TNM/FIGO Classification, Pathology of the Placenta

Definition

Tumor staging is applied to invasive hydatidiform mole, choriocarcinoma, placental site trophoblastic tumor, and epithelioid trophoblastic tumor. Tumor staging is not applied to complete or partial moles or any benign trophoblastic lesion. Both clinical and pathologic data are incorporated in the TNM and FIGO staging criteria. Tumor confined to the uterus is TNM stage T1, FIGO stage I. Tumor extention to the ovary, tube, vagina, or broad ligaments is TNM stage T2, FIGO stage II. Lymph node metastasis is rare and is staged as metastatic disease, TNM stage M1b, FIGO stage IV. Lung metastasis is TNM stage M1a, FIGO stage III. All other distant metastasis is TNM stage M1b, FIGO stage IV.

In addition to tumor stage, the World Health Organization (WHO) Prognostic Scoring Index stratifies patients into low-risk or high-risk disease in an effort to guide treatment decisions. The Index is calculated using eight variables: age, antecedant pregnancy, interval of time from index...