Diagnosticul ecografic al fibroamelor ovariene

Introduction

Solid ovarian tumors are peculiar but fascinating neoplasms, from an embryologic, morphologic and clinical point of view. The sex cord stromal ovarian tumors represent a group of ovarian tumors which most often present a wide range of endocrine manifestations due to estrogenic and androgenic hormone secretion. Confoundingly diverse, ovarian tumors are usually morphologically characterized as biphasic neoplasms, composed of both stromal and sex cord elements⁽¹⁾. Tumors in which cells resemble fibroblasts producing collagen or theca-cells belong to the fibroma-thecoma group. Ovarian fibromas are rarely associated with steroid hormone production and account for appro­xi­ma­tively 4% of the cases of all ovarian masses. They are most commonly found in menopausal women in the fourth or fifth decade, and rarely appear in patients youn­ger than 30 years of age.

Ovarian fibromas are sometimes associated with two uncommon syndromes, the basal cell nevus syndrome and Demons-Meigs syndrome. Demons-Meigs syndrome is defined by the presence of a fibrous ovarian tumor accompanied by ascites and pleural effusion which dis­appear after the removal of the tumor. Fibromas with this presentation are commonly edematous⁽²⁾. The ba­sal cell nevus syndrome – also called the nevoid basal cell carcinoma syndrome or Gorlin’s syndrome – is de­fined by the presence of at least one of the following: basal cell carcinoma in early life, keratocysts of the jaw, cal­ci­fi­cation of the dura, mesenteric cystis, ovarian fi­bro­mas. In this case, the ovarian tumors are bilateral, mul­ti­no­du­lar and calcified⁽³⁾.

Mostly clinical asymptomatic or with a nonspecific appearance, ovarian fibromas require a careful approach and a constant differential diagnosis with both gyne­co­logical tumors, especially uterine pathology, and other pelvic masses. The surgical treatment is mandatory due to the difficult differential diagnosis and the possibility of microscopy focal fibrosarcomatous changes and therefore malignant involvement.

Patients and method

This is a retrospective study conducted in a uni­ver­sity-affiliated tertiary gynecological referral center, the “Filantropia” Clinical Hospital of Obstetrics and Gy­ne­cology, Bucharest. All patients admitted between Ja­nua­ry 2018 and December 2018 with an operative diagnosis of an ovarian fibroma were identified from operating theatre records and computerized cli­ni­cal management database. The demographic cha­rac­te­ris­tics, the clinical presentations, the intraoperative fin­d­ings, the operative procedures and the outcomes were re­cor­ded and analyzed.

Results

During the study period, eight cases with an operative diagnosis of ovarian fibroma were identified. There was a total of 189 cases of surgical removal of ovarian masses over the same period of time. The incidence of ovarian fibromas was, therefore, 4.23%. The statistical approach was performed using Excel data analysis.

Patient characteristics

The median age was 45 years old (range: 37-77), and five patients (62.5%) were postmenopausal women. None of the patients reported a positive family history of ovarian fibroma.

Clinical presentation

The most frequent symptom was abdominal pain (n=6, or 75%) associated with abdominal distension (n=5, or 62.5%). One patient presented menorrhagia and another patient was asymptomatic and the tumor was detected during routine gynecological examination. Upon physical examination, an abdominopelvic mass was detected in six patients (75%), and in all these cases it was difficult to differentiate it from a uterine mass.

Preoperative investigations and diagnosis

Transvaginal ultrasound was performed in all pa­tients. The uterus was found to be normal in six cases and enlarged with fibroids in two cases. The size of ova­rian fibromas ranged from 3 to 20 cm. Five pa­tients had completely solid, hypoechoic masses with ul­tra­­sound beam attenuation (62.5%), and three had mixed echogeneity with both solid and cystic components (37.5%) – Figure 1. Free peritoneal fluid in the pouch of Douglas was found in three cases. In these patients, CA-125 value was minimally increased, as well as the sus­picion of malignant ovarian pathology.
 

Intraoperative findings and procedures

All patients underwent surgical treatment: two by laparoscopy and six by laparotomy (Table 1). The intraoperative findings were: clear straw-colored peritoneal fluids of 500 ml up to 2900 ml in three patients, two cases of ovarian fibromas associated with 540° torsion, and two patients presented uterine fibromas (Figure 2). Both patients with torsion had large ovarian masses (15/12 cm and 15/10 cm), and this complication can be related to the size of the tumor. All tumors were unilateral: 5 (62.5%) on the right side, and 3 (37.5%) on the left side. The size of the tumors ranged from 4 to 20 cm, with a median of 10 cm. The tumors were smaller in the laparoscopy group, with a median of 5 cm. Both patients treated through the laparoscopy approach underwent salpingo-oophorectomy. In the laparotomy approach group, three patients underwent unilateral salpingo-oophorectomy and three patients underwent total abdominal hysterectomy with bilateral salpingo-oophorectomy because of the large size of the tumors or suspicion of malignancy. Only three cases showed predominantly solid masses with focal areas of cystic changes. None of the patients had intraoperative surgical complications. The operative time in the laparoscopy group was 50 minutes (range: 40-60 minutes), and in the laparotomy group, 70 minutes (range: 50-90). All patients underwent extemporaneous biopsy, and the histopathological examination confirmed the diagnosis of ovarian fibromas and fibrothecomas, without cellular atypia or mitosis.
 

Postoperative course

The postoperative hospital stay was short both in the laparoscopy group (three days), and in the laparotomy group (four days). Uneventful postoperative outcome was noted in all cases.

Discussion

Ovarian fibromas are benign ovarian masses, difficult to diagnose due to the asymptomatic or nonspecific symptoms. Moreover, it is mandatory to make a careful differential diagnosis, because not only gynecological conditions, such as ovarian and uterine cystic or solid masses, but also pelvic tumors may present similar clinical findings.

Transvaginal ultrasound – and rarely abdominal ultrasound – is an essential investigation to differentiate ovarian fibromas from the more common uterine fibroids and other ovarian benign or malignant masses. The ultrasound findings that describe an ovarian fibroma, as the literature shows, can include a spectrum of sonographic features, from completely solid, hypoechoic masses with ultrasound beam attenuation to mixed echogeneity with both solid and cystic components⁽⁴⁾. The investigator should pay attention to the tumor margins and the connection with the ovary or the uterus. Sometimes, an uterin fibroid with subserosal development can be diagnosed as ovarian fibroma, especially when it is described near the ovary. The vascular pattern on color Doppler assessment can differentiate between a uterine fibroid and an ovarian fibroma. It was observed that a well-vascularized solid pelvic mass with high-speed flow is suggestive of a subserosal fibroid, while a less vascularized tumor with low-speed flow points towards an ovarian fibroma⁽⁵⁾. Another important aspect for the differential diagnosis is that a primary ovarian carcinoma appears rarely as a solid mass, and a secondary ovarian malignancy is typically bilateral⁽¹⁾.

In order to improve the preoperative description of the pelvic mass, computed tomography and magnetic resonance imaging can show particular findings. Ovarian fibromas appear as a solid mass with delayed accumulation of contrast medium on computed tomography scan and show marked T1and T2 hypointensities on magnetic resonance imaging^(6,7).

In spite of the ultrasound findings observed to highly describe an ovarian fibroma, the confirmation of the diagnosis is entirely histological, after surgical treatment. An earlier series of 23 cases of ovarian fibromas made by A. Athchek et al., in 2003, showed that the risk of malignancies in solid ovarian tumors was 8.7% and that the diagnosis can only be established by histological assessment⁽¹⁾. In our study, all tumors were benign, but the number of cases was small, and therefore the absence of the malignancy might be just incidental.

The treatment is represented by conservative surgery by unilateral salpingo-oophorectomy, through a laparoscopy or laparotomy approach, depending on the tumor size. This procedure is available especially for patients at the reproductive age, with relatively small tumors and no other pelvic involvement. When the mass is suspected for malignancy, is large in size and appears in postmenopausal women, the total abdominal hysterectomy and bilateral salpingo-oophorectomy should be considered.

In conclusion, ovarian fibromas are uncommon gynecological conditions that require a proper differential diagnosis and surgical treatment due to the possibility of malignant involvement. The available data in literature about diagnosing and treating ovarian fibromas are poor. The condition should be further investigated in order to improve its management and to facilitate the gynecologist effort for diagnosing ovarian fibromas.