Malignant struma ovarii: a case report of laparoscopic management

Identifying the Carcinogenic Mechanism of Malignant Struma Ovarii Using Whole-Exome Sequencing and DNA Methylation Analysis

Background: Since malignant struma ovarii is a very rare disease, its carcinogenic mechanism has not been elucidated. Here, we sought to identify the genetic lesions that may have led to the carcinogenesis of a rare case of malignant struma ovarii (follicular carcinoma) with peritoneal dissemination. Methods: DNA was extracted from the paraffin-embedded sections of normal uterine tissues and malignant struma ovarii for genetic analysis. Whole-exome sequencing and DNA methylation analysis were then performed. Results: Germline variants of RECQL4, CNTNAP2, and PRDM2, which are tumor-suppressor genes, were detected by whole-exome sequencing. Somatic uniparental disomy (UPD) was also observed in these three genes. Additionally, the methylation of FRMD6-AS2, SESN3, CYTL1, MIR4429, HIF3A, and ATP1B2, which are associated with tumor growth suppression, was detected by DNA methylation analysis. Conclusions: Somatic UPD and DNA methylation in tumor suppressor genes may be associated with the pathogenesis of malignant struma ovarii. To our knowledge, this is the first report of whole-exome sequencing and DNA methylation analysis in malignant struma ovarii. Genetic and DNA methylation analysis may help elucidate the mechanism of carcinogenesis in rare diseases and guide treatment decisions.

Case Report: Recurrent Malignant Struma Ovarii With Hyperthyroidism and Metastases, A Rare Case Report and Review of the Literature

Background: SO (Struma ovarii) is a rare form of ovarian teratoma which originates from ovarian dermoid cysts. Due to the rarity of this disease, relevant studies might not be sufficiently documented, especially cases with hyperthyroidism and multiple metastases.

Case Presentation: A 40-year-old female patient was admitted to our hospital due to management of early pregnancy along with a recurrent abdominal and pelvic mass. Contrast-enhanced CT images showed an irregular mass (10.7 × 8.6 × 12.8 cm) located in the right side from the hypogastrium to the pelvic cavity and another mass (3.8 × 3.7 cm) in the liver. Laboratory examination showed that CA125 (Carbohydrate Antigen-125) was 118.10 U/mL, Tg (thyroglobulin) was >300 ng/ml, FT4 (free thyroxine) was 22.11 pmol/L, and TSH (thyroid-stimulating hormone) was <0.004 mIU/L. She subsequently underwent liver mass dissection, omentectomy, tumor dissection, peritoneal nodule resection, as well as rectal anterior wall nodule resection. The patient was diagnosed with malignant SO (papillary type) along with multiple metastases. Also, we conducted a literature review based on 290 SO cases from 257 articles.

Conclusion: This study showed that malignant SO might be prone to relapse and metastasize (a metastatic rate of 52.94%) and therefore aggressive management might need to be recommended for malignant SO. Also, laparotomy might need to be recommended for large tumors that cannot be resected by laparoscopic surgery since these tumors might be prone to rupture and thus produce peritoneal implants. Furthermore, Graves’ disease might need to be considered in the differential diagnosis.

Metastatic follicular carcinoma arising from struma ovarii

Struma ovarii (SO) is an uncommon monodermal teratoma predominantly composed of mature thyroid tissue. Approximately 5% of SO are malignant; however, metastases are rare. A single female in her 40s, with a medical history of Graves' disease and bilateral cystectomy 10 years prior for right endometriotic cyst and left SO, presented with an enlarging abdominal mass for 4 months. Ultrasound pelvis showed a 13.8 cm left adnexal heterogeneous solid-cystic mass with internal septations and vascularity. She underwent open left salpingo-oophorectomy and resection of fibrous nodules from the right infundibulo-pelvic ligament and fallopian tube. Histology showed highly differentiated metastatic follicular carcinoma. She subsequently underwent total thyroidectomy, total hysterectomy, right salpingo-oophorectomy, tumour debulking and omentectomy followed by radioactive iodine treatment. Four-year follow-up did not show tumour recurrence or metastases. Due to its rarity, there are no well-established guidelines for the management and follow-up of metastatic follicular carcinoma arising from SO.

Malignant struma ovarii: From case to analysis

AIM

To evaluate the clinico-pathologic features, treatment options, prognostic factors, and survival outcomes of malignant struma ovarii based on a systematic literature review in association with our case study.

METHODS

A systematic review of the medical literature was performed to identify articles about malignant struma ovarii from January 1983 until July 2020. We evaluated 178 cases.

RESULTS

The 5-year progression-free survival (PFS) and overall survival (OS) of the entire cohort was 72.5% and 91%, respectively. In univariate analysis, younger age (<43 years), whole strumal cyst diameter >95 mm, presence of a histologic type other than papillary classic-type thyroid carcinoma within the tumor and lymphovascular space invasion were related to poor PFS. Patients who received radioactive iodine ablation (RIA) before the treatment failure had significantly higher PFS than those who did not receive RIA (94.9% vs. 64.8%, p = 0.041, respectively). In univariate analysis, PFS was significantly higher in patients who underwent gynecologic surgery followed by thyroidectomy and RIA compared with those who had surgical treatment only (94.5% vs. 64.3%, p = 0.05, respectively). However, this result could not be identified as an independent prognostic factor in multivariate analysis (p = 0.207). Younger age and absence of capsular involvement were related to significantly increased OS. Histologic type was the only independent prognostic factor for PFS (hazard ratio: 3.30, 95% confidence interval: 1.122-9.748; p = 0.030) CONCLUSION: The most common histologic subtype was the papillary classic type. The presence of a histologic type other than the classic papillary thyroid carcinoma within the tumor was an independent adverse prognostic factor.

Treatment and follow-up in an asymptomatic malignant struma ovarii: A case report

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Struma ovarii is a rare and asymptomatic ovarian tumor and is usually diagnosed by the pathologist.

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Struma ovarii malignancy is from thyroid origin and usually associated with thyroid tumors.

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Management and follow up is not well established.

Introduction

Struma ovarii is a rare ovarian tumor, representing 0.5-1% of all ovarian tumors and 2–5% of ovarian teratomas. It is defined as an ovarian teratoma composed mostly of thyroid tissue. The symptoms are nonspecific, and the imaging studies can help in characterize the mass; however, the definitive diagnosis is usually given by the Pathologist. Classically, the treatment is the surgical resection of the ovarian mass, however there is no consensus regarding the follow-up.

Presentation of case

An asymptomatic malignant struma ovarii in a 43 year-old patient is presented. The diagnosis was postoperatively following a laparoscopic adnexectomy due to an apparently benign ovarian teratoma. The histopathology results revealed a mature ovarian cystic teratoma with papillary carcinoma with immunohistochemical characteristics suggesting a thyroid origin. Seeing that there was no thyroid affectation or metastatic disease, we decided a conservative management. A yearly follow-up with CT scan and tumor markers was performed. The endocrinologist also performed annual controls with thyroid ultrasound and serum tests. The patient has remained asymptomatic during these last four years.

Discussion

There is little evidence in literature on the conservative management in cases with evidence of malignancy. If fertility preservation is desired, an unilateral oophorectomy could be performed, along with levels of serum thyroglobulin as a marker of relapse. Other authors claim for aggressive ovarian cancer surgery followed by a total thyroidectomy. There is still no established management for struma ovarii patients and the choice for a conservative or radical approach depends only on the professional decision.

An Unusual Case of Malignant Struma Ovarii Causing Thyrotoxicosis

BACKGROUND

Struma ovarii (SO) is a specialized monodermal teratoma predominantly composed of mature thyroid tissue, accounting for approximately 5% of all ovarian teratomas. Thyrotoxicosis is seen in about 8% of patients with SO. Most SO cases are benign with only 5-10% being malignant, and malignant SO causing thyrotoxicosis is very uncommon.

CASE

A 64-year-old woman had been diagnosed with thyrotoxicosis 2 years previously. The thyroid gland was palpable with a micronodular texture, and the patient was euthyroid under carbimazole. She presented with abdominal pain and progressive enlargement of the abdomen over a 2-month period. An abdominal ultrasonography revealed a pelvic mass and a large fluid collection. Additional imaging confirmed the presence of a complex right ovarian mass measuring 13 cm. The patient underwent a total abdominal hysterectomy and bilateral salpingo-oophorectomy, omentectomy and appendectomy. The histological examination revealed the presence of 'follicular thyroid-type carcinoma arising in an SO of the right ovary, with metastatic infiltration in the tissue fragments from the pouch of Douglas'. Antithyroid treatment was discontinued 1 month after surgery in light of the pathology result. During the 4-year follow-up, the patient remained euthyroid.

CONCLUSION

There has been controversy about the management of malignant SO, which is a rare entity. Malignant SO causing thyrotoxicosis is even more uncommon. As clinical signs are nonspecific, other causes of thyrotoxicosis must be considered for a differential diagnosis. Our case is one of the very few cases ever reported.

Papillary Carcinoma in Mature Teratoma of Struma Ovarii

A 62-year-old woman had the incidental finding of malignant struma ovarii following surgery for primary endometrial carcinoma. The patient had vaginal bleeding for one year. After gynecological examination, she was referred for fractional curettage which revealed endometrial cancer. The patient underwent total hysterectomy and bilateral adnexectomy. Histological findings of uterus confirm the presence of endometrial cancer. The left ovary showed the presence of mature teratoma with dominant thyroid tissue and focus of papillary carcinoma. Postoperatively she underwent radiation therapy and 3 months later total thyroidectomy. The stimulated thyroglobulin level was detectable. She was referred for radioiodine ablation with a dose of 3,7GBq 131-J. Post therapy scintigraphy shows pathological uptake of 131-J only in the neck. The patient continued treatment of endometrial cancer (external beam therapy). She is currently on suppressive hormone L-thyroxin therapy. Two months later hormonal status, thyroglobulin and antithyroglobulin antibodies showed optimal range.

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

INTRODUCTION

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.

METHODS

We retrospectively reviewed cases of benign struma ovarii treated at KK Women's and Children's Hospital, Singapore, between January 2000 and May 2011.

RESULTS

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.

CONCLUSION

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.

Optimal surgical management of well-differentiated thyroid cancer arising in struma ovarii: a series of 4 patients and a review of 53 reported cases

BACKGROUND

Well-differentiated thyroid cancer arising in struma ovarii is rare. The optimal management of this entity remains undefined. Unilateral cystectomy, unilateral salpingo-oophorectomy (USO), or total abdominal hysterectomy with bilateral salpingo-oophorectomy (TAH/BSO), in addition to total thyroidectomy and radioactive iodine (RAI) ablation, have been employed by various groups. We hypothesized that in patients with thyroid cancer arising within struma ovarii, pelvic surgery alone would be sufficient, provided there is no evidence of gross extra-ovarian extension.

METHODS

We review a series of four patients from a single institution and 53 cases from the literature, comparing the extent of treatment and outcomes. Our literature review focused on low-risk patients with struma ovarii confined to the ovary, without evidence of gross extra-ovarian spread or distant metastases. Cumulative recurrence rate was determined by using the Kaplan-Meier method.

RESULTS

We report the treatment of four patients with well-differentiated thyroid cancer arising within struma ovarii. Patients underwent USO, BSO, or TAH/BSO. One patient underwent prophylactic total thyroidectomy in anticipation of RAI treatment, and was found to have a synchronous papillary thyroid carcinoma. All patients clinically remain without evidence of disease at a median follow-up of 9 (range 0.8-13) years. Treatment strategies in 53 cases from a review of the literature varied. The pooled cumulative recurrence rate of 57 cases with struma ovarii confined to the ovary was 7.5% at 25 years.

CONCLUSIONS

Thyroid cancer arising in struma ovarii is rare. Controversy exists regarding the extent of pelvic resection and management of the thyroid gland. In our series of four patients, all patients are alive without evidence of disease, and the 25-year recurrence rate of 57 cases was low (7.5%), despite a variety of approaches to surgical resection and adjuvant treatment. Extensive pelvic surgery and prophylactic total thyroidectomy to facilitate RAI therapy may be reserved for patients with gross extra-ovarian extension or distant metastases.

Laparoscopic excision of malignant struma ovarii and 1 year follow-up without further treatment

OBJECTIVE

To report the case of a patient with malignant struma ovarii, which was excised endoscopically.

DESIGN

Case study and literature review.

SETTING

Hospital outpatient clinic with subsequent hospitalization.

PATIENT(S)

A 40-year-old gravida 5, para 3 with an incidental ultrasonographic finding of a solid right adnexal mass.

INTERVENTION(S)

Endoscopic resection and 1-year follow-up.

MAIN OUTCOME MEASURE(S)

Treatment options and differential diagnosis.

RESULT(S)

The tumor was excised endoscopically.

CONCLUSION(S)

Malignant struma ovarii is a very rare, highly specialized form of mature ovarian teratoma, in which thyroid tissue is the predominant element. Because of the nonspecific symptoms and a lack of specific features in imaging studies, preoperative diagnosis is very difficult, and there is no standard treatment. Struma ovarii, which is potentially malignant, should be included in the differential diagnosis of an ovarian mass with cystic, solid, or mixed cystic and solid structure. Standardized treatment of malignant struma ovarii still remains undefined; currently the laparoscopic removal of the tumor may be a treatment option, and thyroidectomy and radiotherapy with 131I should be offered.

Malignant struma ovarii: a case report

We present a case of a 40-yr-old woman diagnosed with a primary malignant struma ovarii. The patient was admitted with the complaint of pelvic pain and a large pelvic mass in the mid-portion of lower abdomen on gynecological examination. Pre-operative tumor markers and routine biochemistry were unremarkable. She was treated with total abdominal hysterectomy and right salpingo-oopherectomy. Post-operatively, she was diagnosed with a malignant struma ovarii through the usage of histopathological criteria similar to the guidelines for primary thyroid gland disease. The patient was subsequently performed left salpingo-oopherectomy and retroperitoneal pelvic lympadenectomy for re-staging. Although, left ovary and lymph nodes were histopathologically normal, she was offered thyroidectomy but she refused to accept the offer. Thyroglobulin level was monitored in the post-operative period. She is free of the disease for 18 months.

Typical thyroid-type carcinoma arising in struma ovarii: a report of 4 cases and review of the literature

Struma ovarii has elicited considerable interest because of its many unique features since Ludwig Pick first elucidated its relationship to teratoma in the early part of the 20th century. In this article, we report 3 cases of papillary and 1 of follicular thyroid carcinoma; 2 of these cases were associated with mature cystic teratoma. Metastases occurred in 2 patients, and 1 died of neoplasm. In regard to the occurrence of thyroid-type carcinoma in struma ovarii, precise terminology should be used, and the expression malignant struma ovarii was avoided as a diagnostic term. Upon review of the literature, papillary carcinoma and follicular carcinoma are the most frequent types of malignancy to occur in ovarian struma; other forms of thyroid carcinoma occur only rarely. The diagnostic criteria for cases of papillary carcinoma are similar to those described in the cervical thyroid gland and are based primarily on nuclear and architectural features. In reference to follicular carcinoma, invasion into the surrounding ovarian tissue, vascular invasion, or metastasis is evidence of malignancy. Histological malignancy in a struma does not necessarily equate with biological malignancy, and the majority of thyroid-type carcinomas do not spread beyond the ovary. Occasionally, metastases of ovarian struma have an innocuous histological appearance, and such cases are referred to as highly differentiated follicular carcinoma of ovarian origin (HDFCO). Because its histological appearance resembles that of nonneoplastic thyroid, HDFCO characteristically cannot be diagnosed until the neoplasm spreads beyond the ovary. In this article, we apply the term typical thyroid carcinoma to those forms of thyroid malignancy arising in ovarian struma that closely resemble the types described in the cervical thyroid gland to distinguish them from HDFCO. Typical follicular carcinoma is more aggressive than the somewhat more common papillary carcinoma, and HDFCO is the least aggressive of these tumor types. Cases of thyroid-type carcinoma arising in the ovary sometimes lack evidence of preexisting struma. The more aggressive thyroid-type neoplasms can arise in thyroid tissue within a mature cystic teratoma, or they may overgrow and replace the struma. Primary thyroid-type carcinoma must be distinguished from rare instances of ovarian metastases that originate in the cervical thyroid gland and the less differentiated forms from other ovarian neoplasms such as clear cell adenocarcinoma and tumors with an oxyphilic appearance. In the differential diagnosis with other ovarian neoplasms, cases of thyroid-type carcinoma associated with strumal carcinoid should not be diagnosed as malignant strumal carcinoid because the latter diagnosis might lead to suboptimal therapy.

Malignant Struma Ovarii – A Case Report and Review of the Literature

BACKGROUND

Struma ovarii is a rare monodermal ovarian teratoma composed predominantly of mature thyroid tissue. Of these cases, 5-8% are clinically hyperthyroid and 5-10% of these tumors are malignant.

CASE REPORT

A 53-year-old female presented with a 19 x 5 x 5 cm pelvic mass that was treated with bilateral salpingo-oophorectomy, pelvic and para-aortic lymph node sampling, omentectomy and appendectomy and staging for an ovarian tumor. There was no evidence of distant metastases or lymph node invasion. Re-evaluation of the patient after surgery revealed that she was clinically euthyroid and there was no thyroid malignancy. Histopathology revealed papillary thyroid carcinoma arising in struma ovarii (malignant struma ovarii).

CONCLUSION

Malignant struma ovarii is a very rare malignant ovarian teratoma. In young patients unilateral oophorectomy and complete surgical staging should be considered when the tumor is confined to the one ovary (stage Ia). Long-term follow-up for the detection of metastases or tumor recurrence by serial serum thyroglobulin and (131)I scan or positron emission tomography/computed tomography may be required in selected patients with this rare tumor.

Goitre ovarien: une forme particulière de tératome de l'ovaire

Struma ovarii, a rare form of ovarian tumor, represents less than 3% of ovarian teratomas. The peak frequency occurs during the fifth decade of life. Diagnosis is usually a surprise of pelvic ultrasound or histological analysis. Surgery is the main mode of treatment and prognosis is excellent. Struma ovarii can be associated with thyroid biology abnormalities, or exceptionally become malignant, and thus managed as a thyroid cancer.

Metastatic Struma Ovarii: The Burden of Truth

A 58-year-old woman was found to have metastatic thyroid cancer in her liver. This was identified when she was investigated for upper abdominal pain and underwent biopsy of hepatic lesions. She had no palpable thyroid nodule and had a normal ultrasound of the thyroid. Previously, both ovaries had been removed because of tumors. The pathologic findings in one of the ovaries could not be recovered because the procedure was more than 40 years ago, when the patient was a teenager. By a process of elimination, a diagnosis of metastatic struma ovarii was established. Treatment of metastatic thyroid cancer from struma ovarii, including removal of the normal thyroid and administration of I-131, is presented.

Malignant struma ovarii: A case report

Malignant struma ovarii is a rare form of the ovarian germ cell tumors. Hence, diagnosis and management of malignant struma ovarii have not been clearly defined. We present the case of a 34-year-old woman with papillary carcinoma arising in struma ovarii. The malignant component of this tumor was detected after laparoscopic removal, and a re-staging operation was performed afterwards. There was no evidence of clinical malignancy or metastases. In this paper, clinical features, treatment guidelines, diagnostic features, and immunohistochemical characteristics of this tumor are reviewed.

Malignant struma ovarii mimic clear cell carcinoma

INTRODUCTION

Struma ovarii are quite unusual lesions that represent less than 3% of all teratomas and its malignant transformation is very uncommon. The clinical manifestations are characteristic of pelvic tumor and the hormonal metabolism is not usually modified. Radiography, employing ultrasound procedures, is the most commonly used pre-surgical detection method but only histological examination makes the diagnosis. The malignance recognition by pathological study not always is easy; in this sense, it requires an exhaustive sampling of the lesion, being specially carefully in some aspects related with malignant transformation such as extending beyond the capsula and involving peripheral tissues. A thyroidal differentiation must be confirmed by immunohistochemical study and other local processes with similar histology should be ruled out. Given the exceptional character of malignant forms, there does not appear to be unanimous agreement on a standard therapy with a somewhat uncertain prognosis.

CASE REPORT

We show a case of a 22-year-old patient with an ovarian tumor that was discovered by ultrasound examination and surgically removed. The histologic study revealed struma ovarii with malignant transformation towards follicular carcinoma and unlike previously published cases, had a prevalence of clear cells. The patient was submitted to a second surgical staging intervention, with conservative surgery and follow-up controls being considered given that was a young woman with a desire to have children. Laparoscopy was employed as the best method capable to facilitate shorter convalescence.

OUTCOME

Clinical and analytical controls, measuring thyroglobulin levels, has been satisfactory up to the present.