Ovarian pathology in rhesus macaques: a 12-year retrospective

Selected Resources for Pathology Evaluation of Nonhuman Primates in Nonclinical Safety Assessment

Humans and nonhuman primates (NHPs) share numerous anatomical and physiological characteristics, thereby explaining the importance of NHPs as essential animal models for translational medicine and nonclinical toxicity testing. Researchers, toxicologic pathologists, toxicologists, and regulatory reviewers must be familiar with normal and abnormal NHP biological traits when designing, performing, and interpreting data sets from NHP studies. The current compilation presents a list of essential books, journal articles, and websites that provide context to safety assessment and research scientists working with NHP models. The resources used most frequently by the authors have been briefly annotated to permit readers to rapidly ascertain their applicability to particular research endeavors. The references are aimed primarily for toxicologic pathologists working with cynomolgus and rhesus macaques and common marmosets in efficacy and safety assessment studies.

Naturally Occurring Endocrine Disorders in Non-Human Primates: A Comprehensive Review

Literature concerning veterinary medicine of non-human primates is continuously updated, yet endocrine disorders remain underreported. While case or survey reports of individual endocrinopathies are available, a comprehensive review is not. An exhaustive literature search on this subject via widely used academic search systems, (e.g., Google Scholar, PubMed, BioOne complete and Web of Science), and peer-reviewed publications, proceedings, and newsletters was performed. Selected major endocrine entities will be described with emphasis on clinical signs, morphologic appearances, concomitant diseases, as well as available treatment options. Mostly, no clinical signs were noted and on gross pathology, the endocrine organs were unremarkable. An endocrine-related diagnosis was frequently made as an incidental finding after standard histopathological examination. During the review, the pancreas represented the most affected endocrine organ and diabetes mellitus represented the most clinically significant disorder. Currently, no standard procedure for diagnosing, monitoring, or treating endocrine disorders in non-human primates exists.

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.

Successful surgical management of massive ovarian teratoma in a rhesus macaque (Macaca mulatta)

A 5 years-old Rhesus macaque was presented with abdominal enlargement. The clinical, radiographic and ultrasonographic findings suggested that a massive mass occupying the whole of the abdomen. The mass was surgically removed, and histopathology confirmed ovarian teratoma. The macaque recovered uneventfully; however, the management to avoid self-mutilation of skin sutures was challenging.

Effects of glyphosate-based herbicide-contaminated diets on reproductive organ toxicity and hypothalamic-pituitary-ovarian axis hormones in weaned piglets

At present, glyphosate (GLP) is the most produced and used herbicide in the world. With the large-scale use of glyphosate-based herbicides (GBHs), their toxic effects on animals and plants have increasingly become a concern. Based on the Codex Alimentarius Commission (CODEX) dose (20 mg kg-1) and the dose set by the government (40 mg kg-1), four experimental groups in which Roundup® (R) herbicide was added to the feed of weaned piglets at GLP concentrations of 0, 10, 20, and 40 mg kg-1 were designed. The results showed that R had no significant effect on the vulvar size or index of reproductive organs but that it could affect the tissue morphology and ultrastructure of the uterus and ovary. With the increase in GLP concentration, the activities of antioxidant enzymes [SOD (P < 0.05) and GPx (P = 0.002)] in the uterus showed significant increases. Compared with the control group, the content of hydrogen peroxide (H2O2) in the treatment groups increased significantly (P < 0.05), the malondialdehyde (MDA) content in the 10 mg kg-1 treatment group was significantly higher than that in the control group. We measured hypothalamic-pituitary-ovarian axis (HPOA) hormones and also found that GLP significantly increased luteinizing hormone-releasing hormone (LHRH), gonadotropin-releasing hormone (GnRH) and testosterone (T) content (P < 0.05) and decreased follicle-stimulating hormone (FSH) content (P < 0.05). In summary, although R does not affect the vulvar size or reproductive organ index of weaned piglets, it changes the morphology and ultrastructure of the uterus and ovaries, interferes with the synthesis and secretion of HPOA hormones, and causes changes in the balance of the antioxidant system of uterus. This study provided a theoretical basis for preventing reproductive system harm caused by GBHs.

Urogenital Lesions in Nonhuman Primates at 2 National Primate Research Centers

Given their genetic and anatomic similarities to humans, nonhuman primates (NHPs) may serve as animal models for urogenital diseases of humans. The purpose of this study was to examine the frequency of spontaneous urogenital lesions occurring over a 30-year period at the Yerkes and Southwest National Primate Research Centers and to compare and contrast lesions occurring in Old World versus New World primates. Lesions occurring in the chimpanzee (Pan troglodytes), baboon (Papio spp.), rhesus macaque (Macaca mulatta), cynomolgus macaque (Macaca fascicularis), pig-tailed macaque (Macaca nemestrina), sooty mangabey (Cercocebus atys), common marmoset (Callithrix jacchus), cotton-top tamarin (Sanguinus oedipus), and squirrel monkey (Saimiri sciureus) are discussed. The most common lesions of the kidney were medullary amyloidosis, renal cysts, renal tubular degeneration, glomerulonephritis or glomerulopathy, nephritis, nephrocalcinosis, pyelonephritis, and hydronephrosis. Specific causes of renal tubular disease included pigmentary nephrosis and tubular lipidosis. Renal tumors, including renal adenoma and carcinoma, lymphoma, and nephroblastoma, were infrequent diagnoses in all species. Endometriosis was the most frequently diagnosed lesion of the female genital tract. Of the animals examined in this study, it was most frequent in Old World primates. Leiomyoma was the most common uterine tumor. Granulosa cell tumor was the most frequently observed neoplasm of the ovaries, followed by teratoma. Of animals included in the study, most ovarian tumors occurred in baboons. Neoplasms of the male reproductive tract included interstitial cell tumor, seminoma, penile squamous cell carcinoma, penile papilloma, and histiocytoma. In New World monkeys, renal lesions were reported more frequently than genital lesions.

Ovarian Neoplastic Changes in Dairy Cows with Adenomyosis - Histopathological Study

Introduction

This paper presents the results of the microscopic examination of dairy cow ovaries.

Material and Methods

The examined dairy cows were culled in a slaughterhouse. In all of them, pathological changes (n = 82) associated with adenomyosis had been previously diagnosed, and additionally in some cows (n = 18) so had mammary gland cell injury, including mastitis purulenta.

Results

There was vast variability among the investigated individuals in the degree of disease and type of pathological changes in the examined tissue specimens. In all examined ovaries, the most prominent lesions were neoplastic metaplasia of various cell types. They were PEComa, rete ovarii cell neoplasm, granulosa cell tumour, and a single case of haemangioma cavernosum, and the first of these types of ovarian tumours was the prominent neoplasia. In some cases, they grew simultaneously with the other types of tumours, but tumour tissue never extended beyond the ovarian capsule. Sometimes, the ovarian tumours were of microscopic volume, for instance the foci of granulosa cell tumours.

Conclusion

The lack of changes in ovarian anatomic structure, and minute neoplastic tissue foci, make it impossible to diagnose these lesions in the ovaries of living animals. The presented original data may be valuable in understanding the aetiology of dairy cow infertility, as well as in facilitating urgently needed research into findings new methods, which might be used in the diagnosis of neoplastic diseases ante mortem.

LESIONS OF THE FEMALE REPRODUCTIVE TRACT IN JAPANESE MACAQUE ( MACACA FUSCATA) FROM TWO CAPTIVE COLONIES

Reproductive lesions have been described in various nonhuman primate species, including rhesus macaques ( Macaca mulatta), cynomolgus macaques ( Macaca fascicularis), baboons ( Papio spp.), squirrel monkeys ( Saimiri sciureus), and chimpanzees ( Pan spp.); however, there are few publications describing reproductive disease and pathology in Japanese macaques ( Macaca fuscata). A retrospective evaluation of postmortem reports for two captive M. fuscata populations housed within zoos from 1982 through 2015 was completed, comparing reproductive diseases diagnosed by gross pathology and histopathology. Disease prevalence, organs affected, and median age at death between the two institutions was also compared. Fifteen female captive M. fuscata, ranging in age from 15 to 29 yr were identified with reproductive tract lesions, including endometriosis, endometritis, leiomyoma, leiomyosarcoma, and adenomyosis. No significant differences were identified in disease prevalence, organs affected, and median age of death between the two institutions. Endometriosis was the most common disease process identified and was found in 10 of the 15 cases (66.7%), followed by leiomyoma (4 of 15; 26.7%). In four cases (26.7%), severe endometriosis and secondary hemorrhage was indicated as the cause of death or the primary reason for humane euthanasia. These findings were compared with a separate population of Japanese macaques managed within a research facility in the United States, with a prevalence of endometriosis of 7.6%. This study discusses possible risk factors and potential treatment options for the management of endometriosis in captive M. fuscata.

Proceedings of the 2018 National Toxicology Program Satellite Symposium

The 2018 annual National Toxicology Program Satellite Symposium, entitled "Pathology Potpourri," was held in Indianapolis, Indiana, at the Society of Toxicologic Pathology's 37th annual meeting. The goal of this symposium was to present and discuss challenging diagnostic pathology and/or nomenclature issues. This article presents summaries of the speakers' talks along with select images that were used by the audience for voting and discussion. Various lesions and other topics covered during the symposium included seminiferous tubule dysgenesis in rats, ameloblast and odontoblast degeneration/necrosis in a Sprague Dawley rat, intestinal leiomyositis in a beagle dog, gallbladder mucinous hyperplasia, focus of hepatocellular alteration and bile duct alteration in otters, renal tubule cytoplasmic vacuolation with basophilic granules in mice treated swith antisense oligonucleotide therapy, a uterine choriocarcinoma in a rhesus macaque, and rete ovarii proliferative ovarian lesions in various aged rat strains. One particularly provocative lesion was a malignant neoplastic proliferation in the renal pelvic region of a cynomolgus macaque from a 21-day study. Additional challenging lesions included thyroid proliferative lesions in zebra fish and gross findings in fish larvae during routine chemical screening. The Rabbit and Minipig International Harmonization of Nomenclature and Diagnostic Criteria Organ Working Groups also presented a series of challenging lesions.

An extragonadal teratoma in a female cynomolgus monkey (Macaca fascicularis)

Extragonadal teratomas have not been reported in nonhuman primates. A female cynomolgus monkey, a vehicle control in an exploratory toxicity study, was necropsied. Microscopic examination of an extragonadal mass in the animal's craniodorsal retroperitoneum revealed a teratoma. This is the first report of an extragonadal teratoma in a nonhuman primate.

Meeting report: Spontaneous lesions and diseases in wild, captive-bred, and zoo-housed nonhuman primates and in nonhuman primate species used in drug safety studies

The combination of loss of habitat, human population encroachment, and increased demand of select nonhuman primates for biomedical research has significantly affected populations. There remains a need for knowledge and expertise in understanding background findings as related to the age, source, strain, and disease status of nonhuman primates. In particular, for safety/biomedical studies, a broader understanding and documentation of lesions would help clarify background from drug-related findings. A workshop and a minisymposium on spontaneous lesions and diseases in nonhuman primates were sponsored by the concurrent Annual Meetings of the American College of Veterinary Pathologists and the American Society for Veterinary Clinical Pathology held December 3-4, 2011, in Nashville, Tennessee. The first session had presentations from Drs Lowenstine and Montali, pathologists with extensive experience in wild and zoo populations of nonhuman primates, which was followed by presentations of 20 unique case reports of rare or newly observed spontaneous lesions in nonhuman primates (see online files for access to digital whole-slide images corresponding to each case report at http://www.scanscope.com/ACVP%20Slide%20Seminars/2011/Primate%20Pathology/view.apml). The minisymposium was composed of 5 nonhuman-primate researchers (Drs Bradley, Cline, Sasseville, Miller, Hutto) who concentrated on background and spontaneous lesions in nonhuman primates used in drug safety studies. Cynomolgus and rhesus macaques were emphasized, with some material presented on common marmosets. Congenital, acquired, inflammatory, and neoplastic changes were highlighed with a focus on clinical, macroscopic, and histopathologic findings that could confound the interpretation of drug safety studies.

Bilateral ovarian cysts originating from rete ovarii in an African green monkey (Cercopithecus aethiops)

Ovarian cyst is common incidental finding in humans and many animals and includes follicular cysts, cystic rete ovarii and mesonephric duct cysts. Ovarian cyst is often associated with reproductive disorders in humans and animals. We found accidentally bilateral cystic masses in ovaries in an African green monkey. Grossly, the left and right ovarian cystic masses were single unilocular cystic structures measuring 0.6 and 1.8 cm in diameter, respectively. Histologically, both cysts were thin-walled structures that arose from the center of the ovary and displaced ovarian tissue peripherally. The cysts were lined by a single layer of nonciliated low cuboidal epithelium. Immunohistochemically, epithelial cells in the cysts were positive for cytokeratin, and the stromal cells were positive for smooth muscle actin but negative for vimentin. These results suggest that these ovarian cysts in an African green monkey are cystic rete ovarii. To our knowledge, this is the first report of cystic rete ovarii in African green monkeys and may be of value in relation to research of the pathogenesis and treatment of ovarian cyst.

Immunohistochemical characterization of nonhuman primate ovarian sex cord-stromal tumors

This study evaluates the immunoreactivity of 12 sex cord-stromal tumors of nonhuman primates (11 granulosa cell tumors and 1 luteoma). The markers selected are used in the characterization of gonadal tumors in dogs and other species, including cytokeratins AE1/AE3, GATA-4, inhibin-α, neuron-specific enolase, protein gene product 9.5, and vimentin. A normal nonhuman primate ovary was used as a control and to optimize immunolabeling. Staining was graded as follows: 0 (nonstaining), 1+ (< 10% positive cells), 2+ (10%-50% positive cells), and 3+ (> 50% positive cells). Calretinin, GATA-4, neuron-specific enolase, and vimentin were the most consistently expressed markers (12 of 12). Cytokeratins AE1/AE3 were also consistently expressed (11 of 12). Inhibin-α and protein gene product 9.5 were expressed in 8 and 10 sex cord-stromal tumors, respectively. Results indicate that immunoreactivity of nonhuman primate sex cord-stromal tumors is similar to that observed in other species and that calretinin, GATA-4, and neuron-specific enolase are the most consistently expressed markers in nonhuman primate sex cord-stromal tumors.

Evaluating the progenitor cells of ovarian cancer: analysis of current animal models

Serous ovarian cancer is one of the most lethal gynecological malignancies. Progress on effective diagnostics and therapeutics for this disease are hampered by ambiguity as to the cellular origins of this histotype of ovarian cancer, as well as limited suitable animal models to analyze early stages of disease. In this report, we will review current animal models with respect to the two proposed progenitor cells for serous ovarian cancer, the ovarian surface epithelium and the fallopian tube epithelium.