Jain P*, Shah R**, Mali K**, Warke HS***.
(* Junior Resident, ** Assistant Professor, *** Associate Professor, Department of Obstetrics and Gynecology, Seth G S Medical College and K E M Hospital, Mumbai, India.)
Ovarian fibroma is a rare and benign tumor of the ovary. Most commonly it is found in women during the perimenopausal or postmenopausal age group. It has a variable presentation and is generally asymptomatic. Although the tumor is benign, it closely resembles malignant tumors. We describe here a case of a 55year old woman with a pelvic mass diagnosed preoperatively on Magnetic Resonance Imaging (MRI) to be a large pedunculated uterine fibroid. She underwent total abdominal hysterectomy with bilateral salpingoopherectomy as the frozen section was suggestive of an ovarian fibroma. This case reveals the diagnostic dilemma in cases with pelvic mass.
Ovarian fibroma is a tumor of stromal cell origin. It accounts for around 4% of all ovarian tumors and usually occurs in perimenopausal and postmenopausal women. These tumors are usually unilateral, solid, hard and have a bosselated external surface. It may be associated with ascites and right sided hydrothorax known as Meig’s syndrome. However, due to variation in presentation, differences in shape and size of the tumor, it is often misdiagnosed as a uterine myoma.[1-3] In cases where tumor size is large and associated with ascites or hydrothorax and elevated CA-125 levels, it is misdiagnosed as a malignancy.
A 55 year old nulligravida, married for 35 years presented with complaints of pain in abdomen and distension since 4 years. Pain was dull aching, generalized and intermittent in nature. Patient was menopausal since 10 years. On examination, her general condition was fair, she was afebrile, pulse was 84 per minute and blood pressure was 120/80 mm of Hg. Abdominal examination revealed a palpable mass of around 26 weeks size which was hard in consistency, had irregular surface and was mobile. On speculum examination, cervix and vagina was healthy with minimal white discharge. Bimanual examination revealed a 26 weeks hard ballotable mass arising from the pelvis with irregular surface was felt. Chest radiograph showed minimal infiltrates in the basal portions of the lung and increased bronchovascular markings raising a possibility of tuberculosis causing elevated CA-125 levels. On pelvic ultrasound (USG), uterus was normal in shape and size. A vascularised solid looking mass occupying whole of the pelvis and extending upto the supraumblical region was seen. Differential diagnosis of an ovarian mass or a pedunculated fibroid along with moderate ascites was given. MRI pelvis suggested a large pedunculated uterine fibroid with moderate ascites.[Fig.1] Tumor markers revealed raised CA 125 (208.8 U/ml) and LDH (378 U/L). Pap smear was inflammatory. USG guided ascitic fluid tapping was done, which showed predominantly lymphocytes and no evidence of malignant cells. Ascitic fluid protein was 5.15, ADA levels of ascitic fluid were in the normal range. Hence the possibility of abdominal tuberculosis was ruled out. Consent for total abdominal hysterectomy SOS bilateral salpingo oopherectomy was taken. Exploratory laparotomy revealed a large solid multilobulated mass of 15x20 cm arising from right ovary occupying the entire peritoneal cavity which had undergone torsion.[Fig.2] The mass was separate from the fallopian tube. Uterus was less than normal size. Around l.5 liters of ascitic fluid was drained. Frozen section of the ovarian mass was sent and frozen section revealed spindle cell tumor of the ovary. No evidence of malignancy was seen. Total abdominal hysterectomy with bilateral salpingoophorectomy was done. Contralateral ovary and fallopian tube was normal. Postoperatively the patient had an uneventful course. The histopathology report confirmed the findings of ovarian fibroma.
Fig.1 . MRI pelvis showing a large uterine fibroid.
Fig.2 . Large solid multilobulated ovarian mass.
Ovarian fibromas are tumors which are of stromal cell origin. They are composed of spindle cells, oval or round cells that are capable of producing collagen. Fibromas are mostly solid, spherical, lobulated encapsulated grey white masses which are covered by ovarian serosa. Fibromas occur at all ages, but mostly present during perimenopausal and postmenopausal age group. Very rarely they may also present with peritoneal implants without any atypical feature in the primary tumor. Removal of these tumors by surgical intervention is recommended because of the probability of malignancy. The surgical approach can be done either by open or via laparoscopic method, but surgeons are generally reluctant to use laparoscopic approach as the benign nature of the disease cannot be definitely diagnosed preoperatively and it might be difficult to resect the tumor safely with preservation of ovarian function. CA-125 has been used as a tumor marker for the diagnosis of ovarian carcinoma to distinguish it from benign lesions. But unfortunately, it has not proved to be a reliable predictor to distinguish between them. In this case, there was a strong suspicion of large uterine fibroid, the only test that created the diagnostic quandary was the raised CA 125 levels which suggested that the mass could be large ovarian mass with or without malignant lesions, leiomyosarcoma and even the possibility of abdominal Koch’s could not be completely ruled out. Therefore, surgery was planned with the possibility of malignant lesion and decision of frozen section to be sent intraoperatively was taken. Intraoperatively, a large ovarian mass of around 15x18 cm was seen along with torsion which was sent for frozen section, which revealed spindle cell tumor of ovary i.e fibroma and patient uneventfully underwent total abdominal hysterectomy with bilateral salpingoopherectomy. The histopathology report also turned out to be fibroma. The choice of treatment would have been the same for a young patient, but consent would have been changed to exploratory laparotomy with myomectomy SOS right salpingoopherectomy. This case emphasizes the importance of variable presentation of the tumor and also highlights the non specificity of CA -125 as a poor marker of ovarian malignancy. Hence, the role of histopathological examination should not be underestimated even in very obvious cases. MRI is used as a diagnostic tool in diagnosis of ovarian tumors. But it also shows variable appearances. On MRI T2 images ovarian fibromas can have 3 patterns of appearance. They can be seen as homogenous hypointense masses, heterogenous masses with isointense and few patchy hyperintense areas or heterogenous masses with predominantly hyperintense and few isointense parts. On T1 weighted images, mostly they present as homogenous masses with cystic degeneration. After contrast, they may show homogenous mild enhancement in all phases. At times the diagnosis of the pelvic masses remains a dilemma. The role of radiological modalities in diagnosing such tumors has to be correlated with other diagnostic modalities and clinical findings to reach an appropriate diagnosis and the final diagnosis is obtained on histopathology.
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Jain P, Shah R, Mali K, Warke HS. Ovarian Mass Or Uterine Mass – A Diagnostic Quandary. JPGO 2019. Vol. 6 No.6. Available from: https://www.jpgo.org/2019/06/ovarian-mass-or-uterine-mass-diagnostic.html