Cervical pregnancy is the second most common site of ectopic pregnancy, with several risk factors including multiple cesarean sections, cervical surgery, in vitro fertilization (IVF), pelvic inflammatory disease (PID), and intrauterine contraceptive devices (IUCD). Our patient had a history of multiple miscarriages, which could have contributed to the unusual implantation site.
Gestational choriocarcinoma typically follows a hydatidiform mole, normal pregnancy, or, most commonly, spontaneous abortion, while non-gestational choriocarcinoma arises from pluripotent germ cells (4). It occurs in 1 in 5,333 tubal pregnancies and 1 in 1.6 million normal intrauterine pregnancies. Although only 0.76–4% of choriocarcinoma cases develop in ectopic locations, they are usually more aggressive and often associated with distant metastasis (5). Gestational choriocarcinoma commonly arises in the uterine cavity and is associated with coincident or antecedent pregnancy. Extrauterine choriocarcinomas are rare, mostly originating from the uterine cervix or ovaries, with fewer than 200 cases reported in the literature (6). Choriocarcinoma can develop between 5 weeks to 15 years after the antecedent pregnancy, including post-menopause, though the latent period is usually less than 1 year following a molar or normal pregnancy (7). The condition is graded according to the FIGO staging and prognostic risk score (8).
Approximately 30% of choriocarcinoma cases have metastatic disease at the time of diagnosis. The lungs are the most common site of metastasis (80%), followed by the vagina (30%) and liver (10%). Brain metastasis occurs in 3–28% of patients (9). Despite choriocarcinoma's excellent prognosis, presence of disease at an unusual site can complicate or delay diagnosis. Patients often present with vaginal bleeding and elevated B-HCG levels, which may be misdiagnosed as ectopic pregnancy (10). Delays in diagnosis can also arise from a failure to elicit a history of prior pregnancy or because the presentation occurs so long after the antecedent event that the patient may not recall it. Such delays can lead to advanced metastatic disease, which can be fatal (5). In addition to elevated urinary and blood B-HCG levels, immunohistochemical localization of B-HCG is crucial for diagnosing and monitoring choriocarcinoma. However, histologic examination of uterine curettage is the only method that can establish a definitive diagnosis and significantly influences initial patient management (11). Macroscopically, choriocarcinoma appears as a hemorrhagic mass with necrotic areas and irregular borders. Microscopically, it features a central area of cytotrophoblasts surrounded by syncytiotrophoblasts, nuclear atypia, numerous mitotic figures, and clear areas of necrosis and hemorrhage. Numerous foci of lymphovascular invasion also facilitate metastatic spread (12).
In conclusion, while cervical pregnancy is a relatively uncommon form of ectopic pregnancy, its association with choriocarcinoma, particularly in unusual or metastatic presentations, underscores the importance of thorough clinical and histological evaluation. Prompt diagnosis and appropriate management are essential to improve outcomes in these complex cases. Choriocarcinoma is completely curable, even with multiple metastases. Single and multi-agent chemotherapy is the preferred treatment for choriocarcinoma. In cases of severe, life-threatening vaginal bleeding, a hysterectomy may be necessary. Patients presenting with irregular vaginal bleeding, elevated B-HCG levels, and tumors at unusual sites should undergo thorough investigation and immediate treatment, as the prognosis is excellent, even with metastases.