Case reports of old ectopic pregnancies with intrauterine devices
This case report describes a rare instance of chronic ectopic pregnancy in a woman with an intrauterine device that mimicked a malignant ovarian tumor, highlighting the critical need to consider this diagnosis even when serum β-hCG levels are negative.
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In the human body, a pregnancy begins when a fertilized egg travels to the uterus and attaches itself to the lining to grow. Sometimes, however, this journey goes wrong, and the egg settles in the wrong place, such as the fallopian tube. This condition is known as an ectopic pregnancy. While most of these cases are emergencies that cause sudden, severe pain and bleeding, a rare and quieter version exists. In this chronic form, the embryo stops developing but does not leave the body immediately. Instead, the tissue slowly organizes, hardens, and forms a mass that can stick to nearby organs. Because the body's usual pregnancy signals fade away, doctors often struggle to identify this lingering condition, especially when it mimics other serious problems like tumors.
This story comes from a hospital in Zigong, China, where a team of doctors encountered a patient whose symptoms pointed toward a dangerous mystery. The patient was a thirty-five-year-old woman who had been using an intrauterine device, a small T-shaped object placed inside the uterus to prevent pregnancy, for three years. Four months before her visit, she began experiencing irregular menstrual cycles. Her periods, which usually lasted five days, stretched out to more than ten days, and the flow changed from a normal rhythm to a messy pattern of brown discharge followed by heavy bleeding with large clots. She also felt a constant heaviness in her lower abdomen and found herself needing to urinate frequently.
When she arrived at the hospital, her vital signs were stable, and a physical examination revealed a distinct, tender lump about the size of a large orange near her right side. An ultrasound scan showed a chaotic mix of tissues in that area, measuring roughly five centimeters across, with blood flowing through it. A follow-up CT scan confirmed the presence of a large, irregular mass with uneven density, but it also showed that the intrauterine device was sitting correctly inside the uterus. The doctors ran a battery of blood tests to look for signs of cancer or active pregnancy. The results were puzzling: the test for a pregnancy hormone was negative, and all markers for ovarian cancer were normal. The mass looked like a tumor, but the blood said it was not cancer, and the pregnancy test said there was no pregnancy.
Faced with a large, complex mass that could not be explained by standard tests, the medical team decided to perform surgery to remove it and examine it directly. During the operation, they found that the woman's right fallopian tube was swollen and contained a cystic, solid mass. Between the tube and the surrounding pelvic wall, a pocket of old, clotted blood had formed, creating a six-centimeter capsule filled with dark, tissue-like material. The left side of her reproductive system was healthy, and her ovaries appeared normal. When the surgeons sent the removed tissue to a laboratory for detailed analysis under a microscope, the mystery was solved. The tissue contained remnants of a pregnancy that had died long ago, specifically degenerated structures from a fertilized egg that had implanted in the fallopian tube. This confirmed the diagnosis of a chronic ectopic pregnancy.
The case highlights a difficult reality in medicine: a pregnancy can be present in the body even when standard blood tests say it is not. In this specific instance, the pregnancy hormone levels had dropped so low that the test came back negative, yet the physical evidence of the pregnancy remained trapped in the body. The doctors noted that the patient's history of menstrual irregularities and the presence of the mass were the true clues, rather than the blood test results. By removing the mass and studying it, they were able to confirm that the woman was suffering from a rare, slow-growing form of ectopic pregnancy that had been hiding in plain sight.
This report serves as a reminder that even when a pregnancy test is negative, doctors must remain alert to the possibility of a chronic ectopic pregnancy in women of childbearing age who have unusual pelvic masses or persistent bleeding. The condition is tricky because it does not always cause the sudden, dramatic symptoms of a ruptured pregnancy. Instead, it can masquerade as a tumor or an infection, leading to confusion and delayed treatment. In this case, the combination of careful imaging, a willingness to look beyond a single negative test, and surgical exploration allowed the team to find the truth. The patient recovered quickly and was discharged from the hospital just three days after the procedure, having been freed from a condition that could have caused serious complications if left undiagnosed.
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