Case Study Mystery: Swollen, Painful Belly Button During Menstruation

"Medical Journeys" is a set of clinical resources reviewed by physicians, meant for the medical team as well as the patients they serve. Each episode of this 12-part journey through a disease state contains both a physician guide and a downloadable/printable patient resource. "Medical Journeys" chart a path each step of the way for physicians and patients and provide continual resources and support, as the caregiver team navigates the course of a disease.

This month: A noteworthy case study.

What is causing this nulliparous woman to have menstrual changes, along with cyclical, gradually increasing, swelling around her navel? That's the question that prompted the ultrasound examination that began a 35-year-old patient's diagnostic journey, as described by Chidimma Akudo Omeke and colleagues at Enugu State University of Science and Technology Teaching Hospital in Nigeria.

As they wrote in their case report in International Journal of Surgery Case Reports, the patient presented to the gynecology clinic for follow-up after a uterine fibroid was detected on an ultrasound. She told clinicians that about 4 years previously, she had noticed that her abdomen was enlarged, and that the swelling had gradually increased. She also began having severe menstrual cramps, heavy bleeding, and pain during her period.

She noted that about a year earlier she had noticed that every month during menstruation, her belly button increased in size and became painful, but then returned to its normal size after menses; there was no evidence of bleeding or discharge. She had not undergone surgery in the past, nor had she experienced pain during intercourse, changes in bowel habits, urinary symptoms, or weight loss.

Clinicians found her abdomen to be distended and mobile with respiration. They noted a hyperpigmented 4×4 umbilical mass that was firm with no expansile cough impulse and not tender to touch. The mass was just beneath the skin and not attached to any adjacent structures or tissues, and it was not reducible. The patient also had a non-tender mass of 32 weeks size in her pelvis, with a nodular surface.

Clinicians performed an ultrasound of the abdomen and pelvis, revealing that the patient's uterus was enlarged and contained several round heteroechoic masses, some with rim calcification. The largest of these was 8.9 cm in diameter. The endometrial stripe was distorted; the ovaries were normal in appearance. There was no adnexal mass or fluid in the pouch of Douglas. Results of preoperative lab tests including a complete blood count and biochemical and coagulation profile were normal.

Clinicians diagnosed the patient as having a very large uterine fibroid and umbilical endometriosis. She underwent surgery to remove both the fibroid and the umbilical mass, and surgery revealed:

• A firm umbilical nodule 4×4 cm in size

• A soft subcutaneous mass surrounding the umbilicus measuring 3×2 cm

• Within the subserosa, intramural, and submucous areas, about 14 uterine fibroids of various sizes, up to a maximum of 20×15 cm

Both uterine tubes had adhered to the uterus, and the left tube was kinked. The ovaries appeared to be normal, and there was no evidence of endometriosis within the pelvis.

Histologic examination of the fibroid nodules identified 14 encapsulated nodular masses of 0.7 to 13 cm. Cut surfaces were similar, whitish, and whorled. Likewise, under the microscope, sections of the nodular masses were also similar, interlacing fascicles of smooth muscle cells with abundant eosinophilic fusiform cytoplasm, with no signs of nuclear atypia or mitotic activity. The stroma contained hyalinized areas.

Based on these findings, clinicians made a diagnosis of uterine leiomyomatosis.

Omeke and co-authors noted that the umbilical end tissue was a spherical nodular mass measuring 4×3×2 cm. There was an ellipse of skin fragment on the surface measuring 4×2 cm. The cut surface was greyish white with some dark brown spots. Periumbilical tissue was a cystic spherical mass measuring 3×2×1 cm, with the cut section showing a smooth monocystic cavity containing dark brown fluid.

Microscopic examination of samples from the umbilicus and surrounding tissue then revealed connective tissue containing frequent foci of endometrial glands and stroma. A single layer of columnar cells with no evidence of atypia lined the glands, and the stroma showed no evidence of invasion by the glands or signs of tissue reaction, the case authors noted.

They therefore then arrived at a diagnosis of umbilical and peri-umbilical endometriosis.

The team reported that the patient's recovery from surgery was uneventful, and on day 10 following the surgery, she was discharged.

At a follow-up assessment 2 weeks later, she was counseled about the findings of the histology report, and her condition remained stable on two follow-up assessments.

Discussion

Omeke and co-authors noted that despite the rarity of this case of primary umbilical endometriosis in a nulliparous woman being treated for multiple uterine fibroids, clinicians assessing umbilical disorders should consider this among the possible differential diagnoses, "even if the patient has no typical symptoms of pelvic endometriosis."

The group explained that although endometriosis most often affects sites such as the peritoneum, ovaries, anterior and posterior pouch of Douglas, posterior broad ligaments, uterosacral ligaments, fallopian tubes, sigmoid colon, appendix, and round ligaments, it is also known to occur less commonly in the umbilicus and even locations such as the lungs, thorax, brain, and pericardium.

Symptoms include chronic pelvic pain, severe and frequent cramps and pain during menstruation, pain with intercourse, and infertility.

Endometriosis that develops in the umbilicus accounts for approximately 0.5% to 1.2% of all cases, and of those, about 75% occur spontaneously as primary endometriosis, the case authors said.

Secondary umbilical endometriosis typically occurs as a result of surgery, such as a caesarean section, abdominal hysterectomy, appendectomy, or laparoscopy, due to iatrogenic seeding of endometrial tissue, the authors explained.

Coexisting umbilical and pelvic endometriosis has been theorized to be due to lymphatic and hematogenic transplantation, although development of the isolated umbilical endometriosis that affected this patient "may occur through metaplasia of urachal residues," the team wrote.

Umbilical endometriosis generally presents as a rubbery or firm nodule ranging in size from a few millimeters to 6 cm. Although it may not cause any symptoms, umbilical endometriosis typically presents with umbilical swelling (90% of cases), associated with cyclical pain in about 80% of patients, and bleeding or discharge in about half of those affected, Omeke and co-authors noted.

Differential diagnoses to consider, they said, include granuloma, umbilical polyps, hemangioma, melanocytic nevus, seborrheic keratosis, granular cell tumour, umbilical hernia, lipoma, keloid, hypertrophic scars, and cutaneous metastasis of cancers.

The 4×4 cm size of this patient's umbilical lesion is comparable to those observed in a series of five African patients with umbilical endometriosis, in which the largest lesion was 4 cm across and the average size was 3.02 cm.

The patient's case also appears to be one of two reported that had no evidence of pelvic endometriosis, Omeke and co-authors noted, citing a case of umbilical and ovarian endometriosis coexisting with multiple uterine myomas, and other reports of coexisting pelvic endometriosis with uterine leiomyoma.

While clinical findings may be sufficient to diagnose umbilical endometriosis, the diagnostic gold standard includes histological findings, and other helpful investigations include ultrasonography, computed tomography, magnetic resonance imaging, and Doppler ultrasonography.

Analgesics and hormonal therapy can be used to relieve symptoms, the case authors wrote, although "the treatment of choice is surgical excision which [as in this case] could be done at the time of myomectomy." They noted that medical treatments used for short-term symptomatic relief include non-steroidal anti-inflammatory drugs, combined oral contraceptive pills, danazol, gestrinone, gonadotropin-releasing hormone agonists, and antagonists.

Coexisting primary umbilical endometriosis and uterine fibroids "should be suspected in women of reproductive age who complain of cyclical umbilical disorders in addition to abdominal swelling or other symptoms of uterine fibroids," Omeke and co-authors concluded.

Read previous installments of this series:

Part 1: Endometriosis: Understanding the Pathogenesis and Pathophysiology

Part 2: Diagnosing Endometriosis

Part 3: Managing Endometriosis: Research and Recommendations

Part 4: Case Study: Endometriosis or Hernia?

Part 5: Endometriosis: Fertility and Pregnancy

Part 6: The Latest on What to Know About Managing Endometriomas

Part 7: Enhancing the Doctor-Patient Dialogue About Endometriosis