Frequency of Thyroid Carcinoma in a Recent Series of 539 Consecutive Thyroidectomies for Multinodular Goiter

Implications of radiofrequency ablation in patients undergoing thyroid surgery for benign disease in the United States

BACKGROUND

Radiofrequency ablation is an alternative strategy for the management of benign thyroid conditions. We analyzed the proportion of patients who underwent thyroid surgery for benign conditions who would be potentially eligible for radiofrequency ablation.

METHODS

We identified patients who underwent thyroid surgery from 2015 to 2019 at the study institution for Bethesda II cytopathology or toxic adenoma. Patients were considered potentially eligible for radiofrequency ablation if they had a dominant nodule >2 cm with or without compression symptoms, a dominant nodule <2 cm with compression symptoms, or a toxic adenoma.

RESULTS

Of 411 patients in total, 284 (69.1%) would be eligible to consider thyroid radiofrequency ablation. In the radiofrequency ablation-eligible group, 20 (7.0%) experienced voice change after surgery, and 2 (0.7%) were dissatisfied or concerned about their scar. In the radiofrequency ablation-eligible group, 70 patients (24.6%) had malignancy diagnosed by final pathology, and 23 patients (8.1%) had cancers that were equal to or larger than 1 cm in size.

CONCLUSION

Many patients who undergo surgery for benign thyroid disease could be considered for radiofrequency ablation as an alternative treatment modality. Given the rate of occult malignancy, optimal evaluation of nondominant nodules before radiofrequency ablation and long-term thyroid surveillance for patients who undergo radiofrequency ablation should be further studied.

Papillary and Medullary Thyroid Carcinomas Presenting as Collision Tumors: A Case Series of 21 Cases at a Tertiary Care Cancer Center

Collision tumor is the occurrence of two histologically and morphologically distinct tumors within the same organ with no histological admixture. Collision tumors of the thyroid are extremely rare constituting < 1% of all thyroid tumors. Clinical profiles and pathological features of Medullary thyroid carcinoma (MTC) and Papillary thyroid carcinoma (PTC) presenting as Collision tumors of thyroid, diagnosed between 2009 and 2019, at a tertiary care cancer center were retrospectively analyzed. Collision tumors comprised 4.7% of all MTC cases diagnosed over 10 years. A total of 21 cases (11males, 11 females, M:F = 1) were retrieved with the mean age of patients being 45.33 years (range 26-77 years). More than half of PTCs involved the right lobe of the thyroid (66.6%). About half (53.4%) of MTCs affected the left lobe. Imaging done pre-operatively failed to identify the smaller second tumor in 60% of the cases with both tumours in separate lobes. Pre-operative FNAC showed only MTC in all 8 cases in which it was done. Papillary microcarcinoma (m-PTC) was seen in 85.7% cases, with one case of multifocal m-PTC. MTC (mean size 3.12 cm), on an average, was 3 times larger than the PTC (mean size 0.91 cm). The histological variants of MTC included-oncocytic (1/21, 4.7%), spindle cell (1/21, 4.7%), epithelial (3/21, 14.2%) and classical (16/21, 76.2%) and of PTC included classic PTC (12/21, 57.14%), Hurthle cell (2/21, 9.52%), tall cell (1/21, 4.76%) and follicular variant of PTC (6/21, 28.57%). The microscopic extrathyroidal extension (ETE) due to MTC and PTC component was 42.8% and 9.5% respectively. Lymph node metastasis was seen in 16 (76.2%) cases; 87.5% (14/16) of which were contributed by MTC, 12.5% (2/16) by PTC alone, and 12.5% (2/16) cases showed metastasis from both MTC and PTC. MTC had a higher stage than PTC in 85.5% of cases. Collision tumors of the thyroid are exceedingly rare, and possibly underdiagnosed due to variation in sampling techniques, especially of the grossly "normal lobe". The low incidence in our cohort is in favor of the "Chance theory" of co-occurrence. This diagnosis is important due to its therapeutic and prognostic implications.

Value of 99mTc-MIBI SPECT/CT parathyroid imaging and ultrasonography for concomitant thyroid carcinoma

PURPOSE

We aimed to assess the frequency of carcinoma in cases with suspected parathyroid adenoma and test the value of Tc-methoxyisobutylisonitrile (Tc-MIBI) single-photon emission computed tomography/computed tomography (SPECT/CT) parathyroid imaging and neck ultrasonography in detecting concomitant thyroid carcinoma.

PATIENTS AND METHODS

We enrolled 741 patients with clinically suspected parathyroid adenoma who underwent Tc-MIBI planer scans and SPECT/CT of the skull base, neck, and thorax; patients also underwent ultrasonography within 1 month before SPECT/CT. Each case with suspected lesion was analyzed and correlated with pathology. We estimated the frequency of carcinoma detection on SPECT/CT performed for suspected parathyroid adenoma. The sensitivity, specificity, and accuracy of detecting thyroid carcinoma were estimated for both SPECT/CT and ultrasonography.

RESULTS

In total, 222 patients with 250 pathology results were assessed. Of these, 54 patients showed carcinoma. With respect to the anatomical distribution of the incidental findings, 19 (35.19%) had parathyroid carcinoma, 20 (37.04%) had papillary thyroid carcinoma, three (5.56%) had follicular thyroid carcinoma, six (11.11%) had medullary thyroid carcinoma, and six (11.11%) had other carcinomas. For thyroid carcinoma detection, the sensitivity, specificity, and accuracy were 35.71, 88.16, and 80.49% for SPECT/CT and 73.81, 95.10, and 91.99% for ultrasonography, respectively.

CONCLUSION

The frequency of carcinoma is high on Tc-MIBI SPECT/CT performed for suspected parathyroid adenoma. Although Tc-MIBI SPECT/CT plays an important role in the diagnosis and location of parathyroid adenoma, ultrasonography appears to be more suitable for identifying a concomitant thyroid carcinoma. This may vitally influence the choice of therapeutic regimen in patients with primary hyperparathyroidism.

Etiopathology, clinical features, and treatment of diffuse and multinodular nontoxic goiters

Goiter, an enlargement of the thyroid gland, is a common problem in clinical practice associated with iodine deficiency, increase in serum thyroid-stimulating hormone (TSH) level, natural goitrogens, smoking, and lack of selenium and iron. Evidence suggests that heredity also has an important role in the etiology of goiter. The current classification divides goiter into diffuse and nodular, which may be further subdivided into toxic (associated with symptoms of hyperthyroidism, suppressed TSH or both), or nontoxic (associated with a normal TSH level). Nodular thyroid disease with the presence of single or multiple nodules requires evaluation due to the risk of malignancy, toxicity, and local compressive symptoms. Measurement of TSH, accurate imaging with high-resolution ultrasonography or computed tomography, and fine-needle aspiration biopsy are the appropriate methods for evaluation and management of goiter. This review discusses the clinical presentation, diagnostic evaluation, and treatment considerations of nontoxic diffuse and nodular goiters.

Targeted Next-Generation Sequencing Analysis of a Pendred Syndrome-Associated Thyroid Carcinoma

Pendred syndrome is an autosomal recessive disorder characterized by hearing loss and goiter and is caused by bi-allelic mutations (homozygous or compound heterozygous) of the PDS (SLC26A4) gene. The incidence of Pendred syndrome is 7.5-10/100,000 in the general population, and it carries a 1 % risk of developing thyroid carcinoma. Herein, we report a case of a patient with Pendred syndrome who developed a follicular variant of papillary thyroid carcinoma (FVPTC)-that is approximately at an odd of 1/1,000,000. Targeted next-generation sequencing with ThyroSeq v2 was performed on the tumor, and only a TP53 mutation (TP53 p.R175H) was identified. The mutation was limited to the tumor nodule of FVPTC as shown by immunohistochemistry. This report represents the first extensive molecular study of a Pendred syndrome-associated thyroid carcinoma. The evidences support that thyroid carcinomas arising from dyshormonogenetic goiter require additional genetic alteration in addition to the purported thyroid-stimulating hormone (TSH) overstimulation. It is intrigue to note that the mutant p53 is involved in the development of a low-grade malignant thyroid tumor as FVPTC in this patient.

Safety and Effectiveness of Total Thyroidectomy and Its Comparison with Subtotal Thyroidectomy and Other Thyroid Surgeries: A Systematic Review

Diseases associated with the thyroid gland are one of the most frequently seen endocrine disorders across the globe. Total thyroidectomy is currently the preferred treatment for many thyroid diseases. Controversies exist among surgeons regarding safety of total thyroidectomy due to the risk associated with it like postoperative hypoparathyroidism or recurrent laryngeal nerve damage. Since, in the recent years, the incidence of thyroidectomy is in increasing trend in south Indian population, this review aims to study the available data regarding the appropriateness and safety of total thyroidectomy and compares it with subtotal thyroidectomy and other thyroid surgeries. This is a retrospective comprehensive review of various articles and publications regarding total and partial thyroidectomy performed across the world. Many retrospective studies and few prospective studies suggest that the incidence of transient hypocalcemia is higher after total thyroidectomy than after subtotal thyroidectomy, but the incidence of other complications including recurrent laryngeal nerve palsy and postoperative hematoma is not significantly different between the two procedures. Hence in our review we found that total thyroidectomy is safe and cost effective with low complication rates and provides little significant advantage of being safer procedure compared to subtotal thyroidectomy.

Complications in thyroid resurgery: a single institutional experience on 233 patients from a whole series of 4,752 homogeneously treated patients

The aim of this study was to examine a homogeneous, consecutive recent series of patients who underwent reoperation on the thyroid bed to assess the incidence of the complications commonly correlated with resurgery. We reviewed clinical charts of 233 patients who underwent resurgery taken from a total of 4,752 patients previously operated on for benign and malignant thyroid diseases from 2006 to 2010 by the same surgical team. We evaluated the incidence of postoperative hemorrhage, hypoparathyroidism, and recurrent laryngeal nerve (RLN) palsy. Analyses were done separately in relation to the type of the type of resurgery adopted: (A) monolateral completion; (B) bilateral completion, after monolateral (B1) or bilateral prior surgery (B2); and (C) lymph node dissection. We also separately analyzed patients according to their final histological diagnosis of benign or malignant disease. Regarding hemorrhage, 6/233 patients (2.5 %) underwent surgical revision of the thyroid within 12 h for postoperative hemorrhage. They included 2 (1.5 %) of the 129 monolateral reoperations (A), 3 (4 %) of the 74 bilateral reoperations (B), and 1 (3.3 %) of the 30 central dissections for nodal relapse (C). Transient and definitive postoperative hypoparathyroidism was recorded in 78 (36.4 %) and 7 (3.3 %) of the 214 eligible patients. Transient RLN palsy occurred in 21 RLNs at risk (7 %) and definitive RLN palsy in 5 (1.7 %). Elective total thyroidectomy cannot always be supported as an effective policy for preventing recurrences in patients with a single, benign node: lobectomy, preferably with extemporaneous histological examination, unquestionably represents the best minimal approach to thyroid resection.

Regulatory T cells and plasmacytoid dendritic cells contribute to the immune escape of papillary thyroid cancer coexisting with multinodular non-toxic goiter

Immunosuppressive lymphocytes, such as regulatory T cells (Tregs) and plasmacytoid dendritic cells (pDCs), play crucial roles in tumor escape. To investigate the roles of Tregs and pDCs in papillary thyroid cancer (PTC) plus multinodular non-toxic goiter (MNG), thyroid tissue and blood samples from 30 patients with PTC plus MNG and 30 MNG alone were analyzed for CD4(+) T cell, CD8(+) T cell, FoxP3(+) Treg, ICOS(+)FoxP3(+) Treg, and pDC numbers by immunohistochemistry (IHC), immunofluorescence, and flow cytometry. Plasma concentration of the cytokines interleukin 10 (IL-10) and transforming growth factor β (TGF-β) were measured by enzyme-linked immunosorbent assay as well. Both in thyroid tissue and peripheral blood, the numbers of Foxp3(+) Treg were significantly higher in patients with PTC plus MNG compared to patients with MNG alone; and as a prognostic marker, ICOS(+)Foxp3(+) Tregs represent a stronger predictor of disease progression than the total numbers of Foxp3(+) Tregs. Furthermore, a positive correlation between pDC and ICOS(+)Foxp3(+) Treg numbers in tissue of patients with PTC plus MNG was observed, suggesting that PTC-derived pDCs may induce the differentiation of naive CD4(+) T cells into ICOS(+)Foxp3(+)Tregs. This may be one of the mechanisms underlying tumor escape in PTC plus MNG patients. Our results suggest that Tregs and pDCs together contribute to the tumor escape in patients with PTC plus MNG.

Assessment of nodular goitre

Nodular goitres are enlargements of the thyroid gland. In the absence of thyroid dysfunction, autoimmune thyroid disease, thyroiditis and thyroid malignancy, they constitute an entity described as non-toxic nodular goitre, which occurs both endemically and sporadically. In the early phase of goitrogenesis, goitres are diffuse and, with time, such goitres tend to become nodular. Concomitantly, thyroid function often becomes autonomous, and therefore the patients gradually develop hyperthyroidism. Some non-toxic goitre patients have no symptoms at all, or just complaints of cosmetic disfigurement. In the diagnostic evaluation protocol, neck palpation and several imaging methods are available: ultrasonography (US), the new developed US elastography, scintigraphy, computed tomography (CT) scan and magnetic resonance imaging (MRI). Fine-needle aspiration biopsy (FNAB) provides the most direct and specific information about a thyroid nodule. Recently, a combination of cytology and molecular testing has shown significant improvement in the diagnostic accuracy and allowed for better prediction of malignancy in thyroid nodular disease.

Concurrent occurrence of medullary thyroid carcinoma and papillary thyroid carcinoma in the same thyroid should be considered as coincidental

OBJECTIVES

The simultaneous occurrence of medullary thyroid carcinoma (MTC) and papillary thyroid carcinoma (PTC) in the same thyroid gland is documented. In this study, we evaluated the prevalence and characteristics of patients with concurrent MTC and PTC. Design Retrospective analysis of patients with MTC in a single centre and review of the literature.

PATIENTS AND MEASUREMENTS

Patients with MTC who underwent initial surgical treatment between 1996 and 2006 at Asan Medical Centre, Seoul, Korea were enrolled. We additionally reviewed the medical records of patients who initially underwent surgery for Graves' disease (GD) or follicular thyroid carcinoma (FTC) during the same period. The concurrent occurrence rate of PTC in MTC patients was compared with that in GD and FTC patients.

RESULTS

Ten of 53 (19%) MTC patients displayed the concomitant PTC. In all 10 cases, the MTC and PTC components were separated by normal thyroid tissue, with the maximal diameters of PTC being less than 1.0 cm in the majority of patients. The rates of concurrent PTC in patients with MTC, GD and FTC were 19%, 15% and 19%, respectively, which were not significantly different.

CONCLUSIONS

Our results suggest that the occurrence of concurrent MTC/PTC is generally a simple reflection of incidental papillary microcarcinoma.

TIMP1 and SERPIN-A overexpression and TFF3 and CRABP1 underexpression as biomarkers for papillary thyroid carcinoma

BACKGROUND

No molecular pathways or specific genes are consistently associated with sporadic cases of papillary thyroid carcinoma (PTC), despite that it is the most common thyroid malignancy. Nodular goiter is an enlargement of the thyroid that is a compensatory response to a perturbation in normal thyroid homeostasis. It has been disputed in the literature that patients presenting with goiter have a higher incidence of PTC. The identification of molecular events that are common to both goiter and PTC could explain the overlap of these two disorders.

METHODS

We used high-density oligonuleotide arrays to perform molecular profiling of PTC and nodular goiter with paired normal samples.

RESULTS

Specifically, increased expression of SERPIN-A (proteinase inhibitor-alpha antitrypsin) and TIMP 1 (tissue inhibitor of metalloproteinase 1) identified these as candidate molecular biomarkers for PTC. Decreases in the CRABP1 (cellular retinoic acid binding protein 1) and TFF3 (trefoil factor 3) expression levels identified these as candidate molecular biomarkers as well. The same analysis was performed to identify genes showing specific alterations in goiter tissues.

CONCLUSIONS

This is the first report to our knowledge that compares the gene expression profiles of PTC and goiter. Our results suggest that PTC and goiter share very limited overlap in transcript expression.

Fate of the non-operated, non-toxic goitre in a defined population

BACKGROUND

There is lack of consensus in Europe regarding the management of patients with benign goitre. This study evaluated the long-term results of recommending no surgery for clinically and cytologically benign goitre.

METHODS

Some 261 patients (median age 56 years) referred for surgical evaluation for goitre were followed prospectively for a median of 130 months. All hospital and primary care charts were reviewed and living patients interviewed by telephone.

RESULTS

During follow-up, 36.4 per cent of patients were re-referred for a new surgical evaluation, mainly because of growth of the goitre and/or worsening of local symptoms. Fifty-seven (21.8 per cent) of the patients had surgery, and 13 developed thyrotoxicosis. Five patients (1.9 per cent) were diagnosed with thyroid carcinoma, three of whom (all elderly women) died from the disease. Some 95.0 per cent of patients were satisfied with the expectant policy, but 13.1 per cent had been worried about thyroid cancer despite the reassurance of a benign diagnosis.

CONCLUSION

Patients with benign goitre can be treated conservatively with good results. However, there is a small risk that aggressive carcinoma will develop and about a quarter of patients may need surgery within 10 years of the decision to wait and see.

High incidence of thyroid cancer in long-standing goiters with thyroglobulin mutations

In this paper, we report the high prevalence of thyroid malignancy in patients with thyroglobulin mutations in Japan. Mutations of the thyroglobulin gene cause defective thyroid hormone synthesis, resulting in congenital hypothyroidism. Since our report in 1999 on the thyroglobulin mutations C1264R and C1996S, we have identified 14 adult patients (7 males and 7 females) from 9 unrelated families. They visited hospitals for treatment of huge goiters that first appeared in childhood. Persistent growth of the thyroid gland, probably caused by thyrotropin (TSH) stimulation, partially compensated thyroid hormone production, resulting in lowered serum TSH concentrations in turn. Consequently, many patients had to undergo multiple operations. Of 11 patients who had undergone surgery, 7 had thyroid cancers. Of five patients whose thyroid tissue was available, we found a heterozygous activating mutation, either V599E or K600E, in cancerous tissue from each of 2 patients. From these observations, we conclude that goiter resulting from thyroglobulin mutations is associated with thyroid cancer.

Total thyroidectomy for multinodular goiter in the elderly

BACKGROUND

Total thyroidectomy for multinodular goiter (MNG) is increasingly being performed for the elderly population and yet their perioperative and long-term outcomes remain unclear.

METHODS

A total of 279 patients who underwent total thyroidectomy for MNG in a university-based hospital during a 9-year period were analyzed according to their age at the time of operation.

RESULTS

The duration of operation (P=.023), intraoperative blood loss (P=.030), weight of resected thyroid glands (P<.001) and proportion of retrosternal goiter (P<.001) were significantly greater in the elderly group (>/=70 years) (n = 55), but the incidence of surgically related complications, including recurrent laryngeal nerve palsy and hypoparathyroidism, was similar. Postoperative pneumonia occurred more frequently in the elderly group (P=.034). The number of comorbidities tended to correlate with the length of hospital stay and long-term survival in elderly patients.

CONCLUSIONS

Total thyroidectomy for MNG in elderly patients had a similar perioperative outcome as their younger counterparts, but their long-term outcome is likely to be influenced by the number of comorbidities.

Prevalence of differentiated thyroid cancer in 810 cases of surgically treated goiter in Yemen

BACKGROUND

In 1990, the World Health Organization (WHO) suggested that severe iodine deficiency exists in Yemen. Therefore, we looked at the prevalence of differentiated thyroid goiter in 810 cases consecutively treated by surgery for goiter.

METHODS

This was a retrospective study of 810 surgically operated cases of goiter over a 5-year period (1999-2003). All cases were evaluated on H&E stained sections from embedded, 10% buffered formalin fixed tissue blocks. Special stains and immunohistochemical analysis were done in Yemen and abroad. Most patients were older than 20 years of age and were from the high altitude areas (2000 to 2600 meters above sea level), where iodine deficiency disorders (IDD) are well documented.

RESULTS

In the 810 cases, 729 (90%) were females and the remaining 81 (10%) were males, with female-to-male ratio of 9:1. Differentiated thyroid cancer (DTC) was found in 170 (21%) cases, including 148 (86.4%) females and 22 (13.6%) males. Nearly 60% of the cases were in the age group of 21-40 years. Papillary carcinoma was the most common type of DTC (164 cases, 96.5%).

CONCLUSIONS

In a Yemeni population, which has a high prevalence of iodine deficiency, 21% of patients operated on for nodular goiter without pre-operative fine needle aspiration biopsy had thyroid cancer, mostly of the papillary type. In this study, males and elderly patients with goiter had a higher chance of having malignancy.

Medullary and papillary tumors are frequently associated in the same thyroid gland without evidence of reciprocal influence in their biologic behavior

Papillary thyroid microcarcinoma (mPTC), is a very frequent incidental finding with a frequency varying from a few percent to 35% at postmortem histopathologic examinations. However, the presence of mPTC in patients undergoing thyroidectomy for multinodular goiter (MNG) and for Graves' disease (GD) has been found to be lower. Patients with medullary thyroid carcinoma (MTC) and papillary thyroid carcinoma (PTC) association have been published as anecdotal case reports, as well as kindred with familial MTC or multiple endocrine neoplasia (MEN) 2A with some members simultaneously affected by MTC and PTC. We studied the prevalence and the biological behavior of MTC associated with PTC, with particular attention to those cases in which a mPTC was incidentally found. Twenty-seven of 196 (13.8%) MTC cases showed an association with PTC and in particular 21 of 190 (11.05%) with an incidental mPTC. This percentage is higher than that reported in the literature on the association of mPTC with GD (2.8%-4.5%) and MNG (3%). Also the percentage of the more general association of MTC/PTC, not restricted to mPTC, found in our series (13.8%) is higher than that reported in studies that analyzed the prevalence of PTC (any size) in patients treated for MNG (7.5%). A similarly high percentage of MTC/PTC had not been reported before and in particular there are no reports on large series of MTC/PTC. We also analyzed the epidemiologic, clinical, and pathologic features of MTC associated and not associated with PTC without finding any difference. In particular the outcome of the MTC did not appear to be influenced by the presence of the PTC and the specific radioiodine treatments. Moreover, although we cannot completely exclude a shared pathogenic event as the cause of both MTC and PTC, the molecular analysis of RET gene alterations did not show any common mutation.

Thyroid nodular lesion: analysis of cancer risk based on Kuma Hospital experience

It is a difficult question, whether it is malignant or not, when you follow up patients with thyroid nodular lesions. Cytological examination helps to solve this issue more accurately but a cancer risk still exists in patients with a negative cytology, non-diagnostic or suspicious follicular neoplasms. Analysis of cancer risk in patients with benign thyroid nodular lesions was carried out among 1044 cases who underwent thyroid surgery at Kuma Hospital, Kobe, Japan, in 2000. The purpose of this study was to provide evidence of cancer risk in those patients in Japan. Among the 356 cases with benign nodular lesions, 99 cases of papillary carcinoma were found in the thyroid parenchyma. Seventy-nine of the 99 cases were clinical cancer and were found preoperatively by cytology, while 20 out of 277 (7.22%) cases were found postoperatively as incidental carcinoma. The incidence of follicular carcinoma of a minimally invasive type in the index nodule was 22 out of 279 (7.89%) cases in patients who were surgically treated.

Predictive factors of thyroid carcinoma in non-toxic multinodular goitre

The management of nontoxic multinodular goitre (NMNG) remains controversial. The challenge for the clinician is to identify the small proportion of NMNG patients with associated thyroid carcinoma who would thus benefit from surgery. We studied retrospectively the medical records of 80 patients with NMNG and coexisting thyroid carcinoma who underwent total thyroidectomy. Eighty total thyroidectomy patients with NMNG whose histology was benign were then randomnly chosen as controls. In univariate analysis, the following parameters were significantly more frequent in the carcinoma group: rapid growth of the goitre (p = 0.002), presence of microcalcifications (p = 0.01), hypoechogenicity (p = 0.02), firm consistency of a nodule (p = 0.03), and presence of a dominant cold nodule on scintigraphy (p = 0.03). In the multiple regression analysis, the variables significantly associated with carcinoma were rapid growth (Odds ratio (OR) = 4.13, 95% confidence interval(CI): 1.72-9.89), hypo-echogenicity (OR = 3.11, 95% CI: 1.13-8.51) and the presence of a dominant nodule (OR = 2.26, 95% CI: 1.06-4.79)). In the cancer group, tumour size was positively correlated with compression signs (p = 0.01), age (p = 0.02), the presence of a dominant nodule on scintigraphy (p = 0.02), and with rapid growth (p = 0.04). Concerning nodule size estimated on US (ultrasound), the majority (65%) of patients without carcinoma had nodules < 3 cm, whereas 73% of patients with clinical thyroid carcinoma (> or = 1 cm on histology) had nodules with a diameter of > or = 3 cm on US (p = 0.02). In conclusion, our study suggests that surgical treatment of NMNG should be proposed in the presence of rapid nodular growth, compression signs, dominant nodule on scintigraphy, nodule size > or 3 cm and hypo-echogenicity.

Doença nodular de tireóide

A tireóide normal é uma estrutura homogênea na qual, com muita freqüência, observamos a formação de nódulos. Nódulos maiores que 1,0cm costumam ser detectados clinicamente pela palpação. Um exame cuidadoso pode demonstrar a presença de nódulos em, pelo menos, 4% da população. A etiologia da doença nodular de tireóide é multifatorial, compreendendo um espectro que vai do pequeno nódulo achado de forma incidental a um grande bócio multinodular intra-torácico. Os principais aspectos com relação à avaliação diagnóstica estão relacionados à caracterização funcional e morfológica através do TSH sérico e algum tipo de imagem. Para afastar a malignidade, cuja incidência é praticamente a mesma em pacientes com nódulo solitário ou bócio multinodular (BMN), a punção aspirativa com agulha fina (PAAF) é o método de escolha. O nódulo único benigno de tireóide, frio ou quente à cintilografia, pode ser tratado com injeção percutânea de etanol ou cirurgia. O tratamento do BMN pode ser cirúrgico ou com radioiodo, se a captação de 131I for adequada. É provável que a introdução do TSH recombinante humano possa influenciar de forma importante o tratamento com 131I do BMN. O nódulo quente pode, ainda, ser tratado com 131I ou cirurgia. O tratamento supressivo com levotiroxina não é indicado no tratamento do nódulo benigno de tireóide.

Management of simple nodular goiter: current status and future perspectives

The simple nodular goiter, the etiology of which is multifactorial, encompasses the spectrum from the incidental asymptomatic small solitary nodule to the large intrathoracic goiter, causing pressure symptoms as well as cosmetic complaints. Its management is still the cause of considerable controversy. The mainstay in the diagnostic evaluation is related to functional and morphological characterization with serum TSH and (some kind of) imaging. Because malignancy is just as common in patients with a multinodular goiter as patients with a solitary nodule, we support the increasing use of fine-needle aspiration biopsy (cytology). Most patients need no treatment after malignancy is ruled out. In case of cosmetic or pressure symptoms, the choice in multinodular goiter stands between surgery, which is still the first choice, and radioiodine if uptake is adequate. In addition to surgery, the solitary nodule, whether hot or cold, can be treated with percutaneous ethanol injection therapy. If hot, radioiodine is the therapy of choice. Randomized studies are scarce, and the side effects of nonsurgical therapy are coming into focus. Therefore, the use of the optimum option in the individual patient cannot at present be based on evidence. However, we are of the view that levothyroxine, although widely used, should no longer be recommended routinely for this condition. Within a few years, the introduction of recombinant human TSH and laser therapy may profoundly alter the nonsurgical treatment of simple nodular goiter.

Aggressive metastatic follicular thyroid carcinoma with anaplastic transformation arising from a long-standing goiter in a patient with Pendred's syndrome

In this article we describe detailed pathological and molecular genetics studies in a consanguineous kindred with Pendred's syndrome. The index patient was a 53-year-old female patient with congenital deafness and goiter. Her parents were first-degree cousins. She had a large goiter (150 g) that had been present since childhood. One of her sisters and a niece are also deaf and have goiter as well. The presence of Pendred's syndrome was confirmed by a positive perchlorate test and the demonstration of a Mondini malformation. Thyroid function tests (under levothyroxine [LT4] therapy) were in the euthyroid range with a thyrotropin [TSH] level of 2.8 microU/mL (0.2-3.2), a serum total thyroxine (T4) of 90 nmol/L (54-142), and a serum total triiodothyronine (T3) of 2.7 nmol/L (0.8-2.4). Total thyroidectomy was performed, and the mass in the right lobe was found to have invaded adjacent tissues. The histopathological findings were consistent with a follicular carcinoma with areas of anaplastic transformation and lung metastasis. The patient was treated twice with 100 mCi 131iodine (3,700 MBq) and received suppressive doses of LT4. Postoperatively, the serum thyroglobulin (Tg) levels remained markedly elevated (2,352 to 41,336 ng/mL). The patient died of a sudden severe episode of hemoptysis. Sequence analysis of the PDS gene performed with DNA from the two relatives with Pendred's syndrome revealed the presence of a deletion of thymidine 279 in exon 3, a point mutation that results in a frameshift and a premature stop codon at codon 96 in the pendrin molecule. We concluded that prolonged TSH stimulation because of iodine deficiency or dyshormonogenesis in combination with mutations of oncogenes and/or tumor suppressor genes, may result in the development of follicular thyroid carcinomas that undergo transformation into anaplastic cancers. It is likely that these pathogenetic mechanisms have been involved in the development of aggressive metastatic thyroid cancer in this unusual patient with Pendred's syndrome.

Overexpression of epidermal growth factor and epidermal growth factor-receptor mRNAs in dyshormonogenetic goiters

Thyroid malignancy has been induced by long-term endogenous thyrotropin (TSH) stimulation in experimental animals, leading to local and distant metastasis. It has been postulated that constant and prolonged endogenous TSH stimulation in dyshormonogenetic thyroid tissues could result in thyroid neoplasia. The possible role of growth factors and oncogenes in goitrogenesis and favoring neoplasia has also been mentioned. Overexpression of certain growth factors and/or their receptors, and of oncogenes implicated in growth promotion may play a significant role in the relatively frequent finding of thyroid malignancy in congenital goiters. In this study the expression of epidermal growth factor (EGF), epidermal growth factor receptor (EGF-R), transforming growth factor-beta (TGF-beta), c-myc, and p53 mRNAs was determined in 14 thyroid tissue samples: 6 from patients with thyroid peroxidase (TPO) gene mutations, 4 with thyroglobulin (Tg) gene defects and 4 normal thyroid tissues. EGF mRNA overexpression was seen in 7 of 10 dyshormonogenetic tissues (3.5 to 12.0 arbitrary optical densitometry units [AODU]) and considered significantly higher (p < 0.01) when compared to normal thyroid tissues (0.25 to 0.32 AODU). Moreover, overexpression of EGF-R mRNA was present in 6 of 10 dyshormonogenetic tissues (2.23 to 13.03 AODU) and considered significantly higher (p < 0.01) when compared to normal thyroid tissues (0.42 to 0.65 AODU). There was no difference in c-myc, p53, and TGF-beta mRNAs expression between dyshormonogenetic and normal tissues. The overexpression of EGF and EGF-R mRNAs found in dyshormonogenetic tissues may suggest that this growth factor may play a role in cellular proliferation and contribute to goiter formation.

Multinodular goitre: 'much more to it than simply iodine deficiency'

For over a century, multinodular goitre (MNG) has been looked upon as the simple consequence of iodine deficiency. This view is now no longer tenable. Indeed, many characteristics of MNG do not fit with the iodine deficiency concept. For example, nodular goitre is a frequent disease even in those countries where the population is never exposed to iodine shortage. Moreover, neither multinodularity, nor the proverbial heterogeneity of growth and function or the autonomous, thyroid stimulating hormone (TSH)-independent growth of many goitres are compatible with the iodine deficiency concept, let alone subclinical or overt thyrotoxicosis which often complicates the course of a MNG. Recent investigations have led to the conclusion that MNGs are true benign neoplasias that are due to the high intrinsic growth potential of a variable, genetically predetermined fraction of all thyrocytes. Gross and heritable metabolic and functional differences between the individual thyrocytes, from which new follicles are generated during goitrogenesis, are the cause of the often spectacular functional and structural heterogeneity of MNG. Superimposed iodine deficiency changes the epidemiology, but not the basic mechanisms of goitrogenesis. These new pathogenetic concepts have a profound impact on the clinical management of MNG.

The use of fine-needle aspiration biopsy under ultrasound guidance to assess the risk of malignancy in patients with a multinodular goiter

PURPOSE

Fine-needle aspiration biopsy (FNAB) is a commonly performed procedure used in the evaluation of solitary thyroid nodules, in which the risk of malignancy is approximately 5% in most patients. Recently, the use of ultrasound (US) guidance in FNAB has been shown to enhance the diagnostic efficacy of this procedure. However, the risk of malignancy in thyroid nodules occurring within a multinodular goiter (MNG) has not been completely clarified, nor has the optimal means of investigating such nodules using FNAB.

SUBJECTS AND METHODS

We performed a retrospective study of all patients seen over a 4-year period with a MNG that had one or more nodules who underwent FNAB under US guidance. The results from the history and physical examination, thyroid function and antibody tests, radionuclide studies, thyroid sonogram, cytology of aspirated nodules, and surgical pathology were recorded and analyzed.

RESULTS

A total of 93 nodules were aspirated in 61 patients with MNG. Adequate material was obtained in 96% of aspirates on the first attempt. Sixty-seven aspirates in 44 patients yielded benign cytology and 22 aspirates in 15 patients yielded suspicious cytology. All patients with suspicious cytology underwent thyroid surgery. Thyroid cancer was found in 5 of these nodules, including 4 cases of papillary cancer and 1 case of Hürthle cell cancer, and 1 additional patient had occult papillary cancer discovered. The overall malignancy rate in thyroid nodules among the patients with MNG was approximately 5%.

CONCLUSIONS

FNAB under US guidance is a useful diagnostic modality in the evaluation of thyroid nodules in selected patients with MNG. Because the risk of thyroid malignancy in these nodules is comparable to that which exists in solitary thyroid nodules, the possibility of thyroid malignancy should be considered in all patients with MNG.