THE DECEPTIVE SAC: A RARE RADIOLOGICAL MANIFESTATION OF HYDATIDIFORM MOLE

Abstract

Hydatidiform mole is an uncommon gestational trophoblastic disease characterized by abnormal proliferation of trophoblastic tissue and cystic degeneration of chorionic villi. Its classic presentation includes vaginal bleeding, excessive uterine size, and markedly elevated serum β-hCG levels; however, atypical or asymptomatic presentations can pose diagnostic pitfalls. We report the case of a 25-year-old female who presented for a routine obstetric ultrasound check-up. The initial ultrasound revealed a mildly bulky uterus with a heterogeneous endometrial area containing multiple cystic spaces and no gestational sac or fetus. Subsequent magnetic resonance imaging (MRI) demonstrated a bulky endometrium that appeared heterogeneously hyperintense on T2-weighted imaging with few T2 hypointense areas, and heterogeneous but predominantly low signal on diffusion-weighted imaging (DWI) and apparent diffusion coefficient (ADC) maps. Following these radiological findings, serum β-hCG levels were suggested and found to be 4800 mIU/mL. Correlating the imaging features with the elevated β-hCG level, the diagnosis of hydatidiform molar pregnancy was established. This case highlights the importance of maintaining a high index of suspicion for molar pregnancy even during routine screening, the value of advanced MRI sequences (T2, DWI/ADC) in characterizing atypical lesions, and the critical role of serum β-hCG in confirming the diagnosis.