Mixed Trophoblastic Tumour After Early Pregnancy Loss and Spontaneous Conception During Surveillance: A Case Report.

Mixed trophoblastic tumours (MTTs), which include choriocarcinoma and intermediate trophoblastic tumours like placental site trophoblastic tumour (PSTT), are very uncommon types of gestational trophoblastic neoplasia (GTN). Diagnosing and treating them continues to be challenging, especially when preserving fertility is important. A 37-year-old woman (G2P1) reported with a positive pregnancy test, abdominal pain, and brown vaginal discharge at 3+6 weeks of gestation. Initial examinations revealed variable serum β-hCG levels and ultrasound evidence of early intrauterine pregnancy. Followed by spontaneous miscarriage, a histology analysis of the products of conception showed an MTT (choriocarcinoma and PSTT). Staging CT and MRI showed no metastases, and β-hCG levels returned to normal. The patient was recommended for a hysterectomy with ovarian preservation. A second opinion confirmed this, but she wants to preserve her fertility. Later, a hysteroscopic-guided biopsy showed no signs of residual disease, and a follow-up was set up. During follow-up, she became pregnant spontaneously and is now continuing the care under a consultant-led maternal medicine team. This case highlights the diagnostic complexity of MTTs, the interplay between oncological safety and fertility preservation, and the necessity of multidisciplinary consultation.