A rare case of placentae site
trophoblastic tumor (PSTT) studied by immunohistochemistry and nuclear
DNA analysis is reported. The patient, a 24-year-old Japanese female, complained of
amenorrhea.
Dilatation and curettage revealed a small specimen that contained trophoblastic cells and caused intractable
bleeding. Pelvic sonography revealed a 5-cm mass in the posterior uterine wall with multiple cystic lesions of several sizes. The cystic lesions were shown to be dilated vessels by magnetic resonance imaging (MRI) and digital subtraction angiography (DSA). Serum beta-
hCG (beta subunit of
human chorionic gonadotropin) was 3.7 ng/ml. Total abdominal
hysterectomy revealed a well-circumscribed, yellow, soft mass in the posterior uterine wall. Microscopic findings were consistent with PSTT and the mitotic count was extremely low. Immunohistochemically, most of the
tumor cells were intensely stained with
human placental lactogen, whereas few were stained with
human chorionic gonadotropin. The nuclear
DNA content of the trophoblastic cells showed a sharp peak at the
triploid range coexistent with a few cells of higher ploidy. This is the first report of sonographic findings and nuclear
DNA analysis by spot cytometry in a case of PSTT.