Benign Struma Ovarii Research Articles

Level of HE4 is Correlated with Diagnosis of Struma Ovarii: A Case Report

Patient: Female, 75Final Diagnosis: Ovarian teratomaSymptoms: Chronic pelvic painMedication: —Clinical Procedure: Tumor resectionSpecialty: OncologyObjective:Rare diseaseBackground:Struma ovarii is a rare ovarian teratoma with non-specific clinical presentation that can mimic malignancy, especially when combined with the presence of ascites. Since the surgical procedures performed for benign and malignant tumors are quite different, pre-operative differential diagnosis is key. In this case report we compare the levels of biomarkers CA 125 and HE4 in the differential diagnosis of a suspicious ovarian tumor.Case Report:A 75-year-old woman with a palpable mass at the left adnexa, ascites, and high levels of CA 125, underwent a subtotal abdominal hysterectomy and bilateral salpingo-oophorectomy. Histology reported benign struma ovarii.Conclusions:Even though transvaginal ultrasound and CA 125 levels suggested malignancy, HE4 measurements correctly diagnosed benignity.

Metastatic malignant struma ovarii with coexistence of Hashimoto's thyroiditis.

SummaryStruma ovarii is a rare ovarian teratoma characterized by the presence of thyroid tissue as the major component. Malignant transformation of the thyroidal component (malignant struma ovarii) has been reported in approximately 5% of struma ovarii. The management and follow-up of this unusual disease remain controversial. We report the case of a woman with a history of autoimmune thyroiditis and a previous resection of a benign struma ovarii that underwent hystero-annexiectomy for malignant struma ovarii with multiple papillary thyroid cancer foci and peritoneal involvement. Total thyroidectomy and subsequent radioiodine treatment lead to complete disease remission after 104 months of follow-up. The diagnosis and natural progression of malignant struma ovarii are difficult to discern, and relapses can occur several years after diagnosis. A multidisciplinary approach is mandatory; after surgical excision of malignant struma, thyroidectomy in combination with 131I therapy should be considered after risk stratification in accordance with a standard approach in differentiated thyroid cancer patients.Learning pointsMalignant struma ovarii is a rare disease; diagnosis is difficult and management is not well defined.Predominant sites of metastasis are adjacent pelvic structures.Thyroidectomy and 131I therapy should be considered after risk stratification in accordance with standard approaches in DTC patients.

Struma ovarii complicating pregnancy: a case report

Struma ovarii represents an ovarian mature teratoma with thyroid tissue comprising more than 50% of the ovarian tumor. It is a rare condition, representing approximately 1% of all ovarian tumors with a potential malignant transformation 5% to10%. When it is combined with pregnancy, it renders its management in this circumstance is extreme challenging. The authors present a case of benign struma ovarii diagnosed as a right adnexal mass during first trimester of pregnancy with an uneventful clinical course.

Late Bone Metastasis of Histologically Bland Struma Ovarii: The Unpredictability of Its Biologic Behavior.

Struma ovarii (SO) is a subtype of ovarian teratoma that contains mostly thyroid tissue comprising more than 50% of the tumor volume [1]. It is the most common type of monodermal teratoma of the ovary, accounting for approximately 2.7% of all teratomas [1]. Most cases of typical SO are benign with exceptional cases showing malignant features of papillary carcinoma, vascular invasion, or invasion into surrounding tissue. However, there are rare cases of histologically benign SO with malignant biological behavior, variously designated as peritoneal strumosis, malignant SO, metastatic SO, or highly differentiated follicular carinomas [2,3]. Here, we report on a patient who developed a vertebral metastasis ten years after oophorectomy for SO that finally proved to be malignant.

Sonographic and Pathologic Features of Struma Ovarii.

To investigate the sonographic features of struma ovarii and its corresponding histopathologic findings. The sonographic and histopathological features of 72 patients with histopathologically comfirmed struma ovarii who were treated in Peking Union Medical College Hospital from January 2005 to December 2014 were retrospectively reviewed. Of these 72 patients,71 had benign struma ovarii(73 lesions)and one patient had malignant struma ovarii(1 lesion). On ultrasonography,all the 73 benign lesions had distinct margin,45(61.6%)had multilocular cystic or cystic-solid mass,49(67.1%)had irregular shape,and 28(38.4%)had nodular solid protrusions in the cystic areas. On the color Doppler flow imaging,36(49.3%)lesions had blood flow signals. The ultrasonographic features of the malignant struma ovarii lesion were multilocular cystic-solid mass with several nodular solid protrusions in the cysic areas;on the color Doppler flow imaging,blood flow signals were visible within septa and solid areas. The sonographic features of struma ovarii are diverse. If ultrasonography reveals multilocular cystic or cystic-solid mass with distinct margin and isoechoic or hyperechoic nodular solid protrusions in the cystic areas with visible blood flow signals,the diagnosis of struma ovarii should be considered.

Coexistence of benign struma ovarii, pseudo-Meigs' syndrome and elevated serum CA 125: Case report and review of the literature.

Struma ovarii is an uncommon ovarian teratoma comprised predominantly of mature thyroid tissue. The combination of pseudo-Meigs’ syndrome, and elevation of CA 125 to the struma ovarii is a rare condition that can mimic ovarian malignancy. We reported a case of benign struma ovarii, presenting with the clinical features of advanced ovarian carcinoma: complex pelvic mass, gross ascites, bilateral pleural effusion and markedly elevated serum CA 125 levels. The patient underwent total abdominal hysterectomy and bilateral salpingo-oophorectomy. Ascites and pleural effusion were not evident and the CA 125 levels returned to normal following surgical excision. A systematic review of reported cases of coexistent benign struma ovarii, pseudo-Meigs’ syndrome and elevated serum CA 125 was performed. Struma ovarii accompanied by pseudo-Meigs’ syndrome and elevated serum CA 125 should be considered in the differential diagnosis of ovarian epithelial cancer.

Struma ovarii: management and follow-up of a rare ovarian tumour.

Struma ovarii represents about 1.0% of all ovarian tumours. While management involves surgery, there is a paucity of data regarding the extent and approach of surgery, and postoperative management. This study aimed to delineate the management of struma ovarii, its associated complications, and postoperative follow-up and investigations. We retrospectively reviewed cases of benign struma ovarii treated at KK Women's and Children's Hospital, Singapore, between January 2000 and May 2011. A total of 68 patients underwent surgical removal of ovarian cyst or mass (24 cystectomy, 20 salpingo-oopherectomy and 24 total hysterectomy and bilateral salpingo-oopherectomy). Of the 68 surgeries, 39 (57.4%) included intraoperative frozen section sampling or procedures for staging of ovarian malignancy. The majority (73.5%) of surgeries were laparotomies. Histology revealed benign struma ovarii in all (98.5%) but one patient. Only 7 (10.3%) patients had postoperative complications - 3 wound-related, 2 thyroid-related, 1 incisional hernia and 1 nonspecific. The mean length of hospital stay was 4.2 days. During follow-up, 45 (66.2%) patients required no additional investigations. The most common investigation done was ultrasonography (n = 18, 26.5%). While no recurrences were diagnosed histologically, two patients were subsequently found to have complex/dermoid ovarian cysts on the ipsilateral side of the previous struma ovarii on ultrasonography. Simple surgery is recommended for patients with struma ovarii, especially if they have fertility potential. Laparoscopic surgery is the recommended approach due to its shorter recovery time and lower morbidity. Most patients do not require extended periods of follow-up or postoperative investigations.

Ovarian struma - report of a rare case.

A 34-year-old primipara with no live child came to the gynecology department with complaints of increased and prolonged menstrual bleeding and lower abdominal pain for three months. Her previous menstrual cycles were normal. She was married for 15 y. She was para one. It was an intrauterine death at eight months of pregnancy delivered vaginally 14 y ago. Her medical and surgical history was not significant. No history of malignancy in family. On general examination, her vitals were stable. There was no evidence of hyperthyroidism. Her systemic examination was normal. Examination of abdomen revealed no mass or ascites. Cervix was normal on speculum examination. On bimanual examination, a mobile, non-tender cystic mass measuring approximately 10x8 cm was palpable in the right and anterior fornix. Uterus was normal, left fornix felt free. Rectal examination confirmed above findings. Ultrasonogram of abdomen and pelvis showed a right adnexal cyst measuring 7x8x6.2 cm with muItiple septations. CA-125 levels were within normal limits (7.5 U/ml). Thyroid function tests were within normal limits. Exploratory laparotomy was done. Peroperatively, a multicystic mass of size 8x7x8 cm consisting of right tube and ovary was seen in the right adnexa. Uterus and left adnexa were normal. There was no ascites and no omental adhesions. As she was anxious to conceive, only right salphingo-ophorectomy was done. Dye test showed patent left fallopian tube. Postoperative period was uneventful. On gross examination, ovarian cyst measured 8x5x3 cm. External surface was bosselated and cut section revealed a multiloculated cyst with one solid area measuring 3x2x1 cm. Attached fimbrial end of the right fallopian tube measured 3 cm in length [Table/Fig-1]. [Table/Fig-1]: Gross appearance Microscopic examination showed ovarian parenchyma with cystic follicles [Table/Fig-2] and a cyst lined by a single layer of cuboidal to columnar epithelium [Table/Fig-3]. The wall of the cyst showed multiple colloid-filled thyroid follicles of varying sizes lined by a single layer of cuboidal epithelium. Sections from the right fallopian tube showed normal morphology. [Table/Fig-4,​,5].5]. A diagnosis of Benign struma ovarii - cystic variant was then made. [Table/Fig-2]: Ovarian cyst wall showing ovarian parenchyma (H and E x40) [Table/Fig-3]: Areas showing cyst wall lined by a single layer of cuboidal to columnar epithelium. (H and E x100) [Table/Fig-4]: The wall of the cyst shows multiple colloid-filled thyroid follicles of varying sizes (H and E x100) [Table/Fig-5]: Thyroid follicles lined by a single layer of cuboidal epithelium enclosing colloid (H and E x400) Struma ovarii is an uncommon gynecological tumour accounting for 1% of all ovarian tumours and 3 to 5% of all dermoid tumours of ovary [1–3]. The diagnosis rests on histopathological examination of the tissue which shows thyroid follicles filled with eosinophilic colloid. Rarely, degenerative changes such as calcification, fibrosis or hemosiderophages may be seen [4]. Surgical management is the treatment of choice for struma ovarii. For women desiring fertility, simple ovarian cystectomy or salphingo-oopherectomy seems to be optimal [4,5]. In this case, since she was young with no live child and clinically appeared benign, only right salphingo-oopherectomy was done. For benign disease, standard surgical follow up is sufficient and the prognosis is excellent [6].

A Rare Case of Histologic Benign Struma Ovarii With Distant Metastasis

Struma ovarii (SO) is a rare variant of ovarian teratoma composed mainly of mature thyroid tissue. It is usually benign in histology. We present a case of benign SO with frequent recurrence and widespread extra-ovarian seeding. A 28-year-old woman was diagnosed initially with dermoid cysts over the right ovary. Over a 7-year period, frequent recurrence of ovarian tumor was accompanied by peritoneal strumosis and distant metastasis to liver and lung. Bilateral salpingo-oophorectomy (BSO), total thyroidectomy (TT) and radioactive iodine (RAI) therapy were performed with successfully declining serum thyroglobulin. The patient remains on scheduled follow-up in clinic. Histologic benign SO to behave like biological malignancy with frequent recurrence and distant metastasis is exceptional. Tumor enriched expression of the vascular endothelial growth factor (VEGF) and p53 protein may explain the risk of malignant behavior. There is still a lack of consensus on how to choose the optimal management for histologically benign SO with metastatic behavior. Based on our limited case experience, BSO is preferred. TT and RAI therapy is mandatory if persistence of elevated serum thyroglobulin and wide-seeding of the tumor was detected by I 131 whole body scintigraphy or fluorodeoxyglucose (PET-FDG) scan. J Clin Gynecol Obstet. 2014;3(3):108-113 doi: http://dx.doi.org/10.14740/jcgo232w

Clinical study on 68 cases with struma ovarii

To study the clinical features, treatment and prognosis of struma ovarii. From January 1990 to January 2012, a total of 68 patients were diagnosed struma ovarii at the Department of Obstetrics and Gynecology, Peking Union Medical College Hospital. Clinical data of these patients were studied retrospectively. (1) Characteristics of patients: the median age of patients was 42 years old (17-81 years). Of those patients, 64 cases (94%) were diagnosed begin struma ovarii and 4 (6%) were malignant struma ovarii. (2) CLINICAL FEATURE: 32(47%, 32/68) patients were identified with pelvic mass by ultrasonic test, 28 cases(41%) had clinical abdominal pain, 8 (12%) touched a mass from abdominal wall. Preoperative CA(125) were tested in 54 patients, but only 8 cases (15%) had moderate elevation. All patients receive ultrasound examination, and 51 cases (75%) were mulitcystic lesions with many septi, 3 (4%) solid lesions and 14 (21%) solid-cystic tumors. The mean diameter of tumors was (8 ± 3) cm. Ascites was present in 4 (6%, 4/68) patients. Sixty-seven patients had unilateral lesions, and 1 patient had bilateral lesions. No patient had hyperthyroidism presentation. Nineteen cases underwent thyroid function test after operation, and the results were normal. (3) TREATMENT: all patients underwent surgical treatment. Among patients with begin struma ovarii, 25 cases underwent cystectomy, 15 cases unilateral, 2 bilateral salpingo-oophorectomy, 22 cases hysterectomy + unilateral or bilateral salpingo-oophorectomy. Four malignant struma ovarii, 1 patient underwent fertility-sparing staging surgery, 2 patients unilateral salpingo-oophorectomy, 1 case hysterectomy + bilateral salpingo-oophorectomy. Two patients received chemotherapy after surgery. (4) PROGNOSIS: all patients were followed up in Peking Union Medical College Hospital. The median follow-up time of benign struma ovarii was 5.4 years (6 months-21 years) and there were no recurrence. The median follow-up time of malignant struma ovarii was 11.5 years (9-20 years). Three cases had long-term recurrence at 2, 7 and 16 years respectively after surgery. They were received surgical treatment after recurrence and all were alive. Two cases were given by thyroidectomy and ¹³¹I treatment. Struma ovarii is a rare ovarian monodermal teratoma. Tumorectomy or salpingo-oophorectomy is the appropriate therapeutic treatment for benign struma ovarii. The incidence of malignant struma ovarii is low, and there are no standard treatments. Because of higher long-term recurrence rate, these patients need close follow-up.

Diagnosis of Struma Ovarii in a Patient with Papillary Thyroid Carcinoma – Verification via 124I-PET/US Fusion

Struma ovarii is an extremely rare and mostly benign germ-cell tumor containing predominantly differentiated thyrocytes. Simultaneous presentation of thyroid cancer and benign struma ovarii is rare; only sporadic case reports have been published (C. Ghander et al. Gynecol Oncol 2006; 102: 378 – 380 and A. Jammah et al. Arq Bras Endocrinol Metabol 2011; 55: 490 – 493 and W. Macdonald et al. Clin Nucl Med 2007; 32: 380 – 382). We describe a case of an incidentally detected struma ovarii in a patient with papillary thyroid cancer (PTC), with verification by 124I-positron emission tomography/computed tomography (PET/CT). 124I-PET/CT has been extensively described for patients with metastatic thyroid cancer, and a few studies report also on its role in benign thyroid diseases (Freudenberg et al. Eur Radiol 2004; 14: 2092 – 2098 and Darr et al. Clin Nucl Med 2013, [epub ahead of print]). However, due to its limited spatial resolution and soft-tissue contrast, CT has disadvantages in the detection of small structures or lesions in the pelvis, where soft-tissue contrast is poor. Therefore, ultrasound (US) is more suitable for depicting pathological structures located in soft tissue.

Coexistence of Graves’ disease, papillary thyroid carcinoma and unilateral benign struma ovarii: Case report and review of the literature

BackgroundStruma ovarii is a rare cause of hyperthyroidism, while coexistence with Graves’ disease has been scarcely reported. Patient FindingsWe report a patient with Graves’ disease and unilateral benign functioning struma ovarii, accompanied by ascites, pleural effusion and elevated cancer antigen-125 (CA-125) levels. In subsequent thyroidectomy, incidental papillary thyroid carcinoma was also identified. The functionality of struma ovarii tissue in our patient was supported by the immunohistochemical identification of TSH receptors (TSHR), which may stimulate growth and thyroid hormone production in the presence of circulating TSHR stimulating antibodies (TSHR-Ab). Review of the literatureA systematic review of reported cases of coexistent Graves’ disease and struma ovarii was performed. ConclusionsThe diagnosis of struma ovarii may be masked by Graves’ disease and, therefore, be delayed for several years. Furthermore, ascites, pleural effusion and increased CA-125 may result from a benign struma ovarii. The presence of TSHR in the struma ovarii tissue along with their absence in the surrounding ovarian tissue indirectly suggests that struma ovarii is functional. It is unclear whether TSHR-Ab play a role in the development of thyroid carcinomas in such patients.

Intra-operative consult for cystic struma ovarii—An experience in an academic medical center: A study of 53 cases over 21 years

Struma ovarii often escapes recognition during intraoperative consultation because of its rarity, subtle characteristic gross appearance, and lack of clinical suspicion. An intraoperative diagnosis of benign struma ovarii enables the general gynecologic surgeon to continue the planned surgery. However, a diagnosis of malignnancy in a struma ovarii would alter the course of surgery with the involvement of a gynecologic oncology surgeon. We present here that our experience with intraoperative consultation for preoperatively undiagnosed struma ovarii presenting as an adnexal cystic or solid mass at our teaching hospital. Fifty-three cases of struma ovarii, 5.2% of all cystic teratoma of the same period, were diagnosed between January 1991 and March 2011. All intraoperative consultation reports, gross descriptions and final pathology reports were reviewed. The H&E stained slides and in selected cases, immunohistochemistry stained slides, were reviewed. Of the 53 cases of struma ovarii, intraoperative consultation was requested on 48 cases. Frozen section was done on 24 cases and only gross examination was felt appropriate in remaining 24 cases. 83% cases were diagnosed when a frozen section was done. None of the remaining 24 cases were recognized as struma by gross inspection. Our findings reveal that in a large number of cases the diagnosis of struma ovarii remained unrecognized during intraoperative consultation, indicating its often subtle/deceptive gross morphologic appearance. However, the purpose of the intraoperative consultation was served, as appropriate information was provided to the surgeon to guide the surgical management.

Struma ovarii recurrence with peritoneal strumosis: A case report

Background: Malignant transformation of thyroid tissue in struma ovarii and metastasis are uncommon. Benign thyroid tissue may spread to the peritoneal cavity in rare cases, and pathologic examination of the peritoneal implants shows multiple nodules of varying sizes of mature thyroid tissue similar to struma ovarii. This condition is termed “peritoneal strumosis”. It is very rare and therefore, both the criteria for diagnosis and its management are under discussion. The recommended treatment of metastatic struma ovarii should contain, in addition to local resection of the extraovarian tumor, total thyroidectomy in conjunction with radioiodine scanning and radioiodine ablation. Case report: A 38 year-old woman had presented with benign struma ovarii 12 years previously. She was referred to our department because of a right ovarian tumor. After confirming the diagnoses of metastatic recurrent benign struma ovarii, we performed debulking surgery with the aim of resecting all tumor masses. The uterus, left adnexa, and pelvic peritoneum were surgically extracted “en bloc”. No macroscopic tumor was left post-operatively. The first post operative 123 I scintography with15 MBq iodine-123 one month post-operatively showed a small but suspicious focus in the front left perivesical pelvic area. In the ventral visual presentation multiple discrete foci, located in right perivesical, supravesical and in the ventral upper abdomen, were seen. We then referred the patient for thyroidectomy and radioiodine ablation. The following periodic follow-ups of the patient did not show any signs of recurrence or progression of the disease. Conclusion: Patient with benign metastatic struma ovarii (also known as Highly differentiated follicular carcinoma of ovarian origin - HDFCO) may affectively be treated with local resection of the extraovarian tumor and subsequent thyroidectomy followed by radioactive iodine ablation.

Struma Ovarii Associated with Pseudo-Meigs’ Syndrome and Elevated Serum CA 125: A Case Report and Literature Review

The association of struma ovarii with Pseudo-Meigs’ syndrome and elevation of CA 125 has been reported in literature. Here we report a 55-year-old with benign struma ovarii who presented with ascites, small left pleural effusion, suspicious left ovarian mass and elevated serum CA 125 level. Repeated cytology tests were negative for malignancy. The radiologic appearance was highly suggestive of an ovarian malignancy and due to her overall state of illness the patient received 3 cycles of chemotherapy. Chemotherapy had no impact on the rate of accumulation of ascites, CA 125 level or the size of the ovarian mass highlighting the need to reconsider the initial diagnosis. Diagnostic left oophorectomy revealed struma ovarii and was followed by resolution of the ascites and normalization of the serum CA 125. No recurrence of the ascites or of the tumor has been observed during the 5 months follow-up. Struma ovarii or other dermoid variants should be considered in the differential diagnosis in patients with ascites, pleural effusions and elevated CA125 level but with negative cytology. Diagnostic laparoscopic oophorectomy should also be considered within the standard protocol for diagnosis of indeterminate adnexal masses.

A Case of Incidental Struma Ovarii Confounded with the Metastasis of Papillary Thyroid Cancer

A focal radioactive iodine uptake in the pelvis of a patient with differentiated thyroid cancer needs differential diagnosis besides bone metastasis. Struma ovarii is a rare monodermal ovarian teratoma composed predominantly of mature thyroid tissue; 5-10% of these tumors are malignant. As diagnosis and surgery of thyroid cancer have increased recently, incidental cases of struma ovarii, after radioactive iodine treatment, were occasionally reported. Rare cases of ovary metastasis of thyroid cancer were also reported. We report a case of benign struma ovarii incidentally found in a patient with papillary thyroid cancer. The patient showed a sus tained high level of thyroglobulin and focal radioactive iodine uptake in the right pelvis, confused with distant metastasis, after total thyroidectomy and radioactive iodine treatment. (Endocrinol Metab 27:227-231, 2012)

Struma ovarii in breast cancer

We described a case of benign struma ovarii associated to bilateral mature cystic ovarian teratoma in an asymptomatic post-menopausal woman with breast cancer. The patient synchronously underwent surgical treatment of breast and ovarian tumors.

Unilateral malignant struma ovarii in a case of bilateral ovarian teratoma with raised CA-125 level: A rare case with treatment dilemmas

Struma ovarii are specialized form of mature ovarian teratoma comprised predominantly of thyroid tissue (>50%). Most of the struma ovarii are benign; rarely can they undergo malignant transformation. Elevated CA-125 levels with benign struma ovarii have been seen in only 5 cases in literature. The association of malignant struma ovarii and high CA-125 levels with pseudo-Meig syndrome has been reported in only 2 cases in English literature. We describe a case of a 46-year-old multigravida who presented with an abdominal mass and raised CA-125 levels. Radiological investigations revealed bilateral cystic adnexal masses with ossified elements on left side suggesting a teratoma. Intraoperative frozen section and final pathology revealed bilateral teratoma with follicular variant of papillary thyroid carcinoma arising in the left ovary. To the best of our knowledge, this is the first case of malignant struma ovarii in combination with bilateral teratoma. The dilemmas related to preoperative diagnoses with elevated CA-125 levels, mimicking an epithelial ovarian neoplasm; intraoperative frozen section consultation; management and follow-up issues in this rare malignancy are discussed.

Bilateral benign non functional struma ovarii with Pseudo-Meigs′ syndrome

Bilateral presentation of benign Struma ovarii is rare and has not been reported frequently in published literature. A 70-year-old postmenopausal female presented with progressive ascites, bilateral pleural effusion and elevated CA-125 levels. The contrast-enhanced computed tomography (CECT) of the abdomen and pelvis revealed a heterogenous mass in the left adnexa. These findings were suspicious for an ovarian malignancy. After surgery the diagnosis of non functional, bilateral benign Struma ovarii was made. Struma ovarii is a specialized ovarian teratoma composed predominantly of mature thyroid tissue. It is associated with pleural effusion and ascites (Pseudo-Meigs' syndrome) in 5% of cases. The combination of struma ovarii and elevated CA-125 levels has been reported infrequently. This is a rare case of bilateral benign struma ovarii associated with Pseudo-Meigs' syndrome and elevated CA-125 levels. Surgical excision of the ovarian masses induced immediate resolution of the ascites and pleural effusion and a reduction of the serum CA-125 level.

Coexistence of struma ovarii with marked ascites and elevated CA-125 levels: case report and literature review

Struma ovarii is a rare form of ovarian neoplasm and consists mainly of thyroid tissue. Ascites has been reported in approximately one-third of all the cases. However, the combination of struma ovarii and elevated CA-125 has rarely been reported. We described a case of benign struma ovarii, presenting with the clinical features of ovarian cancer: large complex pelvic mass, gross ascites and markedly elevated serum CA-125 levels. Surgical excision of the ovarian mass was followed by rapid resolution of the ascites and reduction of the serum CA-125 level. Struma ovarii can mimic ovarian malignancy clinically, when presented with ascites and an elevated CA-125 level.