Coexistence of malignant struma ovarii and cervical papillary thyroid carcinoma

Follicular Thyroid Carcinoma Arising from the Struma Ovarii Coexisting with Papillary Thyroid Carcinoma, Hashimoto's Thyroiditis and Polycystic Ovarian Syndrome-a Case Report and Literature Review

Purpose

Struma ovarii is a highly specialized teratoma consisting primarily of mature thyroid tissue. However, malignant struma ovarii coexisting with thyroid carcinoma, not to mention autoimmune disease, is uncommon. Malignant struma ovarii complicated with papillary thyroid carcinoma, Hashimoto's thyroiditis and polycystic ovarian syndrome has never been reported in literature.

Patients and Methods

A 32-year-old female was admitted to our hospital due to a history of abdominal distension and menolipsis over the past half a year. Physical examination touched a 6 × 6 cm mass with a clear boundary, normal movement, and no pressing pain in the right adnexal area, Imaging revealed a cystic solid mass of 6 × 7 cm in the right ovary and the level of tumor markers including CA125, CA199, CA153, CEA, AFP were normal, but with low TSH and increased TPOAb, TGAb, TRAb. Laparoscopic right ovary tumor resection was performed, followed by comprehensive staging surgery, as well as thyroidectomy after pathologic diagnosis. The patient was diagnosed with a combination of follicular thyroid cancer from struma ovarii, papillary thyroid carcinoma and Hashimoto's thyroiditis, along with polycystic ovarian syndrome. Immunohistochemical staining showed positivity for Ag, CK-pan, CK7, PAX8 and TTF-1 in the right ovarian mass, and the left thyroid was positive for the BRAF V600E mutation.

Results

The patient underwent thyroxine suppression therapy and radioactive iodine 131I therapy after operation. Serum thyroglobulin was undetectable, and no signs of recurrence or metastasis were detected in the imaging examination at the 2-year follow-up.

Conclusion

Malignant struma ovarii coexisting with thyroid carcinoma is rare. No report has been identified in literature review on the rare malignant struma ovarii coexisting with thyroid carcinoma, Hashimoto's thyroiditis and polycystic ovarian syndrome. Our case can offer experience of diagnosis and treatment to some extent for such rare case. Therefore, it is essential to consider the association between ovarian tumors and the endocrine system. This case is valuable in understanding the diagnosis and management of such an unusual complicated disease.

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.

RET/PTC rearrangement in papillary thyroid carcinoma arising in malignant struma ovarii with abdominal wall metastasis and cervical thyroid gland: a case report and review of the literature

BACKGROUND

Struma ovarii refers to rare mature cystic teratomas containing at least 50% of thyroid tissue, and malignant transformation is known to be even rarer. The synchronous development of malignant struma ovarii and cervical thyroid carcinoma are also scarce and poorly understood due to limited data about molecular features. Here, we present the first report of RET/PTC 1 rearrangement in synchronous metastatic malignant struma ovarii to the abdominal wall and cervical thyroid cancer.

CASE PRESENTATION

We described a 47-year-old multigravida woman with bilateral adnexal and lower abdominal wall masses detected during the evaluation of abnormal uterine bleeding. The patient underwent a hysterectomy, bilateral salpingo-oophorectomy, and surgical removal of abdominal wall mass. Then, the pathological evaluation revealed papillary thyroid carcinoma (PTC) within struma ovarii and metastatic PTC in the abdominal wall fibro adipose tissue. Further, cervical thyroid gland physical examination and ultrasound illustrated a nodule within the left lobe. Subsequently, a total thyroidectomy was performed, and a histological examination revealed PTC. Furthermore, all affected tissue, i.e., struma ovarii, abdominal wall metastasis, and cervical thyroid gland tested for BRAF and RAS mutations and RET/PTC 1 rearrangement. RET/PTC 1 rearrangement was identified among all three different sites. Finally, after six years of follow-up, the patient had no evidence of recurrence or distant metastasis.

CONCLUSIONS

In light of these findings, malignant struma ovarii might yield a clue to cervical thyroid carcinoma, and the molecular analysis could provide valuable information for understanding the underlying mechanism, tumor clinicopathological behaviors, and prognosis.

Synchronous thyroid cancer and malignant struma ovarii: concordant mutations and microRNA profile, discordant loss of heterozygosity loci

BACKGROUND

Struma ovarii is an unusual ovarian teratoma containing predominantly thyroid tissue. Less than 10% of cases undergo malignant transformation in the thyroid tissue and are considered malignant struma ovarii (MSO). MSO have been reported with concurrent thyroid lesions, but molecular data is lacking.

CASE PRESENTATION

A 42-year-old female developed MSO and synchronous multifocal subcentimeter papillary thyroid carcinoma (PTC). The patient underwent a salpingo-oophrectomy, thyroidectomy, and low-dose radioactive iodine ablation. Both the thyroid subcentimeter PTC and MSO were positive for BRAF V600E mutation, and microRNA expression profiles were similar across all tumor deposits. However, only the malignant component demonstrated extensive loss of heterozygosity (LOH) involving multiple tumor suppressor gene (TSG) chromosomal loci.

CONCLUSIONS

We present the first reported case of MSO with synchronous multifocal subcentimeter PTC in the thyroid containing concordant BRAF V600E mutations and resulting with discordant LOH findings. This data suggests that loss of expression in tumor suppressor gene(s) may be an important contributor to phenotypic expression of malignancy.

It Does Exist! Diagnosis and Management of Thyroid Carcinomas Originating in Struma Ovarii

Thyroid carcinoma originating in struma ovarii comprises a small minority of all cases of struma ovarii. Given the rarity of this diagnosis, literature to guide evaluation and management is limited. The most common carcinoma originating from struma ovarii is papillary thyroid carcinoma. Treatment includes surgery, including a fertility sparing approach if disease is confined to the ovary, with consideration of total thyroidectomy and radioactive iodine ablation for high-risk pathologic features or disease spread beyond the ovary. This review discusses the histopathologic findings, molecular pathology, clinical implications and management, and prognosis of thyroid carcinomas originating in struma ovarii.

Management of malignant struma ovarii: is aggressive therapy justified? Case report and literature review

Background

Struma ovarii (SO) is a rare ovarian teratoma containing predominantly thyroid tissue. In rare situations SO may develop malignancy. Most cases of malignant struma ovarii (MSO) are diagnosed after surgical removal, based on histopathological examination. There are still controversies regarding the extent of surgery and postoperative management in MSO, due to its unpredictable behavior, possible risk of metastasis and relatively high rate of recurrence.

Case Presentation

We present the case of a patient diagnosed with a right ovarian cyst discovered incidentally during routine ultrasound examination. Its rapid growth and pelvic MRI raised the suspicion of a neoplastic process. She underwent total hysterectomy and bilateral adnexectomy. The anatomopathological diagnosis was MSO with follicular variant of papillary thyroid carcinoma. Prophylactic total thyroidectomy was performed, followed by radioactive iodine ablation (RAI), and suppressive therapy with levothyroxine. At 1 year follow-up, the patient was disease free.

Conclusions

Even if latest literature reports consider that completion of local surgery with total thyroidectomy and RAI might be too aggressive in cases of MSO without extraovarian extension, in our case it was decided to follow the protocol for primary thyroid carcinoma, in order to reduce the recurrence risk.

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.

The Clinical and Pathological Characteristics of Malignant Struma Ovarii: An Analysis of 144 Published Patients

The objective of this study is to summarize the clinical and pathologic characteristics of malignant struma ovarii to facilitate the early diagnosis and treatment of this disease. All 144 patients were females from 27 countries. The mean age of the patients at diagnosis was 42.6 years. Overall, 35.71% of the patients underwent unilateral oophorectomy, 58.57% of the patients underwent bilateral oophorectomy, 5.72% of the patients were not ovariectomized, and 38.57% of the patients received radioactive iodine treatment with an average dose of 158.22 mCI each time. “Impure” types accounted for 70.19% of the cases, while pure types accounted for 29.81% of the cases. Among these cases, papillary thyroid carcinoma accounted for 50.00%, follicular thyroid carcinoma accounted for 26.47%, follicular variant of papillary thyroid carcinoma accounted for 18.63%, papillary and follicular mixed thyroid carcinoma accounted for 2.94%, anaplastic carcinoma accounted for 0.98%, and medullary carcinoma accounted for 0.98%. In total, 21 patients (51.22%) had elevated CA125. More than half of the patients (51.94%) had metastasis outside the ovary. The most common metastatic site was the pelvic cavity. The misdiagnosis rate was 17.27%. Mortality was related to metastasis and the cancer type. Gene mutations were found in the NRAS, KRAS, BRAF, and KIT genes and were similar to those in thyroid carcinoma, but some patients (37.5%) did not exhibit any gene mutations. Regardless of the treatment received, the survival rate is high. Treatment could initially include ovariectomy; however, in cases with metastasis and iodine uptake of the metastatic tumor, thyroidectomy, radioactive iodine therapy, and thyroid hormone inhibiting therapy are indicated.

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.

Metastatic Malignant Struma Ovarii and Graves' Disease: A Rare Occurrence

Objective

Malignant struma ovarii (SO) is a rare condition. Although there have been a few reported cases of malignant SO with coexisting Graves’ disease (GD), the exact incidence of metastasis in these cases is not known. We report a rare case of metastatic malignant SO coexisting with GD.

Methods

Clinical examination, pelvic ultrasound, and histopathology of the resected tumor were performed, followed by iodine-131 (I-131) and whole body scan. Antithyroglobulin titers were postoperatively followed.

Results

A 43-year-old woman with a history of left ovarian cystic teratoma with SO resected 8 years ago and recently diagnosed GD presented with lower abdominal fullness. Pelvis ultrasound showed a 13.8-cm left adnexal mass, and she underwent left salpingo- oophorectomy. Histology confirmed an intraovarian thyroid tissue housing a highly differentiated follicular thyroid carcinoma, with metastatic peritoneal deposits. She underwent completion surgery and total thyroidectomy. Histology showed no evidence of intrathyroidal malignancy. I-131 therapy was administered, and posttherapeutic I-131 whole body scan revealed a remnant disease. She was started on suppressive levothyroxine therapy and remained clinically well at her 1-year follow-up with downtrending antithyroglobulin titers.

Conclusion

The coexistence of malignant SO and GD is very rare, and even rarer is the coexistence of metastasis malignant SO and GD. To the best of our knowledge, this is the first reported case of metastatic malignant SO in the setting of GD.

Malignant struma ovarii: next-generation sequencing of six cases revealed Nras, Braf, and Jak3 mutations

PURPOSE

Struma ovarii (SO) is a highly specialized ovarian teratoma, consisting of thyroid tissue. Rarely, carcinomas histologically identical to their thyroid counterparts may occur, and are comprehensively defined as malignant struma ovarii (MSO). Their optimal management is controversial, and the molecular profile of the malignant counterpart in the ovary is incompletely known. In this study, the clinicopathological and molecular features of six MSO from different Italian Institutions were analysed, to explore genetic profiles of potential therapeutic interest.

METHODS

The histopathological features and immunoprofile (according to the known markers Galectin-3, HBME1, cytokeratin 19 and CD56) were reviewed. In addition, all cases underwent genetic analysis with a next-generation sequencing (NGS) hot spot cancer panel detecting mutations in 50 genes involved in cancerogenesis. RET/PTC rearrangements and TERT promoter alterations were also evaluated.

RESULTS

Papillary carcinoma in all similar to its thyroid counterpart was found in five of six cases, including classical (two tumors) and follicular variant (three tumors) types. The last case was a poorly differentiated carcinoma. An activating gene mutation, was detected in five of six cases, including two NRAS, two BRAF, and one JAK3 oncogene mutations. No alterations were found in the other panel genes, nor in TERT promoter, or in RET chromosomal regions.

CONCLUSIONS

MSO is a rare condition. Papillary carcinoma is the predominant malignant type, sharing both histomorphological and molecular features of its thyroid counterpart. Interestingly, the single case of poorly differentiated carcinoma displayed a JAK3 mutation. The presence of such driving mutation could be of potential interest in guiding postoperative treatment.

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 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.

Synchronous Independent Papillary Thyroid Carcinomas in Struma Ovarii and the Thyroid Gland With Different RAS Mutations

Struma ovarii is a rare ovarian teratoma predominantly composed of thyroid tissue. The simultaneous presence of thyroid carcinoma in the struma ovarii and the thyroid gland is extremely rare. It remains unclear if these carcinomas represent independent primary tumors and whether the molecular mechanisms of the tumors developing in the thyroid and ovarian tissues are similar. We present the case of a patient with two independent papillary thyroid carcinomas (PTCs) in struma ovarii and the thyroid gland that are driven by different RAS mutations. A 62-year-old woman with a history of chronic lymphocytic leukemia/small lymphocytic lymphoma was diagnosed with a pelvic mass during a CT scan. She had surgery that included removal of her ovaries. A 7.2-cm classical variant of PTC arising in a struma ovarii was identified in the right ovary. Two months after the pelvic surgery, total thyroidectomy was performed, and a small nodule (0.8 cm) in the left lobe was diagnosed as a classical variant of PTC. Molecular analysis of tissues obtained from both the malignant struma ovarii and thyroid gland was performed. RAS mutations both in the PTC located in the thyroid and ovarian tissues were identified. However, whereas the thyroid gland tumor showed an HRAS Q61R mutation, the PTC in struma ovarii harbored an NRAS Q61R mutation. In this case, the finding of distinct types of RAS point mutation in thyroid cancers at two different locations provides definitive evidence that these cancers are synchronously developed independent primary tumors.

[Thyroid carcinoma on struma ovarii: Diagnosis and treatment]

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 in a 30-year old nulliparous patient

Background

Struma ovarii is a rare monodermal germ cell tumor where the ovary is comprised of at least half thyroid tissue. This phenomenon may indicate an embryological origin.

Case presentation

A 30-year old nulliparous woman presented with acute right lower quadrant pain and underwent laparoscopic right salpingo-oophorectomy. The excised ovarian mass showed evidence of struma-derived papillary thyroid carcinoma. Ultrasound of the thyroid showed mild enlargement with two solid nodules. A fine needle aspirate of a thyroid nodule was positive for malignancy and a total thyroidectomy was performed. Microscopic features of the thyroid were consistent with papillary thyroid carcinoma. The two tumours were considered as synchronous independent primaries based on their histological presentation.

Conclusions

We believe that aggressive surgical management followed by radioiodine therapy is best to reduce recurrence risk and optimize survival. The broad scope of interventions needed to treat malignant struma ovarii require a strong interdisciplinary team.

Concurrent Intrathyroidal Thyroid Cancer and Thyroid Cancer in Struma Ovarii: A Case Report and Literature Review

Context

The presence of differentiated thyroid cancer in mature cystic teratomas in the ovaries is rare, and usually incidentally found on surgical pathology specimens. We present a case of simultaneous intrathyroidal thyroid cancer and thyroid cancer within a struma ovarii, presenting specific diagnostic challenges.

Case Description

A 55-year-old woman had an intrathyroidal, encapsulated 1.2-cm papillary thyroid carcinoma, follicular variant, which was resected. Laboratory studies showed an elevated thyroglobulin level of 35 ng/mL while on suppressive levothyroxine therapy. During preparation for radioactive iodine ablation, thyroglobulin increased dramatically to 3490 ng/mL. A pretreatment whole-body scan showed residual tracer uptake in the thyroid bed and increased radiotracer uptake in the pelvis that raised concern for a pelvic metastasis, given the marked thyroglobulin elevation. After ablation, the posttreatment scan showed intense focal uptake in the pelvis. Single-photon emission computed tomography-computed tomography confirmed that the tracer uptake corresponded to a right adnexal mass. The patient underwent a laparoscopic bilateral salpingo-oophorecotomy with pelvic washings. The final pathology of the right ovary showed papillary thyroid carcinoma arising in a mature cystic teratoma. In addition, there was abundant normal thyroid tissue with colloid surrounding the carcinoma, indicating a source for the dramatic rise in thyroglobulin levels and suggesting that the ovarian papillary thyroid cancer arose within the teratoma and was not metastatic disease. Thyroglobulin measurements have been undetectable for 5 years since surgery and radioiodine treatment.

Conclusions

Concurrent intrathyroidal thyroid cancer and differentiated thyroid cancer in struma ovarii are very rare, but can often be distinguished on clinical grounds.

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.

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.