Papillary thyroid cancer arising in struma ovarii

A rare case of retroperitoneal teratoma with evidence of papillary thyroid carcinoma: a case report

BACKGROUND

Teratomas are germ cell tumors composed of somatic tissues from up to three germ layers. Primary retroperitoneal teratomas usually develop during childhood and are uncommon in adults and in the retroperitoneal space. While there are only a few cases of retroperitoneal thyroid tissue, we report a unique case of a retroperitoneal papillary thyroid carcinoma.

CASE PRESENTATION

A 41-year-old woman presented in our institution due to intermitted unspecific abdominal pain. Magnetic resonance imaging detected a multi-cystic solid retroperitoneal mass ventral to the psoas muscle and the left iliac artery. After surgical removal of the retroperitoneal mass, histology sections of the specimen indicated evidence of papillary thyroid carcinoma cells. A staging computed tomography scan of the body showed no further manifestations. To reduce the risk of recurrence, total thyroidectomy was performed followed by radioiodine therapy with lifelong hormone substitution.

CONCLUSIONS

Primary retroperitoneal teratoma with evidence of papillary thyroid carcinoma is a rare condition. Preoperative diagnosis is difficult due to its non-specific clinical manifestation and lack of specific radiologic findings. Histopathology analysis is necessary for diagnosis. Although surgery is considered the first line treatment, there is still discussion about the extent of resection and the need for total thyroidectomy with adjuvant radioiodine therapy.

Clinical Manifestations of Malignant Struma Ovarii: A Retrospective Case Series in a Tertiary Hospital in Korea

BACKGRUOUND

Malignant struma ovarii (MSO) is a very rare disease in which thyroid cancer originates from the ovary. Because it is rare for endocrinologists to encounter patients with MSO, endocrinologists may have a limited understanding of the disease. Therefore, we analyzed and introduced its incidence and clinical course in a tertiary hospital in Korea.

METHODS

We retrospectively investigated the clinical data of 170 patients who underwent surgery for struma ovarii at the Department of Obstetrics and Gynecology of Samsung Medical Center from 1994 to May 2023.

RESULTS

Among 170 patients with struma ovarii, 15 (8.8%) were diagnosed with MSO. The median age of patients with MSO was 48 years (range, 30 to 74), and the median tumor size was 3.3 cm (range, 0.5 to 11.0). Papillary thyroid carcinoma (46.7%) was the most common subtypes followed by follicular thyroid carcinoma (26.7%). All patients were diagnosed after surgery, with no predictions from preoperative imaging. The surgical extent of gynecological surgery was variable. Four patients (26.7%) underwent thyroidectomy for thyroid cancer, while one underwent total thyroidectomy and radioactive iodine therapy for MSO with peritoneal metastasis. Except for one patient who underwent hemithyroidectomy, thyroid stimulating hormone suppression therapy was performed in four patients. Only 53% of MSO patients were consulted by an endocrinologist. With a median follow-up period of 33 months (range, 4 to 156), 11 patients remained disease-free, one experienced progression with peritoneal seeding, and the remaining one was in treatment. There have been no recurrences or deaths due to MSO.

CONCLUSION

An endocrinologist should be involved in establishing a therapeutic plan for MSO, for which the overall prognosis is generally favorable.

Presentation and treatment of two cases of malignant struma ovarii

BACKGROUND

Malignant Struma Ovarii (MSO) is a rare type of germ cell tumour which is diagnosed postoperatively on surgical pathology specimens by the presence of differentiated thyroid cancer in mature cystic teratomas in the ovaries. Treatment and follow-up procedures are not clearly established due to the paucity of MSO cases. CASE 1: A 44-year-old multiparous female presented with an irregular period. Ultrasound showed a left ovarian lesion mostly a dermoid cyst, however, CT showed a 3.8 × 2.7 × 4 cm complex cystic lesion with thick septation and enhancing soft tissue component. Laparoscopic left salpingo-oophorectomy was performed and histopathology showed a follicular variant of papillary thyroid carcinoma arising in a mature cystic teratoma. Peritoneal cytology was positive for malignancy. A thyroid function test was normal before surgery. Total thyroidectomy was performed followed by radioactive (RAI) iodine therapy. Later, a total laparoscopic hysterectomy and right salpingo-oophorectomy were performed. There is no evidence of recurrent disease during the 26-months follow-up. CASE 2: A 46-year-old single female presented with left lower abdominal pain that had persisted for 2 months. Imaging revealed an 8 × 9 × 9.5 cm left ovarian mass. Laparoscopic left salpingo-oophorectomy was performed and histopathology showed mature cystic teratoma with small papillary thyroid cancer. CT showed no evidence of metastatic disease. Later, the patient had a total thyroidectomy followed by radioactive (RAI) iodine therapy. She was started on thyroxine and later had total abdominal hysterectomy and right salpingo-oophorectomy.

CONCLUSION

MSO is a very rare tumour. Preoperative diagnosis is very difficult because of the nonspecific symptoms and the lack of specific features in imaging studies. Also, there is no consensus on the optimal treatment of women with MSO. Our two cases add to the limited number of MSO cases.

An unusual case of three concomitant primary solid cancers with unique histopathological characteristics

INTRODUCTION AND IMPORTANCE

Struma Ovarii is a rare type of monodermal teratoma with at least 50 % of its mass being thyroid tissue. They make up <1 % of all ovarian tumours and 3 to 5 % of all ovarian teratomas. These tumours are usually benign but malignant transformation is seen in <5 % of cases.

CASE PRESENTATION

We present the case of a 45-year-old lady with three synchronous primary cancers on a background of Struma Ovarii; primary lung adenocarcinoma, papillary thyroid carcinoma and ovarian teratoma. Over the course of 18 months, this lady underwent full pelvic clearance of malignant Struma Ovarii and lymph nodes, total thyroidectomy, and an anatomical lung resection.

CLINICAL DISCUSSION

This case represents an incredibly rare condition of Struma Ovarii for which there is no firm management consensus. Furthermore, the uniqueness of three separate primaries has to the best of our knowledge not previously been reported in the literature.

CONCLUSION

This reinforces the notion that in select patients, radical management with curative intent is entirely possible but requires complete multi-disciplinary and multi-modal sub-specialty collaboration.

Unexpected finding: Papillary thyroid carcinoma arising in a mature ovarian teratoma - A case report and literature review

INTRODUCTION AND IMPORTANCE

Malignant transformation within mature cystic teratomas is a rare occurrence, with an estimated risk ranging from 0.17 % to 2 %. Squamous cell carcinoma is the most common malignancy associated with this condition, while papillary thyroid carcinoma rarely presents within ovarian teratomas. This transformation predominantly affects postmenopausal women but can, albeit rarely, manifest in younger women.

CASE PRESENTATION

We present a case of a 37-year-old woman who was incidentally found to have a right ovarian cyst measuring 20 × 20 × 10 mm during a cesarean section, displaying characteristic features of a teratoma. Histological examination confirmed the presence of papillary thyroid carcinoma originating within the ovarian mature cystic teratoma. Immunohistochemical analysis demonstrated positive staining for specific thyroid differentiation markers, including TTF1 and Thyroglobulin. The patient was in good health otherwise, with normal clinical and radiological evaluations of the thyroid, and no additional treatment was administered. Currently, seven years after surgery, the patient remains free of recurrence.

DISCUSSION/CONCLUSION

Given the rarity of this condition, established treatment protocols are lacking, and its histogenesis remains uncertain. To advance our understanding of pathogenesis, prognosis, and therapeutic strategies for this malignant transformation, the publication of additional cases with similar presentations would be highly valuable.

Incidence, clinical characteristics, and survival outcomes of ovarian strumal diseases: a retrospective cohort study

BACKGROUND

Struma ovarii (SO) is a rare tumor and may transform into ovarian strumal carcinoid (OSC) and/or malignant struma ovarii (MSO), but the incidence, clinical characteristics, and survival outcomes have not been well defined.

METHODS

We conducted a retrospective study of patients with ovarian strumal diseases treated in the our hospital between 1980 and 2022. Subgroup analyses of SO, OSC, and MSO were subsequently performed.

RESULTS

A total of 275 cases (2.14%) were identified in a cohort of 12,864 patients with ovarian teratomas, where SO, OSC, and MSO accounted for 83.3%, 12.0%, and 4.7% of cases, respectively. There were no significant differences in age, tumor sizes, elevated tumor markers, and ascites among the three subgroups. At initial treatment, all patients with SO or OSC had FIGO stage I disease except one SO patient presenting metastatic disease, ten patients had MSO confined to the ovary, whereas other three patients had metastatic diseases. Two patients with SO respectively relapsed at peritoneum and anterior mesorectum, while none of the OSC patients presented tumor recurrence or death despite different surgical procedures employed. The 5-year recurrence-free survival rate was 88.9%, and only one death occurred at 9.5 years after diagnosis in patients with MSO. Radioiodine therapy showed satisfactory therapeutic efficacy, but these patients showed poor responses to the chemotherapy.

CONCLUSION

2.14% of ovarian teratoma could be classified as SO, of which 12.0% and 4.7% of SO may transform into OSC and MSO, repsectively. The survival outcomes were excellent even after SO transformed into OSC or MSO.

SYNOPSIS

SO occupied 2.14% of ovarian teratoma, where 12.0% and 4.7% of SO may transform into OSC and MSO, respectively, and had excellent survival outcomes.

Mature cystic teratoma of the ovary with malignant transformation of tall cell subtype of papillary thyroid carcinoma

Malignancies rarely occur in somatic parts of mature cystic teratoma of the ovary. Squamous cell carcinoma is the most common form of cancer that can develop in mature cystic teratoma. Other less frequent malignancies include melanoma, sarcoma, carcinoid, and germ cell neoplasms. Only three cases have been reported as papillary thyroid carcinoma arising in struma ovarii. We present a unique case of a 31-year-old female patient who presented with a left ovarian cyst and underwent conservative surgical management in the form of cystectomy. Histopathological examination confirmed the diagnosis of a tall cell subtype of papillary thyroid carcinoma arising from a small focus of thyroid tissue in a mature cystic teratoma of the ovary. The patient was followed up for 60 months with an uneventful clinical course. For a better understanding of such rare cancers, collaborative retrospective studies on large databases with other medical centers are required.

Papillary thyroid carcinoma in struma ovarii: management after surgery

A woman in her 40s presented with a 3-month history of lower abdominal pain and intermenstrual bleeding. Ultrasound of the pelvis disclosed a 4 cm left adnexal mass. An MRI of the pelvis revealed a 2.2×3.6×2.4 cm solid, enhancing left ovarian mass. Due to high suspicion for malignancy, she underwent laparoscopic left salpingo-oophorectomy and resection of the tumour. Histopathology revealed papillary thyroid carcinoma in the background of struma ovarii as confirmed by thyroglobulin and thyroid transcription factor-1 positivity on immunohistochemistry. BRAF mutation analysis was negative. An ultrasound of the thyroid gland showed two low-risk nodules. An iodine-123 whole-body scan showed normal uptake in the thyroid gland. Thyroid-stimulating hormone (TSH) was 1.070 mcIU/mL (0.450-4.500), and thyroglobulin was 6.8 ng/mL (1.5-38.5). We risk-stratified this patient as low risk for recurrence. Risk stratification of malignant struma ovarii is essential to determine suitable thyroid targeting adjuvant therapy and reduce the risk of recurrence.

Metastatic malignant struma ovarii: a case report and review of the literature on the management of malignant struma ovarii

OBJECTIVES

To present a case of metastatic struma ovarii, to review the literature on malignant struma ovarii and to discuss the management in locoregional and metastatic disease.

METHODS

We present a case of an 82-year-old patient with a malignant struma ovarii and liver metastasis. The patient was treated with pelvic surgery, total thyroidectomy, radioactive iodine therapy and TSH suppression therapy with levothyroxine. We performed a PubMed search for case reports of metastatic struma ovarii.

RESULTS

43 cases of metastatic struma ovarii were identified. 53.5% of patients presented with metastatic disease at diagnosis. Mean time to development of metastasis was 6.9 years in the group with initial locoregional disease. First-line treatment was pelvic surgery in all patients. Thyroidectomy was performed in 83.7% of patients, subsequent radioactive iodine therapy in 79.1%, followed by TSH suppression therapy in 46.5% of patients. Mean time of follow-up after diagnosis of metastases was 3.6 years, ranging from 0.5 to 24 years. At the end of the follow-up, 51.1% of patients were free of disease, 34.9% were alive with disease, 7.0% died of disease and 7.0% were lost to follow-up.

CONCLUSION

The majority of patients with metastatic struma ovarii were treated with pelvic surgery, total thyroidectomy and radioactive iodine therapy. Suppression of TSH with levothyroxine was given in less than half of the patients. In non-metastatic setting, the same approach could be considered depending on the patient profile.

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.

Struma ovarii and peritoneal strumosis during pregnancy

Background

Struma ovarii is a special type of ovarian dermoid cyst and accounts for approximately 2–3 % of all dermoid tumours. Benign struma ovarii may manifest as distant metastasis, called peritoneal strumosis, which makes it biologically similar to malignancy, and has been reported in limited cases but never discovered during pregnancy.

Case presentation

We report a patient with a history of right struma ovarii cystectomy. During pregnancy, pelvic masses with non-specific clinical presentation were found again. During the caesarean section, contralateral struma ovarii with dissemination of nodules in the peritoneal cavity was found, and pathology revealed that the masses were thyroid follicle ovarian goitres.

Discussion and conclusions

Recurrent benign struma ovarii with extraovarian dissemination is a rare aggressive clinical manifestation different from malignancy. It is emphasized that adequate assessment and complete resection of suspicious masses are of great importance.

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.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08118-7.

FIGO Stage IV and Age Over 55 Years as Prognostic Predicators in Patients With Metastatic Malignant Struma Ovarii

Introduction: Metastatic malignant struma ovarii (MSO) is an extremely rare disease that lacks treatment consensus and accurate prognosis. The objective of this study was to present the clinical, pathological, and treatment characteristics of metastatic MSO, while also investigate the overall survival (OS) rate and factors affecting prognosis in this population.

Materials and Methods: A total of 79 cases of metastatic MSO were reviewed, including four cases of metastatic MSO from our hospital and 75 cases selected from the literature. Logistic regression was used to identify potential factors affecting disease free survival (DFS). The Kaplan-Meier method and log-rank test were used to determine OS; further Cox regression was used to evaluate factors affecting OS.

Results: The mean age of all the patients at diagnosis was 43.8 years. The most common metastatic sites were peritoneum, bone, liver, omentum and lung in descending order. Only two patients (2.6%) coexisted with local primary thyroid cancer. Follicular carcinoma (41.8%) as the most prevalent subtype, followed by papillary carcinoma, follicular variant of papillary carcinoma, and mixed follicular-papillary carcinoma. 36.7% of the patients received conservative surgery, 43.0% of them underwent aggressive surgery, and 15.2% of them did not receive any surgery. 74.7% of patients who received adjuvant therapy underwent radioiodine therapy (RAI). Logistics regression revealed that FIGO stage IV was the only prognostic factor in predicting DFS (P = 0.002; Odds Ratio [OR] 5.333; 95% confidence interval [CI]: 1.839–15.471). Only seven deaths occurred. The OS rates at 5, 10, 15 years were 89.3, 82.4, 65.9%, respectively. Multivariate analysis showed age over 55 years (P = 0.006; OR 9.362; 95%CI: 1.895–46.246) was the only risk factor for OS.

Conclusion: Patients with metastatic MSO have an excellent disease-specific OS rate, FIGO stage IV and age over 55 years were two factors affecting disease prognosis. Conservative surgery with residual ablation by RAI after total thyroidectomy should be preferred since the benefits of aggressive surgery are uncertain.

Papillary Thyroid Cancer in a Struma Ovarii in a 17-Year-Old Nulliparous Patient: A case Report

Introduction: Struma ovarii accounts for 2% of mature teratomas. Struma ovarii is diagnosed when thyroid tissue accounts for >50% of the teratoma. Malignant transformation is rare, occurring in <5% of struma ovarii cases. Case presentation: A 17-year-old patient was diagnosed with papillary thyroid cancer in struma ovarii. The patient exhibited menstrual disorders. Abdominal and pelvic CT revealed a 17 cm mass in the left adnexa. Laparoscopic removal of the left adnexa with enucleation of right ovarian cysts was performed. Histopathological diagnosis was a follicular variant papillary carcinoma measuring 23 mm in diameter. Immunohistochemical positive expression of CK19, TTF-1, and thyroglobulin (Tg) confirmed the diagnosis. Molecular analysis detected the BRAF K601E mutation in ovarian tumor tissues. Preoperative serum Tg concentration was >300 ng/mL, which decreased to 38.2 ng/mL after gynecological surgery with undetectable anti-Tg antibodies. The patient underwent total thyroidectomy with no cancer detected on histopathological examination. The patient was treated with I-131 and showed no recurrence 4 years after the diagnosis. Conclusions: Malignant struma ovarii is diagnosed by surgery. Because papillary carcinoma in struma ovarii is rare and there are no guidelines regarding the management of this type of cancer, therapeutic decisions should be made individually based on clinical and pathological data.

Unusual Case of Malignant Struma Ovarii and Cervical Thyroid Cancer Preceded by Ovarian Teratoma: Case Report and Review of the Literature

Objective

To present a rare case of malignant struma ovarii (MSO) and synchronous thyroid cancer, review the medical literature, and present the latest trends in management.

Methods

The case of a woman with MSO and concomitant thyroid cancer is presented, including clinical presentation, treatment, and follow-up care. A search of the English-language literature was conducted using MEDLINE and Google Scholar data bases.

Results

We found 10 publications (one abstract) describing 10 patients with MSO and concomitant thyroid cancer. Six additional patients were reported by a study that analyzed the SEER (cancer registry) database. The median age of women was 42 years, with the majority of them presenting with abdominal symptoms. Histologically, most tumors were papillary carcinomas in both organs. In 5 patients, there was extrathyroidal tumor extension at time of surgery.

Conclusion

MSO can occasionally coexist with highly aggressive eutopic thyroid cancer. Although this concurrence is even rarer than MSO, clinicians should routinely investigate for possible synchronous thyroid cancer in all cases of MSO and also consider aggressive postoperative treatment including thyroidectomy and radioiodine ablation therapy in cases of MSO.

The Smallest Reported Malignant Struma Ovarii: A Case Report

Introduction

Malignant struma ovarii is a rare neoplasm. It is usually asymptomatic and not commonly diagnosed preoperatively. In addition, there is currently no established diagnostic and therapeutic approach for malignant struma ovarii.

Case Report

A 66-year-old asymptomatic female was referred to our hospital. Computed tomography showed the presence of a well-defined mass with enhancement in the internal and peripheral areas. The patient underwent total abdominal hysterectomy, bilateral salpingo-oophorectomy, and partial omentectomy. Histopathology revealed the presence of a papillary thyroid carcinoma arising from a 2.5-cm-diameter struma ovarii (malignant struma ovarii). According to the criteria of the International Federation of Gynecology and Obstetrics, the patient had stage IA disease. Subsequently, she underwent a thyroid scan with normal findings. At the 3-month follow-up, the patient was alive, in good clinical condition, and disease free.

Conclusion

In this report, we present the smallest malignant struma ovarii reported so far in the literature. Because of the rarity of these tumors and the lack of firm prognostic factors, the treatment decision should be customized for each patient according to the pathological and clinical parameters.

The largest reported papillary thyroid carcinoma arising in struma ovarii and metastasis to opposite ovary: case report and review of literature

Background

Malignant struma ovarii (MSO) is a very rare, germ cell tumor of the ovary, histologically identical to differentiated thyroid cancers. Struma ovarii (SO) is difficult to diagnose on clinical basis or imaging and is mostly discovered incidentally, with few published cases in the literature.

Case presentation

A 42-year old primiparous woman presented with abdominal pain and midline pelvic palpable firm mass arising from the pelvis. Imaging showed pelvic solid cystic mass. Total abdominal hysterectomy, bilateral salpingo-oopherectomy (TAH BSO) and infracolic omentectomy were performed. Histopathology revealed left ovary papillary thyroid carcinoma (PTC) arising in SO (11 cm) and metastatic papillary thyroid carcinoma in the right ovary. Thyroid functions tests were all normal, ultrasound thyroid showed two complex nodules in the left thyroid lobe. Total thyroidectomy was decided, but the patient refused further surgical management and was lost to follow up as she left the country. We undertook a comprehensive literature search, and MSO and thyroid management data from 23 additional publications were analyzed and tabulated. This PTC MSO is probably the largest reported in the literature.

Conclusions

Among the different surgeries for MSO, TAH + BSO appears to have the best clinical outcome. However, unilateral salpingo-oopherectomy/ unilateral oophorectomy and bilateral salpingo-oopherectomy also seem effective. Ovarian cystectomy alone seems associated with higher recurrence. There remains no consensus on the associations between MSO tumor size and potential extent of metastasis, and about the management of thyroid gland. However, surveillance and thyroid gland work up to detect concurrent thyroid cancer are recommended.

A Hormonally Active Malignant Struma Ovarii

Struma ovarii is a rare monodermal variant of ovarian teratoma that contains at least 50% thyroid tissue. Less than 8% of struma ovarii cases present with clinical and biochemical evidence of thyrotoxicosis due to ectopic production of thyroid hormone and only 5% undergo malignant transformation into a papillary thyroid carcinoma. Only isolated cases of hormonally active papillary thyroid carcinoma developing within a struma ovarii have been reported in the literature. We report the case of a 36-year-old woman who presented with clinical signs and symptoms of hyperthyroidism as well as a left adnexal mass, which proved to be a thyroid hormone-producing, malignant struma ovarii.

Management dilemma of thyroid nodules in patients with malignant struma ovarii

Struma ovarii is a rare type of ovarian teratoma comprised of at least 50% thyroid tissue. While most are benign, 70% of malignant cases are diagnosed as papillary carcinoma. Management of patients with thyroid nodules following gynecologic surgery remains controversial and variable. Historically, the treatment of choice has been surgical removal to rule out ovarian carcinoma. Thyroid follow-up and further treatment options are guided by tumor characteristics. The patient in this case presented to the endocrine surgeon with multiple thyroid nodules, dysphagia and a history of struma ovarii that was surgically treated at an outside hospital. Fine needle aspiration demonstrated benign histology. However, due to compressive symptoms and uncertainty of other nodules, the patient underwent a total thyroidectomy. Due to limited published data and treatment guidelines regarding thyroid nodules in patients with a history of malignant struma ovarii, surgery was recommended to rule out papillary thyroid carcinoma and relieve the patient's dysphagia. More research focused on treatment and outcomes of struma ovarii patients with thyroid nodules is essential to establish treatment guidelines for these patients.

Treatment and follow-up of malignant struma ovarii: Regarding two cases

Malignant struma ovarii (SO) is a rare tumor, and as a consequence, treatments and follow-up procedures are not clearly established. Presented in this study are two cases of suspicious ovarian masses, resected and corresponding to malignant SO on histopathology. Similar to thyroid cancer, we proposed complementary radioiodine therapy (¹³¹I) after total thyroidectomy (no malignancy was observed at this level in our two patients). Patients underwent treatment with 3.7 GBq ¹³¹I followed by post-therapy whole-body scintigraphy, which can detect residual disease or occult metastases. Thyroid remnant ablation increases the sensitivity and specificity of follow-up testing using serum thyroglobulin levels as a tumor marker. Our two patients remained disease-free for 3 and 5 years, respectively, after treatment.

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Malignant struma ovarii is a rare ovarian tumor, corresponding to thyroid carcinoma.

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It is generally diagnosed after surgical resection of an ovarian mass.

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Iodine 131 therapy can be proposed for adjuvant therapy, after total thyroidectomy.

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Follow-up must be extended for 20 years, using thyroglobulin level as a tumor marker.

Novel BRAF and KRAS Mutations in Papillary Thyroid Carcinoma Arising in Struma Ovarii

Papillary carcinomas of thyroid type rarely arise within struma ovarii. There are limited data on the immunohistochemical and molecular features of these tumors. Three cases of papillary carcinoma arising in struma ovarii (PCSO) were identified. The clinicopathological features were reviewed and immunohistochemical staining for HBME-1, cytokeratin (CK) 19, and CD56 was performed. Tumor DNA was sequenced for somatic mutations using a panel of 26 oncogenes, with a particular focus on BRAF and KRAS mutations. The patients were aged 22, 48, and 55 years. All cases were FIGO stage IA. Two tumors were of classical histological type, and one was a follicular variant papillary carcinoma. All tumors expressed HBME-1 and two were positive for CK19. CD56 was negative in all three cases. One tumor demonstrated a BRAF G469A mutation in exon 11, and in a second case, a KRAS Q61K double base mutation in exon 3 was detected. These mutations have not been described previously in PCSO. No mutations were detected in the benign follicular components of the tumors adjacent to the malignant papillary tissue. None of the patients had tumor recurrence on clinical follow-up (range 11 months to 8½ years). HBME-1, CK19, and CD56 are useful immunohistochemical markers of PCSO. Novel BRAF and KRAS mutations were identified in two of three tumors suggesting that mutations in PCSO may differ from those commonly identified in papillary carcinoma of the eutopic thyroid. The clinical significance of these mutations is uncertain but follow-up data in this small series support the generally good prognosis of PCSO.

A case report of thyroid carcinoma confined to ovary and concurrently occult in the thyroid: is conservative treatment always advised?

INTRODUCTION

Struma ovarii is an ovarian teratoma, represented in more than 50% by thyroid tissue. Five percent of struma ovarii cases have been proven to be malignant and, as in the thyroid gland, papillary thyroid carcinoma is the most common histotype arising in struma ovarii. Because of the unusual occurrence of this tumor, its management and follow-up after pelvic surgery is still controversial. Usually, total thyroidectomy followed by radioiodine treatment is the choice treatment in metastatic malignant struma ovarii, while these procedures are still controversial in non-metastatic thyroid cancer arising in struma ovarii.

CASE PRESENTATION

We report a female with follicular variant of papillary thyroid carcinoma arising in struma ovarii. After pelvic surgery, thyroid morphofunctional examinations were performed and a single nodular lesion in the left lobe was discovered. The patient underwent total thyroidectomy and histological examination showed a papillary carcinoma. Radioiodine-ablation of residual thyroid tissue was performed and levothyroxine mildly-suppressive treatment was started.

CONCLUSIONS

A more aggressive treatment should not be denied for malignant struma ovarii without any evidence, even when apparently confined into the ovary. However, in selected cases, aggressive treatment may be advisable to decrease the risk of recurrence and to allow an accurate follow-up.

SPECT/CT of metastatic struma ovarii

A 41-year-old woman presented with multiple right lower quadrant masses which were removed and consistent with metastatic follicular thyroid cancer. Thyroidectomy revealed no primary malignancy and evaluation of her ovaries was positive for struma ovarii. The patient was diagnosed with metastatic struma ovarii stage IV. Nine days following the patient's second therapy with I for recurrent disease, planar and SPECT/CT imaging demonstrated multiple I avid peritoneal nodules. At least one of them, located along the medial margin of the spleen, would have been difficult to diagnose without hybrid SPECT/CT imaging.

Synchronous papillary carcinoma thyroid with malignant struma ovarii: A management dilemma

Struma ovarii (SO) is a rare form of ovarian tumor, which is defined by the presence of thyroid tissue comprising more than 50% of the overall tumor volume. The vast majority of the variants of SO are benign; however, malignant tumors have been reported in a small percentage of cases. An aggressive multimodality approach using ovarian cancer staging laparotomy, total thyroidectomy along with radioactive iodine-131 ablation, and thyroxin suppression therapy has been shown to safely treat malignant SO both its initial presentation as well as in the event of any subsequent recurrence with excellent efficacy and possibly better oncological outcomes. The rarity of the disease and the lack of evidence surrounding its management and prognosis continue to remain a challenge to the treating clinician. We present a unique case of malignant SO with an incidental synchronous association of follicular variant of papillary carcinoma of the cervical thyroid gland, this is possibly the second case reported in the English language literature.

[Complications of presumed benign ovarian tumors]

The main risk factor of adnexal torsion is a previous adnexal torsion (LE3). There is no clinical, biological or radiological sign that may exclude the diagnosis of adnexal torsion (LE3). The presence of flow at color Doppler imaging does not allow exclusion of the diagnosis (LE2). An emergent laparoscopy is recommended for adnexal untwisting (Grade B), except in postmenopausal women where oophorectomy is recommended (grade C). A persistent black color of the adnexa after untwisting is not an indication for systematic oophorectomy (grade C), since a functional recovery is possible (LE3). Ovariopexy is not routinely recommended following adnexal untwisting (grade C). The clinical signs of intra-cystic hemorrhage and those of rupture of the corpus luteum are not specific (LE4). MRI is not recommended to confirm the diagnosis of intra-cystic hemorrhage (grade C). Malignant transformation of an ovarian cyst is very rare. The presence of a benign ovarian cyst is not associated with an increased risk of ovarian cancer at long-term follow-up (LE2). For these women, an ultrasound follow-up is not recommended (grade C). Dermoid ovarian cyst containing nerve tissue can trigger the production of pathogenic auto-antibody-anti-NMDA, leading to encephalitis. A high proportion of thyroid tissue in a mature teratoma (struma ovarii) may cause hyperthyroidism.