An Atypical Presentation of Extraovarian Endometrioma

Background: Patients with endometriomas typically pres- ent with an intraovarian mass, often associated with mul- tiple foci of extraovarian lesions. An isolated extraovarian endometrioma is rare and represents a challenging diag - nostic dilemma. Case: 29 yr G6P3033 woman without history of gyneco - logical malignancies presented with worsening left lower abdominal and pelvic pain over one month. Transvaginal ultrasound revealed a complex cystic mass above the blad- der concerning for atypical hemorrhagic cyst versus neo- plasm. Laparoscopy revealed an isolated endometrioma on the bladder peritoneum that was confirmed on histology.

Isolated pelvic endometriomas can occur in the setting of pelvic pain without peritoneal or ovarian involvement and/or adhesive disease. Clinicians should maintain suspicion for endometriosis in patients with a pel- vic mass and pain regardless of the ultrasound appearance of the ovaries. 1Department of Obstetrics and Gynecology, Thomas Jefferson University Hospital, USA 2Division of Reproductive Endocrinology and infertility, Department of Obstetrics and Gynecology, Thomas Jefferson University Hospital, USA CAse PReseNtAtioN Check for updates

Endometriosis is one of the most common causes of pelvic pain in women of reproductive age [1] and can be a diagnostic challenge because of its diverse and nonspecific symptoms and findings. The most com- mon sites of endometriosis are the dependent pelvic structures and include the ovaries, anterior and poste- rior cul-de-sac, posterior broad ligaments, uterosacral ligaments, fallopian tubes and colon. The diagnosis of endometriosis is commonly suspected based on symp- toms such as pelvic pain, dysmenorrhea and/or dyspa - reunia. Physical exam may include reduced pelvic organ mobility, uterosacral mass or tenderness, or a pelvic ISSN: 2377-9004 DOI: 10.23937/2377-9004/1410125 Berger et al. Obstet Gynecol Cases Rev 2018, 5:125 • Page 2 of 3 • pain medication. In the clinic one week later the patient reported that her pain had moderately improved; her abdomen was soft, non-tender, non-distended, with - out rebound or guarding, and with normoactive bowel sounds. Her pelvic exam was notable for tenderness to palpation along the uterus and left adnexa, with a pal - pable, persistent left adnexal mass. The patient underwent diagnostic laparoscopy with a preoperative differential diagnosis of atypical hem- orrhagic cyst versus neoplasm. At surgery a 5 cm × 5 cm × 3 cm chocolate colored cyst was identified on the surface of the bladder serosa consistent in appearance with an endometrioma. The presumed endometrioma was also adherent to the left round ligament and the fundus of the uterus but was not in any way contigu - ous with the left ovary which was normal. The uterus, fallopian tubes, and right ovary were also normal in ap- pearance, and there was no evidence of peritoneal or other intraabdominal endometriosis. There was no sug- gestion of a malignancy. During the process of resecting the mass, the cyst ruptured and dark-sanguinous fluid el sounds and left upper quadrant tenderness without rebound or guarding. She did not have costovertebral angle tenderness nor was there hepatosplenomegaly or Murphy’s sign. Her urinalysis was negative. She was sent home with a diagnosis of non-specific abdominal pain to be treated with acetaminophen with codeine and asked to return for follow up in one week. Her pain initially improved, however, she presented to the Emergency Department four days later with wors- ening pain in the left lower quadrant and suprapubic ar- eas. A transvaginal ultrasound at that time revealed an 8.6 cm × 5.3 cm by 5.6 cm complex cystic mass with uni- form mildly thickened septations and internal echoes in the left adnexa. There was no detectable internal blood flow, nor were there mural nodules (Figure 1 and Figure 2). The radiologist could not confirm that the left ad- nexal mass was ovarian, but also could not identify the left ovary independent of the mass. The right ovary and uterus were normal in appearance and size. The patient was discharged home with a preliminary diagnosis of a complex adnexal cystic mass concerning for atypical hemorrhagic cyst versus ovarian neoplasm and sched- uled to be seen in the gynecology clinic for a definiti ve plan. She was given torsion precautions and narcotic Figure 1: Long transvaginal ultrasound view of 8.6 cm × 5.3 cm by 5.6 cm complex cystic mass with uniform mildly thickened septations and internal echoes. Figure 2: Coronal transvaginal ultrasound view of 8.6 cm × 5.3 cm by 5.6 cm complex cystic mass adjacent to bladder. Figure 3: 20X magnification image with evidence of blood, stroma, containing (arrow) hemosiderin laden macrophages (pigmented histiocytes). Figure 4: 4X magnification image showing evidence of blood, stroma, and inflammatory response. ISSN: 2377-9004 DOI: 10.23937/2377-9004/1410125 Berger et al. Obstet Gynecol Cases Rev 2018, 5:125 • Page 3 of 3 • that retrograde menstrual flow led to seeding adjacent to the bladder surface. This case clearly emphasizes the importance of maintaining a broad differential diagno - sis and considering endometriosis in women with pelvic pain and a mass, even in atypical clinical contexts.

1. Bulun SE (2009) Endometriosis. N Engl J Med 360: 268- 279. 2. Chamié LP, Blasbalg R, Pereira RM, Warmbrand G, Seraf- ini PC (2011) Findings of pelvic endometriosis at transvag- inal US, MR imaging, and laparoscopy. Radiographics 31: E77-E100. 3. Hsu AL, Sinaii N, Segars J, Nieman LK, Stratton P (2011) Relating pelvic pain location to surgical findings of endome- triosis. Obstet Gynecol 118: 223-230. 4. The American Fertility Society (1985) Revised American Fertility Society classification of endometriosis: 1985. Fertil Steril 43: 351-352. 5. Jenkins S, Olive DL, Haney AF (1986) Endometriosis: Pathogenetic implications of the anatomic distribution. Ob- stet Gynecol 67: 335-338. 6. Mettler L, Schollmeyer T, Lehmann-Willenbrock E, Schup- pler U, Schmutzler A, et al. (2003) Accuracy of Laparoscop- ic Diagnosis of Endometriosis. JSLS 7: 15-18. 7. Murphy AA, Green WR, Bobbie D, dela Cruz ZC, Rock JA (1986) Unsuspected endometriosis documented by scan- ning electron microscopy in visually normal peritoneum. Fertil Steril 46: 522-524. 8. Koninckx PR, Ussia A, Adamyan L, Wattiez A, Donnez J (2012) Deep endometriosis: Definition, diagnosis, and treatment. Fertil Steril 98: 564-571. was visualized. The mass was removed, and fluid was evacuated. Pathological evaluation confirmed endome- triotic cyst, with evidence of atrophic glands, hemosid - erin laden macrophages (pigmented histiocytes) (Figure 3) and endometrial stroma with inflammatory response (Figure 4). The patient’s postoperative course was un - complicated and she was discharged home on the day of surgery on oral contraceptive pills. The patient recov- ered well and she was without pain on follow up exam. Comment This case describes an atypical presentation of en- dometriosis. Despite being extraovarian, a complex pel- vic mass in a reproductive age female can be endome- triosis. The patient’s history, complaints, and imaging were concerning for a hemorrhagic cyst or malignancy; there was a low suspicion for endometriosis in light of the patient’s multiparity and atypical symptoms. How- ever, her exploratory laparoscopy revealed a histolog - ically-confirmed endometrioma without peritoneal or ovarian involvement or adhesive disease. Though it is well-known that endometriosis may be subclinical and not visualizable at laparoscopy [7], it is nevertheless sur- prising that the patient had a single, isolated endome- trioma without other findings of endometriosis. Even more unusual was the fact that this woman had no ev - idence of infertility. It could be hypothesized that the endometrioma as seen in this patient is in some ways different from typical deep endometriomas, which is frequently multifocal [8]. However, the gross and histo- logic appearance was fairly characteristic. It is possible