Atypical placental site nodules: Five cases and literature review

Atypical placental site nodules (APSN) are a rare form of trophoblastic disease in pregnancy. There is limited research on APSN, and treatment methods are controversial, with unclear prognosis. This study collected clinical and prognostic data of 5 patients diagnosed with APSN at Xiangya Hospital of Central South University from June 2008 to June 2023, aiming to provide a better understanding of the prognosis of APSN patients and offer scientific evidence for clinical treatment. The average age of the 5 APSN patients was 32.60 years, and all patients underwent dilation and curettage or hysteroscopic surgery or hysteroscopic surgery without hysterectomy. Except for one patient who was lost to follow-up after 30 days, the remaining 4 patients were followed up for 1.36 to 4.61 years. During the follow-up, gynecological ultrasound did not show abnormalities, and serum human chorionic gonadotropin (HCG) tests were negative, with no evidence of malignancy. A search of both English and Chinese databases yielded 8 articles reporting the diagnosis, treatment, and follow-up outcomes of APSN, with 37 cases cumulatively followed up. Among them, 2 (5.41%) cases developed epithelial trophoblastic tumors or placental site trophoblastic tumors during follow-up, but there is insufficient evidence to determine whether these tumors directly originated from APSN or were secondary to APSN. Currently, there is no direct evidence suggesting that APSN has the potential for malignant transformation. Patients with APSN who have completed their childbearing may consider preserving their uterus, but close follow-up is needed to further evaluate the prognosis.