UNASSIGNED: 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.
UNASSIGNED: 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.
UNASSIGNED: 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.
UNASSIGNED: 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.

UNASSIGNED: Follicular thyroid cancer (FTC) typically spreads hematogenously, with bone metastasis being worrisome, often appearing to be resistant to radioactive iodine (RAI) therapy. Metastasis to sternum is exceedingly rare.
METHODS: A 43-year-old Egyptian male presented with chest tightness, cough, and shortness of breath. He was initially treated as bronchial asthma. Later, he was referred to our thyroid surgery clinic as a case of goitre and palpable sternal mass. He looked clinically well, with enlarged anterior neck mass and visible sternal mass, no lymphadenopathy. Laboratory tests showed thyroid-stimulating hormone levels within normal (2.13 mIU/L), and mildly decreased FT4 (10.3 pmol/L). Neck/chest CT demonstrated multinodular goitre with retrosternal extension, expansile lytic lesion in the sternum, and bilateral lung metastases. Thyroid fine needle aspiration and cytology showed FLUS, and true cut biopsy from the sternal lesion showed invasive FTC.
CONCLUSIONS: Rare bilateral FTC presenting as slow-growing sternal metastasis. The patient underwent total thyroidectomy, followed by high dose RAI therapy, and concluded with sternectomy and reconstruction surgery repair using polymethyl methacrylate wrapped in proline mesh. On follow-up, he received further RAI ablation therapy and became RAI refractory. He then received systemic therapy (Lenvatinib). Most recent follow up showed that the disease was controlled (low volume cancer) and he was tolerating treatment well with no reported symptoms.
CONCLUSIONS: Bilateral FTC with sternal metastasis is rare, and can be treated with total thyroidectomy, sternectomy and reconstruction, followed by RAI therapy and systemic therapy where required, hence inferring real survival benefit.

There are conflicting reports on the factors that increase the likelihood of patients dying from follicular thyroid carcinoma (FTC). Therefore, it is critical to identify risk factors of patients with FTC. This study aimed to identify the factors that increase the risk of death of patients with FTC and help clinicians make better treatment and follow-up decisions.
A systematic literature review was conducted in PubMed and Web of Science databases for relevant studies published before January 31, 2023. Their reference lists were also analyzed. Two reviewers extracted data and evaluated the quality of eligible studies independently. Studies on patients who had open thyroidectomy procedures with or without neck dissection were included in this review. The RevMan 5.3 software was used to analyze the data.
This meta-analysis included thirteen studies with a total of 2075 patients. The following variables were associated with an increased risk of death in FTC patients: age > 45 years, male, tumor diameter > 4 cm, multifocality, extrathyroidal extension (ETE), widely invasive (WI), cervical lymph node metastasis (CLNM), distant metastases (DM) and non-radical resection tumor. Lobectomy and no radioactive iodine (RAI) treatment was not associated with the death of FTC patients.
Clinicians should pay closer attention to the following significant risk factors associated with the death of FTC patients: age (> 45), male, multifocality, tumor diameter > 4 cm, ETE, WI, non-radical resection tumor, CLNM, and DM. Individualized initial treatment and close follow-up are needed FTC patients who have these risk factors.

Differentiated thyroid cancer (DTC) is rare in childhood and adolescence although it represents the most frequent endocrine malignancy in this population. DTC includes both papillary thyroid carcinoma (PTC) and follicular thyroid carcinoma (FTC). Most pediatric DTCs are PTCs, while FTCs are rare. To date, no systematic reviews on the global epidemiology of pediatric and adolescent DTC have been published. This systematic review and meta-analysis aims to estimate the overall incidence and prevalence of DTCs in patients aged 0-19 years.
The systematic research was conducted from January 2000 to December 2021 through MEDLINE via PubMed, Cochrane Library, and Embase databases. Two separate meta-analyses were performed for PTC and FTC.
After the selection phase, a total of 15 studies (3,332 screened) met the inclusion criteria and are reported in the present systematic review. Five studies were conducted in Europe, five in North America, two in South America, one in Asia, one reported data for 49 countries and territories across the five continents, and one from both the USA and Africa. Most of the studies (n = 14) reported data obtained from national registries, and only one provided information collected from hospital medical records. Beyond the actual trend over time, our study reported a pooled global incidence rate (IR) of PTC and FTC in the pediatric age of 0.46 (95% CI: 0.33-0.59) and 0.07 (95% CI: 0.02-0.12) per 100,000 person-years, respectively. The highest IRs were recorded among Caucasian girls, and the lowest in black or other races/ethnicities.
Our data confirm that DTC in the pediatric population is a rare condition. The pooled IRs of the studies included in this meta-analysis are ~0.5 for PTC, which is the most common histological type when both genders and all age groups are considered. The implementation of a prospective international registry on pediatric DTC, as part of the wider European Registries for Rare Endocrine Conditions, has been recently proposed. In addition to providing relevant information on the clinical behavior of this rare disease, standardization of data collection will be pivotal to fill current gaps and allow an accurate estimation of the real incidence and risk factors of DTC.

UNASSIGNED: The majority of thyroid malignancies are differentiated thyroid carcinomas (DTCs). We examined the incidence, disease extent, recurrence and disease-specific mortality (DSM) of DTC among Filipinos residing in the Philippines and Filipino immigrants.
UNASSIGNED: In accordance with the 2020 PRISMA statement, we performed a systematic literature search in MEDLINE, Google Scholar, EBSCO, Cochrane and Clinicaltrials.gov for the period January 1, 1980 until January 27, 2022. Pooled incidence rate ratio and pooled proportions of disease extent, recurrence and DSM were determined.
UNASSIGNED: Literature search yielded 1,852 studies. Out of 26 articles retrieved, nine retrospective case controls and cohorts were included. Incidence of DTC was significantly higher in female Filipino immigrants compared with non-Hispanic whites (NHW). Distant metastases and recurrence were more common among Filipinos and Filipino immigrants compared with NHW. Limited data showed higher DSM in Filipino immigrants and NHW than Filipinos, which may be influenced by reporting bias.
UNASSIGNED: This review supports the trend of increased incidence and recurrence of DTC among Filipinos, although case registries are essential to confirm these findings. In the setting of the newly released Philippine guidelines for DTC, prospective studies with active long-term follow-up will help detect any changes in the outcomes of DTC among Filipinos.

BACKGROUND: Thyroid carcinoma is the most common endocrine neoplasm. Multimodal therapy including surgery, radioactive iodine (RAI) therapy, and indefinite suppression of thyroid-stimulating hormone has led to an 85% cure rate in differentiated thyroid tumors (DTT). Approximately 5-10% of patients will have recurrence or metastases that have the potential to become resistant to RAI treatment.1 10-year overall survival rates are reported to be 10% in these patients versus 56% in patients with RAI avid disease.2 Lenvatinib, a multi-tyrosine-kinase inhibitor (TKI), was shown to have a 65% overall response rate in addition to a significant improvement in progression-free survival (PFS), approved to treat RAI-resistant DTTs.3, 4.
METHODS: We are reporting a very rare case of late renal toxicity in a 68-year-old woman with a history of type 2 diabetes and metastatic RAI-resistant follicular thyroid carcinoma (Hurthle cell variant) who developed thrombotic microangiopathy 21 months after initiation of treatment.
METHODS: It was determined that LEN should be held, due to worsening renal function secondary to TKI-induced kidney injury. Although the patient\'s renal function eventually improved and returned to her baseline after discontinuation of LEN, there was marked disease progression after drug cessation.
CONCLUSIONS: Renal toxicity is a rare adverse event (AE) that tends to occur typically within three weeks of initiation of treatment. The utilization of TKIs can lead to glomerulosclerosis, and careful considerations and precautions should be taken by clinicians who intend to initiate TKI therapy in patients with pre-existing diabetes to prevent renal toxicity.

BACKGROUND: The synchronous development of a medullary and papillary carcinoma as two different tumors has only been reported very rarely. The aim of the current report is to describe an extremely rare occurrence of medullary carcinoma, papillary microcarcinoma, and Hashimoto thyroiditis.
METHODS: A 53-year-old man presented with a right-sided neck mass. Ultrasound showed a well-defined nodule in the right mid third with microcalcification and increased nodular vascularity associated with multiple right-sided cervical lymphadenopathy. The histopathological examination showed multifocal medullary carcinoma with incidental finding of unifocal papillary microcarcinoma conventional type on the left side. Additional pathology of Hashimoto thyroiditis with a small intra-thyroidal parathyroid gland in the left thyroid gland. The procedure went perfectly and the patient was discharged home without any difficulties.
CONCLUSIONS: Synchronous existence of these two neoplasms can occur in two forms: distinct medullary carcinoma and papillary carcinoma isolated by normal thyroid tissue, or mixed medullary and follicular-derived thyroid carcinoma, in which single or multiple lesions show morphology and immunoreactivity for both medullary carcinoma and follicular-derived carcinoma.
CONCLUSIONS: The synchronous coexistence of papillary microcarcinoma, medullary carcinoma, and Hashimoto\'s thyroiditis is an uncommon thyroid condition.

BACKGROUND: Follicular thyroid carcinomas (FTCs) rarely metastasize to regional lymph nodes, and descriptions of synchronous lateral lymph node metastases of FTC and papillary thyroid carcinoma (PTC) are lacking.
METHODS: We describe a 43-year-old female with a preoperative cytology indicating a right-sided PTC with lateral lymph node metastases. She underwent a total thyroidectomy and central and lateral lymph node dissection, and histopathology confirmed a multifocal tall cell variant PTC together with a 12 mm minimally invasive FTC in the ipsilateral lobe. While the central compartment demonstrated metastatic PTC, the lateral compartment contained PTC metastases alongside a 15 mm large follicular-patterned mass in a separate lymph node. As the cells lacked PTC associated nuclear changes, the possibility of a lateral lymph node metastasis of FTC was considered, with the possibility of ectopic thyroid tissue as a differential diagnosis. By utilizing next-generation sequencing, a Q61R NRAS mutation was pinpointed, thus proving the tissue as tumorous. The patient underwent radioiodine treatment and is currently monitored following a negative whole-body scan.
CONCLUSIONS: This is probably the first case report of a patient with co-existing lateral lymph node PTC and FTC metastases. Consulting previous publications, there is currently a gap of knowledge in terms of how patients with regional FTC metastases should be followed-up and treated, especially when co-occurring with spread high-risk PTC subtypes. Moreover, what guides a seemingly indolent FTC to spread via the lymphatic system remains to be defined from a molecular standpoint.

Although the incidence of thyroid carcinoma has increased in recent years, follicular thyroid carcinoma with bone metastasis as the first symptom remains rare. Here, we report a case of occult follicular thyroid carcinoma in a 65-year-old female patient admitted to hospital with cerebrovascular disease. Computed tomography findings suggested a diagnosis of meningioma; however, magnetic resonance imaging results showed multiple skull bone destruction with soft tissue masses on the left side of the skull. After surgical resection, the pathology results revealed skull metastasis of follicular thyroid carcinoma. We present this case not only because of the diagnostic challenge it posed, but also because the patient had multiple skull metastases from follicular thyroid carcinoma.

BACKGROUND: Follicular thyroid carcinoma is the second most common malignancy of the thyroid gland. In 2016, the so-called Hurthle cell thyroid carcinoma, formerly known as the oxyphilic variant of the follicular thyroid carcinoma, was reclassified by the World Health Organization as a separate pathological entity, which accounts for approximately 3% of all thyroid cancers. Although Hurthle cell thyroid carcinomas are known for their more aggressive tumor biology, metastases are observed in a minority of cases, and long-term survival can be expected. However, disseminated disease is often associated with poor outcome.
METHODS: In the presented case, a 63-year-old Caucasian female was incidentally diagnosed with Hurthle cell thyroid carcinoma after undergoing hemithyroidectomy for a nodular goiter. Following completion thyroidectomy, two courses of radioactive iodine therapy were administered. After 4 years of uneventful follow-up, the patient gradually developed metastases in five different organs, with the majority representing unusual sites, such as heart, kidney, and pancreas over a course of 14 years. The lesions were either treated with radioactive iodine therapy or removed surgically, depending on iodine avidity.
CONCLUSIONS: Follicular and Hurthle cell thyroid carcinoma are known to potentially spread hematogenously to typical sites, such as lung or bones, however; unusual metastatic sites as presented in our case can also be observed. A search of the literature revealed only scattered reports on patients with multiple metastases in unusual locations. Furthermore, the observed long-term survival of our patient is contradictory to the existing data. As demonstrated, recurrent disease may appear years after the initial diagnosis, emphasizing the importance of consistent aftercare. Radioactive iodine therapy, extracorporeal radiation therapy, and surgical metastasectomy are central therapeutic components. In summary, our case exemplifies that thorough aftercare and aggressive treatment enables long-term survival even in recurrent Hurthle cell thyroid carcinoma displaying unusual multisite metastases.