Ovarian Choriocarcinoma in a Rhesus Monkey Associated with Elevated Serum Chorionic Gonadotropin Levels

Abstract

Abstract.A clinically normal, 3-year-old female rhesus monkey (Macaca mulatta), which was part of a routine toxicology study, had a mass in the right ovary with metastases to the adjacent mesentery and lungs. The histologic features and immunohistochemistry results were consistent with the diagnosis of choriocarcinoma. Neoplastic cell types included cytotrophoblast (positive for cytokeratin), syncytiotrophoblast (positive for human chorionic gonadotropin), and extravillous trophoblast (positive for human placental lactogen). Because the neoplasm was present in the ovary, the uterus was normal, and the animal was not currently pregnant, this was considered a primary ovarian neoplasm of germ cell origin. The monkey had elevated serum levels of chorionic gonadotropin at the beginning of the study, indicating that, as in women, choriocarcinomas in monkeys can be associated with increased gonadotropin levels and that the tumor was preexisting at the start of the toxicology study.

Neoplasia and Proliferative Disorders of Nonhuman Primates

“…Ovarian neoplasms in the rhesus macaque are common and encompass cystadenomas/cystadenocarcinomas (Crews et al, 1967;Flinn, 1967;Amin et al, 1974), choriocarcinoma (Farman et al, 2005), placental site trophoblastic tumor (Marbaix et al, 2008), dysgerminoma (Holmberg et al, 1978), teratoma (Martin et al, 1970;Scott et al, 1975;Rohovsky, 1977;Eydelloth and Swindle, 1983), and granulosa cell tumors (Allen et al, 1970). The two most commonly reported ovarian tumors in the rhesus macaque are granulosa cell tumors and teratomas (Figure 6.10).…”

“…The majority of ovarian neoplasms arise unilaterally; however rare reports exist with tumors arising in both ovaries. Clinically, the majority of cases are found as incidental findings during necropsy; however in occasional cases there are ante- mortem hormonal and physical changes that suggest an ovarian tumor (Farman et al, 2005). Too few cases of ovarian adenocarcinoma have been reported in this species to determine if it is an appropriate model for the human equivalent.…”

Immunohistological Description of Nongestational Ovarian Choriocarcinoma in Two Female Mice With Conditional Loss of Trp53 Driven by the Tie2 Promoter

“…2 Primary unilateral ovarian choriocarcinomas arising spontaneously have been reported only twice as incidental findings in nonhuman primates. 7 Reports of ovarian choriocarcinomas in mice are exceedingly rare, with B6C3F1 strain overrepresented and just 1 study mentioning (but not further characterizing) a single case in genetically engineered mice (GEM) carrying a targeted null mutation of both Hic1 and Trp53 on a 129S4/SvJae and C57BL/6 mixed genetic background. 1,3,8,12,14 The objective of this study is to characterize the distinctive pathological and immunohistological features of this rare neoplasm in 2 mice not related to the B6C3F1 strain and genetically engineered to carry both Trp53 alleles conditionally deleted under the control of Tie2 promoter.…”

“…4 The concurrent presence of other tumors of germ cell origin has been reported in nonhuman primates 7 and it has recently been described in the testes of a Swiss albino mouse, 11 but there is no information so far regarding murine ovarian choriocarcinomas. Furthermore, no metastases were observed in any of the examined cases, although metastatic dissemination to multiple organs has been described in NGCOs affecting nonhuman primates 7 and humans. 4 To confirm the diagnosis of ovarian choriocarcinoma, human chorionic gonadotropic (hCG) immunohistochemistry was performed, but the antibody failed to work properly on formalin-fixed paraffin-embedded murine tissues.…”

Spontaneous Peritoneal Malignant Mesothelioma in a Geriatric Japanese Macaque (Macaca fuscata)

“…Toxicologic pathologists who perform evaluations in these studies require detailed knowledge concerning the characteristics of spontaneously occurring neoplastic lesions. In rhesus monkeys, intestinal adenocarcinoma [17,19], mammary gland ductal carcinoma [5], ampullary carcinoma [24] and ovarian choriocarcinoma [8] have been reported. In cynomologus monkeys, hepatocellular neoplasm [18], choriocarcinoma [23], ovarian teratoma [23], oral squamous cell carcinoma [15], pulmonary tumor [13], cervical and vaginal epithelial neoplasm [25], and ovarian epithelioid trophoblastic tumor [10] have been documented.…”