Do nontriploid partial hydatidiform moles exist? A histologic and flow cytometric reevaluation of nontriploid specimens.

ABSTRACT

OBJECTIVE: To study whether nontriploid partial hydatidiform moles truly exist. STUDY DESIGN: We conducted a reevaluation of pathology and ploidy in 19 putative nontriploid partial hydatidiform moles using standardized histologic diagnostic criteria and repeat flow cytometric testing by the Hedley technique. RESULTS: On review of the 19 moles, 53% (10/19) were diploid nonpartial moles (initially pathologically misclassified), and 37% (7/19) were triploid partial moles (initial ploidy misclassifications). One additional case (5%) was a diploid early complete mole (initially pathologically misclassified). CONCLUSION: Nontriploid partial moles probably do not exist careful reevaluation of putative specimens will probably uncover pathologic or ploid errors in almost all cases.