USMLE Step 2 CK Lecture Notes 2019: Obstetrics/Gynecology (Kaplan Test Prep)

NOTE

Malignant   GTN is  characterized   as  localized   or  metastatic, and is  classified  as  good    prognosis   or

poor    prognosis.

Table II-6-1. Benign    Gestational Trophoblastic   Neoplasia—H Mole

Complete Incomplete

Empty   egg Normal  egg

Paternal    X’s only Maternal   and paternal    X’s

46,XX   (diploidy) 69,XXY   (triploidy)

Fetus   absent Fetus    nonviable

20% →   malignancy 10%  →   malignancy

No  chemotherapy;   serial  β-hCG   titers  until   (–);    follow-up   1   year    on  oral    contraceptive   pill

Table II-6-2. Malignant Gestational Trophoblastic   Neoplasia

Nonmetastatic Good  Prognosis Poor  Prognosis

Uterus  only Pelvis or  lung Brain  or  liver

100%    cure >95%   cure 65%    cure

Single-agent    chemotherapy Multiple   agent   chemotherapy

1   year    follow-up   on  oral    contraceptive   pill    after   β-hCG   (–) 5   year    follow-up   on  oral    contraceptive   pill

Risk factors. Increased prevalence geographically is most common in Taiwan
and the Philippines. Other risk factors are maternal age extremes (age <20, age

35. and folate deficiency.