Medical Mystery: An unexpected ultrasound result

One of my patients came to see me at my office for her annual gynecological visit. She was 26, and generally very healthy.

I asked whether she had experienced any new symptoms or issues since I last saw her the previous year, and she hesitated. She figured it had nothing to do with my specialty, she said, but she did have this odd pain in her lower back. Her primary care physician suggested ibuprofen, but it hadn't helped.

The young woman said the pain, which had started two weeks before, was very low on the right side of her back and felt like something was pushing out from the inside. It wasn't severe, but was "just noticeable" sporadically, lasting 5 to 10 minutes at a time. Exercise didn't make it worse. Rest didn't make it better.

She had had some abdominal bloating, but no change in bowel or bladder function, no fever or irregular bleeding.

My patient was taking birth control pills to help alleviate painful menstrual cycles and took no other medications. Although she felt the pain in her lower back, given her family history of endometriosis and fibroids, I thought a good first step would be to investigate whether there truly was something pushing out from the inside, as she described. I performed an abdominal and pelvic ultrasound and found something I wasn't expecting.

On the ultrasound screen appeared the largest ovarian cyst I had ever seen. It extended above the pubic bone and took over my entire screen, making it impossible to tell whether it came from the right or left. Right away, I sent the woman to the hospital for a more in-depth evaluation. The second ultrasound revealed a 15-centimeter cyst - between the size of a cantaloupe and a honeydew melon, or a fetus at 19 weeks of development.

The cyst had grown from within the ovary, filling up the pelvis and pressing the surrounding organs aside. That's why she felt pain in her lower back.

The patient underwent laparoscopic surgery, during which the cyst was drained and removed, and sent to the lab for further study. It was ultimately found to be benign, but it had replaced the entire right ovary, requiring the removal of the ovary and the right Fallopian tube as well.

Given that the same type of cyst could recur in her remaining ovary, I recommended she preserve her fertility by freezing some of her eggs. We checked her hormonal levels and found they were on par with someone approaching ovarian failure, something she never would have known had she not come in for her checkup. Relieved to have a positive option available to her, the patient went on to freeze her eggs.

Maureen P. Kelly is a reproductive endocrinologist and infertility specialist and medical director of Society Hill Reproductive Medicine.

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