Thyrotoxic adenoma followed by atypical hyperthyroidism due to struma ovarii: clinical and genetic studies

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.

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.

From struma ovarii to Hashimoto disease--an unusual diagnosis of primary hypothyroidism: case report

CAPSULE

Authors report a case of a 52-year-old woman after struma ovarii with chronic lymphocytic inflammation excision. Finally thyroxin treatment was started and patient's hypothyroidism symptoms diminished.

CASE SUMMARY

Struma ovarii is a type of mature teratoma in which thyroid tissue forms the main component. In most cases struma ovarii is composed of normal thyroid tissue while lymphocytic thyroiditis in struma ovarii occurs very rarely. The authors report a case of a 52-year-old woman after ovarian tumor excision. In histopatholgical examination struma ovarii with chronic lymphocytic inflammation was diagnosed. Additional studies revealed a typical ultrasonographic picture of Hashimoto disease in the thyroid gland and an increased concentration of thyroglobulin antibodies. A final diagnosis of Hashimoto disease was confirmed. Initially, thyroid gland function was normal but 11 months after surgery, supplementation therapy with thyroxin was administered. In this case, an early diagnosis of Hashimoto disease resulted from excision of struma ovarii with chronic lymphocytic inflammation. It induced early thyroxin treatment and allowed to reduce hypothyroidism symptoms.

Ectopic thyroid tissue: anatomical, clinical, and surgical implications of a rare entity

Ectopic thyroid tissue is a rare entity resulting from developmental defects at early stages of thyroid gland embryogenesis, during its passage from the floor of the primitive foregut to its final pre-tracheal position. It is frequently found around the course of the thyroglossal duct or laterally in the neck, as well as in distant places such as the mediastinum and the subdiaphragmatic organs. Although most cases are asymptomatic, symptoms related to tumor size and its relationship with surrounding tissues may also appear. Any disease affecting the thyroid gland may also involve the ectopic thyroid, including malignancy. The clinician must distinguish between ectopic thyroid and metastatic deposits emerging from an orthotopic gland, as well as other benign or malignant masses. Thyroid scintigraphy plays the most important role in diagnosing ectopy, but ultrasonography contributes as well. In cases of symptomatic disease, surgery is the treatment of choice, followed by radioiodine ablation and levothyroxine suppression therapy in more refractory cases. This review provides current understanding about the wide clinical spectrum of this rare condition, also referring to optimal diagnostic approach, differential diagnosis, and management strategies.

Laparoscopic excision of malignant struma ovarii and 1 year follow-up without further treatment

OBJECTIVE

To report the case of a patient with malignant struma ovarii, which was excised endoscopically.

DESIGN

Case study and literature review.

SETTING

Hospital outpatient clinic with subsequent hospitalization.

PATIENT(S)

A 40-year-old gravida 5, para 3 with an incidental ultrasonographic finding of a solid right adnexal mass.

INTERVENTION(S)

Endoscopic resection and 1-year follow-up.

MAIN OUTCOME MEASURE(S)

Treatment options and differential diagnosis.

RESULT(S)

The tumor was excised endoscopically.

CONCLUSION(S)

Malignant struma ovarii is a very rare, highly specialized form of mature ovarian teratoma, in which thyroid tissue is the predominant element. Because of the nonspecific symptoms and a lack of specific features in imaging studies, preoperative diagnosis is very difficult, and there is no standard treatment. Struma ovarii, which is potentially malignant, should be included in the differential diagnosis of an ovarian mass with cystic, solid, or mixed cystic and solid structure. Standardized treatment of malignant struma ovarii still remains undefined; currently the laparoscopic removal of the tumor may be a treatment option, and thyroidectomy and radiotherapy with 131I should be offered.

RAS mutation-positive follicular variant of papillary thyroid carcinoma arising in a struma ovarii

Struma ovarii is an ovarian mature teratoma composed exclusively or predominantly of thyroid tissue. Malignant transformation of struma ovarii is rare and poorly understood, although this process is thought to be similar to carcinogenesis in malignant tumors of differentiated thyroid tissue originating in the thyroid gland. Genetic alterations in the mitogen-activated protein kinase pathway, including mutations of BRAF, RAS, and RET genes, have been implicated in the development of differentiated thyroid carcinoma arising in the thyroid gland. We report here a case with RAS mutation detected in a malignant struma ovarii. The patient is a 38-year-old female who had a 2.4 cm ovarian cyst noted incidentally on a first trimester ultrasound. She proceeded to ovarian cystectomy post-delivery, with pathologic examination detecting a papillary thyroid carcinoma, follicular variant, arising in a cystic teratoma. The tumor was tested for BRAF, RAS, and RET/PTC mutations. HRAS codon 61 mutation was identified. This is the first report of RAS mutation detected in the follicular variant of papillary carcinoma arising in a struma ovarii. It provides evidence that tumors developing in this setting involve molecular mechanisms similar to those implicated in tumors developing in the thyroid gland.

Malignant Struma Ovarii – A Case Report and Review of the Literature

BACKGROUND

Struma ovarii is a rare monodermal ovarian teratoma composed predominantly of mature thyroid tissue. Of these cases, 5-8% are clinically hyperthyroid and 5-10% of these tumors are malignant.

CASE REPORT

A 53-year-old female presented with a 19 x 5 x 5 cm pelvic mass that was treated with bilateral salpingo-oophorectomy, pelvic and para-aortic lymph node sampling, omentectomy and appendectomy and staging for an ovarian tumor. There was no evidence of distant metastases or lymph node invasion. Re-evaluation of the patient after surgery revealed that she was clinically euthyroid and there was no thyroid malignancy. Histopathology revealed papillary thyroid carcinoma arising in struma ovarii (malignant struma ovarii).

CONCLUSION

Malignant struma ovarii is a very rare malignant ovarian teratoma. In young patients unilateral oophorectomy and complete surgical staging should be considered when the tumor is confined to the one ovary (stage Ia). Long-term follow-up for the detection of metastases or tumor recurrence by serial serum thyroglobulin and (131)I scan or positron emission tomography/computed tomography may be required in selected patients with this rare tumor.

Goitre ovarien: une forme particulière de tératome de l'ovaire

Struma ovarii, a rare form of ovarian tumor, represents less than 3% of ovarian teratomas. The peak frequency occurs during the fifth decade of life. Diagnosis is usually a surprise of pelvic ultrasound or histological analysis. Surgery is the main mode of treatment and prognosis is excellent. Struma ovarii can be associated with thyroid biology abnormalities, or exceptionally become malignant, and thus managed as a thyroid cancer.

Incidental diagnosis of struma ovarii after thyroidectomy for thyroid cancer: Functional imaging studies and follow-up

BACKGROUND

Struma ovarii is a rare ovarian germ-cell tumor containing thyroid tissue. We report an unusual case of incidental diagnosis of struma ovarii after thyroidectomy for thyroid cancer.

CASE

A 24-year-old woman presented with a papillary thyroid carcinoma (pT3N1). After (131)I administration for thyroid remnant ablation, whole-body scan showed a thyroid bed uptake and a right pelvic uptake corresponding to an ovarian cyst on ultrasonography. Preablation thyroglobulin was more elevated than usually found after total thyroidectomy. (18)F-FDG PET was normal. Histopathological analysis revealed a benign struma ovarii. At 6 months, after oophorectomy, serum-stimulated Tg returned to undetectable value and diagnostic WBS was negative.

CONCLUSION

Only few cases of incidental scintigraphic diagnosis of struma ovarii have been described. To our knowledge, it is the first case revealed after remnant ablation for thyroid carcinoma. The distinction with ovarian metastasis is discussed.

Coexistence of Graves' disease and benign struma ovarii in a patient with marked ascites and elevated CA-125 levels

BACKGROUND

Struma ovarii is the most common monodermal ovarian teratoma and consists mainly of thyroid tissue. Only 5% of patients with this tumor have features of hyperthyroidism. The pathophysiology of hyperthyroidism in struma ovarii is not clear.

CASE

We describe a case of benign struma ovarii, presenting with the clinical features of an ovarian cancer: large complex pelvic mass, large amount of ascites and markedly elevated CA-125 serum levels. The patient was initially treated for Graves' disease, on the basis of ultrasonographic, laboratoristic and scintigraphic evidence. The resistance to the medical treatment led to thyroidectomy. After surgery the hyperthyroidism persisted and, suddenly, the patient presented ascites. A large pelvic mass was then diagnosed which, at the pathologic examination, was diagnosed as a struma ovarii.

CONCLUSION

The struma ovarii always has to be considered when a pelvic mass is associated with features of hyperthyroidism.