Objectives: To assess the value of deoxyribonucleic acid ploidy in the differential diagnosis and clinical follow-up of hydatidiform moles, the histopathologic features, deoxyribonucleic acid ploidy, and clinical follow-up were compared in 347 cases: 143 complete moles, 52 partial moles, and 152 abortions, of which 56 cases were hydropic abortions with histologic features of triploidy but lacked trophoblastic hyperplasia.
Study design: In all cases deoxyribonucleic acid image cytometry was performed, and in 85 of these cases interphase cytogenetics was also performed.
Results: With use of deoxyribonucleic acid image cytometry and interphase cytogenetics, a bimodal polyploid deoxyribonucleic acid pattern was present in 97% of complete moles, 27% of partial moles, and 4% of abortions. All these cases of partial mole were reclassified to complete mole on the basis of this deoxyribonucleic acid pattern and the histopathologic features in spite of the presence of fetal blood cells, amnion, or yolk sac. Deoxyribonucleic acid triploidy was found in 95% of the remaining partial moles, in 77% of hydropic abortions with histologic features of triploidy, and in 14% of the remaining abortions. Reliable differentiation between deoxyribonucleic acid triploid partial moles and hydropic abortions with histologic features of triploidy was not possible on basis of the histopathologic features (trophoblastic hyperplasia) or 3.5c exceeding rates. Deoxyribonucleic acid diploidy was found in 1% of complete moles, 23% of hydropic abortions with features of triploidy, and 78% of the remaining abortions. Deoxyribonucleic acid tetraploidy was rarely found (1% of complete moles, 2% of partial moles, 1% of abortions). Persistent gestational trophoblastic disease developed in 33% of the bimodal deoxyribonucleic acid polyploid cases (all complete moles), in 1% of the diploid cases (concerning one of the two diploid complete moles), and in 1% of the triploid cases (partial moles).
Conclusion: Deoxyribonucleic acid analysis is essential in the diagnosis of hydatidiform moles to decide on clinical follow-up.