Gestational Trophoblastic Disease

Radiologic-Pathologic Correlation

Abstract Introduction Normal And Abnormal Trophoblast Epidemiologic Characteristics

Hydatidiform Mole Complete Hydatidiform Mole Invasive Mole Choriocarcinoma Partial Hydatidiform Mole

Placental Site Trophoblastic Disease Conclusions Source Information References

Partial Hydatidiform Mole

The pathologic characteristics of partial hydatidiform mole differ from those of complete hydatidiform mole in that the former has normal villi interspersed with hydropic villi (Figure 16). In comparison with complete hydatidiform mole, partial hydatidiform moles have much less trophoblastic proliferation, which typically appears as focal projections of syncytiotrophoblast (Figure 17). The abnormal gametogenesis that precedes the partial hydatidiform mole results in a triploid karyotype with both maternal and paternal DNA (usually due to fertilization of a single ovum with two sperm). The fetus is also triploid and does not survive (1,11).

Although partial hydatidiform mole is histopathologically similar to complete hydatidiform mole, there are some important differences (Table 1) (1). Clinically, patients with partial hydatidiform mole may present in a manner indistinguishable from those with complete hydatidiform mole or, for that matter, patients with a first- or second-trimester pregnancy. Quite often, though, these patients present with spontaneous abortion. In some series, this is the most common type of molar pregnancy (exceeding the cases of complete hydatidiform mole), but it is generally underdiagnosed because the karyotype of the abortus is not confirmed (3).

The clues for the sonographer in this diagnosis are the presence of a fetus (although usually with severe, but nonspecific, abnormalities) in combination with a formed placenta containing numerous cystic spaces (Figure 17, Figure 18). These patients are normally followed up with serial measurements of beta-hCG level, even though the risk for persistent gestational trophoblastic neoplasia is lower (3%) than for patients with a complete hydatidiform mole (13).

Abstract Introduction Normal And Abnormal Trophoblast Epidemiologic Characteristics

Hydatidiform Mole Complete Hydatidiform Mole Invasive Mole Choriocarcinoma Partial Hydatidiform Mole

Placental Site Trophoblastic Disease Conclusions Source Information References