The Baffling Diagnosis of a Rare Case of Polypoid Endometriosis: Neoplasm Mimicking in a Young Pregnant Woman—A Case Report and Literature Review

<b>Background</b>: Polypoid endometriosis is a rare variant of endometriosis that presents as a tumorous mass, making it difficult to differentiate it from a malignant tumor. It usually occurs in perimenopausal women or those undergoing hormone therapy, and its presence in a young pregnant woman is extremely uncommon. <b>Case Presentation</b>: This article describes a rare instance of polypoid ovarian endometriosis in a pregnant woman, a condition with few documented cases in the medical literature. An adnexal mass was discovered incidentally during a routine prenatal ultrasound, with imaging features that raised the suspicion of a neoplastic process and prompted surgery to exclude malignancy. However, histopathological examination of the excised lesion confirmed features compatible with polypoid endometriosis, without revealing evidence of cancer. This case highlights the diagnostic challenges of differentiating polypoid endometriosis from ovarian neoplasms, especially during gestation, where imaging findings can be ambiguous. In addition, the hormonal environment inherent in pregnancy may exacerbate the proliferative behavior of endometriotic lesions, thus complicating clinical evaluations. The presence of an adnexal mass in such a setting often requires careful evaluation to balance the risks of surgery with the potential consequences of delayed diagnosis. The data presented emphasize the importance of an accurate diagnosis. In conclusion, a well-coordinated approach ensures the protection of maternal and fetal health. <b>Conclusions</b>: By prioritizing accurate diagnosis and personalized treatment plans, physicians can minimize complications and improve outcomes for both mother and child.