Estruma ovárico maligno y cáncer papilar de tiroides sincrónicos

Malignant Struma Ovarii with Concurrent Thyroid Cancer: Outcomes during and after Pregnancy

INTRODUCTION

Struma ovarii (SO) is a rare ovarian teratoma characterized by the presence of thyroid tissue in more than 50% of the tumor. Malignant transformation is rare and the most common associated malignancy is papillary thyroid carcinoma (PTC). Pregnancy may represent a stimulus to differentiated thyroid cancer (DTC) growth in patients with known structural or biochemical evidence of disease, but data about malignant SO evolution during pregnancy are rare. We present the first reported case of a pregnant patient with malignant SO and biochemical evidence of disease.

CASE PRESENTATION

A previously healthy 35-year-old female diagnosed with a suspicious left pelvic mass on routine ultrasound was submitted to laparoscopic oophorectomy which revealed a malignant SO with areas of PTC. A 15-mm thyroid nodule (Bethesda V in the fine-needle aspiration cytology) was detected by palpation and total thyroidectomy was performed. Histology revealed a 15 mm follicular variant of PTC (T1bNxMx). Subsequently, she received 100 mCi of radioactive iodine therapy (RAIT) with the whole-body scan showing only moderate neck uptake. Her suppressed thyroglobulin (Tg) before RAI was 1.1 ng/mL. She maintained biochemical evidence of disease, with serum Tg levels of 7.6 ng/mL. She got pregnant 14 months after RAIT, and during pregnancy, Tg increased to 21.5 ng/mL. After delivery, Tg decreased to 14 ng/mL but, 6 months later, rose again and reached 31.9 ng/mL on the last follow-up visit. TSH was always suppressed during follow-up. At the time of SO diagnosis, a chest computed tomography scan showed 4 bilateral lung micronodules in the upper lobes which were nonspecific, and 9 months after diagnosis, a pelvic MRI revealed a suspicious cystic nodule located on the oophorectomy bed. These lung and pelvic nodules remained stable during follow-up. Neck ultrasonography, abdominal MRI, and fluorodeoxyglucose-positron emission tomography showed no suspicious lesions.

DISCUSSION/CONCLUSION

As for DTC, pregnancy seems to represent a stimulus to malignant SO growth. This can be caused by the high levels of estrogen during pregnancy that may bind to receptors in malignant cells and/or by the high levels of hCG which is known to stimulate TSH receptors.

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.

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

Objective

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

Methods

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

Results

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

Conclusion

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

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

Background

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

Case presentation

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

Conclusions

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

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

Context

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

Case Description

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

Conclusions

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