[Twin pregnancy with complete hydatidiform mole]

Area of Science:

• Reproductive Medicine
• Gynecologic Pathology

Background:

• Complete hydatidiform mole (CHM) co-occurring with a normal placenta and viable fetus is a rare obstetric event, estimated at 1 in 20,000-100,000 pregnancies.
• This condition presents diagnostic challenges, requiring differentiation from partial hydatidiform mole and placental mesenchymal dysplasia, and is associated with a significant risk of complications, including a 50% rate of persistent trophoblastic disease.

Purpose of the Study:

• To describe a rare case of twin pregnancy with complete hydatidiform mole (CHM) and a viable fetus.
• To illustrate the diagnostic confirmation of CHM and the subsequent development of persistent trophoblastic disease.

Main Methods:

• Morphological examination of placental tissue, including macroscopic and microscopic evaluation.
• Immunohistochemical analysis to assess p57 expression for diagnostic confirmation of CHM.

Main Results:

• The pregnancy resulted in spontaneous abortion at 16-17 weeks.
• Morphological examination revealed a normal fetus and placenta alongside CHM tissue. p57 expression was notably absent in the CHM tissue.
• The patient was diagnosed with persistent trophoblastic disease two months post-abortion.

Conclusions:

• The case underscores the rarity and diagnostic complexities of co-occurring CHM with a viable twin pregnancy.
• It highlights the critical need for accurate diagnosis and vigilant monitoring due to the high risk of persistent trophoblastic disease.