Cystic Ovarian Leiomyoma in a Patient with Progressive Abdominal Pain

Background

Leiomyomas of the ovary are rare, benign, solid tumors of smooth muscle. They typically are seen in women of childbearing age and less frequently in women who are postmenopausal [1,2]. Ovarian leiomyomas can present unilaterally or bilaterally; the majority of bilateral cases occur in young patients [2]. Most patients with ovarian leiomyomas have no symptoms because of the small size of the tumors and the incidental nature of their discovery. Some patients, however, present with abdominal pain with or without distention [3]. Most women with ovarian leiomyomas have a history of uterine leiomyoma and hysterectomy [2]. Here, we report our experience with and considerations about diagnosis and treatment of an unusually large cystic ovarian leiomyoma.

Case Report

A 45-year-old woman with well-controlled diabetes mellitus and hypertension was admitted through the General Surgery Clinic for investigation of abdominal pain and a 4-year history of progressive abdominal distension. Her medical history revealed 3 myomectomies, the first done at age 30 years and the other 2 successively for uterine leiomyomas. At age 40, the patient underwent a total abdominal hysterectomy with right oophorectomy.

On physical examination, the patient’s vital signs were stable. Her abdominal examination revealed a distended abdomen with mild tenderness in the lower portion. Preoperative tumor marker levels were 1.86 for carcinoembryonic antigen (CEA) and 14.62 for human carbohydrate antigen 125 (Ca-125), both within normal limits. Pelvic ultrasonography done outside our hospital revealed a massive intraperitoneal collection of thick fluid with layering and septations in the right and left upper abdomen and the pelvic cavity, with a 15×7-cm heterogenous mass in the right lower abdomen, with cystic areas and hypervascularity. Also, it showed a 5.7×5-cm left adnexal cystic lesion. Preoperative computed tomography (CT) of the abdomen and pelvis revealed an irregular heterogenous-complex lesion on the right side of the pelvic cavity that measured 14×11 cm and was compressing but not invading the bladder. A large amount of loculated fluid was seen in the anterior aspect of the abdominal cavity, which measured 40×24×32 cm and had a thin enhancing wall. A 5.3×3.5-cm cyst also was seen in the left ovary (Figure 1).

Because a peritoneal malignancy was suspected, the Surgical Oncology team recommended resection of the mass and possible hyperthermic intraperitoneal chemotherapy (HIPEC), depending on the results from an intraoperative frozen section. Assessment of the patient by the Anesthesia team showed that she had good functional capacity, her metabolic equivalent of task was >4, and she had no respiratory symptoms or signs of reduced pulmonary function. Her airway assessment was good (normal mouth opening, thyromental distance, temporomandibular join movement, and a Mallampati score of 1). The plan was for general anesthesia (inhaled), invasive monitoring with an arterial line, and regional analgesia in the form of an epidural.

Under general anesthesia and through a laparotomy incision, we found a large pelvic cyst filled with 10.5 L of serous fluid, which was occupying most of the abdominal space and adherent to the pelvic wall. There were no peritoneal deposits or mucinous masses. The intraoperative frozen section specimen showed fibrous inflammation with giant cells, with no clear evidence of mucin. We then dissected the cyst from the pelvic wall, bladder, and rectal mesentery and performed a left oophorectomy and omentectomy without HIPEC (Figure 2). After surgery, the mass was dissected and described as a deflated cyst measuring 39×30.2 cm. The wall was approximately 1.5 cm thick. The outer surface was irregular with a single white deposit and was otherwise smooth, glistening, and intact. The inner surface also was smooth.

Postoperative pathology using hematoxylin and eosin staining and immunohistochemistry with desmin and alpha-smooth muscle actin resulted in a diagnosis of leiomyoma with cystic degeneration (Figure 3). The surgery took 6 h and there were no intraoperative or postoperative complications. The patient’s vital signs were stable throughout the procedure. During surgery, she received 5 L of crystalloids and 2 units of packed red blood cells. Her urine output was approximately 450 mL. The approximate fluid balance was 1.1 L. After successful extubation, the patient was transferred to the Surgical Intensive Care Unit for postoperative care and management. Two days later, she was moved to the non-intensive care unit. Her epidural catheter was removed 48 h after surgery. The patient was discharged home 7 days after surgery in stable condition. When she was seen in the outpatient clinic 2 weeks and 3 and 6 months later, her tumor markers within normal limits. During the 6-month visit, abdominal and pelvic CT showed resolution of the loculated intraperitoneal fluid and no gross local recurrence.

Discussion

Ovarian leiomyomas have been described as rare benign tumors. They reportedly account for 1% of all ovarian tumors. Most ovarian leiomyomas have benign histology but can range from benign to borderline to malignant [3,4]. In a few cases, estrogen and progesterone have been reported to play a role in the development and progression of ovarian leiomyomas.

In some patients, the tumors have s been noted to increase in size with pregnancy and menstruation [5,6]. Patients with ovarian leiomyomas usually have no symptoms. When the tumors are sizable, however, they can present with non-painful abdominal swelling or, less often, minimal abdominal pain. On rare occasions, the tumors can cause compression, resulting in symptoms of urinary frequency and constipation [1–3]. Moreover, ovarian leiomyomas can be primary or secondary, based on the time of presentation. Primary ovarian leiomyomas are thought to arise from smooth muscle cells in vessel walls of the ovaries. Some scholars theorize that they arise from smooth muscle cells in the ovarian ligament or stroma. Others believe that the tumors develop from undifferentiated reproductive cells and cortical smooth muscle cells, or from smooth muscle cells in the form of metaplasia or ovarian endometriosis [3]. Ovarian leiomyomas that develop from tissues external to the ovaries and come into contact with the ovaries are referred to as secondary. As in the patient in our case, who had undergone a hysterectomy and right oophorectomy due to multiple myomas, some tumor cells can remain in or fall from the uterus, attach to the ovary, and grow over time [5–7].

Given the low incidence and indistinct presentation of ovarian leiomyomas, making the diagnosis before surgery can be extremely challenging. The only method for definitive diagnosis is postoperative pathology. Imaging modalities that have been used to diagnose ovarian leiomyomas include ultrasonography, CT, and magnetic resonance imaging (MRI). MRI is preferable because it has excellent sensitivity and reveals detailed anatomical features in multiple planes [6,8].

Performing frozen section histopathology intraoperatively in cases of suspected ovarian leiomyoma is important, as the results provide a better understanding of the type of tumor and help guide surgical decisions. In our patient’s case, intraoperative chemotherapy had been planned but was not given because the frozen section results showed fibrous inflammation with giant cells and no evidence of malignancy [3]. The postoperative pathology report resulted in a diagnosis of leiomyoma with cystic degeneration. Reports in the literature about ovarian leiomyoma describe tumors with an average size of 5.5 cm, the largest documented case measuring 25 cm in diameter [1,3,6,9]. Different histopathological types of leiomyoma have been reported, including typical, cellular, and mitotically active leiomyomas; leiomyomas with bizarre nuclei; and myxoid leiomyomas with all of those types sharing a solid component. When leiomyomas grow, different types of degeneration can occur as they expand beyond their blood supply, including include cystic, hyaline, myxoid, and dystrophic calcification. Cystic degeneration, which was similar to our case, is rare and is observed in about 4% of leiomyomas; only a few cases have been reported in the literature [10–12].

Surgery is of great value for treatment of ovarian leiomyomas and it is important to consider the age of the patient when selecting the type of procedure. For example, in postmenopausal or middle-aged women who are not fertile or do not wish to preserve their fertility, bilateral salpingo-oophorectomy is the best option [3,13]. In our case, the patient had previously undergone a hysterectomy with right oophorectomy and our intervention included a left oophorectomy with excision of the large leiomyoma. After resection, adjuvant chemotherapy was not warranted, given the benign nature of the disease. Furthermore, recurrence of leiomyomas of ovarian origin is uncommon, which makes the prognosis excellent. However, in young women who need to preserve their fertility, surgery to completely eliminate the tumor may not be ideal. Given the possibility of estrogen and progesterone involvement in the progression of ovarian leiomyomas, antiestrogenic therapy may have a role in the postoperative treatment plan, but more studies are needed. Although more reports about ovarian leiomyomas are being published in the literature, they are still considered rare and additional research is needed to better understand the nature and mechanism of the disease and to help identify the most successful method for preoperative diagnosis and optimum management for women in different age groups.

Conclusions

Ovarian leiomyomas are rare ovarian tumors that are difficult to diagnose before surgery. Suspicion for ovarian leiomyoma with cystic degeneration should be high in patients who present with large, cystic masses in adnexal tissues, especially individuals who have a history of hysterectomy for a fibroid uterus and oophorectomy. Intraoperative frozen section is beneficial and considered an effective approach to help determine how to proceed surgically. A postoperative pathology report should follow to reach a definitive diagnosis.