Abstract
<title>Abstract</title> <p>Background Lithopedion, or 'stone fetus,' is an exceptionally rare condition resulting from the calcification of a deceased fetus, most often occurring in extrauterine pregnancies. Intrauterine lithopedion is exceedingly uncommon, with only a handful of cases reported worldwide. The present case describes a 71-year-old woman with an intrauterine lithopedion retained for 35 years, providing valuable insight into the chronic clinical, radiologic, and pathophysiologic aspects of this phenomenon. Case Presentation: A 71-year-old persian woman, gravida 8 para 6, presented with chronic pelvic and abdominal pain of several months’ duration. Her obstetric history revealed a twin pregnancy at age 36, in which one fetus was delivered and the second was retained following intrauterine fetal death. The patient reported regular menstruation for four years after fetal demise and menopause at age 40. Imaging revealed a well-defined calcified intrauterine mass with bony structures. Laboratory findings were unremarkable. Surgical exploration identified a calcified fetus within the uterine cavity. Total abdominal hysterectomy with bilateral salpingo-oophorectomy was performed, and histopathologic evaluation confirmed an intrauterine lithopedion. Conclusion This case represents one of the rarest documented instances of intrauterine lithopedion persisting for over three decades without significant complications. It underscores the importance of thorough obstetric history-taking and advanced imaging in diagnosing rare causes of chronic pelvic pain among elderly women.</p>