CASE


A 27-year-old woman presented to the emergency department (ED) with right upper abdominal pain that had been present for the past 12 hours and progressively worsening abdominal distention that had persisted for 3 months. She had a history of hypothyroidism and rheumatoid arthritis and was taking immunosuppressive medications, including methotrexate and prednisone. The patient described her pain as dull, nonradiating, exacerbated by movement, and associated with increasing anorexia as well as urinary frequency and urgency. However, she reported no dysuria, hematuria, fever, chills, nausea, vomiting, constipation, or diarrhea. She was able to tolerate oral intake. The patient denied using tobacco, alcohol, or illicit drugs. She had reached menarche at age 14 years but suffered from metrorrhagia. When questioned, she said she had never been sexually active and denied any history of sexually transmitted diseases (STDs).


Physical examination revealed a moderately obese female who was in no apparent distress. Her vital signs were within normal limits. Cardiac examination exhibited a regular rate and rhythm without murmurs. Lungs were clear to auscultation. Abdominal examination demonstrated a moderately distended abdomen with tenderness in the right upper quadrant, no Murphy sign, and normal bowel sounds. The results of laboratory tests, including a CBC and complete metabolic panel, were normal except for a WBC count of 12,190/mm3. Urinalysis was normal, and a urine pregnancy test was negative.


Given the patient's right upper quadrant tenderness, an abdominal ultrasound was performed in the ED (Figure 1). To confirm the diagnosis, the patient underwent abdominal/pelvic CT with both oral and IV contrast administration (Figure 2). What do the images reveal?


DISCUSSION


The abdominal ultrasound revealed a large cystic mass, but the origin of the cyst was unclear. CT confirmed a large cystic mass in the abdomen and pelvis. The mass, which arose from the left ovary and measured 41324336 cm (18,548 cm3), significantly displaced the liver superolaterally and the small and large bowels posteriorly. No focal abnormalities were seen in the liver, gallbladder, spleen, adrenal glands, kidneys, pancreas, stomach, small and large bowels, bladder, or uterus. No free fluid or free air was seen in the abdomen or pelvis. The osseous structures were unremarkable.


Given the large size of this cystic lesion and the patient's young age, malignancy was considered as a possible etiology. Tumor markers (cancer antigen 125 [CA-125], human chorionic gonadotropin [hCG], alpha-fetoprotein [AFP], lactic dehydrogenase [LDH], and serum inhibin A and B) were tested and were found to be negative. The patient subsequently underwent an uneventful exploratory laparotomy and left salpingo-oophorectomy, during which the intact mass was removed. Intraoperative examination revealed that the patient's gallbladder was acutely inflamed with multiple stones. This finding was likely responsible for the patient's right upper quadrant pain and tenderness. The pathology of the cystic mass revealed a benign serous cystadenoma. After surgery, the patient had an uneventful recovery.


Diagnosis Giant ovarian serous cystadenomas are extremely rare. This massive serous cystadenoma is one of the largest ever reported in the medical literature. The diagnostic evaluation of a woman with an adnexal mass should begin with a thorough history and physical examination. In most cases, however, the history and physical examination alone are insufficient to make a diagnosis, and ultrasound imaging, with or without laboratory studies, is usually necessary.


Ultrasonography is an easy, rapid test with minimal side effects and can be used to determine whether a mass is ovarian or extraovarian, solid or cystic, simple or complex, and vascular or avascular. Endovaginal ultrasonography can provide a more detailed morphologic examination of pelvic structures. While it requires a handheld probe to be inserted into the vagina, it is typically well-tolerated in reproductive-age women and postmenopausal women who are still engaging in intercourse. Unlike transabdominal ultrasonography, endovaginal ultrasound does not require a full bladder.1 Cross-sectional imaging using CT is the best modality for evaluating the abdomen, pelvis, and retroperitoneum when malignant ovarian disease is suspected.


The discovery of an ovarian cyst can cause considerable anxiety because of the fear that it is or will become malignant. While the majority of ovarian cysts are benign, tumor markers can be obtained to exclude neoplastic ovarian cysts. These markers include serum inhibin in granulosa cell tumors, AFP in endodermal sinus tumors, LDH in dysgerminomas, and both AFP and beta-hCG in embryonal carcinomas.2


The ultimate diagnostic tool is histologic examination. In this patient's case, pathology returned a diagnosis of serous cystadenoma, a benign tumor derived from glandular tissue. 
Surgical excision is typically performed in patients whose cysts are either complex or larger than 5 cm in size, as large ovarian cystadenomas lead to discomfort secondary to pressure on adjacent structures, ovarian torsion, and cyst rupture and hemorrhage. In addition, as in this case, these cysts may cause significant abdominal distention that directly impacts patients' quality of life.


Classification types Ovarian neoplasm is typically divided by origin cell type into three categories: epithelial, stromal, and germ cell. The most common of these is the epithelial type, which includes serous tumors. These serous tumors are characterized by a proliferation of epithelium that resembles the lining of the fallopian tubes. Epithelial ovarian neoplasms are virtually all cystic and occur most frequently in women between age 40 and 60 years. Benign serous tumors, which are bilateral in 10% of cases, include cyst adenomas, adenofibromas, cystadenofibromas, and surface papillomas. While 70% of serous tumors are benign, 5% to 10% have borderline malignant potential, and 20% to 25% can be malignant depending largely on the patient's age. These malignant cysts tend to be multilocular.1 Although the potential for benign ovarian cystadenomas to become malignant has been postulated, it has yet to be proven.3 JAAPA

The authors practice at Brigham and Women's Hospital in Boston, Massachusetts. Hana Dubsky is an emergency medicine PA, Michael Stella is an attending physician in emergency radiology, and Ali Raja is an attending physician in the department of emergency medicine. The authors have indicated no relationships to disclose relating to the content of this article.

Julie Vajnar, PA-C, RT, department editor


REFERENCES


1. Hoffman MS. Overview of the evaluation and management of ovarian masses. In: Rose BD, ed. UpToDate. Waltham, MA: Wolters Kluwer Health; 2010.


2. Mülayim B, Gürakan H, Dagli V, et al. Unaware of a giant serous cyst adenoma: a case report. Arch Gynecol Obstet. 2006;273(6):381-383.


3. Sujatha VV, Babu SC. Giant ovarian serous cystadenoma 
in a postmenopausal woman: a case report. Cases J. 2009;2:7875.