Clinical characteristics and survival outcomes of malignant struma ovarii confined to the ovary.

BACKGROUND: Malignant struma ovarii (MSO) is a unique type of ovarian malignancy that data on the survival outcome is limited and management strategy remains controversial due to its extreme rarity. METHODS: To investigate the clinical characteristics and treatment options in patients with MSO confined to the ovary, while also evaluating the recurrent-free survival (RFS) and overall survival (OS) rate in this population, a retrospective study was conducted. One hundred twenty-five cases of MSO confined to the ovary were enrolled and their clinical characteristics, treatment strategies, and results of follow-up were analyzed. OS and RFS were assessed by Kaplan-Meier analyses and Cox regression models. RESULTS: The most common pathological subtype in this cohort was papillary carcinoma (44.8%). Other reported subtypes, in order of prevalence, were follicular variant of papillary carcinoma, follicular carcinoma, and mixed follicular-papillary carcinoma. Surgical treatment options varied in this cohort that 8.0% of the patients received ovarian cystectomy, 33.6% underwent unilateral salpingo-oophorectomy (USO), 5.6% received bilateral salpingo-oophorectomy (BSO), 21.6% received total abdominal hysterectomy with BSO (TAH/BSO), and 17.6% were treated with debulking surgery; 20.0% of them received radioiodine therapy (RAI). Twenty-seven patients experienced recurrence with a median RFS of 14.0 years (95% confidence interval [CI], 9.5-18.5). The 5-year and 10-year recurrent rate were 27.1, 35.2%, respectively. Eight patients died during follow-up, with five attributed to MSO; the 5-year, 10-year, and 20-year OS rate was 95.3, 88.7 and 88.7%, respectively. However, the univariate and multivariate Cox regression showed no potential risk factor for RFS and OS. CONCLUSION: Patients with MSO confined to the ovary had an excellent survival outcome, despite varied treatment strategies, and the recurrent rate was relatively high. We recommend USO as the preferred surgical option in this population since more aggressive surgery does not improve outcomes and the benefits of RAI are uncertain.

Malignant struma ovarii: surgical, histopathological and survival outcomes for thyroid-type carcinoma of struma ovarii with recommendations for standardising multi-modal management. A retrospective case series sharing the experience of a single institution over 10 years.

PURPOSE: Struma ovarii is rare, accounting for 0.3-1% of ovarian tumours. Malignant transformation may occur, most often into papillary thyroid carcinoma. There is a paucity of data pertaining to malignant struma ovarii. This paper shares a decade of experience of a single institution in the management of this rare ovarian cancer, exploring the characteristics of this tumour and suggesting a standardised approach to treatment and follow-up. METHODS: All patients treated for malignant struma ovarii within a large cancer centre over one decade were identified and data collected retrospectively on presentation, diagnosis, management, follow-up and survival outcomes. A literature review was also undertaken. RESULTS: Eleven cases of malignant struma ovarii were managed in the Oxford Cancer Centre between 2010 and 2019, 6 of which were of papillary thyroid carcinoma sub-type. No cases were correctly diagnosed pre-operatively. All patients had stage I disease and were managed surgically-but with variation in radicality. Patients identified as high-risk based on final histopathology underwent additional thyroidectomy and radio-active iodine ablation therapy. One case of synchronous malignancy of the thyroid gland proper was identified. No disease recurrence occurred. CONCLUSION: Malignant struma ovarii present a diagnostic challenge. Multi-disciplinary team (MDT) input is essential. Unilateral salpingo-oophrectomy may be adequate if stage I; reserving more radical surgery for advanced disease. Histopathological risk-stratification should be used to identify those most likely to benefit from adjuvant thyroid-targeting therapies. Patients require follow-up, anticipating an overall good prognosis.

Malignant struma ovarii: an analysis of 88 cases, including 27 with extraovarian spread.

Struma ovarii that display extraovarian spread or later recurrence is exceedingly rare. Among 88 patients with "malignant" struma ovarii followed for prolonged periods, several features helped to predict the adverse clinical course. Adhesions (graded 2 to 4+), peritoneal fluid (> or =1 L) or ovarian serosal rent were worrisome features, occurring in 74% of 27 biologically malignant tumors but only 10% of 61 clinically benign tumors. The size of the strumal component rather than the overall size of the ovarian teratoma also had some predictive value. Tumors with a strumal component < or =6 cm recurred rarely (7%), whereas 33% of the consult and 88% of the literature cases > or =12 cm were clinically malignant. Except for a papillary pattern or poorly differentiated cancer, no microscopic feature reliably predicted the clinical outcome, including those typically associated with malignancy in primary thyroid tumors. Among the consult cases, 7% with histologic follicular adenomas and 29% with papillary carcinomas were clinically malignant. Unequivocal vascular invasion was rare, precluding assessment of its effect. Optically clear nuclei, when extensive, were useful to diagnose papillary carcinoma, but were present nevertheless in smaller numbers in both macrofollicular and microfollicular adenomas. Eight tumors confined initially to the ovary (stage 1) recurred. Papillary carcinomas recurred earlier (average 4 y) than follicular adenomatous neoplasms (average 11 y, range: 1-29 y). Overall, the survival rate for all patients was 89% at 10 years and 84% at 25 years, indicating the need for routine long-term follow-up.

[Thyroid carcinoma on struma ovarii: Diagnosis and treatment]. / Cancer thyroïdien sur struma ovarii : généralités et principes de prise en charge.

Thyroid carcinoma on struma ovarii (TCSO) is a rare ovarian tumour, derivate from monodermic teratomas. It represents about 0.01% of overall ovarian tumours and 5 to 10% of struma ovarii. The diagnosis is histologic and retrospective after pelvic surgery; radiographic imaging being unspecific. Because of its rarity, the treatment of TCSO is not consensual and should be validated in multidisciplinary team involved in rare ovarian carcinoma. The first treatment is a surgical removal, with a laparoscopic approach. A fertility-conservative surgery is recommended for young women. If the tumour is unresectable and/or with metastatic spread, an adjuvant iodine 131 treatment might be proposed after thyroidectomy. Recurrence of TCSO should be taken care of as a thyroid carcinoma with tyrosine kinase inhibitor in case of progressive distant relapse, refractory to iodine 131 treatment. If the recurrence is localised, a complete surgery is the preferred option. There is no gold standard for the follow up.

Malignant struma ovarii: a population-level analysis of a large series of 68 patients.

BACKGROUND: Malignant struma ovarii (MSO) is a germ cell tumor of the ovary histologically identical to differentiated thyroid cancers. There is a paucity of data on this neoplasm, with fewer than 200 reported cases. The primary objective of this study was to examine the survival rate of women diagnosed with MSO using data from the Surveillance, Epidemiology, and End RESULTS (SEER) database. Secondary objectives were to describe the demographic, clinical, pathologic, and treatment characteristics of this population. METHODS: A retrospective analysis was performed of prospectively collected cancer registry data. A total of 68 patients were identified in the SEER database, 1973-2011. The chi-square test, Student's t-test, and Kaplan-Meier curves were employed for data analyses. RESULTS: All 68 patients were females with a mean age at diagnosis of 43.0 years. Nearly 33% underwent unilateral oophorectomy, 28.6% bilateral oophorectomy, and 28.6% oophorectomy and omentectomy, and 4.8% were treated with debulking surgery. Pelvic radiation was administered to 12.3% of patients. The mean tumor size was 52.8 mm; 80% of malignant struma ovarii were SEER staged as local. Overall survival rates at 5, 10, and 20 years were 96.7%, 94.3%, and 84.9% respectively. Among the patients, there were six deaths recorded; only one was attributed to MSO. Six individuals (8.8%) had a concomitant or subsequent diagnosis of thyroid cancer. Four patients underwent total thyroidectomy, three patients had radioactive iodine, and one patient underwent external beam radiation. Two thirds of thyroid cancers extended outside the thyroid gland. All six patients with thyroid cancer were alive at the end of follow-up. CONCLUSIONS: It was observed that patients with malignant struma ovarii had an excellent disease-specific survival rate, regardless of the management strategy employed. However, MSO patients had a high risk for developing aggressive thyroid cancers. Therefore, MSO patients may benefit from routine thyroid imaging once the diagnosis of MSO is established.