NGCO is an extremely rare malignant tumor that mostly occurs in women of reproductive age [1, 2]. Non-gestational choriocarcinomas commonly arise from germ cells and are not related to pregnancy. Most commonly,NGCOs are mixed and associated with other germ-cell neoplasms [3]. The present case involved choriocarcinoma coexisting with a dysgerminoma. Because of the rarity of NGCOs, limited information is available in the literature.Thus, we presented our case and reviewed other cases concerningtheir clinical characteristics, diagnosis, therapeutic effects, and prognoses using the PubMed database.We found 78 cases of ovarian NGCOs reported in the English literature[4–7]. Liu et al.reviewed 39 cases reported between January 1967 and July 2018[4]. In 2020, Shao et al.conducted a retrospective study, which reported 37 cases of NGCOs[5]. Moreover, another two similar cases were reported by Zhang et al.and Peng et al.in 2019 and2020, respectively[6–7].
NGCO usually occurs in patients who are sexually immature or virgins. The clinical presentation of NGCO is nonspecific and mostly includes vaginal bleeding, abdominal pain and distention, and pelvic masses.Liu et al. reported that the median age,primary tumor size, and serum hCG levels of 39patients with ovarian NGCOs were 30.4 years, 11.3cm, and 15,050IU/L, respectively. NGCO tends to metastasize early to the lungs, bowel, pelvic organs, and liver through blood-borne dissemination [4].
The preoperative diagnosis of NGCO is difficult. In the presence of an adnexal mass, abdominal pain, vaginal bleeding, and elevated hCG, NGCO can be easily mistaken for ectopic pregnancy in reproductive-aged women. In 1963, Saito et al. first reported the diagnostic criteria for NGCO, which included the absence of disease in the uterine cavity, pathological confirmation of disease, exclusion of molar pregnancy, and exclusion of a coexisting intrauterine pregnancy [8].In our case,
markedly elevated hCG levels and a pelvic mass are presented in a girl without a sexual experience and, the presence of a germ-cell tumor was considered first. According to Saito’s criteria and considering that our patient was an 11-year-old girl with no previous sexual experience, the markedly elevated hCG levels and the pathological result comprised of mononucleated cytotrophoblastic cells and polynucleated syncytiotrophoblastic cells led us to the diagnosis of NGCO.It is difficult to differentiate gestational choriocarcinoma from an NGCO after performing the routine histological examination in patients ofreproductive age because the immunohistochemical features are the same. More recently, it was stated that DNA polymorphism analysis couldbe used to distinguish between the two tumor types [9, 10]. DNA polymorphic analysis can verify the presence or absence of paternal DNA. We can make the final diagnosis of gestational choriocarcinoma when paternal DNA was present. DNA polymorphic analysis makes the diagnosis of NGCO easier in patients who had sexual intercourse.However, the cost of this method restricts its use.
In our case,the initial approach to the treatment of NGCO included laparotomy. The use of laparoscopy for ovarian tumors remains controversial. Xin et al. reported a positive oncologic outcome through laparoscopy; one of its advantages was the ability to allow rapid initiation of adjuvant chemotherapy [11]. However, the use of laparoscopy in NGCO appears to be limited, and there are few reports on the safety aspects of this approach.
To date, no standard treatment has been established for NGCO because of its low incidence. Liu et al. reported that 54% of cases received comprehensive staging surgery and chemotherapy; the remaining cases received fertility-preserving surgery and chemotherapy [4]. The 3-year overall survival rates for patients with FIGO stages I, II, III, and IV were 100%, 100%, 100%, and 25%,respectively [4]. Shao et al. reported 37 cases of NGCO that received surgery and a median of fourcourses of chemotherapy. The overall complete response rate, relapse rate, and 3- and 5-year survival rates were 81.1%, 16.7%, and 80.0% and 75.5%, respectively [5]. Goswami et al. and Kong et al. reported that the survival rates of patients who underwent surgery followed by chemotherapy were 81% and 86.1%, respectively,and the survival rates of thosewho underwent surgery without chemotherapy were 28% and 33.3%, respectively [3, 12]. Because NGCO occurs mostly in sexually immature and virgin patients, fertility-sparing surgery should be considered. There is no consensus on the optimal post-surgery chemotherapy because ofthe limited data on NGCOs. Choriocarcinoma responds well to a methotrexate-based regimen. Therefore, more aggressive combination chemotherapy (such as etoposide, methotrexate, and actinomycin-D administration)has been used in several reported cases. Non-gestational choriocarcinoma is considered to arise from a germ-cell tumor. Therefore, NGCOs may be resistant to these chemotherapy protocols. Furthermore, BEP and PVB(cisplatin, vinblastine, andbleomycin) regimens have also been administered. The current patient underwent conservative surgery and postoperative chemotherapy,resulting in a favorable decline in postoperative hCG levels. An analysis of our case and those reported in previous case studies suggested that NGCO responds well to surgery combined with chemotherapy.