Giant Uterine Leiomyoma Mimicking a 28-Week Gravid Uterus in a Young Nulliparous Woman: A Case Report of Fertility-Preserving Myomectomy

In the landscape of women's health, the uterus is a resilient organ, yet it is prone to developing benign growths known as leiomyomas, or fibroids. These are non-cancerous tumors made of muscle and connective tissue that form within the uterine wall. While most remain small and unnoticed, a rare few grow to extraordinary sizes, becoming what doctors call "giant" fibroids. When these masses reach such dimensions, they can distort the abdomen so severely that they mimic the appearance of a late-stage pregnancy, creating a complex diagnostic puzzle. The challenge for physicians is not only to remove the mass safely but to do so in a way that preserves the patient's ability to have children in the future, a goal that becomes especially critical for young women who have never given birth. Another layer of complexity arises when blood tests show elevated levels of a substance called CA-125, a marker often associated with ovarian cancer. In the presence of a massive fibroid, this elevation can be misleading, causing unnecessary fear of malignancy when the cause is actually benign.

This case report details the journey of a twenty-seven-year-old woman who arrived at a hospital in late 2021 with a large, hard lump in her lower abdomen. She was unmarried and had never been pregnant. For two months, she had felt a heavy dragging sensation in her belly, and just a week before her visit, she noticed a distinct lump. Despite the size of the mass, which doctors estimated to be the size of a uterus at twenty-eight weeks of pregnancy, she had no pain and her menstrual cycles remained normal. She had gained a small amount of weight quickly and suffered from constipation, likely due to the pressure the mass was exerting on her internal organs. Her medical history was largely unremarkable, save for a previous diagnosis of vitamin D deficiency.

When the medical team examined her, the physical evidence was striking. A visible bulge occupied her lower abdomen, extending up to her navel. The mass felt firm and nodular, moving side to side but not up and down, and it was clearly attached to the uterus rather than floating freely like an ovarian cyst would. To confirm the nature of the growth, the team performed an ultrasound. The images revealed a uterus that was grossly enlarged, dominated by a single massive tumor measuring 17.7 by 16.9 by 13.6 centimeters located at the back of the uterus, along with a second, smaller tumor on the front. The scan also showed a small, simple cyst on her left ovary, which appeared benign, and no free fluid in the pelvic cavity.

A significant point of concern for the doctors was a blood test result showing a CA-125 level of 68 units per milliliter. The standard threshold for this marker is 35 units per milliliter, and levels above this often raise suspicion for ovarian cancer. However, the medical team recognized that large fibroids can cause a modest rise in this marker due to the sheer size of the tumor and the irritation it causes to the lining of the abdomen. They weighed the possibility of a malignant ovarian tumor against the strong evidence pointing to a benign fibroid uterus. The fact that the mass moved in unison with the cervix during examination and that the ultrasound showed a clear origin from the uterine muscle led them to conclude that this was a giant fibroid, not cancer.

The decision was made to perform a surgery to remove the fibroids while preserving the uterus, a procedure known as a myomectomy. Before the operation, the patient and her family were counseled thoroughly. They were told that while the surgery offered a chance at future pregnancy, there were risks involved, including the possibility of needing a blood transfusion, the chance that the fibroids might grow back, and the small but real possibility that the surgery might need to be converted into a hysterectomy if complications arose. The patient agreed to proceed with the fertility-sparing approach.

During the operation, the surgeons found the uterus to be enormous, matching the twenty-eight-week size predicted by the exam. They identified the large posterior mass, which showed signs of degeneration, or breakdown of tissue, and a smaller mass near the top left corner. The team carefully cut out the large tumor, stopped the bleeding, and reconstructed the uterine wall using a specific stitching technique designed to hold the tissue together securely. They then removed the smaller tumor, taking great care to leave the nearby fallopian tube intact. To manage any remaining oozing of blood, they placed a special sponge inside the abdomen. The surgery lasted about an hour, and the removed tissue was sent to a laboratory for analysis.

The post-operative period required careful monitoring. The patient's blood pressure and heart rate remained stable, but her hemoglobin level, a measure of the blood's ability to carry oxygen, dropped from 12.10 grams per deciliter before surgery to 9.7 grams per deciliter afterward. This drop was expected given the size of the mass and the nature of the surgery. She received a transfusion of blood products and iron supplements to help her body recover. Her temperature rose slightly on the day of surgery but was managed with medication, and she did not develop any signs of infection. By the fourth day after the operation, she was feeling well, her vital signs had returned to normal, and she was discharged from the hospital.

The final confirmation came from the laboratory analysis of the removed tissue. The pathologist examined the samples under a microscope and confirmed that both masses were benign leiomyomas, with no signs of cancer. This result validated the team's decision to avoid a more radical surgery and to proceed with the fertility-preserving approach. The case highlights that even when a fibroid grows to a size that mimics a late-term pregnancy and causes blood markers to appear suspicious, it is possible to safely remove the tumor and keep the uterus intact. It also serves as a reminder that a modest elevation in CA-125 should not automatically trigger a diagnosis of cancer when a large fibroid is present, as the tumor itself can cause this rise. For this young woman, the successful outcome meant that her reproductive potential remained intact, offering her a future where she could pursue pregnancy if she chose to do so.