Intraplacental Choriocarcinoma: Rare or Underdiagnosed? Report of 2 Cases Diagnosed after an Incomplete Miscarriage and a Preterm Spontaneous Vaginal Delivery

Abstract

Intraplacental choriocarcinoma is a rare malignant tumor diagnosed after an abortion, an ectopic pregnancy, or a term or preterm pregnancy or following the diagnosis of a hydatidiform mole. During pregnancy, it may be more common than reported, as most patients are asymptomatic and placental choriocarcinomas are usually inconspicuous macroscopically and are often mistaken for an infarct. Based upon a case study methodology, we describe 2 cases of intraplacental choriocarcinoma: the first case was identified in the product of a uterine curettage following an incomplete miscarriage and the second in one of the placentas of a bichorionic twin pregnancy. Maternal investigation did not reveal evidence of metastatic disease and neither did the infants' one in the second case. The two cases underwent maternal surveillance with serum hCG and remained disease-free until the present. In conclusion, intraplacental choriocarcinoma is easily underdiagnosed but with current treatment, even in the presence of metastasis, the prognosis is excellent. A routine microscopic examination of all the placentas and products of miscarriage can increase the real incidence of this entity and consequently improve its management.

Figure 1

Placental histological features from case 1 at 8 weeks of gestational age [(a), (b), and (c)] and case 2 at 32 weeks of gestational age [(d), (e), and (f)]. Chorionic villi (small arrow) surrounded by tumor trophoblast cells [cytotrophoblast and intermediate trophoblast with patchy small foci of syncytiotrophoblast (arrow)]. Mitotic figures (head arrow).