases in prosimians have been sporadically reported in the literature. To provide a comprehensive review of prosimian neoplasia, a retrospective evaluation of neoplasia in a large captive prosimian colony and an extensive literature review were performed. Primates that belong to the Order Primata, Suborder Prosimii with histologic evidence of neoplasia were included. One hundred twenty-three cases of spontaneous neoplasia were identified in 101 prosimians from the Duke Lemur Center, and 124 cases were reported in 116 prosimians in the literature. Overall, this review compiled a total of 247 neoplasms in 217 prosimians. Of the 217 affected animals, 88 of 217 were males (41%), 100 of 217 were females (46%), and sex was not reported in 29 of 217 (13%). Ages ranged from 2 days to 36 years. Prosimian families represented were Lemuridae (80/217 [37%]), Cheirogaleidae (61/217 [28%]), Galagidae (44/217 [20%]), Lorisidae (28/217 [13%]), and Indriidae (4/217 [2%]). The most commonly affected species were the gray mouse lemur (Microcebus murinus) (28/217 [13%]), thick-tailed greater bush baby (Otolemur crassicaudatus) (23/217 [11%]), and black lemur (Eulemur macaco) (19/217 [9%]). Organ systems affected, in order of descending occurrence, were digestive (75/247 [30%]), reproductive (40/247 [16%]), hematopoietic (34/247 [14%]), integumentary (28/247 [11%]), endocrine (26/247 [11%]), and urinary (17/247 [7%]). The respiratory, nervous, musculoskeletal, and cardiovascular systems were infrequently affected. The most common neoplasms were hepatocellular (32/247 [13%]), lymphoma and/or leukemia (29/247 [12%]), biliary (15/247 [6%]), and mammary neoplasms (12/247 [5%]). This article should serve as a valuable reference for the types and relative frequencies of neoplasms that occur in prosimian species.

Malignant Nephroblastoma in a Common Marmoset (Callithrix jacchus)

Necropsy of a 17-month-old male common marmoset ( Callithrix jacchus) with a history of increased abdominal girth resulted in the finding of a unilateral polycystic renal neoplasm. Detailed histopathologic and immunohistochemical investigations revealed different tissue types within the tumor including stromal connective tissue and fusiform mesenchymal cell formations surrounding blastemal cells as well as different developmental stages of organ-specific epithelial cells accompanied by extensive cyst formation. Metastases were not observed. In consideration of the macroscopic, histologic, and immunohistochemical findings, the tumor was classified as a nephroblastoma closely resembling the so-called Wilms' tumor, a malignant embryonic renal tumor frequently observed in humans, especially in young children. In contrast, this tumor entity has rarely been observed in nonhuman primates. This report represents the first documented case of a cystic variant of nephroblastoma in a nonhuman primate.

Nephroblastomatosis and nephroblastoma in nonhuman primates

Wilms' tumors, or nephroblastomas, are renal embryonal malignancies with a high incidence in humans. Nephroblastomas are uncommon in nonhuman primates. This report describes three cases of spontaneous proliferative renal tumors in young monkeys: two cases of unilateral kidney nephroblastomas in baboons and a nephroblastomatosis in a cynomolgus macaque. Histologically, both baboon tumors were typical of Wilms' tumors found in humans, with proliferative epithelial cells forming tubules and aborted glomeruli, nephrogenic rests and proliferative fibrovascular tissue. The left kidney of the macaque was markedly enlarged and histologically similar to the baboon tumors, although normal kidney architecture was completely effaced by primitive tubules and occasional glomeruli surrounded by edematous stromal tissue. Cytogenetic analysis did not detect any macaque or baboon equivalents to human Wilms' tumor chromosomal abnormalities. By human pathology classification, the diffuse nature of the macaque tumor is more consistent with nephroblastomatosis than nephroblastoma. This differentiation is the first to be reported in a species other than human. The nephroblastomas described here are the first nephroblastomas to be reported in baboons. Our observations indicate that nonhuman primate nephroblastomatosis and nephroblastomas develop in a similar way to Wilms' tumors in humans, although no genetic marker has been associated with nephroblastomas of nonhuman primates thus far.

A retrospective study of multicentric bovine renal cell tumors

Tissues from twenty mature cows with primary renal cell tumors were submitted over an 11-year period because of gross lesions detected during routine slaughter and inspection. Tumors visualized grossly were multiple and bilateral in seven cattle, multiple within one kidney in four cattle, and solitary in nine cattle. The tumors were primarily cortical, yellow-orange to tan, proliferative, well circumscribed, and extended above the capsular surface of the kidney. Tumors were microscopically multiple even when grossly described as solitary lesions, except in one cow. Twelve tumors (60%) were microscopically multiple in one kidney, seven tumors (35%) were multiple and bilateral, and only one cow (5%) exhibited extrarenal metastasis. Tumors from nineteen cows were composed of eosinophilic granular epithelial cells; tumors from one cow were clear cell type. Each tumor contained several histologic patterns. Corpora amylacea, proteinaceous secretions, and hemosiderin were characteristic findings in bovine renal cell carcinoma. All 20 cows with renal cell tumors exhibited positive immunoreactivity to uromodulin (Tamm-Horsfall protein).