Sari H. Green, Resident, Surgical Education, Los Angeles County Harbor UCLA Medical Center, Torrance, CA; Kenneth S. Waxman, Director, Department of Surgical Education, Cottage Hospital, Santa Barbara, CA; Peter L. Morris, Director of Pathology, Cottage Hospital, Santa Barbara, CA; Benjamin D. Shadle, Resident, Surgical Education, Cottage Hospital, Santa Barbara, CA
Sari H. Green, BA
Resident, Surgical Education
Los Angeles County Harbor UCLA
Department of Surgical Education
Santa Barbara, CA
Peter L. Morris, MD
Director of Pathology
Santa Barbara, CA
Benjamin D. Shadle,MD
Resident, Surgical Education
Santa Barbara, CA
Endometriosis is a condition in which endometrial stroma and glands are found outside of the uterine cavity. The endometrial tissue is generally found within the pelvic cavity and involves the ovaries, uterine ligaments, fallopian tubes, pouch of Douglas, or pelvic sidewall. Extra-pelvic sites also have been reported, including the abdominal viscera, abdominal wall, extremities, lungs, and brain. We describe our experience with an umbilical hernia that was associated with endometriosis and initially thought to be an incarcerated hernia with possible bowel strangulation.
A 29-year-old woman was referred to our clinic for repair of an umbilical hernia. She had a 7-month history of a tender umbilical mass that had increased in size gradually and was sometimes associated with right lower quadrant pain. She had no other symptoms suggestive of endometriosis and reported normal menstruation. The patient noted that the mass had slowly changed from its initial reddish-pink color to a bluish-grey color. When queried, she could not recall any specific changes to the mass or associated pain in relation to her menstrual cycle. Her only history of abdominal surgery was a Cesarean section to deliver twins 5 years earlier, which had left a low, transverse incision scar.
Physical examination revealed a 2 x 2-cm, tender, irreducible umbilical hernia with dark skin discoloration. No other masses were observed in the abdomen or by the low transverse scar. The initial impression was that she had an incarcerated hernia with possible bowel strangulation. The possibility of a Sister Joseph's nodule representing an underlying malignancy was also considered.
Surgical exploration revealed an umbilical hernia. A firm, dark-grey lesion was identified within the tissue and excised. The hernia defect was repaired, and the surgical specimen was sent to pathology for evaluation. Microscopic sections revealed an admixture of benign endometrial glands and stroma consistent with endometriosis (Figure). There was associated reactive fibrosis and chronic inflammation. The endometrial tissue was in the dermis and in the soft tissue adjacent to the peritoneal lining of the hernia sac, but no endometrial tissue was found within the hernia sac itself. The patient was released to home the same day as the procedure, recovered well from surgery, and continues to be asymptomatic. Follow-up vaginal pelvic ultrasonography performed several weeks postoperatively showed no evidence of endometriosis.
There are a variety of theories regarding the cause of endometriosis. None have been proven, nor does any one theory explain all the different manifestations of the disease. The retrograde theory, which contends that endometrial tissue refluxes through the fallopian tubes during menstruation and implants at ectopic sites, would explain the high percentage of cases occurring in the pelvis. The presence of remote, extra-pelvic sites is better explained by the metaplasia theory, which suggests that multipotential cells can develop into endometrial tissue, often stimulated by inflammation.
A series of 82 cases of cutaneous endometriosis indicates that scar tissue is particularly susceptible to endometrial implantation.1 Abdominal wall endometriosis is usually associated with incisional abdominal scars and occurs most commonly following a Cesarean section. It has been suggested that the umbilicus acts as a physiologic scar with a predisposition for developing endometriosis. Umbilical endometriosis has been well described in the literature, occurring either spontaneously or following laparoscopic procedures in which a trocar was placed through the umbilicus. To our knowledge, only three cases of endometriosis occurring in association with an umbilical hernia have been reported previously.2-4
In 1994, Yu and associates described their experience with a 30-year-old woman who had an 18-month history of cyclic umbilical pain and bleeding.2 A 1.5 x 1.5 x 1.0-cm lesion was found in the umbilical area, adjacent to a small umbilical hernia. Histologic analysis of the lesion revealed endometriosis with chronic inflammation, hemosiderin, and fibrosis.
In 2000, Ramsanahie and associates reported a case of endometriosis in the scarless abdominal wall of a 33-year-old woman.3 She had a 2-year history of intermittent pain associated with an umbilical mass and underlying umbilical hernia. The mass increased in size and tenderness prior to menstruation. The patient had borne nine children, all by normal vaginal delivery. Physical examination revealed a 2 x 1-cm, firm, round, cherry-red nodule at the umbilicus with an underlying umbilical hernia. Postoperative histological analysis showed endometriosis. Subsequent laparoscopy showed no signs of pelvic endometriosis.
In 2001, Yuen and colleagues reported the case of a 43-year-old woman who, for several months, had experienced umbilical pain that came on during her menses.4 This patient, like ours, had no other symptoms suggestive of endometriosis. She had a lower midline incision scar from a Cesarean section that had been performed 9 years earlier. Physical examination revealed a tender, irreducible umbilical hernia with skin discoloration. Histologic analysis showed a focus of endometrial tissue within the lower dermis.
Endometriosis is of interest to the general surgeon because it is often mistaken for a suture granuloma, abscess, cyst, lipoma, or incisional hernia.5 Between 0.5% and 1% of all endometriosis cases involve the umbilicus, thereby presenting a hazard in the diagnostic evaluation of umbilical hernias. As our case illustrates, some patients may perceive no correlation between their symptoms and menstrual cycle. The diagnosis is often made incidentally by histologic examination of the specimen.6
Endometriosis should be considered in the differential diagnosis of all premenopausal women who present with umbilical swelling and pain. In nonemergent cases, magnetic resonance imaging is the best modality for evaluating extrapelvic endometriosis.2 Making an appropriate diagnosis is important, because up to 50% of patients have concurrent pelvic endometriosis, which can lead to infertility and reseeding of endometrial tissue to extra-pelvic sites. Referral to a gynecologist for further evaluation is recommended when endometriosis is suspected.
In rare incidences, endometriosis can present a diagnostic challenge to the general surgeon evaluating an umbilical hernia. Our patient presented with a 7-month history of a tender, discolored umbilical mass. She reported no correlation between her pain and menses and was initially thought have an incarcerated hernia with possible bowel strangulation. Histologic examination of the surgical specimen revealed endometriosis adjacent to the hernia sac. This case highlights the importance of considering endometriosis in the differential diagnosis of any premenopausal woman who presents with umbilical swelling and pain, regardless of whether the pain correlates with her menses.