Unusual Thyroid Carcinoma Metastases: a Case Series and Literature Review

Occult Papillary Carcinoma Thyroid with Solitary Appendicular Bone Metastasis in Proximal Humerus - A Case Report

Introduction

An occult presentation of primary thyroid malignancy refers to a clinically silent primary tumor that initially manifests through metastasis or secondary paraneoplastic phenomena. Papillary carcinoma is a well-recognized thyroid malignancy associated with this pattern of presentation, but bone metastases are uncommon in occult papillary thyroid carcinoma (OPTC), with reported cases typically involving the axial skeleton.

Case Report

A woman in her 70s presented with swelling and pain in her right arm. Examination revealed an oval swelling on the proximal humerus. Radiographs and magnetic resonance images suggested a lytic lesion in the proximal humerus. Upon metastatic workup, biopsy, and immunohistochemistry, the diagnosis turned out to be metastasis from occult papillary thyroid cancer.

Conclusion

Bone metastases are uncommon in OPTC, with reported cases typically involving the axial skeleton. Metastasis to the appendicular skeleton as the initial presentation is exceptionally rare.

A Rare Case of Scalp Metastasis from Encapsulated Angioinvasive Follicular Thyroid Carcinoma

Cutaneous metastases from thyroid carcinomas are extremely rare; however, the scalp is a common site for cutaneous metastases from follicular thyroid carcinomas (FTCs). We report the case of a 77-year-old male patient with a blood-rich scalp lesion. Histopathological tests of punch biopsy specimens revealed subcutaneous well-formed follicular structures that were similar to those found in the thyroid gland. Immunohistochemistry using thyroid transcription factor-1 (TTF-1) and paired-box gene family 8 (PAX8) revealed an FTC metastasis. We performed total thyroidectomy and resection of the scalp lesion at the same time and administered postoperative radioactive iodine treatment. The primary thyroid lesion was diagnosed as an FTC based on extracapsular extension and vessel invasion. The patient has not experienced disease recurrence since the treatment. When scalp metastasis of thyroid carcinoma is suspected, we recommend total extirpation, including the primary tumor and scalp metastasis, for an improved prognosis.

Skin metastasis of papillary thyroid carcinoma: A case report and literature review

The present study reports a rare case of skin metastasis in a 26-year-old female patient with a history of PTC positive for the BRAF V600E mutation. During the 2.5-year follow-up period after the initial surgical treatment of PTC, no evidence of distant metastasis was found via thyroglobulin measurements, neck ultrasound, or neck and chest computed tomography. However, following this period, the patient reported two skin nodules on the left side of the neck. Ultrasound-guided punch biopsy was performed, and the pathology results demonstrated that the patient had skin metastases from the PTC. The patient received surgical resection and complete removal of nodules, and was subsequently discharged from the hospital. A literature review showed that there are numerous potential mechanisms for skin metastasis, and the treatments are diverse and dependent on the patient condition. While surgical treatment may effectively improve patient symptoms and prognosis, long-term surveillance for recurrence is recommended for high-risk cases. Skin metastasis of PTC should be suspected in patients who develop an upper body skin lesion with a history of PTC, even without evidence of disease metastasis. For high-risk patients with skin metastasis of PTC with BRAF and TERT gene mutations, long-term surveillance for recurrence should be recommended in cases with a poor prognosis, and further research of these cases should be conducted in the future to optimize surgical and medical care.

Thyroid Gland as a Metastatic Site for Hepatocellular Carcinoma: A Rare Case Report

Background

Thyroid gland metastasis from distant primary tumors is uncommon, with liver cancer being a particularly rare source. This case report describes the clinical challenges and diagnostic journey of a thyroid mass in a patient with chronic hepatitis B, liver cirrhosis, and hepatocellular carcinoma, underscoring the rarity and complexity of such metastatic relationships.

Case Presentation

A 63-year-old male with a long-standing history of hepatitis B-related liver cirrhosis and a recent diagnosis of hepatocellular carcinoma presented with a rapidly enlarging painful right-sided thyroid mass associated with swelling but no systemic symptoms such as fever or dysphonia. This prompted a thorough diagnostic workup. Enhanced neck scans indicated a mass potentially originating from the thyroid with tracheal compression, yet crucially, there was no evidence of lung involvement based on the chest CT. Despite the rarity of liver-to-thyroid metastasis, the patient's multifaceted medical history warranted a broad differential diagnosis.

Intervention and Outcome

Surgical intervention included a right-sided thyroidectomy and partial left thyroidectomy under general anesthesia. Histopathological examination unexpectedly confirmed the presence of metastatic thyroid cancer originating from the primary liver tumor. This led to further extensive surgical management, including lymph node dissection in the central neck area. The postoperative regimen was adapted to include thyroid hormone replacement and ongoing treatment for hepatocellular carcinoma. The patient's postoperative recovery was closely monitored, reflecting stable disease with no immediate complications.

Conclusion

This case highlights the clinical rarity and diagnostic challenges of liver cancer metastasizing to the thyroid. It emphasizes the need for vigilance in patients with known primary malignancies, especially hepatocellular carcinoma, presenting with new thyroid abnormalities. This advocates for a comprehensive diagnostic approach in such atypical presentations.

Brain Metastases in Differentiated Thyroid Cancer: Clinical Presentation, Diagnosis, and Management

Background: Brain metastases (BM) are the most common intracranial neoplasms in adults and are a significant cause of morbidity and mortality. The brain is an unusual site for distant metastases of thyroid cancer; indeed, the most common sites are lungs and bones. In this narrative review, we discuss about the clinical characteristics, diagnosis, and treatment options for patients with BM from differentiated thyroid cancer (DTC). Summary: BM can be discovered before initial therapy due to symptoms, but in most patients, BM is diagnosed during follow-up because of imaging performed before starting tyrosine kinase inhibitors (TKI) or due to the onset of neurological symptoms. Older male patients with follicular thyroid cancer (FTC), poorly differentiated thyroid cancer (PDTC), and distant metastases may have an increased risk of developing BM. The gold standard for detection of BM is magnetic resonance imaging with contrast agent administration, which is superior to contrast-enhanced computed tomography. The treatment strategies for patients with BM from DTC remain controversial. Patients with poor performance status are candidates for palliative and supportive care. Neurosurgery is usually reserved for cases where symptoms persist despite medical treatment, especially in patients with favorable prognostic factors and larger lesions. It should also be considered for patients with a single BM in a surgically accessible location, particularly if the primary disease is controlled without other systemic metastases. Additionally, stereotactic radiosurgery (SRS) may be the preferred option for treating small lesions, especially those in inaccessible areas of the brain or when surgery is not advisable. Whole brain radiotherapy is less frequently used in treating these patients due to its potential side effects and the debated effectiveness. Therefore, it is typically reserved for cases involving multiple BM that are too large for SRS. TKIs are effective in patients with progressive radioiodine-refractory thyroid cancer and multiple metastases. Conclusions: Although routine screening for BM is not recommended, older male patients with FTC or PDTC and distant metastases may be at higher risk and should be carefully evaluated for BM. According to current data, patients who are suitable for neurosurgery seem to have the highest survival benefit, while SRS may be appropriate for selected patient.

Unusual Metastatic Sites and Radioiodine Uptake in Patients of Differentiated Thyroid Carcinoma with Atypical Clinical Presentations: Utilization of 131 I-Whole-Body Scintigraphy with Regional SPECT/CT

Differentiated thyroid carcinoma (DTC) usually is slow growing and carries a good prognosis. It most commonly tends to spread locally to regional lymph nodes in 20 to 60% of patients. The presence of distant metastasis impacts overall survival and prognosis. The lungs, bones, and the brain are typically involved in distant sites with less common metastatic sites that include the liver, kidney, skeletal muscle, adrenal glands, bladder, and skin. These unusual sites are rare and pose a diagnostic challenge and impact clinical decision-making to a great extent. The radioiodine 131 I whole-body scintigraphy with single-photon emission computed tomography/computed tomography can provide a thorough investigation of unusual sites of uptake leading to diagnosis of these metastases. We present a case series of DTC showing unusual sites of metastasis and/or radioiodine uptake in urinary bladder, in the third metacarpal bone of left hand and lastly in the forearm at postoperative hypertrophic scar area.

Two Cases of Adrenal Cysts Lined by Thyroid Follicular Epithelium: Addressing Cellular Origin and Malignancy Concerns

Adrenal cysts lined by thyroid follicular epithelium are rare, with only 14 reported cases of "ectopic thyroid tissue" to date. While the primary consideration for differential diagnosis is thyroid carcinoma metastasis, exclusion of metastases is determined based on the absence of a primary thyroid lesion, serological euthyroidism, lack of thyroglobulin elevation, and absence of epithelial atypia. Herein, we report 2 cases of adrenal cysts lined by thyroid follicular epithelium. Case 1 was a 60-year-old woman with a right adrenal cyst. Case 2 was a 51-year-old man with a left adrenal cyst. Over time, both cysts became larger, necessitating an adrenalectomy. Cystic epithelia were lined with thyroid follicular epithelium, exhibiting moderate atypia. Human bone marrow endothelial cell marker-1 and galectin-3 were focally positive; CK19 was positive in Case 1, and all 3 markers were positive in Case 2, previously reported as an immunophenotype of thyroid carcinoma. CD56 expression was positive in both cases. Targeted next-generation sequencing revealed several low-frequency mutations; however, no major driver alterations for thyroid cancer were detected. Adrenal cysts can be lined by thyroid follicular epithelium. Challenges arise in determining the malignant or benign nature of adrenal cysts.

Unusual mesentery metastasis of differentiated thyroid cancer: a case report

Distant metastases of well-differentiated thyroid cancers (WDTCs) to bone and lungs are well known, while intra-abdominal, mesenteric metastases are very rare. Herein, we report a case of intra-abdominal, mesenteric metastasis of WDTC. A 62-year-old man underwent thyroid lobectomy for follicular thyroid cancer. One year later, lung metastasis was observed. The patient simultaneously underwent lung wedge resection and complete thyroidectomy. Eleven years later, serum thyroglobulin level was elevated. On the work-up study, a metastatic lesion in the lungs and a mass in the mesentery were identified. Two lesions of the lung and mesentery were surgically resected. The mass in the mesentery was pathologically diagnosed as metastatic WDTC.

Rare Columnar Cell Variant Papillary Thyroid Carcinoma with Metastasis to Pancreas and Lungs at Initial Presentation: A Case Report and Review of Literature

Papillary thyroid cancer (PTC) is the most common endocrine malignancy, accounting for 85% of differentiated thyroid cancers. A small percentage of PTC variants are considered more aggressive, such as the tall cell variant associated with the V600E mutation in the BRAF gene and the rarer columnar variant, which is described in only 0.2% of cases and has a poor prognosis. Although locoregional metastases to neck lymph nodes are common, distant metastases of PTC are rare at presentation with only 5 to 7% reported in the literature. We present a very rare case of columnar cell variant PTC with synchronous metastasis to the lungs and indolent focus in the pancreas at initial diagnosis, which has never been reported in the literature. Our patient presented with non-radioactive iodine (RAI) responsive PTC with diffuse metastases to the lungs and one synchronous focal metastatic lesion in the pancreas. After multidisciplinary discussions, pancreatectomy/metastasectomy was deferred due to the disseminated PTC with multiple metastases to the lungs, lack of pancreas-related symptoms in the patient, and inherent complication risks. The patient was treated with systemic therapy using a tyrosine kinase inhibitor (lenvatinib), which is the standard of care for non-RAI responsive PTC and showed a complete radiologic resolution of the pancreatic lesion, however, with partial yet nonprogressive metastatic disease in the lungs.

Breast metastasis in follicular thyroid cancer patient

In this case report, we aimed to present the findings of a follicular thyroid carcinoma patient with breast metastasis, which is rarely reported in the literature. A 33-year-old female who had been operated for thyroid cancer 17 years ago, but whose pathology report could not be reached was suspected of recurrence in the left lobe region of the thyroid gland. Fine-needle aspiration biopsy was done in this region, and the biopsy result was reported as thyroid follicular carcinoma. ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT) was performed for re-staging before surgery. In the PET/CT, it was found that there was residual thyroid tissue in the right and left lobe region and superior to these lesions in the left side, there were lesions which destruct to the hyoid bone, and there were multiple nodular lesions in both lungs which measured with maximum 15 mm × 12 mm, and all these lesions have increased ¹⁸F-FDG uptake. In addition to these lesions, a nodular lesion with the size of ~11 mm ×10 mm in the upper-middle quadrant of the right breast, and it was showing increased ¹⁸F-FDG uptake (maximum standardized uptake value: 3). Pathology results of the left neck region operation materials were reported as papillary and follicular carcinoma of the thyroid gland. Right lumpectomy was performed for the lesion in the right breast during the same session with thyroid operation. The pathology result of this lesion was also reported as metastasis of thyroid follicular cancer. Posttreatment iodine-131 whole-body scan after surgery was reported as there was abnormal accumulation in residual thyroid tissues on the right side of the neck and lung metastases. In patients with thyroid cancer, the possibility of metastasis of the breasts should be considered when there is a lesion in the breast tissue.

Cerebellar Metastasis From Thyroid Carcinoma With Prominent 123 I Uptake But Less Impressive MRI Findings in a Pediatric Patient

ABSTRACT

Papillary thyroid carcinoma in childhood frequently presents with locoregional lymph node metastases. The distant metastases often involve lungs and the bone, whereas brain metastasis is rare. We report a case of classic variant-papillary thyroid carcinoma with right cerebellar metastasis in a 7-year-old girl on a 123 I SPECT/CT study. A brain MRI on the same day shows a tiny millimetric enhancing nodule in the right cerebellum with no perceivable perilesional edema, confirming the 123 I scan findings.

Rare sites of metastases in patients with differentiated thyroid carcinoma and added value of SPECT/CT over planar whole body radioactive iodine scan

Background

Being aware of the unusual or rare location of thyroid metastases helps in early diagnosis and proper patient management. Rare metastases (RM) can be missed resulting in diagnostic pitfalls and delayed treatment. The use of single-photon emission computed tomography/computed tomography (SPECT/CT) imaging in the follow-up of differentiated thyroid cancer (DTC) patients provides precise anatomical localization and characterization of RM that may be missed or misinterpreted in planar whole body iodine-131 (WBI) scan. There is a lack of knowledge about dealing with such patients, the treatment they should receive, and therapy response due to the rarity of such cases. In this work, we reported these rare cases increasing awareness about them and their methods of treatment with response to therapy and evaluated the added value of SPECT/CT imaging in changing patients’ management.

Materials and methods

In this study we reviewed all patients with DTC referred to our unit either for initial radioactive iodine-131 therapy (RAIT) or under follow-up from January 2019 to January 2022. When a suspected lesion was detected in a conventional planar WBI scan whether follow-up scan or post-therapeutic scan, SPECT/CT was acquired immediately in the same session for that region. Additional imaging modalities were performed for confirmation. Response to the given treatment either disease progression (DP) or favorable response which include complete response (CR), partial regression (PR) and stable disease (SD) recorded for each patient.

Results

Two hundred and forty patients with DTC referred to our unit over a three-year period (from January 2019 to January 2022) were reviewed. Forty patients developed lung and bone distant metastases. Twenty-one patients were thought to have metastases at unusual sites. Due to incomplete data (no SPECT/CT pictures or confirmatory imaging), 6/21 patients were eliminated. We studied 15 patients with RM (9 females, 6 males) with a median age of 52 years (range 27–79). All patients received the initial RAIT after thyroidectomy in addition to other therapeutic modalities, e.g., radiotherapy (RTH), chemotherapy (CTH) or surgical tumor excision after detection of RM. Ten out of 15 patients (66.67%) showed favorable response to therapy (2 patients had CR, 6 patients had PR and 2 patients had SD), whereas only 5 patients had DP. Additional SPECT/CT changed management in 10/15 patients (66, 67%) of patients.

Conclusion

RM identification is mandatory to avoid misdiagnosis and delayed therapy. Increasing the awareness about such rare cases allows for better management. SPECT/CT could significantly impact patients' management through its precise anatomic localization and lesion characterization.

Rare distant metastases to pancreas, liver, and lung as initial presentation of mixed tall cell and columnar cell variants of papillary thyroid cancer

Summary

The most common sites of distant metastases of papillary thyroid carcinoma (PTC) are lung and bone. Widespread distant metastases of PTC are rare and associated with poor overall prognosis. Metastases to sites such as liver and pancreas are extremely rare, and literature is sparse on overall survival. In this report, we present a 57-year-old man whose initial presentation of PTC was with pancreatic, liver, and lung metastases, and subsequently developed metastases to bone and brain. He underwent a total thyroidectomy, neck dissection, and tracheal resection. Pathology revealed a predominant columnar cell variant PTC with focal areas of tall cell variant, and genomic sequencing showed both PIK3CA and BRAF gene mutations. Radioactive iodine ablation with I-131 did not show any uptake in metastatic sites and he had progression of the metastases within 6 months. Therefore, therapy with lenvatinib was initiated for radioactive iodine refractory disease. Our patient has tolerated the lenvatinib well, and all his sites of metastases decreased in size. His liver and pancreatic lesions took longer to respond but showed response 6 months after initiation of lenvatinib, and he remains on full dose lenvatinib 18 months into treatment.

Learning points

Papillary thyroid carcinoma (PTC) usually metastasizes to lung and bone but can rarely occur in many other sites. Patients with distant metastases have significantly worse long-term prognosis. Lenvatinib can be an effective treatment of radioactive iodine refractory PTC with rare sites of distant metastases. Lenvatinib can be an effective treatment of PTC with BRAF V600E and PIK3CA mutation.

Skin Metastasis Occurring 30 Years After Thyroidectomy for Papillary Thyroid Carcinoma

The skin is an extremely rare site of metastasis from papillary thyroid carcinoma (PTC) and is linked to underlying disseminated malignancy, which reflects a dismal prognosis. We present the case of a 70-years-old Saudi female who presented at our clinic with an eight-month history of two painful and itchy skin nodules over the scalp and the medial aspect of the right arm. She had a history of total thyroidectomy for PTC 30 years prior. Computed tomography-positron emission tomography showed multiple fluorodeoxyglucose avid lung and skeletal metastases. This case highlights the fact that skin nodules in a patient with a history of PTC should be assessed carefully with a high suspicion of skin metastasis to avoid any delay in treatment.

Follicular thyroid carcinoma metastasizing to rare sites and exhibiting variable inter-lesional heterogeneity on 18F-fluorodeoxyglucose positron emission tomography/computed tomography and 131I

A patient of differentiated follicular thyroid carcinoma with unusual sites of metastases is illustrated with ¹³¹I and ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) imaging findings. The described case harbored extremely rare metastasis to the urinary bladder with multi-organ metastatic disease (including unusual sites of right bronchus and hepatic metastases). There was inter-lesional heterogeneity among the metastatic lesions with regard to the ¹³¹I and FDG uptake in the aforementioned lesions. The detection of such heterogeneity has important implications for patient management in metastatic differentiated thyroid carcinoma.

Recurrent Hurthle cell thyroid carcinoma does not preclude long-term survival: a case report and review of the literature

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.

Case presentation

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.

Conclusion

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.

Interventional Radiology Approaches for Liver Metastases from Thyroid Cancer: A Case Series and Overview of the Literature

Background

Liver metastases (LMs) from thyroid cancer (TC) are relatively uncommon in clinical practice and their management is challenging. Interventional radiology loco-regional treatments (LRTs), including radiofrequency ablation (RFA) and trans-arterial chemoembolization (TACE), have been successfully employed to treat LMs from various types of cancer.

Methods

We analyzed the role of LRTs in the management of unresectable LMs from differentiated and medullary TCs performed at our institution from 2015 to 2020. A review of the available English literature regarding this topic was also performed.

Results

Six hepatic LRTs were performed in 4 TC patients with LMs, in 2 cases after the start of treatment with a tyrosine kinase inhibitor (TKI). A partial response was obtained in 2 patients; the diameter of the largest targeted lesion was 18 mm in both of them. The remaining procedures were performed on larger lesions and a stable disease was achieved in all but one case. Acute LRT-related complications were transient and mild. In literature, the largest studies were focused on TACE in LMs from MTC, showing good tolerance and remarkable disease control, especially in case of limited liver tumour involvement.

Conclusion

LRTs for LMs represent a valuable option for the treatment of metastatic TC in case of isolated hepatic progression or for symptoms relief, also after the start of TKI treatment as part of a multimodal approach. The best disease control is obtained when hepatic metastatic burden is limited. These procedures are generally well tolerated; however, a cautious multidisciplinary selection of the candidates is mandatory.

Multiple ectopic goiter in the retroperitoneum, abdominal wall, liver, and diaphragm: A case report and review of literature

BACKGROUND

Ectopic thyroid is a rare developmental disorder, typically found in lingual areas, and most distantly in the abdomen. Thyroid ectopia in multiple regions is extremely rare. To date, there are no reports of ectopic goiter in four regions of the abdominal cavity in a single patient.

CASE SUMMARY

We present a case of thyroid ectopia in four areas of the abdomen, comprising normal orthotopic thyroid tissue. A 36-year-old woman, who underwent ovarian teratoma resection 10 years previously due to symptomatic ovarian teratoma, was referred to our hospital for treatment of an incidental hepatic mass. Magnetic resonance imaging and computed tomography (CT) of the abdomen showed a heterogeneously enhanced lobulated lesion in the sixth and seventh hepatic segment adjacent to the diaphragm. The mass was surgically excised, and histologic examination determined an ectopic nodular goiter. At the one-year follow-up, the abdominal CT scan, whole-body radionuclide I131 examination, and abdominal wall biopsy showed similar lesions in the left renal fascia and anterior abdominal wall.

CONCLUSION

Multiple para-ectopic thyroid is often misdiagnosed, owing to its extremely rare incidence and non-specific clinical manifestations and imaging features. A combination of multiple examinations is necessary for diagnostic accuracy.

Adrenal metastasis as the initial diagnosis of synchronous papillary and follicular thyroid cancer

Background

Differentiated thyroid cancer uncommonly presents with distant metastases. Adrenal metastasis from differentiated thyroid cancer presenting as the initial finding is even less common.

Case Presentation

A 71-year-old male was incidentally found on chest CT to have bilateral thyroid nodules, which were confirmed on ultrasound. Fine needle aspiration of the dominant right 3.3 cm nodule contained histologic features most consistent with Bethesda classification III, and repeat fine needle aspiration revealed pathology consistent with Bethesda classification II. Follow-up thyroid ultrasound showed 1% increase and 14% increase in nodule volume at one and two years, respectively, compared to baseline. Prior to the second annual thyroid ultrasound, the patient was incidentally found to have a 4.1 cm heterogeneously enhancing mass in the right adrenal gland on CT of the abdomen and pelvis. Biochemical evaluation was unremarkable with the exception of morning cortisol of 3.2 µg/dL after dexamethasone suppression. The patient then underwent laparoscopic right adrenal gland excision, which revealed metastatic follicular thyroid carcinoma. Total thyroidectomy was then performed, with pathology showing a 4.8 cm well-differentiated follicular thyroid carcinoma of the right lobe, a 0.5 cm noninvasive follicular thyroid neoplasm with papillary-like nuclear features of the left lobe, and a 0.1 cm papillary microcarcinoma of the left lobe. Thyrotropin-stimulated whole body scan showed normal physiologic uptake of the remnant thyroid tissue without evidence of other iodine avid disease. The patient then received radioactive iodine. At follow-up 14 months after total thyroidectomy, he remains free of recurrent disease.

Conclusion

Despite following the recommended protocol for evaluation and surveillance of thyroid nodules, thyroid cancer can be challenging to diagnose, and may not be diagnosed until distant metastases are identified.

Liver resection for metastatic thyroid carcinoma. Case report and literature review

Liver resection for metastatic cancer has become the standard of care for specific groups of patients, including noncolorectal non-neuroendocrine liver metastases (NCNNELM). Liver metastasis from differentiated thyroid carcinoma is considered rare, with an approximated frequency of 0.5%. We present a case of metastatic papillary thyroid carcinoma (PTC) to the liver and literature review. Herein, we report a 72-year-old male that underwent formal left hepatectomy for 4.4 cm metastatic PTC generating left bile duct obstruction. Two months after, presented with multiple small lesions within the hepatic parenchyma and diffuse ductal dilatation of the right biliary system. Therefore, treated with a percutaneous biliary drain placement without complications. In a patient diagnosed with initial Stage II PTC, undergoing total thyroidectomy 10 years before presenting to the clinic. Bearing over a decade of treatments for local and distal recurrences. We believe approaching strategies for this specific disease should be developed to establish standard management.

Pitfalls in Challenging Thyroid Tumors: Emphasis on Differential Diagnosis and Ancillary Biomarkers

Thyroid pathology encompasses a heterogenous group of clinicopathological entities including rare and diagnostically challenging neoplasms. The review is focused on morphological, immunohistochemical, and molecular features of rare thyroid neoplasms that can pose diagnostic problems. The tumors are organized based on growth patterns including thyroid neoplasms with predominantly papillary, follicular, solid, and spindle cell growth pattern, as well as neoplasms with distinct cytological characteristics. A special section is also dedicated to rare thyroid tumors with peculiar patterns including thyroid carcinoma with Ewing family tumor elements and intrathyroidal thymic-related neoplasms.

Unusual metastases from differentiated thyroid cancers: A multicenter study in Korea

Background

Although infrequent, distant metastasis from differentiated thyroid cancer is the main cause of mortality in patients and mostly involves the lung, bone, and brain. Distant metastases to other sites in differentiated thyroid cancer patients are rare, thus, the clinical course of unusual metastases has not been adequately researched. In the present study, the clinico-pathological findings and treatment outcomes of unusual metastases in differentiated thyroid cancer patients in Korea were evaluated.

Patients and methods

We retrospectively reviewed the medical records of differentiated thyroid cancer patients with unusual metastases in four Korean tertiary hospitals (Chonnam National University Hwasun Hospital, Asan Medical Center, Busan National University Hospital, Severance Hospital). Unusual metastases were diagnosed using (1) cytology or histology and/or (2) imaging studies including fluorodeoxyglucose F 18 positron emission tomography/computed tomography and/or iodine 131 whole body scans with simultaneously elevated serum levels of thyroglobulin. The pathological findings of primary thyroid cancer, diagnostic method for unusual metastases, and treatment responses of unusual metastases were examined.

Results

In all, 25 unusual metastatic foci of 19 patients were analyzed; 13 patients (68.4%) had papillary thyroid carcinoma including 4 follicular variant papillary thyroid carcinomas. The median time interval between the first diagnosis of primary thyroid cancer and unusual metastases diagnosis was 110 months (11.0–138.0 months). Only 4 patients (21.1%) had synchronous unusual metastases and 6 patients (31.6%) were symptomatic. Unusual metastases included 19 metastases to solid organs (6 to kidney, 5 to liver, 4 to pancreas, 3 to adrenal gland, and 1 to ovary) and 6 to the skin and muscles. Unusual metastases were pathologically proven in 10 patients (52.6%) and 11 of 16 patients (68.8%) who received iodine 131 whole body scans had radioiodine-refractory differentiated thyroid cancer. Among 5 patients treated with tyrosine kinase inhibitors, 4 treated with lenvatinib showed stable disease or a partial response at the first treatment response. Six patients (31.6%) died due to disease progression during the median 20.0-month follow-up period (11.0–55.0 months).

Conclusion

Unusual metastases from differentiated thyroid cancer are thought to be underestimated due to disease rarity and their metachronous nature with other distant metastases. The most of unusual metastases in differentiated thyroid cancer patients are existed with usual distant metastasis and clinical outcomes of those could not be significantly different from the prognosis of usual distant metastasis.

Brain Metastasis of Follicular Thyroid Carcinoma in Pregnancy: A Case Report and Literature Review

Brain metastases (BMs) related to cancer are quite common and represent the most common brain cancer. We present a rare case of a 32-year-old female, 36 weeks pregnant, admitted to the emergency with complaints of severe headache, vomiting, and left hemiparesis associated with drowsiness. Cranial tomography showed an image suggestive of an expansive lesion in the right front-temporo-insular region with an important mass effect. The result of biopsy with immunohistochemistry was compatible with metastasis of follicular thyroid carcinoma (FTC). The knowledge of neurological characteristics in the clinical analysis of patients with thyroid carcinoma must be highly valued, both in the correct interpretation of the signs and in the early investigation through skull imaging exams.

Elimination of Locoregional Recurrences and Skin Metastases in Papillary Thyroid Cancer by Ethanol Ablation and Mohs Surgery

Ultrasound-guided percutaneous ethanol ablation procedures for locoregional recurrences in papillary thyroid carcinoma (PTC) can be repeatedly performed over years. Skin metastases (SM) from PTC generally portend a lethal prognosis. Our patient case report demonstrates the innovative use in low-risk PTC (LRPTC) of treatment modalities designed to prevent neck re-explorations and capable of eliminating both locoregional recurrences and SM. In 2004, a 48-year-old man presented with neck nodal metastases due to PTC. He underwent a near-total thyroidectomy and nodal dissection, confirming an 8-mm PTC involving 2 ipsilateral node metastases. Postoperatively, he received 2 doses of radioactive iodine (RAI) for remnant uptake (cumulative dose 338 mCi); posttherapy scanning was unrevealing. In 2007, he underwent right neck dissection for further node metastases. In 2008, a guided biopsy confirmed a level IV node metastasis. He was referred to our institution for ethanol ablation. Two node metastases were ablated and subsequently disappeared. During 2010-2016, he developed an additional 6 node metastases, which were treated with ethanol ablation; all disappeared on high-resolution sonography. FDG-PET-CT scans in 2009 and 2016 were negative for distant spread. In 2016, a SM in his right neck was removed by dermatologic surgery. In 2017-2018, 2 further SM were excised with negative margins, one after Mohs surgery. He has now been disease-free for 20 months. In conclusion, despite 3 neck surgeries and 2 RAI therapies, our patient repeatedly developed both locoregional recurrences and SM. All 11 disease foci were eliminated with minimally invasive procedures which should more often be considered as effective treatment options in LRPTC.

Palliative Electrochemotherapy Treatment of Cutaneous Metastases in a Patient with Advanced Thyroid Papillary Carcinoma

Advanced papillary thyroid carcinoma (PTC) with cutaneous metastases may cause pain, ulceration, and bleeding. Electrochemotherapy (ECT) is a minimally invasive treatment of tumors located in the skin and subcutaneous tissue. The electric pulses potentiate the toxicity of cytostatic agents entering the tumor cell. It is highly effective especially to relieve pain and improve the quality of life. The adverse events are local and transient. A case of progressive metastatic PTC who developed bleeding cutaneous metastases treated with ECT is described.

Personalized selective internal radiation therapy in liver metastasis of thyroid cancer with impaired liver function: A case report

Follicular thyroid cancer (FTC) is a less common form of differentiated thyroid cancer. Liver metastasis of differentiated thyroid cancer frequently occurs in the late onset of the metastatic disease, are often unrescetable and noniodine avid, leading to a poor prognosis. A 69-year-old man with a 14-year history of multi-metastatic follicular thyroid cancer was treated iteratively with 131-Iodine allowing to maintain a stable disease. Upon a recent exponential increase of the thyroglobulin, a peritoneal mass and a voluminous hepatic metastasis were discovered, comorbidities and an insufficient future remnant liver function excluded liver surgical resection. The tumour board proposed a resection of the peritoneal mass followed by selective internal radiation therapy of the liver mass. Due to the already impaired liver function, personalized dosimetry allowed a safe treatment delivering low activity to the nontumoral liver followed by a clinical and imaging response of the liver mass at 3 months. At our knowledge, this is the first case of thyroid liver metastasis treated by selective internal radiation therapy.

Cholestatic syndrome as initial manifestation of pancreatic metastasis of papillary thyroid carcinoma: case report and review

Most papillary thyroid carcinomas (PTC) harbor excellent prognosis. Although rare, distant metastases normally occur in lungs and/or bones. Here we describe a rare case of pancreatic metastasis presenting with rapid onset cholestatic syndrome. A literature review was also performed. A 73-year-old man with a high risk PTC was submitted to total thyroidectomy (TT) followed by radioiodine therapy. After initial therapy, he persisted with progressive rising serum thyroglobulin levels but with no evidence of structural disease. Recently, the patient presented with a rapid onset and progressive cholestatic syndrome. A 4 cm lesion in pancreas was identified, with echoendoscopy fine-needle aspiration biopsy (FNAB) confirming a pancreatic metastasis from PTC. The patient was submitted to a successful pancreaticoduodenectomy. Pancreatic metastases of PTC are rare and few long-term follow-up data are available to guide management. Fourteen cases were former reported, mean age was 65.7 years-old with mean time between PTC and pancreatic metastasis diagnosis of 7.9 years. Nine of them had another distant metastasis, nine were diagnosed by FNAB and just two received sorafenib.

Metastatic Thyroid Cancer Presenting as Renal Cortical Mass

The authors present a rare case of primary diagnosis of metastatic, differentiated thyroid cancer presenting as a solitary, large renal mass. Renal cortical masses which represent metastatic primary malignancies are often small, multifocal, and in the setting of active malignancy. Surgical excision of this patient's renal mass demonstrated the unexpected diagnosis and subsequent endocrine surgical intervention.

Multidisciplinary Diagnosis of Subcutaneous Soft Tissue Metastasis of Follicular Thyroid Carcinoma: A Case Report

Background: Subcutaneous soft tissue metastasis of follicular thyroid carcinoma (FTC) is rarely diagnosed before surgery for clinicians. Case Report: We present a case of a 67-year-old man with a history of FTC and papillary thyroid microcarcinoma for 5 years. Multiple protruding subcutaneous nodules of the neck were found and removed from the surface of the sternocleidomastoid muscle. Ultrasound, computed tomography and technetium-99 m pertechnetate single-photon emission computed tomography of the neck were performed before the operation, which unfortunately indicated suspicious malignant lesions. Serum Tg was > 300 ng/ml (0.83-68.0 ng/ml), TSH was 36.580 uIU/ml (0.380-4.340 uIU/ml) and AbTg was negative. The pathologic diagnosis was metastatic FTC, invading the surrounding striated muscle, adipose tissue and vessels. Immunohistochemical staining revealed the tumor cells to be positive for thyroglobulin and TTF-1. The specimens of these nodules were further investigated for TERT promoter mutation and the result revealed mutated type (position g 1,295, 228 C>T). Conclusion: Preoperative diagnosis and prognostic prediction of metastatic FTC may be available through a combination of clinical, multimodal imaging and molecular genetic test (viz. multidisciplinary diagnosis). A long-term standardized follow-up is required for patients with a previous diagnosis of FTC.

Chest wall lymph node metastasis from follicular thyroid carcinoma: a rare case report

BACKGROUND

Distant metastases from follicular thyroid carcinoma are mainly hematogenous and are commonly observed in the lungs and bones. Other rare sites are the parotid gland, skin, brain, ovary, adrenal gland, kidney, pancreas and breast, with chest wall lymph node metastasis being even more rare.

CASE PRESENTATION

Over the past 10 years, three surgeries were performed on a 69-year-old women with a history of follicular thyroid cancer and its metastatic lesions. The patient presented with a 3-month history of masses in the left chest. She underwent detailed examination of the chest wall tumors, and surgery was then performed to resect all of the tumors. Based on the histopathology, these lymph nodes were confirmed to harbor metastatic follicular thyroid carcinoma.

CONCLUSION

This study reports the first case of follicular thyroid carcinoma metastasis to the chest wall lymph node.

Unusual metastases from differentiated thyroid carcinoma: analysis of 36 cases

PURPOSE

Metastases of differentiated thyroid cancer (DTC) in sites different from lungs and bone are unusual (UM); their impact in management and prognosis remains unknown. Our aim was to evaluate the prevalence of UM, to describe their characteristics and to analyze their impact in disease outcome and mortality.

METHODS

We retrospectively reviewed the file records from 8 different centers. Those patients with DTC and UM were included. UM were diagnosed by: (i) biopsy/cytology and/or (ii) radioiodine (RAI) uptake associated to elevated thyroglobulin (Tg) levels and/or c) presence of one or more structural lesion/s with 18-FDG uptake in the PET/CT scan and elevated Tg levels.

RESULTS

Thirty-six (0.9%) out of a total of 3982 DTC patients were diagnosed with UM; 75% had papillary histology. The most frequent localization was central nervous system (CNS, 31%). UM were metachronous in 75%, symptomatic in 55.6% and fulfilled RAI-refractoriness criteria in 77.8% of cases. Metastatic lesions in lung/bone and/or locoregional disease were present in 34 cases (94.4%). Diagnosis of UM changed the therapeutic approach in 72.2% of patients. After a median follow up of 13 months, 21 (58.3%) patients died from DTC related causes. In 8 of them CNS progression was the immediate cause of death.

CONCLUSIONS

Prevalence of UM was low; they were frequently metachronic and RAI-refractory. Although UM were found in patients with widespread disease, their diagnosis usually led to changes in therapy. UM were associated with poor prognosis and high frequency of disease-specific mortality.

Orbital Radioiodine Uptake on Scintigraphy in a Patient with Thyroid Cancer

BACKGROUND

Orbital radioiodine uptake in patients with thyroid cancer is very uncommon with only a few reported cases, most of them being metastasis. The accumulation of ¹³¹I in nonthyroidal tissues and body fluids can lead to false-positive results in scintigraphy, which are sometimes difficult to differentiate from true metastases.

CASE REPORT

A post-therapy ¹³¹I whole-body (WBI) scintigraphy in an asymptomatic 57-year-old female with papillary thyroid carcinoma (PTC) previously treated with total thyroidectomy and 6 ablative radioiodine doses showed a focal uptake in the right eyeball region. The lesion, placed in the orbital space, was surgically removed, and histology revealed a conjunctival inclusion cyst.

DISCUSSION

Ocular and orbital metastases from thyroid cancer, as well as some non-neoplastic disorders or contamination, are possible causes for ¹³¹I uptake in the orbital region in scintigraphy. Conjunctival inclusion cyst is a condition associated with incidental ¹³¹I uptake that had not been reported before and should be ruled out as a non-metastatic cause of orbital radioiodine uptake in patients with PTC.

mRNA and miRNA expression profiling of follicular variant of papillary thyroid carcinoma with and without distant metastases

Follicular Variant of Papillary Thyroid Carcinoma (FVPTC) is usually associated with a good outcome. Nevertheless, in rare cases, it develops distant metastases (1-9%). Our goal was to investigate whether mRNA and miRNA expression profiles may help distinguish between metastatic versus non-metastatic FVPTCs. Twenty-four primary FVPTCs, 12 metastatic and 12 non-metastatic, with similar clinicopathological features were selected and analyzed by nanoString nCounter technology using two distinct panels for expression analysis of 740 mRNA and 798 miRNAs. Data analysis was performed using the nanoString nSolver 3.0 software. Forty-seven mRNA and 35 miRNAs were differentially expressed between the two groups. Using these mRNA and miRNAs, metastatic and non-metastatic FVPTCs were clearly divided into two distinct clusters. Our results indicate that FVPTCs with metastatic abilities have different expression profiles compared to the non-metastatic. A prospective validation is needed to evaluate the usefulness of this molecular approach in the early identification of high-risk FVPTCs.

An H-TERT Mutated Skin Metastasis as First Occurrence in a Case of Follicular Thyroid Carcinoma

Differentiated thyroid cancer arising from thyroid follicular epithelial cells is the most frequent endocrine malignancy, and skin metastases are very rare. We describe a case of a 70-year-old women with a history of an indeterminate thyroid nodule on cytology. A painless, erythematous skin nodule of about 7 mm diameter was removed from the scalp and diagnosed as a metastasis from thyroid cancer. After total thyroidectomy, a histological diagnosis of follicular thyroid cancer was made. Two cycles of radioactive iodine were performed. Both the follicular thyroid carcinoma (FTC) and the metastasis were investigated for the presence of BRAF/RAS and TERT promoter mutations. The results showed that the cutaneous metastasis was BRAF wild-type and TERT promoter-mutated (position g.1,295,228 C>T); in contrast, the primary thyroid lesion was negative for both molecular markers.

An Unusual Case of Metastatic Follicular Thyroid Cancer 40 Years after Initial Diagnosis

Thyroid cancer recurrence can occur decades after initial diagnosis despite excellent response to therapy. Thyroid cancer recurrence is evaluated using serum thyroglobulin (Tg) and imaging studies including I-131 WBS and neck ultrasound. Limitations in Tg measurement and WBS may result in failure to detect recurrence. We report the case of a 63-year-old man who was noted to have rhonchi during a routine visit. He had a past history of follicular thyroid cancer that was diagnosed 40 years ago and treated with total thyroidectomy and radioactive iodine. He had excellent response to therapy with undetectable Tg levels, normal neck ultrasounds, and multiple negative whole body scans (WBS) due to which he was discharged from endocrinology clinic after 37 years of follow-up. Chest X-ray revealed a left lung mass with biopsy positive for thyroid cancer. Tg remained undetectable with negative anti-Tg antibody. Left pneumonectomy was done which revealed a mix of 70% differentiated thyroid cancer and 30% poorly differentiated/anaplastic thyroid cancer. He received two cycles of Doxorubicin and Paclitaxel. At 4 months follow-up after surgery, he had 3 subcentimeter nodules in his right lung. This case highlights that physical exam remains an essential tool to evaluate for recurrence. Since the lungs are the most common site of metastasis in follicular thyroid cancer, a chest X-ray may help detect metastasis that is missed on other modalities.

Papillary thyroid carcinoma metastatic to the pancreas: Case report

Papillary thyroid carcinoma (PTC) is generally associated with an excellent long-term outcome. Distant metastasis is rare with only 5-7% of patients developing distant disease. Metastasis of PTC to the pancreas is an exceedingly rare occurrence. To date, few cases have been reported. We present the case of an 81-year-old man with past medical history of PTC status post total thyroidectomy with local recurrence treated with radioactive iodine and selective neck dissection. Ten years after his initial diagnosis, PET-CT scan revealed a new hypermetabolic 1.1 cm × 0.9 cm left lower lobe lung nodule and hypermetabolism in the proximal body of the pancreas. Follow-up MRI cholangiogram showed a 1.0 × 0.8 cm T1 hypointense lesion in the proximal body of the pancreas. Endoscopic ultrasound-guided fine-needle aspiration biopsy of the pancreatic mass showed neoplastic epithelial cells arranged in papillary clusters with fibrovascular cores and syncytial sheets with high nuclear to cytoplasmic ratio, visible nucleoli, nuclear pallor, focal nuclear grooves, and rare intranuclear pseudoinclusions. Immunohistochemical stains performed on the smears showed positive nuclear expression of TTF-1 and PAX-8. The findings were consistent with metastatic PTC. Surgical resection of the lung nodule confirmed metastatic PTC. Pancreatic metastases usually occur after long time intervals with reports of up to 8 years in PTC. This makes the diagnosis more challenging, and metastatic disease should always be in the differential diagnosis in cases presenting with a pancreatic mass, especially in patients with a prior malignancy.

Clinical Status and Treatment of Liver Metastasis of Differentiated Thyroid Cancer Using Tyrosine Kinase Inhibitors

BACKGROUND

Treatment of patients with liver metastasis of differentiated thyroid carcinoma (DTC) has not been sufficiently defined, because liver metastasis of DTC has been described mostly as case reports. Additionally, such patients are considered end-of-treatment responders. A relatively new approach using tyrosine kinase inhibitors (TKIs) may provide opportunities to manage systemic metastasis. This study aims to define the clinical features of DTC patients with liver metastasis and evaluate the benefits of TKIs.

METHODS

We retrospectively analyzed clinical features of 29 patients (mean age 67.8 years) diagnosed with liver metastasis of DTC at our institution between January 1981 and May 2017.

RESULTS

All patients had distant metastasis at other organ sites upon diagnosis of liver metastasis; 41% of them developed new metastasis afterward. Management after diagnosis of liver metastasis comprised palliative care (48%), radioactive iodine therapy (28%), and TKI therapy (24%). The median survival after diagnosis of liver metastasis was only 4.8 months. Survival rates were significantly better in patients with performance statuses between 0 and 2 on the Eastern Cooperative Oncology Group scale at diagnosis of liver metastasis (n = 22, 76%) treated with TKI compared to those who were not (P = 0.017; log-rank test; hazard ratio 0.19). One-year survival rates were 71.4 and 26.7% for patients treated with or without TKI, respectively.

CONCLUSIONS

Patients with liver metastasis had poor clinical prognosis. When other distant metastases existed at diagnosis of liver metastasis, TKI therapy was considered an effective therapeutic option for patients with liver metastasis of DTC.

An Unusual Case of Papillary Thyroid Carcinoma Iodine-131 Avid Metastasis to the Adrenal Gland

SUMMARY – Papillary thyroid carcinoma (PTC) is considered one of the most favorable tumors, indolent, with rare distant dissemination. Lungs and bones are the most common metastatic sites. Unusual sites of PTC distant metastases are extremely rare. Brain, liver, skin, kidney, pancreas, and adrenal gland PTC metastases have been sporadically reported in the literature. An 86-year-old female patient underwent total thyroidectomy and neck dissection due to PTC. Postoperative whole body iodine-131 scintigraphy with I-131 SPECT/CT of the abdomen revealed radioiodne avid left adrenal gland metastasis together with high postoperative serum thyroglobulin (Tg) value of more than 5000 µg/L and high serum Tg antibodies. Considering the above-mentioned findings, patient‘s age and multiple comorbidities, radioiodine therapy was applied. PTC metastases to the adrenal gland are extremely rare, and to our knowledge, only nine cases have been reported in the literature. This case report complements rare examples of unusual PTC metastases.

Thyroid-Like Intrahepatic Cholangiocarcinoma: Report of a Case and Review of the Literature

Intrahepatic cholangiocarcinoma is a relatively uncommon malignant neoplasm. We recently encountered an unusual case of intrahepatic cholangiocarcinoma that histologically resembled a thyroid carcinoma. A thorough review of the English literature revealed only 2 similar cases that have been previously reported. Immunohistochemical studies are imperative to confirm the diagnosis of cholangiocarcinoma and to exclude the possibility of metastatic thyroid carcinoma and other malignancies with thyroid-like features.

Skin metastasis on the neck: an unusual presentation of recurrence of papillary thyroid carcinoma

Skin metastasis of papillary thyroid carcinoma (PTC) is rare. Here, two cases of skin metastases of PTC are presented. Both of the patients were females, one is 83 and the other is 65 years old. The patients were admitted to the hospital with a movable skin lesion on anterior neck region. Free T3 and T4 levels were in normal levels and TSH levels were low in both patients. The 83-year-old patient underwent total thyroidectomy due to papillary thyroid cancer and received ¹³¹I ablation therapy and then thyroid suppression therapy. After the surgery, the patient lived without evidence of disease for 3 years and then skin metastasis occurred. The 65-year-old patient had a total thyroidectomy 5 years ago due to PTC then neck dissection due to metastasis 3 years later and then received ¹³¹I ablation therapy. Thyroid ultrasonography of both patients showed hypoechoic nodules with central vascularization. In the histological examination of both patients, cystic lesions filled with papillary structures were seen. Fine needle aspiration biopsy (FNAB) taken from both patients were papillary carcinoma with solid trabecular pattern. PTC tends to metastasize to regional lymph nodes but distant metastasis is rare. When distant metastasis develops, prognosis of the disease is poor. Therefore, skin metastasis of papillary thyroid cancer is a poor prognostic factor. If the patient does not have a thyroid malignancy history, diagnosis of PTC metastatic to the skin may be difficult since primary skin tumors such as apocrine tumors have similar histopathological features. However, in the presented cases since there was a PTC history, the diagnosis was easier with the help of histopathological examination. Skin metastasis of PTC should be kept in mind when differential diagnosis of atypical skin lesions are made especially in the patients with thyroid malignancy history.

Unilateral adrenal mass as the sole initial manifestation of differentiated thyroid cancer

Unilateral adrenal metastases without disseminated disease has rarely been reported in differentiated thyroid carcinoma (DTC). A 72-year-old female presented with vague abdominal discomfort and loss of appetite of 2 months duration. She had undergone left hemithyroidectomy for a benign thyroid nodule 18 years ago. A contrast CT of the abdomen showed a large left adrenal mass measuring 11×9 cm, suspicious of adrenocortical carcinoma. Hormonal evaluation was in keeping with a non-functional tumour. The patient underwent left adrenalectomy, histopathology of which revealed metastatic well-differentiated thyroid carcinoma. Ultrasound of thyroid done postoperatively showed a subcentimetric hypoechoic lesion with increased vascularity and microcalcifications in the right thyroid bed. Histopathology from a completion thyroidectomy specimen was consistent with follicular variant of papillary thyroid carcinoma. She was treated with high-dose radioiodine ablation therapy and has remained disease-free on follow-up for more than a year.

Renal metastases as the initial presentation of papillary thyroid carcinoma: A case report and literature review

Distant metastasis of thyroid carcinoma is rare, and it occurs particularly rarely in renal regions, which represent ~3% of all thyroid distant metastases, with fewer than 30 single case study reports existing in the literature. The present study (and subsequent literature review) of papillary thyroid carcinoma (PTC) reports the case of a 53-year-old male patient who presented with a left renal mass and who had no previous history of thyroid disease. Following renal and thyroid surgery, postoperative pathology confirmed the case to be a follicular variant of PTC, accompanied by renal metastasis. The patient exhibited brain metastasis during a later follow-up. In conclusion, thyroid metastases to the renal site are extremely rare events, particularly for men who present initially with renal neoplasms, which may easily be misdiagnosed as renal cell carcinoma. PTC tends to have a good prognosis; however, when it is accompanied by distant metastasis, the prognosis becomes less favorable.

Isolated Liver Metastasis in Hürthle Cell Thyroid Cancer Treated with Microwave Ablation

Hürthle cell thyroid cancer (HCTC) is a less common form of differentiated thyroid cancer. It rarely metastasizes to the liver, and when it does, the metastasis is almost never isolated. Here we report a 62-year-old male with widely invasive Hürthle cell thyroid cancer, who underwent total thyroidectomy and received adjuvant treatment with I-131 with posttreatment scan showing no evidence of metastatic disease. His thyroglobulin however continued to rise after that and eventually an isolated liver metastasis was identified. He underwent laparoscopic microwave ablation of the liver metastasis, with dramatic decline in thyroglobulin and no structural disease identified to date. This case highlights the rare occurrence of isolated liver metastasis from HCTC and also illustrates the utility of thermoablation as an alternative to surgical resection in the treatment of small isolated liver metastases from HCTC.