Non-gestational choriocarcinoma: unraveling the similarities and distinctions from its gestational counterpart

Choriocarcinoma is a highly vascular and invasive tumor of anaplastic trophoblast, predominantly made up of cytotrophoblasts and syncytiotrophoblasts without villi. Based on its origin, choriocarcinoma can be either gestational or non-gestational. Non-gestational choriocarcinoma can be of germ cell origin, or can be seen in association with a somatic high-grade malignancy. It is difficult to differentiate gestational from non-gestational choriocarcinoma, especially in the reproductive age group. It is important to distinguish between the two, for accurate staging and prognostication, deciding the primary treatment modality, (ie, surgery or chemotherapy), and tailoring follow-up timeframes after diagnosis. An extensive literature search was performed regarding all cases of non-gestational choriocarcinoma, published before March 2023. A note was made of whether the origin of choriocarcinoma was ascertained and how gestational choriocarcinoma was differentiated from non-gestational choriocarcinoma. The keywords used for literature search were "non-gestational choriocarcinoma", "primary choriocarcinoma", "ovarian choriocarcinoma", "ovarian germ cell tumors", or "choriocarcinomatous differentiation". This review aims to summarize the similarities and differences in the epidemiology, pathogenesis, clinical presentation, and management guidelines between gestational and non-gestational choriocarcinoma, which can form an important educational resource for clinicians and laboratory physicians dealing with such cases.