Musculoskeletal Pain and Right Leg Paresthesia Revealed as Large Ovarian Mucinous Cystadenoma: A Case Report

Introduction

Epithelial neoplasms are the most common and heterogenous group of ovarian tumors [1]. Approximately 10–15% are primary ovarian mucinous neoplasms. Almost 80% of these consist of benign mucinous neoplasms (cystadenomas and adenofibromas), while the rest are borderline neoplasms (intestinal type or Mullerian type), non-invasive (intraepithelial and intraglandular) carcinomas, and invasive carcinomas [2,3]. Benign mucinous cystadenomas usually affect women under 40 years of age, while the mean age at diagnosis of mucinous carcinoma is 45 years [3,4]. Primary mucinous ovarian neoplasms often present with clinical signs and symptoms of a large unilateral pelvic mass [2,3]. We report a case of a 31-year-old woman who presented with increasing sacrococcygeal pain and right leg paresthesia over a 2-year period. She was treated for possible musculoskeletal and spine problems. She was finally diagnosed with a large right ovarian mucinous cystadenoma expanding in the sacrococcygeal region. She was successfully treated with complete excision of the tumor and subsequent right salpingo-oophorectomy, resulting in complete remission of all of her clinical symptoms.

Case Report

A 31-year-old Cypriot woman presented to our clinic complaining of a dull pain in the coccyx and sacral regions together with right leg paresthesia that had been worsening over the preceding 2 years. The pain occurred independently of any physical activities and was not exacerbated by any pressure on the above-described area. During the 6 months preceding her visit to our clinic, the pain had increased both in intensity and frequency, and significantly affected her daily physical activities and the quality of her life. She also experienced numbness and burning sensations to her right posterior thigh. She was treated with several courses of physical therapy by a chiropractor together with medical therapy given by her general practitioner, which mainly included non-steroidal anti-inflammatory drugs and opioids, without any significant improvement of her symptoms. She had experienced 2 cesarean sections in the past, as well as laparoscopic right ovarian cystectomy for an asymptomatic cystadenoma, which was found incidentally during her gynecological examination 5 years before the visit to our clinic. She had also had an abdominoplasty (excision of abdominal fat and skin for cosmetic purposes). No family history of any genetic disorder was reported. Her mental health was excellent. She was not being treated with any other medication except for the analgesic therapy described.

On physical examination, the patient appeared to be in good condition, having normal respiratory and heart rate, as well as normal temperature and blood pressure. Her body mass index (BMI) was 39 kg/m2. Moderate hypoesthesia of the right posterior thigh and 4+/5 strength of left knee extension were found in the neurological examination. The rest of the clinical examination was unremarkable. She experienced mild normocytic normochromic anemia (hemoglobin 11.3 g/dL), while white blood cell count, erythrocyte sedimentation rate, and C-reactive protein levels were found to be normal. Other laboratory investigations were within normal limits, including liver and renal function indices, electrolytes, and thyroid profile.

The unrelenting and gradually worsening pain raised concerns for other possible intra-abdominal causes. Her bimanual vaginal examination was normal. A transvaginal ultrasound (TVS-US), which was done during her gynecologic examination, showed a smooth multilocular right ovarian tumor (15×8.5 cm), with no solid components and no detectable Doppler signal (Figure 1). Magnetic resonance imaging (MRI) of the pelvis disclosed a smooth multilocular tumor (largest dimensions, 16×9 cm), with no solid components and less than 4 papillary structures (Figure 2). The mass originated from the right ovary, filled the Douglas pouch, and disrupted the rectosigmoid entering to the sacrococcygeal region. All tumor markers (CEA, CA 15-3, and CA-125) were within normal levels. Open surgical excision of the right ovarian tumor together with right salpingo-oophorectomy was performed by 2 consultant gynecologists from our center (Figure 3). During the surgery, a mass with well-defined borders near the left lateral body, firmly attached to the presacral fascia, was identified.

Gross examination revealed a well circumscribed, thin-walled, multilocular cystic lesion measuring 15×8.5 cm with smooth outer and inner surfaces filled with mucinous fluid. The histopathological examination disclosed a cyst lined by a columnar, intestinal-like epithelium without atypia or mitotic features (Figure 4). The stroma was fibromatous, while normal ovarian tissue was found in the periphery of the cyst, suggesting mucinous cystadenoma of the right ovary. The patient experienced an uneventful postoperative period. She was discharged without complications. Patient adherence to medical discharge instructions was excellent. The patient remained in excellent condition with complete remission of all her clinical symptoms after 18 months of follow-up.

Discussion

A significant percentage of ovarian epithelial tumors are mucinous ovarian neoplasms. Most of them are benign or borderline (heterogeneous group of non-invasive tumors of uncertain malignant potential with characteristic histology), tend to be cystic, and 76% are multi-locular. MRI has great sensitivity and specificity for distinguishing benign from malignant disease in the setting of an indeterminate adnexal and/or ovarian mass [3–6]. Although mucinous cystadenomas are mostly benign, close follow-up is essential as they can slowly transform into borderline neoplasms and eventually invasive ovarian cancer [3–7]. Tumor markers (including CA-125) can be useful in differentiating malignant vs benign neoplasms, but they should be used wisely, since some benign neoplasms can express these markers [3,5–7].

Our patient displayed the typical age of diagnosis for benign mucinous cystadenomas; between 20–40 years, although cases in the premenarchal age have been reported [3,4,8,9]. Small ovarian cystadenomas are generally asymptomatic and found incidentally during an ultrasound examination for another gynecologic disorder; they range in size between 1 to 4 cm [3,4,10]. As their size becomes larger, they elicit symptoms and clinical signs that are not specific, resulting from mass effect on adjacent structures or from tumor torsion. The main clinical symptoms and signs are abdominal and/or pelvic pain, fullness, and discomfort, as well as a palpable abdominal mass [1,3,10,11]. Large cystadenomas have also been associated with nausea and vomiting, urinary problems, persistent cough, back pain, metrorrhagia, and feminization (secondary to hyperestrogenism promoted by the neoplasm) [12–14]. Rarely, borderline mucinous tumors with pseudomyxoma peritonei have been described, although the primary origin of the tumor in this entity is usually associated with neoplasms of the appendix and not from ruptured primary ovarian mucinous neoplasms [3,4]. To our knowledge, this is the first published case of a large benign mucinous cystadenoma presenting with symptoms of chronic sacrococcygeal pain and leg paresthesia.

The sacrococcygeal region (also referred to as “presacral region”) is the anatomic area defined anteriorly by the rectal fascia propria and posteriorly by the presacral fascia surrounding the sacrum and coccyx [15–17]. It is occupied by blood/lymphatic vessels, connective tissue, and nerves. The iliac vessels, the ureters, and the lateral stalks of the rectum are found in its lateral side [15,16]. Since the evolution of the large mucinous cystadenoma was found in this area, it could be speculated that nerve compression from the tumor and irritation of certain branches of the sacral plexus could be responsible for the chronic pain and the symptoms of paresthesia the patient described, which were at first misdiagnosed as primary musculoskeletal and spinal defects. The delayed diagnosis of this lesion for 2 years promoted its enlargement and gradually exacerbated her symptoms.

Our patient had experienced laparoscopic removal of a right ovarian cystadenoma 5 years earlier. It could be speculated that she underwent insufficient surgical excision in the first surgical procedure, which was not performed by our team, and that this promoted recurrence of the lesion. A wealth of evidence suggests that surgical removal of the involved ovary and adnexa decreases the rate of local recurrence as compared with simple cystectomy, if cystectomy is not completed thoroughly [2–4,6]. Great vigilance must also be taken to prevent any spillage of the cyst contents that could increase the risk of recurrence (especially for large multilocular lesions like the tumor seen in our patient). This was one of the reasons that open surgery was preferred instead of laparoscopy. In cases in which ovarian cancer is found, when surgeons are operating laparoscopically, great care must be taken to avoid metastasis. There are also concerns about trocar insertion site metastasis promoted either by the chimney effect created by the pneumoperitoneum or by direct seeding after contamination of surgical instruments with cancer cells [18,19]. Given the benign pathologic features of mucinous cystadenomas, the prognosis of these tumors is excellent.

Conclusions

Large ovarian mucinous cystadenomas that develop in the sacrococcygeal region can lead to symptoms that mimic musculoskeletal and spine problems. Early diagnosis and therapy are of great importance to achieve complete excision of the tumor and remission of all clinical symptoms.