[Use of flow cytometry in the diagnosis of gestational trophoblastic disease].
BACKGROUND
Histopathologic analysis of aborted tissue in molar pregnancy is frequently complicated by scarcity of tissue as well as by the fact that ultrasound and biochemistry permit the clinical diagnosis of gestational trophoblastic disease at the very beginning of pregnancy, when all classical morphologic features have not yet developed. Flow cytometry is today a widely used method that can help the pathologist reach a correct diagnosis, having implications for the patient.


OBJECTIVE
To show the role of flow cytometry in addition to classical histopathologic methods in the early diagnosis of gestational trophoblastic disease, i. e. molar pregnancy.


METHODS
A total of 103 consecutively received placental tissue samples from spontaneous/medically induced abortions were histopathologically examined and submitted to flow cytometry analysis.


RESULTS
The patient mean age was 31 (range 19-50) years, and mean gestational age was 10 (range 5-19) weeks. Residual placental tissue with or without degenerative changes was found in 51.5% of the samples; in 8.7% embryonal/fetal tissues were identified as well. The histopathologic diagnosis of partial hydatiform mole was made in 34% and of complete hydatiform mole in 5.8% of cases. The difference in mean age of women according to histopathologic findings or placental ploidy was not significant. Flow cytometry revealed 42.7% of diploid samples, 58.3% of aneuploid samples and 1% of tetraploid samples. Of 53 samples showing normal morphology or degenerative hydropic changes, 60.4% were diploid and 39.6% aneuploid; of 9 samples containing fetal tissues 44.4% were diploid and 55.5% aneuploid (NS). A significant difference (p < 0.01) was found between the placental tissue ploidy with histopathologic diagnosis of residual placental tissue, and with histopathologic diagnosis of partial hydatiform mole (p < 0.001); when fetal tissues were present the difference was not significant


CONCLUSIONS
This study confirmed the partial hydatiform mole to be a common but clinically underdiagnosed condition. Except for the knowledge whether the abortion was caused by cytogenetic factors, flow cytometry helps the pathologist reach an accurate diagnosis and has a place in daily practice.
Kos
Marina
M
Zavod za patologiju, Medicinski fakultet Sveucilista u Zagrebu, Zagreb, Hrvatska, Croatia. dr_marina_kos@yahoo.com
Pavlović
Maja
M
Pazur
Vedran
V
D000328:Adult; D003581:Cytodiagnosis; D005260:Female; D005434:Flow Cytometry; D031901:Gestational Trophoblastic Disease / Q000175:diagnosis* / Q000235:genetics / Q000473:pathology; D006801:Humans; D008875:Middle Aged; D010920:Placenta / Q000473:pathology*; D011003:Ploidies; D011247:Pregnancy