Molar Pregnancies

Abstract

The term “gestational trophoblastic neoplasia” (GTN) has become popular in recent years, although it comprises entities that are clearly not neoplastic, such as triploid “partial” moles. Others commonly now refer to these entities as GTDs (gestational trophoblastic diseases) which seems more appropriate as the term includes both nonneoplastic trophoblastic lesions (hydatidiform moles, placental site nodules, exaggerated placental site) as well as trophoblastic tumors (choriocarcinoma, placental site trophoblastic tumor, epithelioid trophoblastic tumor). Driscoll (1981), in an excellent review of the morphology of these diseases, strongly favored abandonment of the time-honored term hydatidiform mole. Fox (1989) has added fuel to the fire by suggesting the following: “Is it, in fact, justifiable to continue distinguishing complete from partial moles in routine histopathological practice?” He based this opinion primarily on the exceptional finding of a single case of choriocarcinoma said to have followed a partial mole (Looi and Sivanesaratnam 1981). Since then, several additional cases have been described in which choriocarcinoma has followed a partial mole (Gardner and Lage 1992; Seckl et al. 2000). Persistent trophoblastic disease has also been described by Rice et al. (1990), Sebire et al. (2003), and Cheung et al. (2004). More recently, Fox (1997), in analyzing the histologic differences between CHM and PHM, concluded that a degree of subjectivity accompanies these decisions, an opinion with which we strongly agree. Malinowski et al. (1995) go even further by suggesting a continuum to exist from molar degeneration to choriocarcinoma when they suggested the existence of the “sad fetus syndrome,” the association of a fetus with molar or neoplastic conditions. This view is not ours, however. After all, choriocarcinoma is also an occasional sequela of an apparently “normal” gestation, as Fox readily conceded in which there may have been a choriocarcinomatous cell line ab initio.