Dysmorphic villi mimicking partial mole in a case with del(18)(q21)

Area of Science:

• Reproductive Biology
• Human Genetics
• Pathology

Background:

• Placental histopathology is crucial for understanding pregnancy outcomes.
• Hydatidiform mole morphology is typically associated with specific genetic abnormalities.
• Chromosomal aberrations can lead to significant pregnancy complications.

Observation:

• Histopathologic examination of a placenta from an early second-trimester abortion revealed significant villous scalloping.
• Intravillous trophoblastic pseudoinclusions and mild trophoblastic hyperplasia were prominent features.
• These findings mimicked the characteristic appearance of a partial hydatidiform mole.

Findings:

• The placental karyotype was identified as 46,XY,del(18)(q21), a structural chromosomal abnormality.
• The observed histopathologic changes, typically seen in numerical chromosomal aberrations, were associated with this structural abnormality.
• This represents a novel association between specific placental morphologies and structural chromosomal defects.

Implications:

• This case expands the known histopathologic spectrum associated with chromosomal abnormalities.
• It highlights the importance of karyotyping in cases with atypical placental findings.
• Understanding these associations can improve diagnostic accuracy and genetic counseling.