A case of metastatic struma ovarii treated with 131I therapy: focus on preservation of fertility and selected review of the literature

Thyroid Carcinoma Arising From Struma Ovarii at Adolescence: A Challenging Case With Favorable Outcome

Malignant struma ovarii (MSO) is a rare and aggressive ovarian tumor that mostly affects adults but can occur in adolescents. Prompt recognition, accurate diagnosis, and multidisciplinary management are essential for favorable outcomes. Herein, we report the youngest case of an 11-year-old girl with a large MSO. First, conventional imaging revealed a large left ovarian mass, leading to a left oophorectomy. Subsequently, histopathological examination confirmed papillary thyroid carcinoma within MSO. Thyroid and fertility-preserving surgery were chosen after multidisciplinary consultation. Despite challenges, the patient had a positive outcome with no recurrence after 36 months. Therefore, the adoption of less invasive surgical approaches and vigilant follow-up can achieve remission, but more research is needed to further enhance our understanding of the disease's risk stratification and optimal treatment strategies.

Thyroid papillary cancer elements arising from struma ovarii with benign peritoneal strumosis: Utility of iodine-123 imaging in diagnostics and treatment planning

Key Clinical Message

In this case of struma ovarii a right-sided ovarian mass contained features of papillary thyroid cancer. Diagnostic iodine-123 revealed multiple foci of extraovarian spread, likely as a manifestation of concomitant peritoneal strumosis. Unilateral oophorectomy, partial peritonectomy, and adjuvant iodine-131 treatment were performed for successful curative treatment.

Abstract

Struma ovarii is a rare form of mature teratoma defined by a predominance of thyroid tissue. Approximately 5% of all ovarian strumae exhibit malignant transformation. Due to their extreme rarity, there has been a lack of consensus concerning uniform diagnostic criteria. Appropriate, risk-stratified treatment strategies also remain widely unelaborated, based only on a small number of cases reported in the literature. We describe the case of a 35-year-old female, who presented after undergoing unilateral oophorectomy for a right-sided ovarian mass. Histological workup revealed a struma ovarii containing papillary thyroid cancer (PTC). Postoperative I-123 scintigraphy with single photon emission computed tomography (SPECT) detected multifocal extra-ovarian spread to the peritoneum, containing likely benign strumosis upon pathological examination. The subsequent treatment strategy involved an ablative concept including total thyroidectomy and subsequent I-131 radioiodine therapy. Throughout a 3-year follow-up, the patient has remained without recurrence with thyroglobulin levels ranging below detection limits. Surgical resection with adjuvant radioiodine therapy is a curative therapeutic strategy in cases of struma ovarii with thyroid-type carcinoma and peritoneal strumosis. Its benefits lay in avoiding more extensive surgery, potentially maintaining fertility, facilitating follow-up, and minimizing the risk of recurrence. Reliable criteria for risk stratification are needed to identify patients who are most likely to benefit from this treatment approach.

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.

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.

Transplantation of cryopreserved ovarian tissue in a patient affected by metastatic struma ovarii and endometriosis

In this case report, the outcomes of cryopreserved ovarian tissue transplantation performed in a patient affected by struma-ovarii associated with mature cystic teratoma, recurrent endometriotic cysts and diffuse peritoneal malignant struma-ovarii implants were described. Before cryopreservation, the patient underwent two left ovarian surgeries for enucleation cysts 8 years after righ salpingo-oophorectomy for struma-ovarii. Ovarian biopsy was collected in another hospital and transported to our laboratory for cryopreservation. The patient was submitted to radioiodine-therapy for metastases from malignant struma-ovarii. After treatment she experienced premature ovarian failure. Ten years after cryopreservation, a first orthotopic transplantation was performed in the left ovary and in a peritoneal pocket. Before transplantation, ovarian samples were analyzed to assess neoplastic contamination and tissue quality. Three years later, a second transplantation was heterotopically performed in abdominal subcutaneous sites. The analysis on thawed ovarian tissue did not reveal micrometastasis and they showed follicle and stroma damages. After transplantation few small follicles were observed at ultrasound examination and hormonal levels remained at menopausal values. To date no ovarian function recovery has been observed. The report highlights that ovarian tissue cryopreservation after multiple ovarian surgery may have some limitations. An accurate counseling should be offered to patients who wish to preserve fertility.

Isolated Scapular Metastasis in a Patient with Malignant Struma Ovarii: A Case Report

CASE

We report the case of a 38-year-old woman who presented with a lytic bone lesion in the left scapula. A biopsy showed a tumor with the histologic appearance of thyroid tissue. She also was found to have a thyroid nodule and an enlarged ovary, both of which were excised. The thyroid nodule turned out to be a benign colloid nodule, and the ovary contained a monodermal teratoma composed of thyroid tissue (struma ovarii). The lesion in the scapula eventually was proven to be metastatic malignant struma ovarii.

CONCLUSION

Malignant struma ovarii with bone metastases is very rare, and its diagnosis is a challenge. There are some documented cases with bone metastases, mostly to the thoracic and lumbar spine. The optimal treatment of choice for the bone lesion is unknown because of the rarity of its presentation.

Long-term survival in metastatic malignant struma ovarii treated with oral chemotherapy: A case report

Malignant struma ovarii is a rare type of ovarian tumor. Metastasis from malignant struma ovarii is rare and has only been documented in 5–6% of cases. The natural history and optimal treatment strategy for malignant struma ovarii remains controversial due to its rarity. The current report presents the case of a 45-year-old female who presented with a tumor of the rib bone. Following resection, the postoperative diagnosis was a metastasizing thyroid carcinoma. No abnormality was detected in the thyroid gland, however, computed tomography revealed a tumor in the left ovary. The patient underwent a left salpingo-oophorectomy and a wedge resection of the right ovary. The postoperative diagnosis was determined as a mature cystic teratoma with malignant struma ovarii (thyroid type, follicular carcinoma) of the left ovary and mature cystic teratoma of the right ovary. Four years subsequent to the initial diagnosis, multiple lung metastases were detected. The following chemotherapies were administered sequentially and intermittently: Tegafur-uracil, paclitaxel/carboplatin and oral etoposide. During this period, the metastatic lesions extended into the bone and progressed slowly. The patient continues to survive with the disease and 24 years have passed since the initial diagnosis, 20 years following the diagnosis of multiple lung metastates. The present report describes a rare case of malignant struma ovarii in which surgical resection and pathological examination of a metastatic rib tumor resulted in the identification of the primary ovarian lesion. The clinical behavior of malignant struma ovarii does not necessarily indicate a histological malignancy, therefore, prediction of future metastasis is difficult and the optimal treatment strategy for malignant struma ovarii is controversial. The present case indicates that the long-term use of oral anticancer agents may facilitate the maintenance of tumor dormancy.

131I therapy using rhTSH stimulation and dosimetry in metastatic malignant struma ovarii

A 38-year-old woman with metastatic malignant struma ovarii, including massive liver metastases and retroperitoneal lymphadenopathy, underwent ovarian resection and retroperitoneal lymph nodes excision, partial hepatectomy, and radiofrequency ablation for liver metastases. She underwent thyroidectomy and received three I treatments using recombinant human thyrotropin stimulation and radioiodine dosimetry. posttherapy I imaging, anatomic images, and thyroglobulin levels showed significant diminution in the tumor burdens and remarkable decline in thyroglobulin levels. This case provided valuable information on recombinant human thyrotropin-assisted I ablation in conjunction with dosimetry in an unusual presentation of iodine-avid malignant struma ovarii with bulky metastases.

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.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Lethal, malignant, metastatic struma ovarii

BACKGROUND

Struma ovarii (SO) is extremely rare, with less than 200 reported cases in the medical literature. SO is defined by the presence of an ovarian tumor containing thyroid tissue as the predominant cell type. Malignant transformation is rare and lethal cases of SO are even rarer. We report on a patient presenting with left ovarian cystic SO and lethal outcome.

SUMMARY

A 45-year-old woman was diagnosed with a follicular variant of papillary carcinoma on laparotomy and left salpingo-oophorectomy. She had persistently elevated serum thyroglobulin following total thyroidectomy + radioiodine and second-look surgery. Imaging scan analysis showed pelvic tumor recurrence and hypervascular liver metastases during follow-up as well as peritoneal carcinomatosis in the pelvis, right abdominal wall, and malignant ascites. The patient died from cachexia at 37 months after diagnosis.

CONCLUSIONS

Such an aggressive malignant disease and lethal course of SO is rare. Total thyroidectomy is mandatory to exclude a primary thyroid neoplasm and for radioiodine therapy and follow-up. SO may spread to contralateral ovary, pelvic nodes, peritoneum, liver, lungs, and bones through hematogeneous spread, which is different from the dissemination pattern of papillary thyroid carcinomas. Imaging highlights the mixed behavior of this ovarian tumor.

Expression of benign and malignant thyroid tissue in ovarian teratomas and the importance of multimodal management as illustrated by a BRAF-positive follicular variant of papillary thyroid cancer

BACKGROUND

The most common type of ovarian germ cell tumor is the teratoma. Thyroid tissue, both benign and malignant, may be a component of an ovarian teratoma. Here we review this topic and illustrate major features by presenting multimodal management of a patient with BRAF-positive disseminated follicular thyroid cancer arising in an ovarian teratoma.

SUMMARY

Malignant thyroid tissue is often difficult to distinguish from benign thyroid tissue arising in ovarian teratomas. Preoperatively, an elevated thyroglobulin (Tg) level, laboratory or clinical evidence of hyperthyroidism, or ultrasonography appearance of "struma pearl" should prompt referral to oncologist for surgical management of a possibly malignant ovarian teratoma. Postoperatively, tumor tissue should be referred to pathologists experienced with differentiating benign from malignant struma ovarii. Once diagnosed, treatment of this rare condition should be handled by a team of specialists with combined treatment modalities. We cared for woman with disseminated thyroid cancer arising in an ovarian teratoma whose history illustrates the complexity of managing ovarian teratomas with malignant thyroid tissue. At age 33 she had an intraoperative rupture of an ovarian cyst, thought to be struma ovarii. During her next pregnancy, pelvic masses were noted; biopsies revealed well-differentiated papillary thyroid carcinoma, follicular variant. She was euthyroid, but had elevated serum Tg levels. Surgical staging demonstrated widely metastatic intraabdominal dissemination. A thyroidectomy revealed no malignancy. A post-(131)I treatment scan revealed diffuse uptake throughout the abdomen. She then developed abdominal pain and, on computed tomography, was found to have multiple intraabdominal foci of disease. Serum Tg was 264 ng/mL while on L-thyroxine for hypothyroidism and to obtain thyrotropin suppression. A 18 fluorodeoxyglucose positron emission tomography scan showed no pathological uptake. The tumor was found to be BRAF mutation positive (K601E). She underwent extensive secondary debulking and a second course of (131)I with lithium pretreatment. Posttreatment scan revealed diffuse abdominal uptake. Six months posttherapy, the patient is asymptomatic with a serum Tg of 18.1 ng/mL.

CONCLUSIONS

Aggressive multimodal management appears to be the most promising approach for malignant thyroid tissue arising in ovarian teratomas.