Occult Thyroid Cancer Research Articles

Papillary Carcinoma Arising from Ectopic Thyroid Tissue in the Spinal Cord

Ectopically located thyroid tissue is uncommon and if present, is usually found in the lateral neck. Rarely, this may give rise to a carcinoma. The diagnosis rests on post-surgical histopathologic examination. We present a rare case of papillary carcinoma arising from ectopic thyroid tissue in the spinal cord in a 12-year old girl who developed spinal cord compression T4 level in 2004. She underwent laminectomy with tumor excision and histopathologic diagnosis was ependymoma. The spinal cord mass recurred when she was 17 years old (in 2009) and the tumor was excised. Tissue staining with thyroglobulin, thyroid transcription factor-1 (TTF-1) and epithelial membrane antigen (EMA) were positive. Pathologic diagnosis was papillary carcinoma. Subsequently, she underwent a total thyroidectomy to confirm an occult primary thyroid cancer; however, histopathologic examination of the thyroid was benign. Whole body scan using I-131 did not reveal extrathyroidal uptake. Radioactive iodine ablation was not done. She was maintained on a suppressive dose of levothyroxine. She remained paraplegic, with no evidence of tumor recurrence two years since her last surgery.

Incidental Thyroid Cancer Found during Surgery for Head and Neck Squamous Cell Carcinoma

Objective: We aim to determine the clinical significance of incidental thyroid cancer found during surgery for HNSCC. We examined the clinical outcome of these patients with regard to both HNSCC and thyroid cancer to determine the need for treatment of incidental thyroid disease. Method: Using our head and neck cancer registry, we retrospectively reviewed 2,538 neck dissections performed at our institution over a 15-year period. We identified 29 patients who had an incidental pathologic finding of thyroid disease at surgery. We reviewed demographics, diagnoses, histopathology, initial and subsequent management, and outcome. Results: Papillary thyroid cancer was the principal thyroid cancer in every case in our cohort. Fifteen patients died during the period of the study (2.4-year mean follow-up), with 14 patients still alive (4.3-year mean follow-up). Seven patients received further treatment for their thyroid: 2 with completion thyroidectomy, 2 with I-131 ablation, and 3 with both. During the follow-up period, none of the patients developed tissue proven recurrence of thyroid cancer. Cause of death was unrelated to thyroid cancer in all of the patients who died during the follow-up period. Conclusion: Thyroid cancer, in general, has excellent prognosis. This study suggests that further management of occult thyroid cancer discovered in patients undergoing surgery for HNSCC may not be necessary.

Ultrasonographic screening for occult thyroid cancer

It has been shown that occult thyroid carcinoma can be identified in about 10% of thyroid glands in autopsy. The purpose of this study was to evaluate the prevalence of asymptomatic thyroid carcinoma in the Hong Kong Chinese population by ultrasonographic screening. Volunteer subjects without symptoms of thyroid disease were recruited for ultrasonographic screening for thyroid cancer. A total of 1140 subjects were recruited in this study. Thyroid nodules were found in 45% subjects (511 of 1140); the mean age was 48 years. Ultrasonographic-guided aspiration cytology was performed in 258 subjects. Twenty-six subjects (2.3%) had cytologic findings suspicious of malignancy. Fourteen subjects (1.2%) had pathologic diagnosis of thyroid cancer, including 13 papillary carcinomas and 1 follicular carcinoma. A high incidence of occult thyroid cancer could be identified on ultrasonographic screening. Subjects could benefit with early diagnosis with either early intervention or close monitoring.

A Case of Occult Thyroid Cancer Diagnosed as Metastasis to Mediastinal Lymph Nodes During Surgery for Primary Lung Cancer

背景．縦隔リンパ節転移を発見契機とした甲状腺癌の報告は少ない．症例．77歳男性．検診で右上葉に腫瘤が認められた．PETで肺腫瘤にSUVmax 8.2の集積を認めた．高位縦隔リンパ節2個にも異常集積を認めた．胸骨正中切開下に，右上葉切除+縦隔リンパ節郭清を施行した．混合型小細胞癌（小細胞癌+腺癌）と診断された．縦隔リンパ節は甲状腺乳頭癌の転移であった．術後補助化学療法後に甲状腺の手術を施行し，8 mmの甲状腺乳頭癌が認められた．結語．肺癌手術時に縦隔リンパ節転移で発見された不顕性甲状腺癌の1例を報告した．肺癌で気管周囲にリンパ節転移を認める時，不顕性甲状腺癌の転移の可能性がある．

Solitary metastasis from occult thyroid cancer mimicking a convexity meningioma: a case report

Solitary metastasis from occult thyroid cancer mimicking a convexity meningioma: a case report

Nodal Metastasis From Occult Thyroid Cancer Detected by FDG PET-CT in a Patient With 2 Known Malignancies

Nodal Metastasis From Occult Thyroid Cancer Detected by FDG PET-CT in a Patient With 2 Known Malignancies

Trends Analysis of Characteristics of Thyroid Cancer Patients in One Medical Center

Background: The incidence of thyroid cancer is rapidly increasing. The aim of this study is to examine time trends in the characteristics of thyroid cancer and to determine the cause of the increase of thyroid cancer. Methods: We evaluated 4,646 patients that underwent surgery at the Asan Medical Center for thyroid cancer between 1995 and 2006. Patients were evaluated concerning the histology, size of the primary tumor, sex, and age at the time of surgery. Results: Surgically treated case of thyroid cancer increased from 91 in 1995 to 960 in 2006―a 10.5-fold increase during the 12-year period. Based on the histological categories, the proportion of papillary thyroid carcinomas (PTCs) increased from 79.1% to 94.5% during the 12-year period. According to the primary tumor size in the PTCs, the proportion of PTCs measuring 1 cm or smaller increased from 14% to 56% during the 12-year period. Whereas the proportion of PTCs measuring from 1 cm to 2 cm were similar (between 31% and 41% during the 12-year period), the proportion of PTC measuring from 2 cm to 4 cm decreased from 51% to 11% during the 12-year period. Thyroid cancer affected women more often than men by a ratio of 3.7. PTC was most common in patients in their forties, especially among women. Conclusions: The increasing number of surgica lly treated cases of thyroid cancer is predominantly due to an increase of papillary thyroid cancer measuring 1 cm or less. These trends suggest that the increase in surgically treated cases of thyroid cancer reflects increased detection of occult thyroid cancer due to advances in medical surveillance of impalpable nodules rather than a true increase in the number of thyroid cancers. (J Kor Endocr Soc 23:35~43, 2008)

Latency period of thyroid neoplasia after radiation exposure.

To determine the temporal sequence for developing benign and malignant thyroid neoplasms after radiation. Therapeutic radiation is associated with thyroid neoplasms in humans and animals. Some question whether thyroid cancers develop de novo or from benign thyroid neoplasms. Little information, however, is available concerning the time to development of benign and malignant thyroid neoplasms after radiation exposure. We retrospectively analyzed the records of 171 consecutive patients who had a history of exposure to radiation and were treated surgically at University of California, San Francisco-affiliated hospitals for thyroid neoplasms between 1960 and 1999. There were 66 men and 105 women aged 9 to 80 years (mean, 47.0 years). One hundred patients had benign and 71 had malignant tumors (58 papillary cancers, 10 follicular cancers, 1 Hurthle cell cancer, 1 medullary cancer, and 1 carcinosarcoma). The mean latency period for benign tumors was longer than that for malignant lesions (mean, 34.1 and 28.4 years, P = 0.018; median, 38.0 years and 30.0 years, P = 0.001). Follicular carcinomas developed sooner (mean, 20.5 years; median, 20 years) than did follicular adenomas (mean, 35.3 years; median, 36.5 years; P = 0.003, P = 0.0009). Patients with papillary thyroid cancers presenting as occult papillary cancers (<1 cm) and as a dominant nodule had similar latency periods (mean, 34.0 and 28.0 years P = 0.29; median, 37.5 and 30.5 years, P = 0.09), respectively. Although there could be selection bias regarding referral of patients, our data document that malignant thyroid tumors after radiation exposure, including follicular carcinomas, present earlier than do benign thyroid tumors. Occult and manifest papillary thyroid cancers present at about the same time interval after radiation exposure. Our findings question whether benign thyroid neoplasms progress to malignant thyroid neoplasms and that most occult thyroid cancers do not progress to malignant thyroid cancers in radiation-exposed patients.

Prevalence, clinical and ultrasonographic characteristics of thyroid incidentalomas.

High-resolution ultrasonography (US) has made possible the detection of asymptomatic small thyroid nodules. Thyroid incidentalomas have created a clinical dilemma as to how to properly manage such incidental findings. We investigated the prevalence, the clinical and US characteristics, and optimal diagnostic approach to incidentally detected benign and malignant thyroid nodules < 1.5 cm. Retrospective review was done on 1475 patients who had visited Samsung Medical Center, Soul Korea from January 1999 to December 2000. The prevalence of thyroid incidentalomas was 13.4%. The malignancy rate within thyroid incidentalomas was 28.8%. There were no significant differences in age, nodule size and number, thyroid function test, and Tc99m thyroid scan between benign and malignant incidentalomas. US characteristics of solid echostructure, irregular margin, and calcification showed meaningful diagnostic value in detecting malignancy in thyroid incidentalomas (p < 0.05). Most malignant incidentalomas were low stage. In conclusion, occult thyroid cancers are a fairly common finding. There were no significant differences in clinical and laboratory parameters between benign and malignant thyroid nodules <1.5 cm; however, US findings can be used in the decision of optimal management strategies.

Accuracy of fine-needle aspiration cytology in patients with radiation-induced thyroid neoplasms.

Fine-needle aspiration cytology (FNAC) is useful for selecting patients with thyroid nodules for thyroidectomy. Its value in patients who have been exposed to low-dose therapeutic radiation is questionable because these patients have an increased risk of multifocal benign and malignant tumours, and thyroid cancer is common in such patients. Between 1960 and 1999, 171 patients with one or more thyroid nodules who had a history of exposure to radiation underwent operation; 49 of these patients had preoperative FNAC. The cytology results in these 49 patients were compared with those of an age- and sex-matched control group of patients with thyroid nodules who did not have a history of radiation exposure. Of those who had been exposed to radiation, six of 20 patients with 'benign' cytology by FNAC and six of 16 patients with 'suspicious' cytology had thyroid cancer. All 13 specimens considered to be malignant on FNAC were indeed malignant. There was a higher rate of false-negative cytological examinations among patients with a history of irradiation that in those without. FNAC of thyroid nodules in patients with a history of irradiation is not as accurate as that in non-irradiated patients, primarily because of coexisting occult thyroid cancers.

Bilateral En Bloc Resection of the Thyroid without Division of the Isthmus: A Technical Alternative to Conventional Subtotal Resection in Multinodular Goitre

Background: Bilateral multinodular goitre is a manifestation of unspecific proliferation of thyroid tissue often accompanied by multiple cold nodules scintigraphically. The suspicion of thyroid cancer cannot be completely excluded by the patient’s history, physical examination, ultrasonography, fine needle aspiration cytology, or intraoperative frozen section. To evaluate surgically related morbidity and the incidence of occult thyroid cancer in multinodular goitres, the technique of bilateralen bloc resection has been analysed.

Biologic basis for the treatment of microscopic, occult well-differentiated thyroid cancer

Background. Management of thyroid microcancer or occult well-differentiated thyroid cancer (OWDTC) is controversial. Our present study compared some clinical features of OWDTC and gross well-differentiated 10-mm thyroid carcinoma (GWDTC), which may offer a basis for treatment policy. Methods. From 1964 to 2000, 1000 patients underwent thyroidectomy for thyroid cancer. We randomly selected 428 cases for study in which node sampling was carried out in 88% of GWDTC and 60% of OWDTC and who were demographically comparable. All data were obtained by chart review and analyzed by chi-square test. Results. With the maximum limit of 10 mm for defining OWDTC, we found 113 such cases with a mean size of 6.1 mm and 315 GWDTC cases with a mean size of 27.6 mm. The incidence of metastatic nodal disease was 16.8% in OWDTC cases and 25.7% in GWDTC cases (P =.057). Distant metastases occurred in 1 of 113 (0.9%) cases of OWDTC and 11 of 315 (3.5%) cases of GWDTC (P =.149). After a mean follow-up time of 55.8 months, neck metastatic recurrent disease occurred in 3 of 113 (2.7%) cases of OWDTC and 7 of 315 (2.2%) cases of GWDTC (P =.770). OWDTC was found in 11.1% of the GWDTC group undergoing an operation. Multicentricity occurred in 31.9% of OWDTC cases and 35.9% of GWDTC cases (P =.447). No cause-specific death occurred. Conclusions. One cannot be dogmatic in treatment of microcancer, but one is justified in extending similar treatment principles for OWDTC as in GWDTC, which in our center usually indicates near-total thyroidectomy and consideration for radioactive iodine ablation. (Surgery 2001;130:1050-4.)

Incidental Thyroid Carcinoma Identified by Positron Emission Tomography Scanning Obtained for Metastatic Evaluation

Positron emission tomography (PET) scanning is an emerging technology with substantial implications for patients with solid tumors. PET is useful in identifying sites of metastatic disease as well as primary malignancy and evaluating suspicious findings found via other imaging modalities. PET is becoming a standard modality for metastatic evaluation of a variety of malignancies. However, this imaging is not limited by histology and may reveal clinically occult second lesions. We present five cases of a clinically occult thyroid cancer found in patients who underwent PET scanning for metastatic evaluations. The principal diagnoses included two patients with malignant melanoma, one each with gastric, rectal, and colonic adenocarcinoma. None of the cases had findings on physical examination. Increased uptake in the region of the thyroid was evident on the PET scan, and fine-needle aspiration biopsy indicated papillary carcinoma of the thyroid in all five cases. Although evaluation of metastatic disease is the primary purpose for PET in this setting the discovery of occult thyroid malignancy is an additional benefit of such imaging. This emphasizes the importance of investigating suspicious areas found by PET and not simply assuming that these are all sites of metastatic disease. Furthermore incidental findings of uptake in the region of the thyroid make consideration of a primary carcinoma mandatory.

Development of cholecystokinin-B/gastrin-receptor binding peptides for diagnosis and therapy: Results of a clinical phase-I/II study for the staging of known and occult metastatic medullary thyroid cancer

Development of cholecystokinin-B/gastrin-receptor binding peptides for diagnosis and therapy: Results of a clinical phase-I/II study for the staging of known and occult metastatic medullary thyroid cancer

Mediastinal Lymph Node Involvement as the Initial Manifestation of Occult Thyroid Cancer in the Surgical Treatment of Lung Cancer: Report of a Case

Mediastinal Lymph Node Involvement as the Initial Manifestation of Occult Thyroid Cancer in the Surgical Treatment of Lung Cancer: Report of a Case

Thyroid cancer associated with adenomatous goiter: an analysis of the incidence and clinical factors.

We evaluated the incidence of thyroid cancer in patients with adenomatous goiter and investigated the clinical factors distinguishing patients with occult thyroid cancer, defined as a tumor size smaller than or equal to 10 mm, from those with clinical thyroid cancer, defined as a tumor size larger than 10 mm. Of 835 patients with histologically confirmed adenomatous goiter, 256 (30.7%) also had thyroid cancer, being occult in 137 patients and clinical in 119 patients. There was no correlation between the maximum size of the thyroid cancer tumor and the age of the patient, and the percentage of patients with thyroid cancer in each group was not influenced by age. There were no significant differences in age, sex, the serum concentrations of free triiodothyronine, free thyroxine, thyrotropin, and thyroglobulin, or the urinary iodine creatinine ratio. The frequency of calcified lesions being detected by ultrasonography (US) and/or neck X-ray in the patients with clinical thyroid cancer was significantly greater than that in those with occult cancer at 83% vs 57%, respectively (P < 0.0001). This study disclosed a high prevalence of thyroid cancer associated with adenomatous goiter, and the results suggest that a considerable number of associated carcinomas remain occult. The detection of calcification in the thyroid gland is one of the surgical indications for patients with adenomatous goiter.

Thyroid Nodular Disease: Diagnostic Evaluation and Management-Reply

The recommendations made by Raber and Vierhapper are neither accurate nor cost-effective. Their concerns were based on retrospective analysis of 2087 scintigraphically cold nodules, done as part of nodule evaluation. We agree that thyroid cancer can be found in small nodules, but the prevalence of occult thyroid cancer is small, with a mean (±SD) prevalence estimated to be 3.9%±4.1%. 1 Performing thyroid ultrasonography as an initial tool will only confuse the issue by the discovery of other nodules that, according to the recommendation of Raber and Vierhapper, will need further evaluation. There are no data to support this. To our knowledge, there is no study that prospectively examines these impalpable thyroid nodules. Autopsy studies have shown these nodules to be benign. 2 At the same time, in Japanese subjects, who have the highest prevalence of occult cancers, the death rate is very low, since the majority of these cancers are

Improved detection of medullary thyroid cancer with radiolabeled antibodies to carcinoembryonic antigen.

This investigation was undertaken to assess the targeting of established and occult medullary thyroid cancer (MTC) with radiolabeled monoclonal antibodies (MAbs) reactive with carcinoembryonic antigen (CEA). Twenty-six assessable patients with known (n = 17) or occult (n = 9) MTC were studied with radiolabeled anti-CEA MAbs. Scintigraphic images were collected to determine targeting of tumor lesions. The targeting results of technetium 99m (99mTc)-,iodine 123 (123I)-, and iodine 131 (131I)-labeled anti-CEA antibodies (all directed against the same epitope of CEA) indicated that all these reagents were capable of detecting established and occult MTC. The sensitivity for detection of known sites of disease ranged from 76% to 100% for the various anti-CEA MAbs used, when compared with computed tomography (CT), magnetic resonance imaging (MRI), bone scan, or other imaging modalities. Moreover, the antibody scan was positive in seven of nine patients with occult disease (patients with negative conventional imaging studies, but who had elevated calcitonin and/or CEA levels). Three of seven patients underwent surgery and the disease was confirmed by histopathology in all three. Anti-CEA MAbs are excellent agents for imaging recurrent, residual, or metastatic MTC. The high lesion sensitivity in patients with known lesions, combined with the ability to detect disease, may make these agents ideal for staging patients, monitoring disease pretherapy or posttherapy, and especially for evaluating patients with recurrent or persistent hypercalcitonemia or CEA elevations after primary surgery. Analogous to radioiodine in the evaluation of patients with differentiated thyroid cancer, radiolabeled anti-CEA MAbs may achieve a similar role in diagnosing and monitoring patients with MTC.

A Case of Double Cancer: Tongue Cancer and Occult Thyroid Cancer Found by Radical Neck Dissection of Tongue Cancer

A Case of Double Cancer: Tongue Cancer and Occult Thyroid Cancer Found by Radical Neck Dissection of Tongue Cancer

Occult thyroid cancer discovered by fine‐needle aspiration cytology of cervical lymph node: A report of three cases

Three cases of occult thyroid cancer measuring 10, 6, and 3 mm in diameter were discovered by fine-needle aspiration cytology of cervical lymph nodes. In these three cases, thyroid tumors were not palpable, and scintigraphic, echographic, and soft-tissue radiologic examinations demonstrated no abnormalities of the thyroid glands. Cytologically, the presence of intranuclear cytoplasmic inclusions, nuclear grooves, and colloid was characteristic in aspirated materials. Histologically, all three cases were diagnosed as papillary carcinoma. Fine-needle aspiration cytology of cervical lymph node was very useful to find occult carcinoma of the thyroid gland.