Thyroid-type carcinoma of struma ovarii

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.

Metastatic malignant struma ovarii to the pituitary presenting as a sellar mass and responding to total thyroidectomy with adjuvant radioactive iodine therapy

Malignant struma ovarii (MSO) is a rare ovarian teratoma composed primarily of thyroid tissue. Common sites of metastasis include peritoneum, bone, liver, lung, gastrointestinal tract and omentum. We present a woman in her 50s with a history of remote oophorectomy presenting with hypopituitarism and a 2.7 cm sellar mass. Trans-sphenoidal surgery for presumed pituitary macroadenoma achieved near total resection and resultant pathology surprisingly showed ectopic thyroid tissue. The patient acquired her ovarian pathology report from Southeast Asia which showed struma ovarii of the left ovary. The pituitary mass was thus determined to be a metastatic lesion from MSO. She underwent total thyroidectomy and radioactive iodine ablation therapy with good initial response and no regrowth of the tissue or emergence of distant metastases after 5 years of annual follow-up. To our knowledge, this is the first reported case of MSO to the pituitary.

A case report of malignant struma ovarii with papillary thyroid carcinoma

Key clinical message

Struma ovarii (SO), is a rare and specialized ovarian teratoma. The treatment is controversial depending on the risk of recurrence and metastasis. Here a SO with papillary thyroid carcinoma is reported and the approach is thoroughly discussed.

Abstract

Struma ovarii (SO) is a highly specialized ovarian teratoma primarily composed of thyroid tissue. Clinical features associated with SO include lower abdominal discomfort, unusual vaginal bleeding, ascites, and hyperthyroidism. While SO rarely transforms into malignancy, the optimal degree of treatment remains controversial due to the varying risks of recurrence and metastasis. In this report, we present the case of a 64-year-old woman experiencing abdominal pain and diagnosed with SO, accompanied by papillary thyroid carcinoma. We thoroughly discuss the evaluation and management of this rare condition.

Follicular thyroid carcinoma within a struma ovarii: a case report

Struma ovarii comprises 1% of all ovarian tumors and 3% of ovarian teratomas. It occurs in older females. Struma ovarii is often asymptomatic, unilateral, and accidentally detected through abdominal ultrasound or computed tomography. It presents with palpable abdominal pain or irregular menstrual cycles. Generally, it is treated with surgical resection, even though the best procedure in these cases remains under discussion. In this study, we present a case of a 28-year-old female with severe pain in the right iliac fossa. Physical examination and radiological images showed a large mass. A bilateral salpingo-oophorectomy with omentectomy, a total mass resection, and an abdominal hysterectomy were performed. A biopsy confirmed the diagnosis of a follicular thyroid tumor. The management decision is based on clinical and pathological data. This is particularly challenging due to its rarity and the insufficient guidelines regarding the management of this type of cancer.

Struma Ovarii with Papillary Thyroid Carcinoma and Metastasis to the Appendix: A Case Report and Literature Review

Struma ovarii is an infrequent type of teratoma arising from the ovary accounting for only 2% of all ovarian teratomas. These tumors have a benign biology with rare malignant transformation in about 3% of cases. The most common malignant transformation that arises from struma ovarii is papillary thyroid carcinoma. These neoplasms act in the same way as those arising from the thyroid gland, but due to the rarity of their occurrence there is still a debate over therapeutic options. We present a case of a 41-year-old Ethiopian Para IX woman presented with abdominal swelling for four years, accompanied by dull pain, satiety, and weight loss. Her vital signs were normal, and her abdominal examination revealed a large abdominopelvic mass. Her CA-125 was elevated, and her blood count, organ function tests, and serum electrolyte levels were normal. Abdominal ultrasound revealed a complex abdominopelvic mass with cystic and solid components, possibly ovarian teratoma. The patient underwent surgery, revealing a 14 by 10 cm right ovarian mass and a 3×3 cm appendiceal mass. Subsequently, total abdominal hysterectomy, bilateral salpingo-oophorectomy, total omentectomy, and appendectomy was done. Histopathologic evaluation revealed follicular proliferation of enlarged cells, with no papillary growth pattern. The case was diagnosed as malignant struma ovarii, a follicular variant of papillary thyroid carcinoma (FVPTC) with secondary deposits on the appendix. A complete thyroidectomy was done after the histopathology diagnosis. Malignant struma ovarii is rare making it challenging to treat since there are no established prognosticating histopathologic or clinical characteristics. The tumor size and metastasis determine the surgical treatment scope. Large-scale investigations are essential for prognostication and treatment options considering pathologic traits.

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.

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.

Highly Differentiated Follicular Carcinoma of Ovarian Origin: A Systematic Review of the Literature

(1) Background: Highly differentiated follicular carcinoma of ovarian origin (HDFCO) is an extremely uncommon neoplasm, associated with struma ovarii. There are scarce cases reported in the literature and, subsequently, no reliable conclusions on its pathophysiology, treatment, and prognosis can be drawn. The goal of this study is to enrich the literature on the topic by adding our own experience with a case, and simultaneously accumulate all cases published up to date. (2) Methods: The present review was performed in accordance with the guidelines for systematic reviews and meta-analyses (PRISMA). PubMed (1966-2022), Scopus (2004-2022), and Clinicaltrials.gov databases were screened for relevant articles published up to July 2022. (3) Results: Twenty patients with HDFCO were identified. The included patients were aged 47.15 years (range 24-74). The predominant origin was ovarian (60%) and extraperitoneal spread was confirmed in 15% of the cases. Surgical treatment varied from conservative to radical (35.3% vs. 41.2%, respectively) and the administration of supplementary therapy and thyroidectomy was not universal. Combined thyroidectomy/radioactive iodine therapy was applied in just 62.5% of the reported cases. There was one patient who demonstrated disease recurrence and lives with the disease. No disease related morbidity was reported. (4) Conclusions: HDFCO represents a low-grade malignant tumor, whose rarity does not allow for reliable conclusions. Standard treatment including complete surgical excision and supplementary treatment seems to offer a favorable prognosis in selected cases.

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.

Malignant struma ovarii with thyroid-type papillary and poorly differentiated carcinoma: a case report

Background

Malignant struma ovarii is a very rare type of gynecologic cancer. Although its most common histological subtype is a pure type of papillary thyroid carcinoma containing two components, papillary carcinoma and poorly differentiated carcinoma, malignant struma ovarii is still extremely rare. As a result, the optimal treatment for this type of tumor remains uncertain due to its rarity.

Case presentation

A 62-year-old Japanese female presented with a pelvic tumor and clinical diagnosis of malignant tumor of the ovary. She underwent complete debulking surgery, total abdominal hysterectomy, bilateral salpingo-oophorectomy, and omentectomy. The histology of the ovarian tumor revealed malignant struma ovarii with thyroid-type papillary projections and poorly differentiated carcinoma. Because of the complete resection and the absence of distant metastasis, the patient did not receive any adjuvant therapy. At 24 months after surgery, she was free of disease.

Conclusion

This is a rare case report of malignant struma ovarii, without recurrence, in which the component was papillary thyroid carcinoma mixed with poorly differentiated carcinoma. Foregoing adjuvant therapy might be one option for malignant struma ovarii in cases with complete resection and no distant metastasis. In addition, we should consider that long-term follow-up is needed for malignant struma ovarii.

Struma ovarii with contralateral ovarian teratoma: A case report

Struma ovarii (SO) is a rare form of ovarian teratoma in which the thyroid tissue constitutes over 50% of the tumor. SO comprise 1% of all ovarian tumors. We report the case of a 61-year-old woman who was admitted to the hospital because of frequent urination and dysuria. Abdominal magnetic resonance imaging revealed a mass measuring approximately 16 cm in diameter in the right adnexal area. After transabdominal bilateral adnexectomy, pathological examination revealed a teratoma of the ovary on the right and goiter of the ovary with focal thyroid cancer on the left side. Subsequent total thyroidectomy was performed, and no cancer was found on pathological examination. The patient was treated with thyroxine for a long time after the operation, and there was no recurrence 3 years after diagnosis.

A rare case of highly differentiated follicular carcinoma in ovary with FGFR4 Gly388Arg polymorphism: a case report and literature review

BACKGROUND

Highly differentiated follicular carcinoma (HDFCO) is a rare form of struma-derived thyroid-type carcinoma in ovary, defined as ovarian struma spreading beyond ovary but consisting of benign thyroid tissues. No more than 30 cases of HDFCO have been reported since it was first recognized in 2008. The clinicopathologic and molecular features of HDFCO remain unclear up till now.

CASE PRESENTATION

A 38-year-old, para 1 gravida 5 woman has a long history of recurrent right ovarian cysts. Histological evaluation showed the tumor progressed from ovarian mature cystic teratoma (OMCT) to highly differentiated follicular carcinoma (HDFCO) during three relapses. Whole-exome sequencing revealed the germline FGFR4 Gly388Arg polymorphism. Repeated operations were performed to remove lesions for the first two relapses. On the third recurrence, the patient received radical surgery with subsequent thyroidectomy and radioactive iodine ablation. No evidence of disease was observed by February 2022 (8 months).

CONCLUSIONS

The germline FGFR4 Gly388Arg polymorphism may accelerate the malignant transformation of HDFCO, probably by working as a second hit in the developing spectrum.

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 with papillary carcinoma combined with retroperitoneal lymph node metastasis: A case report

BACKGROUND

Struma ovarii is a rare specific ovarian tumor. It is a highly differentiated monodermal teratoma with a malignant transformation rate as low as 5%. Thus, malignant transformation and metastasis are extremely rare. The clinical manifestations of this disease are not typical and are easily misdiagnosed.

CASE SUMMARY

A 55-year-old female patient had a history of pain in the right hepatic region for approximately 1 year. Computed tomography and magnetic resonance imaging showed a solid cystic mass in the right adnexal region and a solid mass in the right retroperitoneum. The patient underwent surgical resection, and the combined morphological and immunohistochemical results led to the final diagnosis of right struma ovarii with papillary carcinoma and right retroperitoneal lymph node metastasis.

CONCLUSION

Malignant struma ovarii with distant metastasis is extremely rare, and the clinical manifestations of this disease are nonspecific. Accurate preoperative diagnoses are difficult to obtain, and pathological examination is the gold standard for diagnosing this disease.

High dose radioiodine therapy preceded by fertility preservation surgery in metastatic malignant struma ovarii: A tale of endurance and prudent management

Struma ovarii is a type of mature ovarian teratoma which accounts for roughly 0.5%–1% (1) of all ovarian tumours and approximately 3% of all ovarian teratomas (2). To be classified as struma ovarii, more than 50% of the tumour must be comprised of thyroid tissue (3). Malignant struma ovarii being rare, no proper guidelines exists regarding its surgical approach or postoperative management. Metastatic malignant struma ovarii, in addition to radical surgery for ovarian mass will require total thyroidectomy to facilitate high dose radioiodine therapy. Here we present the case of a newly married, nulliparous, young lady in her third decade who was diagnosed with malignant struma ovarii with metastatic deposits in fallopian tube and extensive deposits in mesentery and peritoneum., She underwent cryopreservation of embryos followed by bilateral salphingo-oopherectomy + omentectomy + stripping of peritoneum over bladder, abdominal side walls, pelvic peritoneum + appendectomy with preservation of uterus. Total thyroidectomy was done simultaneously. Subsequently she underwent high dose radioiodine therapy. Complete ablation of the residual metastatic deposits were achieved by one sitting of therapy.

Struma Ovarii: A Thyroxine-Producing Ovarian Tumor in Pregnancy

Struma ovarii is a rare dermoid tumor that consists of more than 50% thyroid tissue. The incidence of struma ovarii is reported to be 1% of all ovarian tumors and 2-5% of all ovarian teratomas. The authors present a case of struma ovarii diagnosed during the first trimester of pregnancy in a primigravida patient and discuss the clinical presentation, diagnosis, and management options for such rare tumors, both in and outside of pregnancy. 

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.

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.

Follicular carcinoma arising from struma ovarii. A case report

Struma ovarii is a monodermal variant of ovarian teratoma. Thyroid-type carcinoma arising in struma ovarii is rare. The most common type is papillary carcinoma, followed by typical follicular carcinoma. A 75-year-old hypertensive patient consulted for the sensation of a painless pelvic mass that has been progressing for six months. The abdominopelvic ultrasound showed a right lateralized abdominopelvic mass measuring 14x13x8 cm with a solid and cystic double component. The patient underwent a unilateral right adnexectomy. Grossly, the tumor was encapsulated and lobulated. On cut sections, it was solid brown whitish in color and gelatinous. On histological examination, it was formed of follicular structures of variable size filled with a dense colloid. From this goiter a malignant tumor proliferation arose, arranged in sheets, trabeculae and follicular structures, and the tumor cells were cubic or polyhedral moderately atypical with few mitotic figures. There were no papillary-like nuclear features. There was focal capsular and vascular invasion. Immunohistochemical study showed positive immunostaining of tumor cells with TTF1. Postoperative course was uneventful. The exact prognosis of thyroid-type carcinoma arising in struma ovarii is still unclear because of its rarity, inadequate follow-up, and the absence of consensus in diagnosis and treatment.

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.

Papillary Thyroid Carcinoma in Struma Ovarii

Struma ovarii is a variant of a germ cell tumor composed predominantly of thyroid tissue. It is most often unilateral. The incidence of malignancy arising in patients with struma ovarii is rare. Here, we present a case of struma ovarii in a female presented with abdominal distension. The patient was treated with a total hysterectomy and bilateral salpingo-oophorectomy, which revealed an enlarged cystically dilated ovary. Histopathologic examination showed mature thyroid follicles with abundant colloid consistent with struma ovarii and focal area with nuclear features of papillary thyroid carcinoma. No other teratomatous elements were identified. Thyroid hormone levels were within their respective reference ranges. A diagnosis of struma ovarii should be considered in the differential diagnosis of pelvic masses in peri- and postmenopausal patients.

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.

Imprint cytology of strumal carcinoid of the ovary: A case report with immunocytochemical analysis

Strumal carcinoid is a rare ovarian tumor defined as carcinoid associated with struma ovarii. We report here the second cytological case of strumal carcinoid and performed immunocytochemical analysis for the first time. A 68-year-old Japanese female was found to have a solid tumor with small cystic components in the left ovary, and bilateral salpingo-oophorectomy was performed. The Papanicolaou smear of the imprint cytological specimen of the left ovarian tumor revealed presence of two distinct components. The first component included thyroid follicles, which was composed of flat sheets of polygonal epithelial cells without nuclear groove and intranuclear inclusion. The other component was composed of trabecular clusters of columnar cells containing round to slender nuclei with "salt and pepper" chromatin. Immunocytochemical analysis revealed that synaptophysin was expressed in the latter component. Therefore, a cytodiagnosis of strumal carcinoid was made. Histopathological analyses confirmed the diagnosis of strumal carcinoid. Albeit rare, carcinoid tumor occurs in the ovary, and the recognition of characteristic nuclear features and cellular arrangement leads to correct cytodiagnosis. Presence of struma ovarii component suggests an ovarian origin. Moreover, immunocytochemical analysis for neuroendocrine markers aids its differential diagnosis from granulosa cell tumor and carcinoma arising from struma ovarii.

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.

Management of highly differentiated thyroid follicular carcinoma of ovarian origin with a minimally invasive approach

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Peritoneal strumosis is highly differentiated thyroid follicular carcinoma of ovarian origin.

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Minimally invasive surgical techniques for peritonectomy can resect extra-ovarian disease.

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Multi-disciplinary collaboration allowed avoidance of thyroid ablation and thyroidectomy.

Emerging entities in renal cell neoplasia: thyroid-like follicular renal cell carcinoma and multifocal oncocytoma-like tumours associated with oncocytosis

The list of accepted entities of renal cell neoplasia has burgeoned since the turn of the century through recognition of rare tumour types and the discovery of genetic mutations driving renal neoplasia syndromes. This growth has not finished and in this report we present examples of each of these types which were not included in the 2016 World Health Organization classification of renal neoplasia, but are candidates for inclusion in the next edition of the classification. Thyroid-like follicular renal cell carcinoma is a rare tumour type with a distinctive microscopic appearance resembling follicles of the thyroid gland. Thirty-nine cases have been described and the findings have been reasonably consistent. Oncocytoma-like tumours associated with oncocytosis arise as a result of somatic mutations in the mitochondrial genome. The differential diagnosis is mainly with the renal lesions of the Birt-Hogg-Dubé syndrome, which is the result of germline mutations in the folliculin gene. Patients with oncocytoma-like tumours associated with oncocytosis are at great risk of developing renal failure as the proliferating lesions replace the renal parenchyma. Oncocytoma-like tumours have never been found to metastasise.

A phase I study of pazopanib in combination with escalating doses of 131I in patients with well-differentiated thyroid carcinoma borderline refractory to radioiodine

OBJECTIVE

This trial was conducted to evaluate the ability of pazopanib to overcome therapeutic 131I resistance.

MATERIALS, METHODS AND PATIENTS

This phase 1 trial assesses the combination of pazopanib and escalating doses of radioiodine (131I) in patients with recurrent or metastatic thyroid cancer that are borderline or relatively iodine refractory. Radioiodine uptake scans were assessed post therapy and compared to historical pre-treatment scans. Patients underwent FDG PET/CT before and after the initial pazopanib treatment to identify the impact of pazopanib on the cancer prior to 131I therapy.

RESULTS

A dose limiting toxicity (cardiac arrhythmia and grade 3 fatigue) in the first patient in the first cohort prompted expansion to a total of 6 patients. Additional grade 3-4 hematologic toxicity and low accrual in the expanded cohort led to the decision not to pursue further study of the regimen. In patients with measurable disease 4/5 (80%) achieved stable disease. Median progression free survival was 6.7 months. At 3 years of follow up, one patient died due to progressive disease, two are being treated with systemic therapy and 3 continue without requiring subsequent therapy at 15, 27 and 35 months from the last dose of pazopanib. There was no convincing impact of pazopanib on iodine uptake in scans performed pre- and post-therapy compared to scans from historical 131I treatments without pazopanib.

CONCLUSION

Despite a suggestion of therapeutic efficacy, combined pazopanib and 131I resulted in increased toxicity. There was no convincing evidence that the administration of pazopanib improved iodine uptake or retention.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01413113.

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.

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.

Thyroid-Like Follicular Carcinoma of the Kidney

Thyroid-like follicular carcinoma of the kidney (TLFCK) is a rare but emerging renal neoplasm that morphologically mimics follicular carcinoma of the thyroid but lacks immunohistochemical expression of thyroid markers such as TTF-1 and thyroglobulin. Here, a case of an incidentally discovered TLFCK in a 27-year-old man is reported. Histologic evaluation demonstrated an encapsulated proliferation of variably sized thyroid follicle-like epithelial-lined spaces filled with colloid-like eosinophilic secretions. Immunohistochemical analysis confirmed lack of expression of the thyroid markers TTF-1 and thyroglobulin with expression of PAX8 and CD10, confirming a neoplasm of renal origin, which correlated to the clinical and radiographic absence of thyroid pathology. In this report, this case is described with an emphasis on the differential diagnosis.

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.

Poorly Differentiated Thyroid Carcinoma Arising in Struma Ovarii

Struma ovarii is an uncommon type of ovarian mature teratoma with a predominant thyroid component. The morphological spectrum of the thyroid tissue ranges from that of normal thyroid to proliferative adenoma-like lesions and thyroid-type carcinomas (malignant transformation). The histologic features of ovarian strumal lesions sometimes cause diagnostic problems due to the confusion with other types of ovarian neoplasms and the difficulty in the prediction of their clinical behavior. We report an extremely rare case of poorly differentiated thyroid carcinoma arising in struma ovarii. A 22-year-old woman presented with a 15 cm right ovarian mass. The tumor showed a predominantly tubular pattern which raised a differential diagnosis between endometrioid adenocarcinoma and Sertoli cell tumor. A review of the gross specimen with additional tissue sampling helped identify the teratomatous and strumal nature, with a support by immunohistochemical staining. Despite FIGO stage IA by optimal staging procedure and the absence of identifiable lymphovascular invasion, the patient developed pulmonary metastasis 15 months after surgery and died from the progression of the disease 7 years after the diagnosis. This case emphasizes the importance of macroscopic examination of the specimen and the awareness of this uncommon tumor in the differential diagnosis of ovarian neoplasms.

Follicular proliferative lesion arising in struma ovarii

Malignant struma ovarii is extremely rare and difficult to diagnose histologically, particularly in cases of follicular carcinoma. This case study is intended to describe three cases of follicular proliferative lesion arising in struma ovarii that we experienced. The first case was clearly malignant given the clinical picture of multiple recurrences, but there was little histological evidence of malignancy. Our second case featured architectural and cellular atypia and necrosis and was diagnosed as malignant despite the absence of vascular and stromal invasion. Our third case exhibited solid microfollicular proliferation without any definite evidence of malignancy (even the molecular data was negative); however, we could not completely exclude malignant potential after conducting a literature review. In cases such as our third case, it has been previously suggested that a diagnostic term recognizing the low-grade malignant potential, such as “proliferative stromal ovarii” or “follicular proliferative lesion arising in the stromal ovarii” would be appropriate.

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.

Disseminated struma ovarii containing focal anaplastic carcinoma in peritoneal implants: a case report

Malignant changes in struma ovarii have been defined using histopathologic criteria for carcinomas of the cervical thyroid gland. We report a case of struma ovarii with extensive extraovarian spread containing a small focus of anaplastic carcinoma (AC) in peritoneal implants. AC arising in benign-looking struma ovarii with peritoneal implants has not been reported. Multiple pelvic masses were identified on abdominopelvic computed tomography in a 38-yr-old woman. An exploratory laparotomy revealed multiple, variable-sized masses on the omentum, and colonic and uterine serosa. A microscopic but grossly unidentifiable lesion in the right ovary had a histologic appearance that mimicked hyperplastic follicular epithelium of nodular thyroid goiter. Multiple peritoneal implants showed histology similar to the ovarian lesions except a focal area of AC in the omental mass. Anaplastic cells demonstrated characteristic immunoreactivity for p53, cyclin D1, and a high Ki-67 index of about 30%, with loss of expression of thyroid transcription factor-1 and thyroglobulin, whereas the remaining goitrous background showed opposite expression patterns in all aspects. Furthermore, the areas of AC showed p53 mutation by molecular analysis. The AC harboring p53 mutation within extraovarian spread suggests that disseminated struma ovarii mimicking nodular goiter has potential for histologic progression through similar pathogenetic mechanism with cervical thyroid carcinoma despite the innocuous appearance.

Management and follow-up results of an incidental thyroid carcinoma in a young woman with ovarian teratoma

Thyroid cancer in ovarian teratoma is reported to be rare and experiences are limited. A 26-year-old woman had undergone bilateral cystectomy and omentectomy for bilateral cystic adnexial masses. Pathological examination showed 1.5 cm follicular variant papillary thyroid carcinoma on the basis of unilateral mature cystic teratoma. Increased CA-125 and CA19-9 levels decreased to normal reference ranges after surgery, but postoperative magnetic resonance imaging indicated multiple abdominal cystic loci. After total thyroidectomy, high dose I-131 was administered to ablate thyroid tissue. Thereafter, levothyroxine was started to achieve subclinical hyperthyroidism. No iodine uptake was detected in post-therapeutic whole body scan (WBS) other than thyroid bed. This finding supported that tumor did not show dissemination to abdomen. No uptake on the first-year evaluation with low-dose I-131 WBS suggested the complete ablation of the thyroid gland. It is recommended that thyroid carcinoma arising from ectopic thyroid tissue in a teratoma should be managed as thyroid carcinoma in thyroid. However, direct dissemination to contiguous regions in abdomen and hematogenous dissemination to distant organs should be in mind. Radical surgery including total abdominal hysterectomy, bilateral salphingo-oopherectomy, pelvic and paraaortic lymph node excision and thyroidectomy is recommended. Fertility preserving surgery may be the surgical procedure as in the present case.

Metastatic follicular struma ovarii complicating pregnancy: a case report and review of the literature

A 35-year-old woman was determined to have an ovarian cyst and underwent a right ovarian cystectomy at 10 weeks of gestation. A histopathological examination revealed follicular carcinoma arising in a teratoma. No evidence of metastasis was found after delivery. She underwent a total thyroidectomy, followed by radioactive iodine (RAI) therapy. However, her serum thyroglobulin level increased to 1,437 ng/ml (normal range: 0-52 ng/ml) after 10 months. Radioiodine scintigraphy and abdominal computed tomography revealed liver metastasis and peritoneal seeding. She underwent debulking surgery of the liver, right salpinx, and peritoneal seeding nodules. A pathological examination showed metastatic follicular carcinoma with focal poorly differentiated features. Adjuvant RAI therapy was restarted, and her serum thyroglobulin levels returned to normal. In conclusion, metastatic lesions were successfully treated with a combination of debulking surgery and RAI therapy. Close medical follow-up monitoring serum thyroglobulin levels is mandatory in such patients.

Delayed treatment of papillary thyroid carcinoma arising from struma ovarii in a patient with history of bilateral salpingo-oophorectomy: a case report

OBJECTIVE

We present a case of papillary thyroid carcinoma arising from struma ovarii treated erroneously as ovarian adenocarcinoma for more than 3 years.

METHODS

We report clinical, surgical, laboratory, and imaging findings of the study patient and review the relevant literature.

RESULTS

A 64-year-old woman was treated for ovarian adenocarcinoma for more than 3 years before it was determined that she likely had papillary thyroid carcinoma arising from struma ovarii. This is the first reported case of thyroid carcinoma arising from struma ovarii in a patient with a history of bilateral salpingo-oophorectomy. Possible etiologies include residual ovarian tissue after oophorectomy, ectopic thyroid, or metastatic thyroid cancer.

CONCLUSIONS

It is important to include struma ovarii and thyroid carcinoma arising from struma ovarii in the differential diagnosis, even with a history of bilateral salpingo-oophorectomy. This case emphasizes the importance of effective communication among the pathologist, oncologist, and surgeon to ensure timely initiation of appropriate therapy and reduced patient morbidity.

Struma ovarii with follicular thyroid-type carcinoma and neuroendocrine component: case report

Struma ovarii (SO) is a slow-growing ovarian neoplasm with thyroid tissue as its predominant component. It is an uncommon neoplasm, usually asymptomatic with an unknown risk of malignant transformation. Due to difficulties in assessing the rare biological nature and the discrepancies in the reported cases, a consensus on the appropriate treatment has not been definitively reached.

A 50-year-old female was subjected to upper gut endoscopy which showed a 30-mm mass located in the gastric antrum, suggestive of mesenchimal tumor. Incidentally, a pelvic CT scan also documented a solid mass in the right adnexa, with morphological characteristics of ovarian neoplasm. The patient underwent gastrectomy, total hysterectomy, bilateral salpingo-oophorectomy with lymph node dissection, and omentectomy. Histology documented the presence of gastric cavernous angioma, and, in the right adnexa, foci of follicular thyroid-type carcinoma arising in SO with a well-differentiated neuroendocrine component.

Here we report and discuss the clinical and morphological presentation of follicular thyroid-type carcinoma arising in SO. The neoplasm was discovered incidentally and had a favorable clinical outcome at 1-year follow-up.