Lithopedion in a 70-year-old woman: incidental finding in the greater omentum.

Lithopedion is a rare outcome of ectopic pregnancy in which a nonviable fetus undergoes calcification and is retained within the abdominal cavity, often remaining asymptomatic for decades. Some 330 cases have been reported in the medical literature. While modern imaging techniques and early surgical intervention have made the condition extremely rare, it persists in populations with limited healthcare access. We present the case of a 70-year-old woman undergoing omentoplasty for postoperative mediastinitis, during which a lithopedion of approximately 12- to 13-weeks' gestational age was incidentally discovered and removed from the greater omentum. The specimen had been retained for an estimated 20 to 30 years. This case highlights the potential for lithopedia to remain clinically silent, appearing as diagnostic curiosities during unrelated procedures. Differential diagnoses for calcified abdominal masses include benign or malignant tumors and nonneoplastic conditions. Surgical removal is the treatment of choice, unless risks are prohibitive.