The intensity of immunogold labeling of deplasticized acrylic sections compared to deplasticized epoxy sections—Theoretical deductions and experimental data

The purpose of this study was to compare the level of immunogold labeling of deplasticized acrylic sections and deplasticized epoxy sections. Pure protein gels of IgG, albumin and thyroglobulin were produced by glutaraldehyde fixation and embedded in non-crosslinked acrylic resin (Technovit 9100) and epoxy resin (Epon 812), respectively. Ultrathin sections of acrylic and epoxy resin were separately deplasticized in 2-methoxyethyl acetate (MEA) and sodium ethoxide. Quantitative immunogold labeling was performed with anti-IgG, anti-albumin and anti-thyroglobulin antibodies on sections of the corresponding protein gels. For all antibodies tested, the intensity of labeling for deplasticized acrylic sections was significantly higher (two to four times) than for the corresponding deplasticized epoxy sections. The results fit with a theoretically deduced relation: the quotient of the labeling of two deplasticized sections of different resins is equivalent to the square root of the quotient of the labeling of the similar sections not exposed to any kind of pre-treatment. The practical significance of the results is that immunolabeling of deplasticized non-crosslinked acrylic resin results in more intense immunogold labeling than deplasticized epoxy sections. Deplasticizing is most useful when the requirements for ultrastructural preservation according to conventional criteria are moderate. Our theoretically deduced results also indicate that deplasticized Technovit (or other non-crosslinked acrylic resins) sections will be significantly better suited for immunolabeling at the light microscopic level than deplasticized epoxy sections.

Automated sample preparation facilitated by PhyNexus MEA purification system for oligosaccharide mapping of glycoproteins

A reproducible high-throughput sample cleanup method for fluorescent oligosaccharide mapping of glycoproteins is described. Oligosaccharides are released from glycoproteins using PNGase F and labeled with 2-aminobenzoic acid (anthranilic acid, AA). A PhyNexus MEA system was adapted for automated isolation of the fluorescently labeled oligosaccharides from the reaction mixture prior to mapping by HPLC. The oligosaccharide purification uses a normal-phase polyamide resin (DPA-6S) in custom-made pipette tips. The resin volume, wash, and elution steps involved were optimized to obtain high recovery of oligosaccharides with the least amount of contaminating free fluorescent dye in the shortest amount of time. The automated protocol for sample cleanup eliminated all manual manipulations with a recycle time of 23 min. We have reduced the amount of excess AA by 150-fold, allowing quantitative oligosaccharide mapping from as little as 500 ng digested recombinant immunoglobulin G (rIgG). This low sample requirement allows early selection of a cell line with desired characteristics (e.g., oligosaccharide profile and high specific productivity) for the production of glycoprotein drugs. In addition, the use of Tecan or another robotic platform in conjunction with this method should allow the cleanup of 96 samples in 23 min, a significant decrease in the amount of time currently required to process such a large number of samples.

Combined [18F]Fluorodeoxyglucose Positron Emission Tomography and Computed Tomography (FDG-PET/CT) for Detection of Recurrent, 131I-Negative Thyroid Cancer

BACKGROUND

Whole-body (131)I scintigraphy (WBS) and serial thyroglobulin measurement (Tg) are standard methods for detecting thyroid cancer recurrence after total/near total thyroidectomy and (131)I ablation. Some patients develop elevated Tg (Tg-positive) or there is clinical suspicion of recurrence, but WBS are negative (WBS-negative). This may reflect non-iodine-avid recurrence or metastasis. In 2002, the Centers for Medicare and Medicaid Services (CMS) approved positron emission tomography with [(18)F]fluorodeoxyglucose (FDG-PET) for Tg-positive/WBS-negative patients with follicular-cell-origin thyroid cancer. Limited data are available regarding the performance of combined FDG-PET/computed tomography (FDG-PET/CT) for detecting recurrent thyroid cancer in WBS-neg patients.

METHODS

This retrospective review of prospectively collected data analyzed 65 patients who had FDG-PET/CT for suspected thyroid cancer recurrence (April 1998-August 2006). Patients were WBS-negative but were suspected to have recurrence based on Tg levels or clinical grounds. Suspected FDG-PET/CT abnormalities were reported as benign or malignant. Lesions were ultimately declared benign or malignant by surgical pathology or clinical outcome (disease progression).

RESULTS

Of 65 patients who underwent FDG-PET/CT, 47 had positive FDG-PET/CT. Of the positive FDG-PET/CT, 43 studies were true positives, with 21 (49%) confirmed pathologically by surgical resection. The four false positives (3/4 confirmed pathologically) included an infundibular cyst, an inflamed supraclavicular cyst, pneumonitis, and degenerative disc disease. Of the 18 FDG-PET/CT studies that were negative, 17 were true negatives and one was a false negative (metastatic papillary carcinoma). Thus, FDG-PET/CT demonstrated a patient-based sensitivity of 98%, specificity of 81%, positive predictive value of 91%, and negative predictive value of 94%.

CONCLUSIONS

FDG-PET/CT is useful for detecting thyroid cancer recurrence in WBS-negative patients, and can assist decision making.

Clinical relevance of highly sensitive Tg assay in monitoring patients treated for differentiated thyroid cancer

OBJECTIVE

Serum thyroglobulin (Tg) represents a highly specific biomarker for detecting residual thyroid tissue/recurrence/metastases after treatment for differentiated thyroid cancer (DTC). We evaluated the clinical impact of a highly sensitive Tg assay during routine follow-up of DTC patients.

DESIGN

Tg values were measured by a highly sensitive Tg assay during L-T4 suppressive therapy and after recombinant human thyrotropin (rh-TSH) stimulation and were compared with those obtained by using a routinely employed Tg assay.

PATIENTS

One hundred and sixty consecutive DTC-treated patients (papillary carcinoma n = 124, follicular carcinoma n = 36) were studied.

MEASUREMENTS

Measured variables included neck ultrasonography, (131)I whole body scanning, and Tg assayed by Immulite (Diagnostic Products Corporation, Los Angeles, CA) and by the highly sensitive Access assay (Beckman Coulter, Brea, CA).

RESULTS

During L-T4 therapy, measurable Tg was found in only two patients (1% of total) by Immulite and in 23 patients (14% of total) by Access assay. Using the institutional cut-off of 2 microg/l after rh-TSH, a negative response was associated with undetectable Immulite Tg during L-T4 therapy in all patients (negative predictive value, NPV, 100%) and in 137 out of 152 patients with Access assay (NPV 90%). Measurable Tg during L-T4 therapy was found in 17% of positive patients with Immulite and in 100% of patients with Access, respectively.

CONCLUSIONS

The use of a highly sensitive Tg assay may represent a useful diagnostic tool for improving the interpretation of Tg results during monitoring of DTC-treated patients for the early detection of recurrence and for optimizing the use of the more expensive rh-TSH test.

Comparison of seven serum thyroglobulin assays in the follow-up of papillary and follicular thyroid cancer patients

BACKGROUND

Serum thyroglobulin (Tg) is the marker of differentiated thyroid cancer after initial treatment and TSH stimulation increases its sensitivity for the diagnosis of recurrent disease.

AIM

The goal of the study is to compare the diagnostic values of seven methods for serum Tg measurement for detecting recurrent disease both during L-T4 treatment and after TSH stimulation.

METHODS

Thyroid cancer patients who had no evidence of persistent disease after initial treatment (total thyroidectomy and radioiodine ablation) were studied at 3 months on L-T4 treatment (Tg1) and then at 9-12 months after withdrawal or recombinant human TSH stimulation (Tg2). Sera with anti-Tg antibodies or with an abnormal recovery test result were excluded from Tg analysis with the corresponding assay. The results of serum Tg determination were compared to the clinical status of the patient at the end of follow-up.

RESULTS

Thirty recurrences were detected among 944 patients. A control 131I total body scan had a low sensitivity, a low specificity, and a low clinical impact. Assuming a common cutoff for all Tg assays at 0.9 ng/ml, sensitivity ranged from 19-40% and 68-76% and specificity ranged from 92-97% and 81-91% for Tg 1 and Tg2, respectively. Using assays with a functional sensitivity at 0.2-0.3 ng/ml, sensitivity was 54-63% and specificity was 89% for Tg1. Using the two methods with a lowest functional sensitivity at 0.02 and 0.11 ng/ml resulted in a higher sensitivity for Tg1 (81% and 78%), but at the expense of a loss of specificity (42% and 63%); finally, for these two methods, using an optimized functional sensitivity according to receiver operating characteristic curves at 0.22 and 0.27 ng/ml resulted in a sensitivity at 65% and specificity at 85-87% for Tg1.

CONCLUSION

Using an assay with a lower functional sensitivity may give an earlier indication of the presence of Tg in the serum on L-T4 treatment and may be used to study the trend in serum Tg without performing any TSH stimulation. Serum Tg determination obtained after TSH stimulation still permits a more reliable assessment of cure and patient's reassurance.

Thyroglobulin detection in fine-needle aspirates of cervical lymph nodes: a technique for the diagnosis of metastatic differentiated thyroid cancer

BACKGROUND

Fine-needle aspiration cytology is frequently used for differential diagnosis of neck masses of unknown origin. Inconclusive and even false-negative results are not uncommon.

AIM

To evaluate the utility of thyroglobulin (Tg) measurement in fine-needle aspirates (FNA-Tg) for detecting cervical lymph node (CLNs) metastases from differentiated thyroid carcinomas.

METHODS

An ultrasound-guided fine-needle aspiration was done in 67 patients with 83 suspicious enlarged CLNs to obtain material for cytology and Tg measurement in the needle washout, using an immunometric chemiluminescent assay. Measurement of anti-Tg antibodies (FNA-TgAb) was also carried out in half of all the aspirates. Subjects were divided into two groups: one of 16 patients awaiting thyroidectomy and the other of 51 patients in follow-up after surgery.

RESULTS

The first group of patients had positive FNA biopsy (FNAB-Tg) in 14 out of the 18 studied CLNs with a range of 3.2-43 352 ng/ml, while FNAB-cytology indicated metastasis in only 8 out of the 14 CLNs with positive histology. A total of 65 CLNs were studied in the follow-up group. Lymphadenectomy was performed in 23 patients and 28 aspirated CLNs were removed. Histology confirmed the diagnosis of metastasis suggested by FNAB-Tg in 20 CLNs and of reactive lymphadenitis in the remaining 8 CLNs. FNAB-cytology was positive in only 11 CLNs. Sensitivity of FNAB-Tg was not affected by the studied FNAB-TgAb.

CONCLUSIONS

The FNAB-Tg achieved a sensitivity of 100% in both groups. FNAB-Tg is an easy and inexpensive technique which proved to increase the diagnostic of cytology in the early diagnosis of papillary carcinoma recurrence to CLN even in the presence of serum TgAb.

Papillary cystadenocarcinoma: Report of a case of high-grade histopathologic malignancy

Papillary cystadenocarcinoma is an extremely rare malignant tumor of the salivary gland which is cytologically considered to be of low-grade malignancy, showing an indolent biological behavior. Histologically, the tumor is characterized by cysts and papillary endocystic projections. This tumor most commonly arises in the major salivary glands, mainly the parotid gland. We report here a case of papillary cystadenocarcinoma originating from the minor salivary gland, which showed marked growth over a short period of time. Histologically, the tumor was characterized by intense cellular and nuclear pleomorphism and numerous mitotic figures. These findings indicate a tumor of high-grade malignancy.

Evaluation of the surgical completeness after total thyroidectomy for differentiated thyroid carcinoma

BACKGROUND

To quantify the rate of patients without thyroid remnants, to identify predictive factors for the absence of residual thyroid tissue and to evaluate number, site, size and function of thyroid remnants after total thyroidectomy for differentiated thyroid carcinoma (DTC).

METHODS

Thousand one hundred and seventy-eight patients who underwent total thyroidectomy for DTC were evaluated; 343 patients with lymph node or distant metastases and 115 patients with detectable thyroglobulin autoantibodies (TgAb) were excluded. (131)I ablative treatment (RAI) without preliminary diagnostic (131)I whole body scans (DxWBS), and 24-h (131)I quantitative neck uptake (RAIU test) and thyroglobulin (Tg) off L-T4 evaluation were performed in the remaining 720 pts. In 252 patients a 99mTc-pertechnetate pre-operative thyroid scan (99mTc-scan) was used for comparison with (131)I neck scans after RAI to evaluate site of thyroid remnants. Only patients with thyroid remnants were evaluated for successful ablation 6-10 months after RAI.

RESULTS

Post-treatment whole body scan (TxWBS) demonstrated lack of thyroid remnants in 50/720 patients and the best predictive factors for the absence of residual thyroid tissue were RAIU <1% and undetectable Tg off L-T4. Thyroid remnants were present in 670/720 patients. In 252 patients with (99m)Tc-scan, 617 sites of functioning thyroid tissue were found: 381 within and 236 outside the thyroid bed. Complete successful ablation was achieved in 610/670 patients with thyroid remnants.

CONCLUSIONS

This study confirms that most patients (93.1%) have thyroid remnant after total thyroidectomy for DTC. Most thyroid remnants were contralateral to tumour site and were even observed outside thyroid bed. However, a real total thyroidectomy, demonstrated by negative TxWBS, RAIU <1% and undetectable Tg off L-T4, was achieved in 6.9% of patients.

Discrimination of thyroglobulin from thyroid carcinoma tissue and that from benign thyroid tissues with use of competitive assay between lectin and anti-thyroglobulin antibody

Thyroglobulin is produced only by thyroid follicular cells, and has a molecular weight of 660,000 and carbohydrate content of approximately 10%. The composition of carbohydrate chains on thyroglobulin from thyroid carcinoma has been reported to differ from that in normal thyroid tissue. In this study, heterogeneities of carbohydrate chains on thyroglobulin obtained from thyroid tissues were investigated by competitive reaction between lectin and anti-thyroglobulin monoclonal antibody. Concanavalin A, Lens culinaris agglutinin, Ricinus communis agglutinin-120 and Datura stramonium agglutinin were compared. The ratio of Lens culinaris agglutinin-reactive thyroglobulin to thyroglobulin was significantly lower in thyroid carcinoma than in normal thyroid tissue, Graves' disease and benign thyroid tumor. However, no differences between malignant and benign tissues were observed with the other lectins tested. Differences in carbohydrate chain on thyroglobulin were observed between malignant and benign thyroid tissues.

Diagnóstico de metástases de carcinoma papilífero de tiróide através da dosagem de tiroglobulina no líquido obtido da lavagem da agulha utilizada na punção aspirativa

Com a introdução da ultra-sonografia cervical (USC) no seguimento dos pacientes com carcinoma papilífero de tiróide (CPT), tornou-se freqüente o encontro de pequenos linfonodos (LNs) cervicais. Porém, apesar de a USC apresentar alta sensibilidade, o estudo citológico obtido por punção aspirativa (PAAF) e, nos últimos anos, a dosagem da tiroglobulina (Tg) no lavado da agulha da PAAF (Tg-PAAF) vêm assumindo papel importante no diagnóstico de LNs cervicais. O objetivo deste estudo é verificar a acurácia da combinação da USC, citologia e Tg-PAAF em LNs suspeitos. Estudamos 32 pacientes que apresentavam 44 LNs à USC, classificados como "inflamatórios" (19) ou "suspeitos" (25). Dos 25 LNs suspeitos, 15 apresentavam Tg-PAAF elevada (13 com citologia compatível com metástases e 2 com citologia não-diagnóstica). Esses 15 LNs (11 pacientes) foram confirmados como metástase de CP pelo exame histopatológico. Os 19 LNs "inflamatórios" e os 10/25 LNs "suspeitos" apresentaram citologia negativa e Tg-PAAF indetectável. Concluímos que a USC apresenta alta sensibilidade na detecção de linfonodos cervicais, porém citologia e dosagem de Tg-PAAF são fundamentais para o diagnóstico. A associação USC, citologia e Tg-PAAF pode ser considerada a abordagem mais sensível e específica na detecção de LNs metastáticos em pacientes com CPT.

Management of low-risk patients with thyroid carcinoma and detectable thyroglobulin on T4 after thyroidectomy and ablation with iodine-131

OBJECTIVE: To evaluate the positive predictive value of detectable Tg during T4 therapy (Tg on T4) in patients with thyroid cancer after total thyroidectomy and remnant ablation, discussing the work-up in this situation and the empirical indication of 131I. PATIENTS AND METHODS: Initially, 234 low-risk patients [tumor < 5cm, completely resected, no extensive extrathyroid invasion (pT4)] submitted to total thyroidectomy and ablation with 131I (3.75.5 GBq) who presented no ectopic uptake on RxWBS were studied. Of these, 23 patients with detectable Tg on T4 (> 1ng/ml) during the first year after initial therapy were selected. RESULTS: Metastases were detected by neck US in 7 patients, by chest CT in 2 and by US and CT in 3. Four of five patients with lung metastases upon CT had a positive RxWBS. Eleven patients with negative US and CT received a new 131I dose (without DxWBS), and RxWBS showed ectopic uptake in 3 patients. Among the patients with negative RxWBS, 7 remained free of apparent disease and Tg was declining (5 with undetectable Tg on T4 at the end of the study). One patient presented an increase in Tg and FDG-PET was positive for lymph node and bone metastases. CONCLUSIONS: All patients with Tg on T4 > 5ng/ml presented apparent disease. In these cases, even when US and CT are negative, the administration of a therapeutic dose of 131I (without DxWBS) and FDG-PET are recommended. Among patients with detectable Tg on T4 < 5ng/ml and negative US and CT, only 12% presented ectopic uptake on RxWBS. These cases could be followed up by monitoring Tg on T4, and RxWBS and FDG-PET should only be performed if this marker does not decrease after 12 years.

18F-FDG PET/CT in patients with suspected recurrent or metastatic well-differentiated thyroid cancer

PET using 18F-FDG has been shown to effectively detect various types of cancer by their increased glucose metabolism. The aim of this study was to evaluate the use of coregistered PET and CT (PET/CT) in patients with suspected thyroid cancer recurrence.

METHODS

After total thyroidectomy followed by radioiodine ablation, 61 consecutive patients with elevated thyroglobulin levels or a clinical suspicion of recurrent disease underwent 18F-FDG PET/CT. Of these, 59 patients had negative findings on radioiodine (131I) whole-body scintigraphy (WBS). Fifty-three of the 61 patients had both negative 131I WBS findings and elevated thyroglobulin levels. PET/CT images were acquired 60 min after intravenous injection of 400-610 MBq of 18F-FDG using a combined PET/CT scanner. Any increased 18F-FDG uptake was compared with the coregistered CT image to differentiate physiologic from pathologic tracer uptake. 18F-FDG PET/CT findings were correlated with the findings of histology, postradioiodine WBS, ultrasound, or clinical follow-up serving as a reference. The diagnostic accuracy of 18F-FDG PET/CT was evaluated for the entire patient group and for those patients with serum thyroglobulin levels of less than 5, 5-10, and more than 10 ng/mL.

RESULTS

Thirty patients had positive findings on 18F-FDG PET/CT; 26 were true-positive and 4 were false-positive. In 2 patients, increased 18F-FDG uptake identified a second primary malignancy. 18F-FDG PET/CT results were true-negative in 19 patients and false-negative in 12 patients. The overall sensitivity, specificity, and accuracy of 18F-FDG PET/CT were 68.4%, 82.4%, and 73.8%, respectively. The sensitivities of 18F-FDG PET/CT at serum thyroglobulin levels of less than 5, 5-10, and more than 10 ng/mL were 60%, 63%, and 72%, respectively. Clinical management changed for 27 (44%) of 61 patients, including surgery, radiation therapy, or chemotherapy.

CONCLUSION

Coregistered 18F-FDG PET/CT can provide precise anatomic localization of recurrent or metastatic thyroid carcinoma, leading to improved diagnostic accuracy, and can guide therapeutic management. In addition, the findings of this study suggest that further assessment of 131I WBS-negative, thyroglobulin-positive patients by 18F-FDG PET/CT may aid in the clinical management of selected cases regardless of the thyroglobulin level.

Sodium/iodide symporter (NIS) gene expression is the limiting step for the onset of thyroid function in the human fetus

CONTEXT

Terminal differentiation of the human thyroid is characterized by the onset of follicle formation and thyroid hormone synthesis at 11 gestational weeks (GW).

OBJECTIVE

This study aimed to investigate the ontogeny of thyroglobulin (Tg), thyroid peroxidase (TPO), sodium/iodide symporter (NIS), pendrin (PDS), dual oxidase 2 (DUOX2), thyroid-stimulating hormone receptor (TSHR), and thyroid transcription factor 1 (TITF1), forkhead box E1 (FOXE1), and paired box gene 8 (PAX8) in the developing human thyroid.

DESIGN

Thyroid tissues from human embryos and fetuses (7-33 GW; n = 45) were analyzed by quantitative PCR to monitor mRNA expression for each gene and by immunohistochemistry to determine the cellular distribution of TITF1, TSHR, Tg, TPO, NIS, and the onset of T4 production. A broken line regression model was fitted for each gene to compare the loglinear increase in expression before and after the onset of T4 synthesis.

RESULTS

TITF1, FOXE1, PAX8, TSHR, and DUOX2 were stably expressed from 7 to 33 GW. Tg, TPO, and PDS expression was detectable as early as 7 GW and was correlated with gestational age (all, P < 0.01), and the slope of the regression line was significantly different before and after the onset of T4 synthesis at 11 GW (all, P < 0.01). NIS expression appeared last and showed the highest fit by the broken line regression model of all genes (correlation age P < 0.0001, broken line regression P < 0.0001). Immunohistochemical studies detected TITF1, TSHR, and Tg in unpolarized thyrocytes before follicle formation. T(4) and NIS labeling were only found in developing follicles from 11 GW on.

CONCLUSION

These results imply a key role of NIS for the onset of human thyroid function.

Assessment of iodine status using dried blood spot thyroglobulin: development of reference material and establishment of an international reference range in iodine-sufficient children

CONTEXT

Thyroglobulin (Tg) may be a valuable indicator of improving thyroid function in children after salt iodization. A recently developed Tg assay for use on dried whole blood spots (DBS) makes sampling practical, even in remote areas.

OBJECTIVE

The study aim was to develop a reference standard for DBS-Tg, establish an international reference range for DBS-Tg in iodine-sufficient children, and test the standardized DBS-Tg assay in an intervention trial.

DESIGN, PARTICIPANTS, AND INTERVENTIONS

Serum Tg reference material of the European Community Bureau of Reference (CRM-457) was adapted for DBS and its stability tested over 1 yr. DBS-Tg was determined in an international sample of 5- to 14-yr-old children (n = 700) who were euthyroid, anti-Tg antibody negative, and residing in areas of long-term iodine sufficiency. In a 10-month trial in iodine-deficient children, DBS-Tg and other indicators of iodine status were measured before and after introduction of iodized salt.

RESULTS

Stability of the CRM-457 Tg reference standard on DBS over 1 yr of storage at -20 and -50 C was acceptable. In the international sample of children, the third and 97th percentiles of DBS-Tg were 4 and 40 microg/liter, respectively. In the intervention, before introduction of iodized salt, median DBS-Tg was 49 microg/liter, and more than two thirds of children had DBS-Tg values greater than 40 microg/liter. After 5 and 10 months of iodized salt use, median DBS-Tg decreased to 13 and 8 microg/liter, respectively, and only 7 and 3% of children, respectively, had values greater than 40 microg/liter. DBS-Tg correlated well at baseline and 5 months with urinary iodine and thyroid volume.

CONCLUSIONS

The availability of reference material and an international reference range facilitates the use of DBS-Tg for monitoring of iodine nutrition in school-age children.

111In-Pentetreotide uptake in a follicular adenoma of the thyroid gland: a pitfall for 111In-Pentetreotide scintigraphy

A patient with suspicion of a neuroendocrine tumor of the pancreas underwent a somatostatin receptor scintigraphy using 111In-Pentetreotide. 111In-pentetreotide scintigraphy showed discrete uptake of the radiotracer in the head of the pancreas and focal uptake in the right upper thyroid lobe. Tracer uptake in the 24h planar image was higher compared to the 4h image, and decreased after 48 hours. Normal thyroid tissue and thyroid disorders, such as cancers, Hashimoto's thyroiditis, and adenomas often show increased uptake of 111In-pentetreotide resulting in a possible false positive interpretation in patients with neuroendocrine tumor. Adding a 48h planar image might contribute to the differential diagnosis between benign or malignant lesions, as in the present case where the uptake decreased in an adenoma after 48 hours.

[Relapse of differentiated thyroid carcinoma in low-risk patients]

INTRODUCTION

The low incidence of relapse in differentiated thyroid carcinoma (DTC), primarily treated by total thyroidectomy and (131)I ablation, stimulates the search for optimal follow-up algorithms which do not include too many tests but are not connected with a risk of missing early recurrence. The aim of the study was to analyze the impact of the routine follow up examinations for early detection of DTC recurrence in low risk DTC patients.

MATERIAL AND METHODS

The group consisted of 617 DTC patients diagnosed in 1995-1996. In 513 (83%) total thyroidectomy was performed. 449 (73%) received ablative (131)I therapy. After primary approach complete remission (CR) was stated in 453 (73%), persistent disease in 116 (19%), asymptomatic hyperthyroglobulinaemia in 14 (2%). Patients with CR constituted the low risk group analyzed in this study. The median follow up was 4.16 yrs.

RESULTS

Recurrent disease appeared in 28 (6%) patients (23 locoregional, 9 distant metastases, both in 4). Serum Tg (thyroglobulin) level at the moment of relapse diagnosis was detectable in 44% while neck sonography was the first examination to detect recurrence in 56% of cases.

CONCLUSION

In the selected group of DTC patients treated by radical primary approach and showing a low risk of recurrence only half of all relapse cases are diagnosed by the rise of serum Tg level. Regular sonography contributes to the second half of diagnoses. Thus, a special weight should be put on neck sonography as the important element of regular follow up in low risk DTC patients.

The diagnostic value of thyroglobulin concentration in fine-needle aspiration of the cervical lymph nodes in patients with differentiated thyroid cancer

INTRODUCTION

Recurrent differentiated thyroid cancer generally occurs first in the neck. Ultrasound is sensitive in detecting enlarged cervical lymph nodes but is not specific enough. Ultrasound-guided fine-needle biopsy increases the specificity but still may fail to detect a recurrence of the disease in the cystic metastatic lymph nodes. The aim of the study was to estimate the value of Tg concentration in the needle washout after fine-needle aspiration of suspicious lymph nodes.

MATERIAL AND METHODS

The 105 patients studied had presented one or more enlarged suspicious cervical lymph nodes. All had undergone total thyroidectomy and (131)I ablative therapy. Serum thyroglobulin (Tg) concentration was within the 0.15-711.5 ng/ml range (mean 22.24 ng/ml) and Tg recovery range 94-100%. The positive Tg washout concentration cut-off value was established as equal to the mean plus two standard deviations of the Tg washout concentration of patients with negative cytology.

RESULTS

Lymph node involvement was diagnosed by cytology in 15 patients and in 28 lymph nodes. Positive Tg washout concentration was found in 22 patients and in 48 lymph nodes. All the lymph nodes which turned out to have positive cytology had a positive Tg washout concentration. All lymph nodes with positive cytology were positive in pathology. Seven patients and 20 lymph nodes with negative cytology were positive in the Tg washout concentration test. All but one patients and all but two lymph nodes with a positive Tg washout concentration had positive pathology.

CONCLUSIONS

1. Ultrasound-guided fine-needle biopsy is not sensitive enough to detect all metastatic lymph nodes. 2. The Tg washout concentration test is 100% sensitive in the detection of metastatic lymph nodes. 3. Cytology in ultrasound- guided fine-needle biopsy is 100% specific. 4. The Tg washout concentration test carries a risk of false-positive results. 5. Both methods should be used for early detection of metastatic lymph nodes in patients with differentiated thyroid cancer.

[Prognostic value of the expression of thyreoglobulin and oncomarkers (p53, EGFR, ret-oncogene) in different types of papillary carcinoma of the thyroid: clinicomorphological and immunohistochemical studies]

The surgical material obtained from 57 patients was immunohistochemically studied. Immunohistochemistry with quantitative and semiquantitative analyses of the results of test was used to define the expression of oncomarkers p53, EGRF, ret-oncogene, and thyreoglobulin. The expression of thyreoglobulin, EGRF, and ret-oncogene reflects the malignant potential of papillary carcinoma of the thyroid and and may be recommended as a predictive marker. The low expression of thyreoglobulin and the high expression of p53 and ret-oncogene are markers of a poor prognosis and tumor recurrence. EGFR expression is not of predictive value. MB3 proposed by the authors may be recommended for the determination of the malignant potential of papillary carcinoma of the thyroid.

Effect of the traditional Korean immunomodulating formulation, Gamguntang (GGT), on experimental thyroiditis model

The crude herbal formulation, Gamgungtang (GGT), is an immunomodulator showing marked down-regulation of several experimental autoimmune diseases. In this study, its effect on different experimental models of thyroid disease was investigated. Although very effective at preventing thyroid infiltrates in mice immunized with mouse deglycosylated thyroglobulin and complete Freund's adjuvant and in spontaneous models of thyroiditis, it completely failed to modify experimental autoimmune thyroiditis (EAT) induced in mice immunized with mouse thyroglobulin and lipopolysaccharide. There was no significant shift in the observed isotypes of anti-mouse thyroglobulin antibodies and only anti-mouse thyroglobulin antibodies in the spontaneous model were completely down-modulated by the GGT. One surprising fact to emerge was that GGT-treated donor mice, although protected from thyroid lesions themselves, were still able to transfer EAT showing that they must have been effectively primed while being treated with GGT. It is possible that the drug down modulated EAT by interfering with the trafficking of primed effector cells.

Parapharyngeal metastasis from papillary thyroid carcinoma: a case diagnosed by thyroglobulin measurement in peroral fine-needle aspiration of a cystic metastatic lymph node

We report a case of a parapharyngeal cystic metastatic lymph node arising from papillary thyroid carcinoma (PTC). Parapharyngeal metastases arising from PTC are rare and correct diagnosis of the parapharyngeal mass before surgery is difficult. In this case, the diagnosis of a parapharyngeal mass was made pre-operatively by thyroglobulin measurement in peroral fine-needle aspiration with negative cytology.

[Biological investigation of thyroid cancer]

Thyroid carcinomas represent the most common endocrine malignancy, and several biological markers are proposed according to the different types of this cancer: for papillary cancer, thyroglobulin constitutes an excellent prognostic factor and rearrangements of ret oncogene can be useful in diagnosis. In sporadic medullary carcinoma, calcitonin is a diagnosis marker of choice, and coupled with ACE, can prevent relapse. Regarding familial medullary carcinoma, mutation screening in ret oncogene leads to early detection of new cases.

Insular carcinoma of the thyroid with uncommon cytologic features: anisokaryotic cells and microfollicles containing dense colloid

Insular carcinoma of the thyroid is a rare neoplasm, constituting less than 5% of all thyroid tumors. It was Carcangiu et al. who first described this tumor, which exhibits an intermediate biologic behavior between well-differentiated and undifferentiated follicular carcinomas, as a distinct clinicopathologic entity. A 63-year-old female patient with thyroid enlargement was admitted to our institution. Thyroid ultrasonography revealed a 5x4x3cm solid nodule within the right thyroid lobe. The fine needle aspiration was highly cellular; there were individual cells with naked nuclei, loose aggregates, cohesive clusters of follicular cells and infrequent microfollicles with round-oval nuclei containing finely granular chromatin, and scant cytoplasm. There were two uncommon findings not previously reported in the literature. The first one is anisokaryotic nuclei, and the second one is the presence of dense colloid in the center of microfollicles. The aspiration biopsy was reported as malignant. The patient underwent bilateral total thyroidectomy. Histopathologically, the lesion was diagnosed as insular carcinoma. We believe that in addition to the previously described cytopathologic findings, microfollicles with dense colloid core and anisokaryosis may be indicators of insular carcinoma in thyroid FNACs.

A novel compound heterozygous mutation in the thyroglobulin gene resulting in congenital goitrous hypothyroidism with high serum triiodothyronine levels

Thyroglobulin abnormality is a rare cause of congenital hypothyroidism and only a limited number of mutations in the thyroglobulin gene have been reported. We analyzed the thyroglobulin gene in a patient with congenital goitrous hypothyroidism. This girl was identified with hyperthyrotropinemia in a neonatal mass-screening test. The patient had goiter, and her body weight gain was poor. Distal femoral epiphysis was absent on roentgenography. Her serum thyroxine level was low; however, her triiodothyronine level was high. Autoantibodies against triiodothyronine, thyroid peroxidase, and thyroglobulin were all negative. Her serum thyroglobulin level was undetectable. The thyroglobulin gene from the genomic DNA of the patient was analyzed by direct sequencing. Two novel heterozygous missense mutations, Cys1897Tyr (exon 31) and Arg2336Gln (exon 40), were found in the patient. The former mutation was derived from her mother, suggesting a compound heterozygous state. Normal triiodothyronine and low thyroxine concentrations are often observed in patients with thyroglobulin gene mutations. We considered that some patients with thyroglobulin abnormality might have high triiodothyronine levels. In cases of congenital goitrous hypothyroidism with normal-to-high triiodothyronine levels and low serum thyroglobulin levels, thyroglobulin abnormality should be considered.