"Placental polyp": light microscopic and immunohistochemical observations

Area of Science:

• Reproductive Medicine
• Gynecologic Pathology
• Histopathology

Background:

• Placental polyps are rare sequelae of pregnancy, typically presenting shortly after delivery or abortion.
• Chronic placental polyps, especially those persisting for years, are infrequently documented.
• Understanding the long-term composition and viability of placental tissue remnants is crucial for gynecologic health.

Observation:

• A case of chronic placental polyp is described in a 37-year-old woman, 9 years post-abortion.
• The polyp contained necrotic and hyalinized chorionic villi, with some viable syncytiotrophoblast positive for human chorionic gonadotropin (hCG).
• Intermediate trophoblast and syncytiotrophoblast showed positivity for human placental lactogen (hPL), with abundant decidua and ectatic vessels at the base.

Findings:

• Demonstration of persistent cytoplasmic markers for pregnancy (hCG and hPL) in a chronic placental polyp.
• Immunohistochemical analysis confirmed the presence of viable trophoblast cells and placental lactogen in tissue presumed to be 9 years old.
• Histological examination revealed characteristic features of a chronic placental polyp, including hyalinized villi and decidual changes.

Implications:

• Highlights the potential for chronic placental polyps to retain pregnancy-specific markers for extended periods.
• Suggests that placental polyp remnants may be encountered more frequently given the prevalence of induced abortions.
• Emphasizes the importance of considering long-standing placental tissue in the differential diagnosis of gynecologic abnormalities.