Epithelioid trophoblastic tumor: a review of the literature

To identify common characteristics and provide suggestions for future reporting and management of epithelioid trophoblastic tumors (ETTs).

Definitions and treatment strategies are unclear because of low incidence and paucity of reported data. Literature search revealed 52 cases of ETT; 67% presented with abnormal vaginal bleeding, 36% had prior evidence of molar pregnancy and 35% presented with metastases. Mean age at diagnosis was 38 years. Mean pregnancy interval was 76 months. Human chorionic gonadotropin levels were 12-148,460 IU/L.

Histologic and immunohistochemical reporting varied markedly between centers, as did treatment regimens. A total of 13% were reported as dead from disease, though duration of follow-up was variable (range, 1-39 months). Differentiation of prognostic factors in ETT is problematic. Most reported cases lack long-term follow-up, and disease recurrence in ETT can be late and complex. Distinguishing ETT from other diagnoses may lead to underreporting, with an adverse prognosis associated with diagnostic delay.

Case reporting should contain detailed information on clinicopathologic, histologic and immunohistochemical characteristics and treatment. Data centralization in these rare tumors may be beneficial in identifying relevant prognostic parameters.