Mixed medullary and follicular cell carcinoma of the thyroid with lymph node metastasis in a 7-year-old child

A 7-year-old boy presented with midline swelling in the neck. On fine-needle aspiration cytology it was diagnosed as papillary carcinoma of the thyroid. The patient underwent total thyroidectomy. Histopathological examination, immunohistochemistry and electron microscopy revealed the presence of two intermingled components: medullary carcinoma and papillary carcinoma. One of the submandibular lymph nodes had metastasis of both the components. The case was diagnosed as 'mixed medullary and follicular cell carcinoma' with papillary carcinoma pattern and lymph node metastasis. Mixed medullary and follicular cell carcinoma with intermingling of medullary and papillary carcinoma components is a rare tumor. In adults, only eight such cases with lymph node metastasis have been published. To the best of the authors' knowledge no pediatric case has previously been reported in the English-language literature.

Usefulness of recombinant human TSH aided radioiodine doses administered in patients with differentiated thyroid carcinoma

The published studies confirming the safety and efficacy of rhTSH for diagnostic purposes have led to an increased interest in its use for preparation for radioiodine (RI) dose administration in patients with recurrent or persistent differentiated thyroid carcinoma (DTC). In order to establish the efficacy of RI therapy after rhTSH, we have reviewed 39 rhTSH-aided radioiodine treatment in a series of 28 DTC patients. Patients were divided into two groups: GI (n=17), with previous thyroid bed uptake and undetectable thyroglobulin (Tg) levels under levothyroxine treatment and GII (n=11), with proven metastatic local or distant disease. Median follow-up after the first rhTSH-aided radioiodine treatment was 32 +/- 13 months (range 8 to 54 months). Sixteen patients (94%) in GI were rendered disease free and one patient was shown to have persistent disease. In GII, the post therapy whole body scan showed pathological uptakes in all cases: in four patients in lungs, in four in mediastinum and in three in lateral neck. In two patients with mediastinum uptake, Tg levels were undetectable after rhTSH. In the follow-up, two patients with lateral neck uptake were rendered disease free, four patients died (three due to thyroid cancer) and five out of the remaining patients have persistent disease. In conclusion, rhTSH aided therapy was helpful to eliminate normal thyroid bed remnants in 16/17 (94%) patients (GI). rhTSH stimulated Tg was undetectable in two patients with mediastinal metastasis. We believe that rhTSH is a good alternative to levothyroxine withdrawal for the treatment of DTC with radioactive iodine, increasing the quality of life in these patients. Caution should be recommended in the follow-up of unselected DTC patients only with stimulated Tg levels.

Goitre ovarien malin

Malignant transformation of struma ovarii is exceptional (less than 1%). The histolological diagnosis of malignancy is difficult especially in the well differentiated forms. Immunohistochemistry is highly contributive in the anaplastic forms. The prognosis is relatively favorable except for the metastatic and undifferentiated forms. We report a case of malignant struma ovarii with metastasis observed in a 65-year-old woman who died rapidly from her disease. In light of this observation, we discuss the diagnositic, management and outcome features of these particular tumors.

Cerebellar metastasis as first metastasis from papillary thyroid carcinoma

Brain metastasis is an uncommon complication of differentiated thyroid carcinoma. Even more, cerebellar metastases from papillary thyroid carcinoma (PTC) are exceptional. We report a 69-year-old male patient with infiltrative PTC who developed high levels of thyroglobulin (Tg) and deteriorated neurological symptoms four years after the initial diagnosis. Computerized tomography (CT) of the brain demonstrated a cerebellar mass and the patient underwent surgery. Pathology revealed metastasis from PTC. Immunochemistry was positive for Tg. The patient had no other sites of distant metastases. Although PTC has generally a good prognosis, metastases to the cerebellum can occur, even as the first metastatic site, despite the fact that appropriate therapy (surgery, radioactive iodine therapy, TSH suppression therapy, chemotherapy and external radiotherapy) had been given for the primary tumour.

Thyroid follicular adenocarcinoma in a ferret

A 5-year-old male castrated ferret was presented to the Washington State University College of Veterinary Medicine for evaluation of progressive hair loss and a large, rapidly growing ventral neck mass. The patient had been diagnosed previously with an insulinoma, which was managed medically. Fine-needle aspirates of the neck mass were performed. The cytologic results were most consistent with epithelial neoplasia, likely a carcinoma; thyroid origin was considered likely based on tumor location and cell morphology. The tumor grew rapidly, and the owners elected euthanasia 1 week after examination. At necropsy, a circumscribed, ovoid mass disrupted the right cervical musculature next to the right lobe of the thyroid gland. Histopathologic evaluation revealed an infiltrative mass consisting of cuboidal cells arranged in solid sheets and irregular follicles enclosing colloid. The cells were large, with prominent nucleoli, and had a high mitotic rate. The histopathologic diagnosis was consistent with thyroid follicular adenocarcinoma. Immunochemical findings confirmed thyroglobulin production by neoplastic cells, but to a lesser extent than in normal ferret thyroid tissue. To our knowledge, this is the first case of thyroid follicular adenocarcinoma to be reported in a ferret, with only 1 other case of thyroid carcinoma, a C-cell carcinoma, described previously.

Fractionated dosage of radioiodine for the ablation of differentiated thyroid carcinoma

In some countries with a limited number of specialized hospital beds for radionuclide therapy, ablation therapy (RIT) of differentiated thyroid carcinoma (DTC) is performed using a fractionated dosage of radioiodine. The aim of this study was to evaluate the early clinical outcome of ablation with fractionated doses of RIT in comparison to the ablation with a single dose. A subset of 386 subjects with DTC referred for the initial RIT was selected retrospectively for the study. Of these, 113 patients (29.3%) were treated with one (131)I dose of 2.2 GBq (group 1, RIT between 2001 and 2003) and 273 patients (70.7%) with fractionated doses (1.1 GBq + 1.1 GBq administered in 24 hour intervals) (group 2, RIT between 1999 and 2001). The early outcome of the initial RIT was evaluated 6-8 months later by radioiodine uptake test (RIU), thyroglobulin concentration, whole-body diagnostic scan, and neck ultrasound. On the basis of these results, the patients were classified as: CR, complete remission; NCR, no complete remission. Frequency of CR and NCR outcomes and the parameters measured during the follow-up evaluation in both groups were compared. CR outcome was found in 69 patients (61.1%) of group 1 and in 172 patients (63.0%) of group 2 (p = n.s.). No difference in measured parameters was found in both groups at the follow-up evaluation. In uncomplicated cases of DTC, RIT using a regimen of a fractionated dosage, is equally effective as the therapy with a single dose. No influence of stunning was observed in patients treated with a fractionated dosage, but the time interval between the doses was 24 hours.

Chromosomal aberrations in cell lines derived from thyroid tumors spontaneously developed in TRbetaPV/PV mice

The etiology and genetic alterations of follicular thyroid carcinoma are not well understood. By targeting a mutation (PV) into the thyroid hormone receptor beta gene (TRbetaPV mouse), we created a knock-in mutant TRbeta(PV/PV) mouse that spontaneously develop follicular thyroid carcinoma with progression to metastasis similar to human follicular thyroid carcinoma. This mouse model provides a valuable tool to ascertain the nature and the extent of genomic rearrangements that occur during carcinogenesis of the thyroid. Spectral karyotyping analysis (SKY) of seven cell lines derived from thyroid tumors developed in TRbeta(PV/PV) mice showed that all of them had abnormal karyotypes, with chromosome number ranging from near-diploid (39-42 chromosomes) to hypotetraploid (63-79 chromosomes). These seven cell lines also exhibited a variety of structural chromosomal aberrations, including common recurrent translocations and deletions. This SKY analysis shows that the development and progression of follicular thyroid carcinoma in knock-in TRbeta(PV/PV) mutant mice comprise recurrent structural and numerical genomic changes, some of which mimic those described in human thyroid cancer.

Clinical impact of thyroglobulin (Tg) and Tg autoantibody method differences on the management of patients with differentiated thyroid carcinomas

CONTEXT

Changes in thyroglobulin (Tg) and/or Tg antibody (TgAb) methods can disrupt the serial monitoring of differentiated thyroid carcinoma (DTC) patients.

OBJECTIVE

This study compared Tg measurements made in TgAb-negative and TgAb-positive sera using four RIA and 10 immunometric assay (IMA) methods.

DESIGN

TgAb detection using a panel of 12 direct methods was contrasted with four Tg recovery tests. Sera from 110 normal euthyroid subjects (68 TgAb negative/42 TgAb positive) and 131 TgAb-negative DTC patients had Tg and/or TgAb analyses made by 10 laboratories in four countries. Euthyroid controls were used to compare Tg and TgAb ranges, sensitivities, and TgAb interference, whereas DTC patients were used to study Tg assay specificities, hook effects, and the influence of high Tg levels on TgAb measurements.

RESULTS

Tg methods had high between-method variability [47 +/- 3% (+/-sem)] that was only marginally reduced by CRM-457 standardization (37 +/- 3%). All methods had suboptimal sensitivity, and some failed to detect Tg in some normal euthyroid controls. Although direct TgAb measurements were more reliable than exogenous recovery tests, TgAb status was only concordant in 65% of sera. Only four of 42 (9.5%) sera containing TgAb had antibody detected by all direct methods. All IMA methods reported paradoxically undetectable Tg for many TgAb-positive euthyroid controls, suggesting TgAb interference, whereas RIA methods reported appropriate normal range values for these same subjects. Some sera displaying interference had TgAb detected by only a minority of methods.

CONCLUSIONS

Specificity differences, suboptimal sensitivity, hook effects, and an inability to reliably detect interfering TgAb compromise the clinical utility of current Tg and TgAb methods. All of the IMA methods were prone to underestimate serum Tg in the presence of TgAb, whereas the RIA methods appeared resistant to TgAb interference.

Point-of-care assays for autoantibodies to thyroid peroxidase and to thyroglobulin

Point-of-care (POC) assays for autoantibodies to thyroid peroxidase (TPOAb) and to thyroglobulin (TgAb) are described. Both assays are based on the ability of autoantibodies in test samples (whole blood, plasma, or sera) to inhibit the binding of monoclonal antibodies to TPO or to Tg. The assays require no special equipment and give results in 10 minutes. Analysis of samples from healthy blood donors (n = 80), patients with autoimmune thyroid disease (n = 97) and nonthyroid autoimmune diseases (n = 20) showed that results with the POC tests compared well to those obtained by agglutination assay and enzyme-linked immunosorbent assay (ELISA). The reference immunoprecipitation assays (IPA) based on 125I-labeled TPO or Tg were more sensitive than the POC tests particularly in the case of TgAb measurements. However, no samples were found positive by POC test and negative by IPA emphasizing the high specificity of the POC assays. Our results suggest that POC testing for TPOAb and TgAb with assays such as those we describe could be useful in certain situations. These include prediction of postpartum thyroiditis and the development of interferon-alpha-related thyroid disease.

Analysis of thyroglobulin iodination by tandem mass spectrometry using immonium ions of monoiodo- and diiodo-tyrosine

Peptides containing a monoiodo- or diiodo-tyrosine residue (monoiodo-Y, diiodo-Y) were found to generate abundant immonium ions following collision-induced dissociation at m/z 261.97 and 387.87 Da, respectively. These residue-specific marker ions are between about 140 mDa (monoiodo-Y) and 300 mDa (diiodo-Y) mass deficient relative to any other peptide fragment ions of unmodified peptides, qualifying them as highly specific marker ions for tyrosine iodination when analyzed by high resolution tandem mass spectrometry (MS/MS). Two new iodination sites (Y-364 and Y-2165) were pinpointed in bovine thyroglobulin by MS/MS using these iodotyrosine-specific marker ions and combined tryptic/chymotryptic digestion.

Malignant struma ovarii: A case report

Malignant struma ovarii is a rare form of the ovarian germ cell tumors. Hence, diagnosis and management of malignant struma ovarii have not been clearly defined. We present the case of a 34-year-old woman with papillary carcinoma arising in struma ovarii. The malignant component of this tumor was detected after laparoscopic removal, and a re-staging operation was performed afterwards. There was no evidence of clinical malignancy or metastases. In this paper, clinical features, treatment guidelines, diagnostic features, and immunohistochemical characteristics of this tumor are reviewed.

Sequential studies on thyroid antibodies during pregnancy

Thyroid antibodies were measured sequentially in 25 pregnant women from a Sri Lankan population. A high prevalence of antithyroid antibodies, particularly antithyroglobulin antibodies (TgAb) had previously been demonstrated in female schoolchildren drawn from this population. In the present study TgAb were detected in 36.8% of nonpregnant controls while thyroid peroxidase antibody (TPOAb) positivity was present in 26.3%. The prevalence of both antibodies in the pregnancy study group showed a progressive decline compared to nonpregnant controls throughout gestation becoming undetectable in the third trimester. The results are consistent with an immunosuppressive effect of pregnancy in a population in whom high thyroid autoantibody titers may have resulted from a recent salt iodization program.

Are thyroid peroxidase antibodies associated with cardiovascular disease risk in patients with subclinical hypothyroidism?

OBJECTIVE

Conflicting evidence has been reported about whether subclinical hypothyroidism (SCH) is associated with hyperlipidemia or cardiovascular disease. Thyroid peroxidase antibodies (TPOAb) are more common in persons with SCH. The purpose of this study was to evaluate whether the presence of (TPOAb) in people with SCH is associated with markers of cardiovascular disease.

DESIGN

Cross-sectional study using multivariate regression.

PATIENTS

Adults over age 40 who, in the National Health and Nutrition Examination Survey (NHANES) III, met the criteria for SCH (n = 188).

MEASUREMENTS

Participants were stratified into TPOAb-negative (n = 82) and TPOAb-positive (n = 106) groups. Markers of cardiovascular disease risk were compared between the TPOAb-negative and TPOAb-positive groups. Multivariate regression models were performed to adjust for potential confounders.

RESULTS

In bivariate analyses, individuals with and without TPOAb had similar levels of triglycerides, high-density lipoprotein, low-density lipoprotein, total cholesterol and C-reactive protein. Homocysteine levels were higher in the patients without antibodies (P = 0.01). After adjusting for, age, gender, smoking, hypertension, diabetes and use of a lipid-lowering medication, however, no statistically significant relationships were found between the presence of TPOAb and any of the cardiovascular risk markers.

CONCLUSIONS

The presence of thyroid peroxidase antibodies does not appear to correlate with cardiovascular disease risk in patients with subclinical hypothyroidism. This study does not support the measurement of TPOAb antibodies in SCH as a strategy for guiding treatment or assessment of cardiovascular disease risk.

Proportion of various types of thyroid disorders among newborns with congenital hypothyroidism and normally located gland: a regional cohort study

OBJECTIVE

To determine the proportion of the various types of thyroid disorders among newborns detected by the neonatal TSH screening programme, with a normally located thyroid gland. Patients and methods Of the 882 575 infants screened in our centre between 1981 and 2002, 85 infants with a normally located gland had persistent elevation of serum TSH values (an incidence of 1/10 383). Six of these 85 patients were lost to follow-up and were therefore excluded from the study. During follow-up, patients were classified as having permanent or transient hypothyroidism.

RESULTS

Among the 79 patients included in the study, transient (n = 30, 38% of cases) and permanent (n = 49, 62% of cases) congenital hypothyroidism (CH) was demonstrated during the follow-up at the age of 0.7 +/- 0.6 years and 2.6 +/- 1.8 years (P < 0.0001), respectively. The proportion of premature births was significantly higher in the group with transient CH (57%) than in the group with permanent CH (2%) (P < 0.0001). A history of iatrogenic iodine overload was identified during the neonatal period in 69% of transient cases. Among permanent CH cases (n = 49), patients were classified as having a goitre (n = 27, 55% of cases), a normal sized and shaped thyroid gland (n = 14, 29% of cases) or a hypoplastic gland (n = 8, 16% of cases). The latter patients demonstrated global thyroid hypoplasia (n = 3), a right hemithyroid (n = 2), hypoplasia of the left lobe (n = 2), or asymmetry in the location of the two lobes (n = 1). Patients with a normal sized and shaped thyroid gland showed a significantly less severe form of hypothyroidism than those with a goitre or a hypoplastic thyroid gland (P < 0.0002). Among permanent CH cases, those with a goitre (n = 27) had an iodine organification defect (n = 10), Pendred syndrome (n = 1), a defect of thyroglobulin synthesis (n = 8), or a defect of sodium iodine symporter (n = 1), and in seven patients no aetiology could be determined. Among permanent cases with a normal sized and shaped thyroid gland (n = 14), a specific aetiology was found in only one patient (pseudohypoparathyroidism) and two patients had Down's syndrome. Among those with a globally hypoplastic gland, a TSH receptor gene mutation was found in two patients.

CONCLUSIONS

A precise description of the phenotype can enhance our understanding of various forms of neonatal hypothyroidism as well as their prevalence and management. It also helps to identify cases of congenital hypothyroidism of unknown aetiology, which will need to be investigated in collaboration with molecular biologists.

Multiple pulmonary neoplasia positive for thyroglobulin

We present, for the first time, a case of carcinoid metastatic pulmonary tumor positive for thyroglobulin. A 73-yr-old woman diagnosed with metastases of probable thyroid carcinoma, manifested by a mediastinic mass and multiple pulmonary nodules positive for radioiodine (I131). Histological analysis showed typical findings of carcinoid tumor with positive immunohistochemistry for neuron-specific enolase, synaptophysin and thyroglobulin, and negative for chromogranin and calcitonin. We underline the exceptional finding of positive reaction for thyroglobulin, and discuss difficulties in differential diagnosis between metastatic differentiated thyroid and carcinoid neoplasms.

Usefulness of Thyroglobulin Measurement in Fine-needle Aspiration Biopsy Specimens for Diagnosing Cervical Lymph Node Metastasis in Patients with Papillary Thyroid Cancer

The diagnosis of lymph node metastasis in patients with papillary thyroid cancer is an important factor when deciding to perform neck dissection at the initial surgery, as well as for evaluating the lymph node swelling after surgery. Ultrasound (US)-guided fine-needle aspiration biopsy cytology (FNAB-C) is the most useful technique for diagnosing lymph node metastasis. Recently, however, measurement of thyroglobulin in the wash-out of the needle (FNAB-Tg) has been proposed for early detection of neck lymph node metastasis in patients with differentiated thyroid cancer. The purpose of this study was to evaluate the usefulness of FNAB-Tg in detecting lymph node metastasis prior to initial or reoperative thyroid surgery. US-guided FNAB-C was performed on 129 enlarged lymph nodes of 111 patients before surgery. All of them were later histologically confirmed to contain metastasis. Immediately after obtaining an FNAB-C specimen, the needle was rinsed with 0.5 ml of normal saline solution, and the wash-out was subjected to measurement of the Tg level (FNAB-Tg). If the FNAB-Tg level was higher than the serum Tg of the patient, we diagnosed the lymph node as positive (metastatic lymph node). FNAB-Tg sensitivity was 81.4%, and FNAB-C sensitivity was 78.0%. Altogether, 4 (36.4%) of 11 cases judged "benign" and 6 (37.5%) of 16 cases judged "inadequate" by FNAB-C were positive by the FNAB-Tg measurement. Thyroglobulin measurement in fine-needle aspiration biopsy wash-out is thus a useful technique for diagnosing lymph node metastasis of papillary thyroid cancer.

[Pathology and immunohistochemistry of thyroid in severe acute respiratory syndrome]

OBJECTIVE

To study the pathological characteristics of thyroid gland and the changes on hormone content of thyroid cells in severe acute respiratory syndrome (SARS) patients.

METHOD

Hematoxylin and eosin staining and light microscopy were used to examine the histology of the thyroid tissues from 4 dead SARS patients and 5 healthy thyroid samples used as negative controls. Immunohistochemistry was used, with monoclonal antibodies, to detect the thyroglobulin (TG), calcitonin and parathyroid hormone (PTH) in the thyroid glands.

RESULTS

Deformation, enlargement, and dystrophy of follicular cells in thyroid glands were found in the SARS patients. The normal follicular epithelial cells were strongly TG positive, however, the number and intensity of TG positive follicular epithelial cells were significantly lower in the SARS patients. Calcitonin positive cells were found in the normal thyroid glands and not in the thyroid glands of the SARS patients. PTH positive cells were seen in the normal thyroid glands and those of the SARS patients with a slightly weaker intensity of reaction, however, with significant difference in IOD (P < 0.01) and without significant difference in mean slight absorption MOD (P > 0.05).

CONCLUSION

The thyroid tissue structure and morphology in SARS patients were significantly changed, involving both follicular epithelial cells and parafollicular cells; which may imply that the hormonal production of follicular epithelial cells and the parafollicular cells were affected.

Changes in thyroid hormone state in children receiving chemotherapy

OBJECTIVE

The concentrations of thyroid function determinants may change during severe illness. Our goal was to quantify their changes in children with cancer during chemotherapy, and to correlate them to clinical condition and type of drugs.

DESIGN

During a 3-month period all patients admitted for chemotherapy to the paediatric oncology ward were evaluated for inclusion. Patients with brain tumours, neuroblastoma (cranio)spinal irradiation and use of dexamethasone before the first blood sample were excluded.

MEASUREMENTS

Plasma concentrations of T4, T3, rT3, thyroxine-binding globulin (TBG), thyroglobulin (Tg), TSH, IGF-1, cortisol, PRL and physical well-being by means of questionnaires were measured before and during chemotherapy.

RESULTS

In 19 children, 46 courses of chemotherapy and 123 plasma samples were analysed. During chemotherapy, mean concentrations of TSH, T3, Tg and cortisol decreased to 53, 67, 69 and 15% of the baseline value, respectively. Mean plasma rT3 increased to 217% of baseline. In 87% of all courses, one or more thyroid parameter(s) was aberrant. Furthermore, in 23 samples (19%) from 10 patients (53%), the concentration of IGF-1 was below the reference value (adjusted for sex and age). Small changes were seen in scores for clinical condition but none was related to a change in thyroid function determinant. Most changes in thyroid hormones could be attributed to using dexamethasone.

CONCLUSIONS

These results demonstrate that, in children, thyroid hormone state changes significantly during chemotherapy, apparently not related to physical well-being but to the drugs administered. Future investigations should focus on the impact for patient care and possibilities of (preventive) intervention.

Cytologic features of cribriform-morular variant of papillary carcinoma of the thyroid: a case report

BACKGROUND

While the histology of cribriform-morular variant of papillary thyroid carcinoma has been well documented, its appearance on cytologic smears has rarely been described given the rarity of this tumor.

CASE

A 28-year-old woman had a neck lump for an unspecified duration for which she sought medical attention. She was previously well, and there was no significant family history of illness. Fine needle aspiration of the thyroid mass disclosed columnar cells with fine to granular chromatin and nucleargrooves associated with papillary fragments and acinar formation. Occasional groups of epithelial cells forming morules, previously unreported on cytology, were present. An excision specimen of the left thyroid nodule revealed morphologic features of cribriform-morular variant of papillary carcinoma of the thyroid.

CONCLUSION

A diagnosis of cribriform-morular variant of papillary carcinoma of the thyroid could be established on fine needle aspiration cytology, prompting exclusion of familial adenomatous polyposis and distinguishing it from other, more aggressive variants of thyroid carcinoma, such as columnar cell carcinoma.

Chronic iodine overload and apoptosis in cold nodules from endemic multinodular goiters

As apoptosis and necrosis are known to exist during experimental goiter development and involution, we studied them in ten Tunisian multinodular endemic goiters, five of them having received a chronic excess of iodine during six months. Apoptotic thyrocyte nuclei have been counted on hematoxylin-eosin stained semi-thin sections. Using immunoperoxidase on paraffin sections, bcl-2 and bax immunoreactivities have been evidenced, and CD34 positive microvessels counted; ultra-thin sections have also been observed. After six months of iodine overload, apoptotic thyrocytes were ten times more numerous; CD34 positive endothelial cells were diminished by one half bcl-2 immunoreactivity disappeared in thyrocytes and a bax one appeared in thyroid follicular and endothelial cells. Presence of numerous apoptotic follicular and endothelial cells was confirmed using electron microscopy. Chronic iodine excess induces apoptosis and necrosis of thyroid follicular and endothelial cells, leading to thyroglobulin accumulation in connective tissue.

PAX8, TITF1, and FOXE1 gene expression patterns during human development: new insights into human thyroid development and thyroid dysgenesis-associated malformations

Thyroid dysgenesis (TD) is responsible for most cases of congenital hypothyroidism, a condition that affects about one in 4000 newborns. Mutations in PAX8, TITF1, or FOXE1 may account for congenital hypothyroidism in patients with either isolated TD or TD with associated malformations involving kidney, lung, forebrain, and palate. Pax8, titf1, and foxe1 are expressed in the mouse thyroid bud as soon as it differentiates on the pharyngeal floor. Because the spatio-temporal expression of these genes is unknown in humans, we decided to study them at different stages of human embryonic and fetal development. PAX8 and TITF1 were first expressed in the median thyroid primordium. Interestingly, PAX8 was also expressed in the thyroglossal duct and the ultimobranchial bodies. Human FOXE1 expression was detected later than in the mouse. PAX8 was also expressed in the developing central nervous system and kidney, including the ureteric bud and the main collecting ducts. TITF1 was expressed in the ventral forebrain and lung. FOXE1 expression was detected in the oropharyngeal epithelium and thymus. In conclusion, the expression patterns described here show some differences from those reported in the mouse. They explain the malformations associated with TD in patients carrying PAX8, TITF1, and FOXE1 gene mutations.

Are there disadvantages in administering 131I ablation therapy in patients with differentiated thyroid carcinoma without a preablative diagnostic 131I whole-body scan?

OBJECTIVE

To evaluate the risk of performing inappropriate (131)I ablative therapies for thyroid carcinoma in patients lacking thyroid remnants or metastases, using a strategy of treatment without a preliminary iodine-131 diagnostic whole-body scan (DxWBS).

DESIGN

Retrospective evaluation of post-therapy whole-body scans to assess the prevalence of thyroid remnants or metastases after total thyroidectomy. Comparison of (131)I uptake test and thyroglobulin (Tg) off levothyroxine (L-T4) performed before therapy with post-therapy scans, in order to evaluate the ability to predict inappropriate treatments.

PATIENTS

A group of 875 consecutive patients with previous total or near-total thyroidectomy for differentiated thyroid carcinoma underwent (131)I ablative therapy without a preliminary (131)I-DxWBS. All patients were clinically free of distant metastases and macroscopic residual tumour.

MEASUREMENTS

Whole-body scans were performed 2-5 days after the treatment as gold standard for thyroid remnants and metastases; 24-h (131)I quantitative neck uptake test and Tg off L-T4 were performed before (131)I therapy.

RESULTS

The majority of patients (94%) were found to have thyroid remnants or metastases at post-therapy scans, in most cases (91.2%) with detectable Tg off L-T4 and positive 24-h neck uptake. 14 patients (1.6%) with tiny lymph-node metastases positive at post-therapy scans showed undetectable Tg off L-T4. In 30 patients (3.6%) faint positive post-therapy images for thyroid remnants have been classified as false-positive results on the basis of both negative 24-h neck uptake and undetectable Tg off L-T4.

CONCLUSIONS

This study confirms that most patients have residual thyroid tissue after total thyroidectomy and that it seems reasonable to omit routine diagnostic whole-body scans before (131)I treatment with clinical, managerial and economic advantages.

Thyroid anaplastic carcinoma transformed from papillary carcinoma in extrathyroid area

We report a 75-year-old male with anaplastic carcinoma in an extrathyroid area. Thyroid remained unchanged. The patient is alive without incident of tumor recurrence at 3.5 years after total resection and at 5 years after initial symptom. The tumor developed between the sternocleidomastoid muscle and common carotid artery, and was completely separated from the thyroid. The tumor location was consistent with a branchial cyst. The tumor consisted of two parts; an upper solid tumor and a deep cystic tumor. The former showed anaplastic carcinoma with osteoclast-like giant cells. The latter was consistent with thyroid papillary carcinoma. The center was intermingled with these two carcinomas. Anaplastic carcinoma cells were positive for vimentin and papillary carcinoma cells were positive for keratin, thyroglobulin, and thyroid transcription factor-1. These results remain insufficient to find any conclusions concerning the tumor nature; either ectopic thyroid carcinoma arising from a branchial cyst or occult thyroid carcinoma metastasis. This is rare case in which thyroid anaplastic carcinoma transformed from papillary carcinoma in an extrathyroid area.