Epithelioid trophoblastic tumor: a review of the literature.

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

Study Design: 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.

Results: 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.

Conclusion: 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.