Persistent gestational trophoblastic disease: DNA image cytometry and interphase cytogenetics have limited predictive...

Area of Science:

• Gynecology
• Pathology
• Cytogenetics

Background:

• Complete hydatidiform mole (CM) exhibits a wide DNA content spectrum, challenging earlier diploidy reports.
• Conflicting findings exist regarding the association between DNA content and persistent gestational trophoblastic disease (PGTD).

Purpose of the Study:

• To investigate DNA ploidy patterns and chromosomal aberrations in CM with and without PGTD.
• To determine if DNA content variations correlate with PGTD occurrence.
• To re-evaluate partial moles with CM-like DNA ploidy patterns.

Main Methods:

• DNA image cytometry was used to analyze DNA-ploidy patterns (2.5c and 5c exceeding rates) in 71 CM with PGTD, 4 partial moles with PGTD, and 100 CM without PGTD.
• Interphase cytogenetics on paraffin-embedded tissue sections assessed numerical chromosomal aberrations and sex chromosome composition in a pilot study of 20 cases per group.
• DNA probes for chromosomes 1, X, and Y were utilized.

Main Results:

• No significant differences in DNA-ploidy patterns or chromosomal aberrations were found between CM with and without PGTD.
• DNA polyploidy was prevalent in both groups (99% CM with PGTD, 98% CM without PGTD).
• Partial moles exhibited DNA-ploidy patterns consistent with CM and may warrant reclassification.

Conclusions:

• The occurrence of PGTD is not associated with quantitative DNA content variations or sex chromosome anomalies in complete hydatidiform moles.
• Partial moles with CM-like DNA content should be considered for reclassification as CM.
• DNA content and ploidy patterns are not reliable predictors for PGTD in complete hydatidiform moles.