Neuroendocrine metastasis to the thyroid from unknown primary and extrathyroidal disease response to peptide receptor radionuclide therapy

Neuroendocrine tumor (NET) metastasis to the thyroid is rare, and its presentation as the first manifestation of primary malignancy elsewhere is even more uncommon. We present a case of a 41-year-old female who underwent biopsy of enlarging thyroid nodules with findings suspicious for medullary thyroid cancer (MTC). Subsequent thyroidectomy demonstrated NET of unknown primary in the left lower lobe. Immediate workup with 68Ga-DOTATATE-PET/CT revealed abnormal somatostatin receptor (SR) expressing lesions in the liver, right cervical nodes, thoracic paravertebral soft tissue, precoccygeal soft tissue, and right acetabulum concerning for sites of neuroendocrine malignancy. Due to disease progression while on octreotide injections, a decision was made at the multidisciplinary NET board for the patient to receive peptide receptor radionuclide therapy (PRRT) which includes 4 cycles of 77Lu-DOTATATE (Lutathera). The patient had no side effects nor toxicities during the 8 months of PRRT and achieved a partial treatment response in the early post-treatment scan at 6 weeks. This case illustrates the importance of distinguishing NET metastasis to the thyroid from MTC to ensure appropriate workup and treatment as well as predict the response of neuroendocrine malignancies to PRRT based on the visualized overexpression of SR in the SR-PET scans, despite the organ of origin.

Positive Delphian node in laryngeal cancer: Predictive of thyroid gland metastasis?

INTRODUCTION

Laryngeal carcinoma represents the 22nd most common cancer worldwide. Thyroid metastasis from laryngeal cancer is extremely rare. Overall, thyroid gland involvement by metastatic carcinoma represents about 1.1-2.1 % among thyroid malignant diseases.

PRESENTATION OF CASE

A male in his 70s came to our Otolaryngology Unit with a laryngeal squamous cell carcinoma (cT3). Total laryngectomy and bilateral neck dissection were performed. Histological examination revealed a pT3 carcinoma with sub-massive metastasis of the Delphian node. The patient underwent close follow-up. After eight months, neck examination revealed a suspected nodule in the right thyroid lobe. A right thyroid lobectomy was performed, and histological assessment revealed a nodule with squamous carcinoma metastasis in the superior pole of the thyroid lobe. The remaining thyroid tissue was affected by multinodular macrofollicular goitre. The patient underwent adjuvant therapy. One year after the second surgery, he showed no signs of recurrence.

DISCUSSION

Thyroid gland metastasis from laryngeal carcinoma is a very rare occurrence. In literature, we found only three articles that describes thyroid metastasis in overall 7 patients affected by laryngeal squamous cell carcinoma. Positive Delphian lymph node is usually related to poor prognosis: in 2007 a study reported tumour recurrence in 15 out of 25 patients with metastatic Delphian lymph node within the first two years of surgery.

CONCLUSION

Thyroid gland metastasis from laryngeal carcinoma is rare; so close follow-up of oncologic patients is mandatory and, most of all, the positive Delphian node should not be underestimated for its predictive value.

Metastatic Disease to a Concurrent Thyroid Neoplasm: A Case Series and Review of the Literature

BACKGROUND

Metastatic disease to the thyroid gland is uncommon but well-described. Metastatic disease to a concurrent primary thyroid neoplasm is a rare phenomenon. We sought to study patients with metastasis to the thyroid with a focus on the histopathologic and clinical features in tumor-to-tumor metastasis.

METHODS

We identified a series of patients with metastatic disease to the thyroid, with or without a concurrent primary neoplasm, through a search of the files of the Department of Pathology. All relevant slides were retrieved and reviewed, including routine HE and immunohistochemical stains. We performed a detailed English language literature search (1962-2022) and review to identify tumor-to-tumor metastasis involving the thyroid.

RESULTS

We identified 14 patients with metastasis to the thyroid over a 22-year period. Four patients exhibited papillary thyroid carcinoma, with metastatic spread of a different malignancy seeding into the thyroid cancer. We describe the histopathologic diagnostic process and findings, clinical management, and the clinical course of tumor-to-tumor metastasis in greater detail for these 4 patients.

CONCLUSION

Tumor-to-tumor metastasis to the thyroid is a rare event with unique histopathologic features. Our findings suggest that the phenomenon of tumor-to-tumor metastasis serves to highlight broader mechanisms of metastatic disease in general. We provide the largest-to-date and comprehensive review of the literature to identify all previous reported instances of tumor-to-tumor metastasis involving the thyroid.

Clinical characteristics and risk factors of central lymph node and thyroid metastasis in patients with hypopharyngeal carcinoma

OBJECTIVE

Our study sought to analyze the clinical characteristics and risk factors of central lymph node and thyroid metastasis in patients with hypopharyngeal carcinoma.

METHODS

The current study included a total of 152 patients who suffered from hypopharyngeal cancer in our hospital from January 2019 to December 2020. Univariate/multivariate Logistic regression analyses were applied to analyze the risk factors of both central lymph nodes and thyroid metastasis in patients with hypopharyngeal cancer.

RESULTS

Significant differences were found in tobacco use, drinking history, PS score, site of tumor, pT and pN stage, pathological stage, differentiation degree, postoperative calcium ion level and postoperative FT3 level between the thyroid metastasis group and the non-thyroid metastasis group, and between the central lymph node metastasis group and the non-central lymph node metastasis group (P < 0.05). The multivariate logistic regression analysis showed that the risk factors of thyroid metastasis in patients with hypopharyngeal cancer were pathological stage and differentiation degree.

CONCLUSIONS

Patients with hypopharyngeal cancer complicated by thyroid metastasis or central lymph node metastasis may be associated with tobacco use, drinking history, PS score, site of tumor, pT and pN stage, pathological stage, differentiation degree, postoperative calcium ion level, and postoperative FT3 level. Moreover, the risk factors responsible for central lymph node and thyroid metastasis in hypopharyngeal cancer patients were thought related to pathological stage and differentiation degree.

Squamous cell carcinoma of the uterine cervix metastasising to the thyroid gland: a case report

Background

Carcinoma of the uterine cervix (cervical cancer) metastasising to the thyroid gland is a rare phenomenon and only a few cases have been reported. We discuss a patient with cervical cancer presenting with thyroid and cervical lymph node metastasis, exploring the diagnostic difficulty, evaluation and treatment options.

Case presentation

A previously well 56-year-old female presented with multiple neck lumps for 4 months duration. Examination of the neck revealed multiple firm/hard left cervical lymph nodes with a hard thyroid nodule. There were no abdominal masses however, vaginal examination revealed a hard, unhealthy cervix. Contrast enhanced computed tomography revealed a growth in the uterine cervix with lymph node enlargement in the abdomen, chest and neck along with multiple thyroid nodules. Biopsy of the cervix and cervical lymph node and fine needle aspiration cytology of the thyroid nodules were performed, all revealing a squamous cell carcinoma. Pan-endoscopy performed to rule out any concurrent cancer of the upper aerodigestive tract was negative. The patient was started on palliative therapy, but succumbed to the disease after 6 months.

Discussion and conclusion

Patients who present with a thyroid nodule along with multiple cervical lymph nodes should be thoroughly assessed for possible metastatic cancers. Metastasis to the thyroid gland indicates a poor prognosis in the background of carcinoma or the uterine cervix. More awareness among the public and primary care providers is necessary regarding freely available screening programmes for early detection of cervical cancer.

Solitary thyroid metastasis from colorectal cancer: Case report

INTRODUCTION AND IMPORTANCE

Thyroid metastasis of colorectal cancer is rare and the patient with thyroid metastasis has no symptoms early in the disease course. On the other hand, evaluation of thyroid is not generally included in the routine follow-up of colorectal cancer. Therefore, the diagnosis of thyroid metastasis of colorectal cancer may be delayed.

PRESENTATION OF CASE

Chest computed tomography revealed a nodule on the right lobe of the thyroid in 53-year-old woman diagnosed with sigmoid colon adenocarcinoma. This nodule was identified having as increased metabolic activity by 18F-fluorodeoxyglucose positron emission tomography-computed tomography and confirmed to be consisted of cystic and solid portions by ultrasonography. Fine needle aspiration cytology of the nodule revealed metastasis of colon cancer. The patient underwent laparoscopic anterior resection and a total thyroidectomy. The size of the thyroid tumor was 1.2 cm with free resection margin.

DISCUSSION

The clinical features of thyroid metastasis from colorectal cancer are not typical. In addition, follow-up examinations of patients with colorectal cancer do not include imaging studies of the neck, so the diagnosis of thyroid metastases is delayed. The management strategies for thyroid metastasis from colorectal cancer include a total thyroidectomy without prophylactic neck lymph node dissection and chemotherapy. However, as the penetration of chemotherapeutic drugs into the thyroid is difficult, the effect on the thyroid is considered insignificant.

CONCLUSION

Surgical treatment should be considered for treatment of thyroid metastasis.

Long-term survival after surgical resection of metachronous lung, brain and thyroid gland metastases from rectal cancer: A case report

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Brain and thyroid metastasis of rectal cancer are uncommon, and prognosis are poor.

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Lung, brain and thyroid metastasis of rectal cancer was resected metachronous.

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This case survived 19 years after the initial rectal surgery.

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Patients whose metastases were resected completely may get a prolonged survival.

Introduction and importance

Brain and thyroid metastasis from rectal cancer are uncommon, and the prognosis is poor. We report a patient with rectal cancer who developed metachronous lung, brain and thyroid metastases. Each metastatic lesion was curatively resected resulting in prolonged survival.

Case presentation

A 60-year-old male underwent rectal cancer resection, and the pathological diagnosis was tubular adenocarcinoma, pT2,pN1a,M0, pStageⅢa. Ten years after rectal resection, a solitary tumor in the left lung was detected. The tumor was resected thoracoscopically and the pathological diagnosis was metastatic tumor. Three years after the pulmonary resection, a solitary brain tumor was detected. The tumor was removed surgically, and the pathology was metastatic tumor. Two years after brain resection, a thyroid mass was detected. A partial thyroidectomy was performed and the pathology with immunohistochemical staining confirmed the thyroid lesion as a metastasis from the previous rectal cancer. Four years after thyroid resection (19 years after the initial rectal resection), he died from multiple lung and bone metastases.

Clinical discussion

Colorectal metastases to the brain and thyroid gland are uncommon and are usually found with other distant metastases. Overall survival has been reported to be extremely poor. In this patient, lung, brain, and thyroid metastases were solitary and metachronous, and each lesion was curatively resected. Surgical treatment might contribute to prolonged survival.

Conclusion

The treatment strategy of each patient should be individualized and depends on the timing of metastasis development. Selected patients with complete resection of metachronous metastases may have prolonged survival.

Rare presentation of metastatic renal cell carcinoma to thyroid gland: A case report

Introduction

Renal cell carcinoma is known to cause metastasis to unusual sites, but metastasis to the thyroid gland is a rare occurrence, not only that, but 20 years after complete recovery is almost nonexistent.

Case presentation

We are presenting here a case of 79-year-old female who presented to us for asymptomatic progressive thyroid nodule. She had history of right nephrectomy for renal cell carcinoma 20 years ago. Ultrasound guided fine needle aspiration biopsy (FNAB) of the thyroid was non-diagnostic. Total thyroidectomy of the patient was performed, and histopathological evaluation of the specimen revealed the swelling to be of metastatic in nature secondary to renal cell carcinoma.

Discussion

Despite thyroid metastasis being rare, FNAB can prove to be useful tool for diagnosis of thyroid tumors and metastases and can be inconclusive in some cases. Therefore, immunohistochemistry can prove beneficial in diagnosis such cases.

Conclusion

The diagnosis of renal cell carcinoma metastasis is made after immunohistochemical evaluation of the thyroidectomy specimen with thyroidectomy proving to be the modality of treatment for such cases with no further radiation therapy and a yearly follow up plan to screen for other lesions.

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Renal cell carcinoma is one of the most common malignany to metastasize to thyroid.

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Metastatic etiology should always be considered in thyroid nodule patient with history of renal cell carcinoma.

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Diagnosis is mainly by immunohistochemical analysis.

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Surgery has a significant mortality benefit.

Rectal cancer with a metastasis to the thyroid gland: A case report

INTRODUCTION

Metastases to the thyroid gland in patients with colorectal cancer are uncommon. We report a patient with rectal cancer who developed a metastasis to the thyroid gland.

PRESENTATION OF CASE

The patient was a 45-year-old female five years status post rectal cancer resection. A thyroid lesion was detected on PET-CT scan with synchronous lung metastases. After pulmonary resection, a partial thyroidectomy was performed and pathological examination with immunohistochemical staining confirmed that the lesion was a metastasis from previous rectal cancer. She is free from recurrence two years after thyroid surgery.

DISCUSSION

Colorectal metastases to the thyroid gland are usually seen with widespread disease, often with lung and liver metastases. The overall outcomes of previously reported patients with thyroid metastases were extremely poor, with most patients dying within months of diagnosis. Careful attention should be given to other sites of metastatic disease including the thyroid gland during postoperative follow-up. PET scan may be helpful to establish the diagnosis.

CONCLUSION

Treatment decisions must be individualized, and depend on the presence of systemic disease. Selected patients may benefit from resection of metastases, and PET scan may be useful to identify patients who will benefit from resection.

Thyroid metastasis from esophageal adenocarcinoma: a case report and literature review

BACKGROUND

The incidence of metastatic spread of gastrointestinal malignancies to the thyroid gland is relatively low and most of these malignancies originate from the colorectum. Thyroid metastasis originating from the esophagus is poorly documented.

CASE PRESENTATION

A 79-year-old man presented with hoarseness of voice and swallowing difficulty. Eighteen months earlier, he had undergone preoperative chemotherapy (S-1 and oxaliplatin [SOX] therapy) and subtotal esophagectomy with regional lymph nodes dissection and retrosternal narrow gastric tube reconstruction for advanced Barrett's esophageal adenocarcinoma. In the ultrasonographic examination, there was a hypoechoic, indistinct border and heterogeneous nodule in the left lobe of the thyroid gland. Pathological examination of an ultrasound-guided fine-needle aspiration showed adenocarcinoma, supporting a diagnosis of esophageal adenocarcinoma metastases in the thyroid.

CONCLUSION

This is a first case of a patient with thyroid metastasis from Barrett's esophageal adenocarcinoma after subtotal esophagectomy.

Thyroid metastasis from non-small cell lung cancer

Non-thyroid malignancies to the thyroid gland resulting from distant metastases are extremely rare, and such cases are rarely seen in clinical settings. The question of how a tumor metastasizes to the thyroid remains unanswered. Here we report a case of lung adenocarcinoma metastasizing to the thyroid gland. The article covers the pathological features, treatments, examination reports, and the postoperative follow-up reviews of the patient. In this article, we discuss the diagnostic method, the spread route, the prognosis, the mechanism and above all, the treatment. In addition, we searched the PubMed and ISI Web of Science databases for articles published in English using the key words "lung", "thyroid", and "metastasis", and we reviewed nearly all the reports about thyroid malignancies being metastasized from lung cancer. This rare case emphasizes the importance of the multifaceted comprehensiveness of the cephalometry diagnosis, pathological diagnosis, and immunohistochemical analysis to ensure that such rare cases are not missed. We declare that all cases of thyroid malignancies metastasized from the lungs shall be reported at large for further clinical research.

Metastatic renal cell carcinoma to the pancreas, thyroid, & subcutaneous tissue 13 years after Radical nephrectomy: A case report

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Renal cell carcinoma (RCC) is an aggressive cancer accounting for 3% of all malignancies.

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RCC has been reported to be one of the most common malignancies to cause solitary pancreatic metastasis.

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Metastasis to thyroid is reported to occur in 1% of patients, and can present as late as 20 years after the resection of the primary tumor.

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A high index of suspicion is crucial to detect RCC metastasis, in addition to life-long follow-up.

Introduction

Renal cell carcinoma (RCC) accounts for 3% of all adult malignancies and is known for its poor prognosis. At the time of diagnosis up to 30% of patients will present with metastasis. We report multiple metastases of RCC to rare sites; twice to pancreases, thyroid, twice to subcutaneous tissue, and the other kidney- occurring years after the radical nephrectomy.

Case presentation

Our case is of a 51-year-old female who underwent a right radical nephrectomy for RCC. Upon 6 years post-operative surveillance for recurrence, multiple metastatic lesions were found in the head of the pancreas which were resected by a Whipple procedure. Four years later, she presented with a thyroid nodule and fine needle aspiration showed metastatic RCC. The patient underwent a total thyroidectomy. Months later, the patient presented with a right forearm mass. Biopsy showed metastatic RCC. Excision with negative margins was performed. A year later, a metastatic lesion was found in the tail of pancreas in addition to a recurrent metastatic mass over the right forearm. The patient underwent completion pancreatectomy and resection of the forearm mass. One year later, another metastatic lesion was found in the left kidney, for which the patient underwent left partial nephrectomy with negative margins.

Conclusion

RCC is one of the most aggressive malignancies. A high index of suspicion is crucial to detect its metastasis. As some lesions maybe missed because they lack the classical radiological findings or are found in atypical locations, in addition to the latent recurrence of RCC metastasis, a lifelong follow-up is recommended.

Didactic surgical experience of thyroid metastasis from renal cell carcinoma: A case report

BACKGROUND

The optimal therapeutic strategy in treating thyroid metastasis from renal cell carcinoma (RCC) has not been clearly established. Here we describe a case of didactic surgical experience of the disease which caused massive intraoperative bleeding.

CASE SUMMARY

A 59-year-old male patient presented with a thyroid left lobe soft mass detected by chest computed tomography scans prior to the surgical treatment of RCC of the left kidney. The thyroid mass was initially considered to be benign, then he underwent left radical nephrectomy. One year after the nephrectomy, stereotactic radiosurgery was performed for brain metastasis. During follow-up, the thyroid nodule gradually grew, and the patient manifested swallowing discomfort. Under a clinical diagnosis of thyroid follicular neoplasm, left hemithyroidectomy was performed. Although hemithyroidectomy is usually a safe and straightforward procedure, massive bleeding from markedly developed tumor vessels made the operation very difficult. The thyroid tumor was finally diagnosed as metastasis from clear cell RCC.

CONCLUSION

For proper timing of the surgery, a clinician should take into consideration the possibility of thyroid metastasis of RCC when a thyroid lesion is found in patients with RCC or in patients with a previous history of RCC. We recommend that thyroid metastasis of RCC should be resected as early as possible even if a patient has other metastatic sites.

Metastasis to the thyroid gland from a tonsil squamous cell carcinoma

We present a case of rare metastasis of tonsil squamous cell carcinoma to the thyroid gland, after 2 years of treatment without recurrence at the primary site. The patient had incidental finding of a nodule in the left lobe of the thyroid gland during a screening scan for his previous tonsil squamous cell carcinoma that was treated surgically 2 years ago. The patient was completely asymptomatic with normal thyroid function tests. After further investigations and discussion in the MDT meeting, the patient underwent left thyroid lobectomy as a definitive treatment for his thyroid metastasis.

A case report of thyroid metastasis from p16-positive oropharyngeal squamous cell carcinoma

Thyroid metastasis from head and neck squamous cell carcinoma (SCC) is a very rare form of rarely observed metastatic thyroid tumor. We herein report a case of thyroid metastasis from oropharyngeal SCC (OSCC). The patient was a 68-year-old male diagnosed with p16-positive tonsillar OSCC on the right side with multiple lymph node metastases and a thyroid mass, which was determined as metastatic p16-positive OSCC by immunohistochemistry of specimens collected by fine-needle aspiration cytology (FNAC). He received one cycle of induction chemotherapy followed by concurrent chemoradiotherapy. No visible primary lesions were observed after treatment. The disappearance of the tonsillar lesion was considered to be a complete response by the magnetic resonance imaging (MRI) and positron emission tomography-computed tomography (PET-CT). The thyroid lesion was also decreased, but a solid lesion with unclear boundaries in the right thyroid lobe remained. Therefore, the patient underwent total thyroidectomy to remove any residual tumor. Postoperative pathological evaluation revealed no residual viable carcinoma cells in the resected specimen. As illustrated in this case, immunohistochemistry of the FNAC specimen for p16 was successful in determining the thyroid tumor as a metastatic lesion from the oropharynx. Although radical radiotherapy might be sufficient to control thyroid gland metastasis of OSCC, in this case, early-stage remedial surgery was thought to be necessary for a secure radical cure.

Renal cell metastasis to the thyroid gland: An emerging phenomenon

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Intra-thyroid metastases are rare and account for 1–3% of all thyroid malignancies.

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Renal cell carcinoma has overtaken melanoma and breast carcinoma to become the commonest primary source of intra-thyroid metastases.

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Renal cell carcinoma metastasising to the thyroid gland has a mean spread interval of 9 years.

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The pathophysiology and treatment of renal cell thyroid metastases requires further research.

Introduction

Suspected thyroid malignancies are usually assumed to be primary in origin. Rarely, in 1–3% of cases, the tumour arises from a secondary source such as a melanoma or breast carcinoma. There is a growing body of research concerning metastatic spread of renal cell carcinoma to the thyroid gland.

Presentation of case

This case report describes the presentation and diagnostic work-up of an 84yr male presenting with a goitre and hoarse voice. Histopathological examination of the excised 95 × 65 × 55 mm tissue mass revealed metastatic clear cell renal cell carcinoma.

Discussion

This disease pattern has become increasingly apparent in recent literature. A literature review of 150 documented cases worldwide showed that the mean interval for this spread to occur is 9 years.

Conclusion

There is a need for further investigation into the underlying pathophysiology of this phenomenon and increased awareness from clinicians of its existence.

Comparative study of single-center patients with thyroid metastases from colorectal cancer and previously reported cases in the literature

Background

Thyroid metastases from colorectal cancer (CRC) are rare, both in clinical practice and in the literature; hence, their diagnosis, appropriate treatment, and prognostic factors require further investigations.

Methods

A retrospective analysis was performed for four cases of thyroid metastases from CRC, treated in our center between January 2005 and December 2015, and the relevant literature was searched using PubMed, resulting in the identification of 17 patients with detailed information available. The clinical data and follow-up information of our patients and the previously reported cases were collected and compared.

Results

The median age of the 21 patients was 59 years (44.5 and 66 years for our patients and the previously reported cases, respectively). Fifteen (71.4%) primary tumors were distributed throughout the distal colon or rectum (75% [3/4] in our center and 70.5% [12/17] in the previously reported cases). According to our analysis, we found that 81.0% of patients (17/21) showed concomitant lung metastasis. Among them, all four patients in our center showed lung metastasis, and 75% (3/4) developed thyroid metastases after the lung metastasis. In the previously reported cases, the corresponding proportions were 76.5 and 76.5% (13/17) of patients, respectively. The median time after primary tumor diagnosis to thyroid metastasis development was 28 months (26 months in our center and 35 months in the previously reported cases). One patient with advanced CRC in our center died 5 months after the thyroid metastasis was identified, while the remaining three patients are currently alive (longest follow-up time, 27 months). The median survival time after thyroid metastasis during 3 years of follow-up of the previously reported 17 patients was 12 months. There was no difference in the overall survival between patients treated non-surgically (8/21) and patients undergoing thyroidectomy alone or thyroidectomy with adjuvant therapy (13/21) (p = 0.388). In addition, we found that the overall survival of the patients whose other metastases were treated with radical treatment was superior to that in those treated with palliative treatment (p = 0.022).

Conclusions

Thyroid metastases from CRC are rare in clinical practice and are a manifestation of advanced CRC. The prognosis of patients with thyroid metastases from CRC is related to various factors, including the grade of malignancy of the primary lesion, the presence of other metastases, and whether the metastases are timely diagnosed and a radical treatment strategy is employed.

Thyroid metastasis from renal cell carcinoma-A case report after 9 years

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The thyroid gland is a rare site of clinically detectable tumor metastasis.

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Preoperative distinction between primary and secondary thyroid tumors is difficult.

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RCC disseminates in an unpredictable manner and can show late recurrences.

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Metastasis should be considered if history for RCC and a thyroid nodule is present.

Introduction

The thyroid gland is a rare site of clinically detectable tumor metastasis. As thyroid tumors are usually assumed to be primary in origin, its recognition as a secondary is difficult.

Presentation of case

We report a case of an 80-year old female who was referred to the Department of Surgery for a symptomatic thyroid nodule. Her medical history included a radical nephrectomy for renal cell carcinoma (RCC) nine years ago. During follow-up a pancreatic nodule was noted suggestive of a neuroendocrine tumor and the von Hippel-Lindau syndrome had to be ruled out. The fine-needle aspiration biopsy (FNAB) guided by ultrasound (US) of the thyroid nodule was inconclusive and a hemithyroidectomy and isthmectomy were performed. Histological examination revealed metastasis of a clear cell carcinoma.

Discussion

RCC disseminates in an unpredictable manner and can show late recurrences. Although secondary involvement of the thyroid gland by RCC is rare, it is still one of the more common neoplasms to metastasize to this site. There are no specific clinical features and few characteristic findings of metastatic thyroid carcinoma on imaging studies. FNAB is a useful procedure to diagnose metastatic thyroid cancer, but one should remain suspicious when the result for malignant cells is negative or indeterminate. After thyroidectomy the diagnosis of RCC is confirmed immunohistochemically. There is a clear survival benefit if a surgical approach to the thyroid metastasis is chosen.

Conclusion

Thyroid metastasis should be considered in patients with a thyroid nodule and positive history for RCC.

Squamous cell carcinoma of proximal esophagus with simultaneous metastases to thyroid and sternum: a case report and review of the literature

Clinically significant metastatic spread to the thyroid is considered uncommon in spite of the fact that thyroid is a highly vascularized organ. Though it is not a very uncommon finding at autopsies, it is rare to be found in clinical situations, especially in an individual without a prior history of malignancy. We present an apparently healthy 66 year-old male patient with squamous cell carcinoma of the proximal esophagus presenting as a thyroid nodule along with sternal deposit as a coincidental finding. Esophageal carcinoma rarely metastasizes to the thyroid. This case highlights the importance of thorough work-up when evaluating a thyroid mass/nodule. A high index of suspicion should be kept in mind in order to detect the unusual etiologies of thyroid conditions, especially when clinicopathological features are not characteristic for primary thyroid malignancies.

Thyroid gland metastasis arising from primary liver cholangiocarcinoma: The first case report involving surgical operation

INTRODUCTION

A primary cancer causing thyroid metastasis is extremely rare. In western countries, the most common primary tumors causing thyroid metastases include kidney, lung, breast, and gastrointestinal cancers. In contrast, breast is the most common primary site, followed by kidney, colon, and lung cancers in Korea. To the best of our knowledge, surgically confirmed thyroid metastasis from cholangiocarcinoma has not been reported. Herein, we report the first case of thyroid metastasis secondary to cholangiocarcinoma on which surgery was performed.

PRESENTATION OF CASE

A 55-year-old man was diagnosed with hepatic malignancy in December 2008. He subsequently received 2 cycles of transarterial chemoembolization and 4 cycles of radio-frequency ablation between 2008 and 2010. At follow-up in January 2011, brain metastasis was identified in the right parietal area secondary to cholangiocarcinoma. In April 2011, the patient was found to have palpable masses on the left thyroid and lateral neck. The patient subsequently underwent total thyroidectomy followed by left radical neck dissection. Intraoperatively, an ill-defined mass measuring 6.0 cm was found infiltrating the subcutaneous tissue into the prevertebral fascia. Microscopic and immunohistochemical findings confirmed that the thyroid masses and lymph nodes were metastatic cholangiocarcinoma.

DISCUSSION

Positive immunohistochemical staining for cytokeratin 7, cytokeratin 19, and AFP and negative results for TG, TTF-1, and cytokeratin 20 can be definitely helpful in arriving at a correct diagnosis.

CONCLUSION

To the best of our knowledge, this is the first case report on surgically resected thyroid and lateral neck metastases secondary to cholangiocarcinoma.

Thyroid Metastasis of Gastric Cancer: A Rare Occasion With Poor Prognosis

A 68-year-old man was diagnosed as having advanced gastric cancer. Computed tomography showed a thyroid tumor with trachea deviation. This tumor exhibited mosaic echogenecity in ultrasonography. Signet-ring cell carcinoma was found by means of fine needle aspiration biopsy. This tumor gradually became swollen and the thyroid hormone levels in blood were increased without any clinical symptom. Shortly, he died from his illness in the 29th hospital day. Autopsy disclosed that the left lobe of the thyroid gland was highly invaded by malignant cells and that lymphogenic rather than angiogenic metastasis was highly probable. Thyroid metastasis of gastric cancer is extremely rare. The prognosis is very poor. Ultrasonography is a very useful modality especially when coupled with recently developed fine needle aspiration biopsy in differential diagnosis of thyroid tumors once malignancy is suspected. Therapeutic strategy largely depends on the nature of primary malignant tumor. If the tumor is slowly progressive such as renal cell carcinoma and breast cancer, extirpation of thyroid tumors may extend life expectancy. In conclusion, the metastatic thyroid tumor of gastric cancer is rare and shows poor prognosis. Fine needle aspiration biopsy under ultrasonography is strongly recommended as a useful diagnostic tool.

Solitary Asymptomatic Thyroid Metastasis from Hepatocellular Carcinoma Detected by FDG-PET/CT

Thyroid metastases from hepatocellular carcinoma (HCC) seldom occur and are often difficult to diagnose because of their asymptomatic clinical course. We evaluated a very rare case of solitary thyroid metastasis from HCC that showed high uptake of fluorine-18 fluorodeoxyglucose (FDG), when imaged using fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT). The patient was a 74-year-old man and presented with a remarkably elevated des-gamma-carboxy prothrombin level of 1,157 mAU/ml 22 months after hepatic lobectomy. FDG-PET/CT imaging revealed a hypodense tumor with high FDG uptake, with a maximum standardized uptake value of 5.2 in the thyroid left lobe. Solitary thyroid metastasis from HCC was suspected and subsequent fine needle aspiration did indeed reveal HCC. The patient received left thyroidectomy with left regional lymph node dissection. Two months after left thyroidectomy, contrast-enhanced computed tomography showed local recurrence, and the patient received ongoing radiotherapy treatment. To our knowledge, the present study is the first to demonstrate the feasibility of FDG-PET/CT in the diagnosis and management of clinically diagnosed, asymptomatic, solitary thyroid metastasis from HCC.

Severe hypothyroidism induced by thyroid metastasis of cholangiocarcinoma

We report a case of severe hypothyroidism in a cholangiocarcinoma patient with metastasis to the thyroid gland. A 58-year-old man was admitted for upper abdominal discomfort and multiple palpable neck nodules. Abdominal computed tomography (CT) demonstrated the presence of a 4.7-cm tumor in the right hepatic lobe, and core needle biopsy revealed it to be cholangiocarcinoma. Neck CT showed a diffuse, low attenuation thyroid gland, and fine-needle aspiration (FNA) demonstrated metastatic adenocarcinoma. Thyroid function tests were initially normal, but the size of the thyroid gland decreased and severe hypothyroidism developed after chemotherapy was implemented for cholangiocarcinoma. In a patient with malignant disease and a goiter, the possibility of a metastatic tumor involving the thyroid should be seriously considered. Metastatic thyroid cancer and thyroid dysfunction are probably infrequent, but diagnosis is important in the institution of appropriate therapy.