Prevalence of thyroid gland tissue in midline neck dermoid cysts in children and a proposed new 'thyroglossal entrainment' hypothesis for their formation.

BACKGROUND: Thyroglossal duct cysts and dermoid cysts both commonly present as midline neck lumps in children. They are treated as separate entities with different embryological origins. There are isolated reports of thyroid gland tissue in a dermoid cyst, concurrent thyroglossal and dermoid cysts, and cysts with mixed histology. It is not known if these are rare or common. METHODS: All children undergoing excision of a congenital midline neck cyst between January 2017 and December 2022 were identified. Histopathology slides were reviewed in detail. RESULTS: In 53 children, there were 26 thyroglossal duct cysts, 24 dermoids, 1 lymph node and 2 with no diagnostic material identified. Five dermoids (28 per cent) had associated thyroid gland tissue, and 1 (4 per cent) had hybrid histology with keratinising and respiratory epithelium. Infection occurred in 17 per cent of dermoids prior to excision and 8 per cent of dermoids recurred after excision. CONCLUSION: Hybrid histology, infection and recurrence are all common in midline neck dermoids. A new theory for their embryological origin is proposed, with the suggestion that some may need more extensive surgery.

Cancer in thyroglossal duct cysts.

BACKGROUND: Thyroglossal duct cysts (TDC) account for 7% of midline neck swellings. TDC carcinoma (TDCC) is rare, reported in 1% of all TDCs. We aimed to describe the incidence of TDCC, the accuracy of fine needle aspiration cytology (FNAC), and to identify suspicious, predictive ultrasound (USG) features. METHOD: A cross sectional study of TDC patients in the Monash University Endocrine Surgery Database from 2001 to 2021. RESULTS: Eighty-six patients had surgery for TDC, of median age 48 and a female preponderance (62%). Preoperative USG was used in 85% and FNAC in 57%. There were six cases (7%) of TDCC with papillary thyroid cancer (PTC). USG in five TDCC cases showed a solid nodule within the cyst wall. FNAC was undertaken in five TDCC cases from the solid nodule; malignant in one and suspicious for malignancy in two. Two TDCC patients had concurrent total thyroidectomy (TT), and three subsequently had a TT. Multifocal thyroid PTC was found in two patients. One patient had a recurrence in the lateral lymph nodes, nine years after excision of the TDCC and TT. All patients are alive and well with no distant metastases (median follow up 11 years). CONCLUSION: The 7% incidence of TDCC is higher than the usually reported 1% in the literature. We recommend a preoperative USG to evaluate the TDC, thyroid gland and cervical lymph nodes, and an FNAC to target the solid component of the TDC, and favour total thyroidectomy for all patients with TDCC.

Paediatric neck masses in Zaria: A review of clinical profile and treatment outcome.

BACKGROUND: A neck mass is any abnormal lesion in the neck that can be seen, palpated, or identified on imaging. It is one of the most common reasons for presentation to the surgical clinics. AIM: the aim is to analyse the clinical presentation and treatment outcome in children who were diagnosed and managed for neck masses in a tertiary centre in Northwestern Nigeria. MATERIALS AND METHODS: The records of patients managed for neck masses over 7 years between January 2013 and December 2019 were reviewed. Demographic and clinical data were retrieved and analysed using Statistical Product and Service Solution version 23.0 software (SPSS Inc., Chicago, Illinois, USA). RESULTS: A total of 99 cases were reviewed and there were 52 (52.5%) males and 47 (47.5%) females with male-to-female ratio of 1.1:1, and mean age ± standard deviation of 4.4 ± 3.9 years, the primary complaints of all the patients were neck swellings. The anterior triangle was the most common region involved in 86 (86.9%) patients. The majority of the neck masses were congenital, accounting for 71 (71.8%) patients. Ultrasound scanning was the most commonly requested radiological investigation done in 87 (87.8%) patients. .: Thyroglossal duct cyst was the most common paediatric neck mass seen in 41 (41.4%) patients. The majority of the patients 68 (68.7%) had an excisional biopsy of the lesion. Surgical site infection was the most common complication noted in 7.1% of the study population. CONCLUSION: Most of the neck masses were congenital and were managed surgically. Prompt diagnosis with appropriate treatment may result in a good outcome.

Modified Sistrunk procedure in a pediatric population: Infected thyroglossal duct cysts as a risk factor for recurrence and review of the literature.

AIM: To analyze the rate of recurrence and possible risk factors after surgical treatment in pediatric patients with thyroglossal ductus cyst (TGDC), who underwent the Modified Sistrunk Procedure (MSP). DESIGN: Retrospective study. INSTITUTION: The pediatric otorhinolaryngology clinic of a university. MATERIALS AND METHODS: The study included a total of 251 pediatric patients aged between 2 and 17 years, whose histopathological diagnosis was confirmed and who underwent MSP due to TGDC over a period of 10 years from January 2009 to December 2019. The chi-square test was used to determine the relationship between the independent variables and the dependent variables. Parameters used in the study: The parameters were age, gender, the history of infected TGDC before surgery (cellulitis, abscess), incision and drainage in patients with abscess, number of cysts detected in ultrasonographic imaging, postoperative histopathology, and the number of recurrences. RESULTS: The study included a total of 251 pediatric patients. The mean age of the children was 6.2 years (2-17 years), the mean follow-up period was 4.8 years (2-6 years), and 38 (15.13%) recurrences were observed after 251 MSP applications. Five risk factors were found to be statistically significant in terms of recurrence rates (p<0.05). These risk factors were surgery during the school period (6-10 years), history of infected TGDC, abscess formation, incision/drainage before MSP, and multicystic cyst in ultrasonographic evaluation. CONCLUSION: The main determinant for the five significant risk factors among the causes of MSP recurrence is a history of infected TGDC before surgery. When there is no history of TGDC infection in pediatric patients before surgery, surgery should be planned under appropriate conditions before infection occurs. The risk of infected TGDC, cellulitis, and abscess formation increases at school age in particular due to frequent upper respiratory tract infections. When there is a cyst infection, antibiotic treatment should be applied, and incision and drainage should be avoided as much as possible in the presence of an abscess.

Congenital Neck Masses.

ABSTRACT: Congenital neck masses (CNMs) are developmental malformations that present with a wide spectrum of clinical symptoms and signs. They account for 21% to 45% of neck masses in children and 5% to 14% in adults. This study aimed to present the clinical manifestations and treatment of CNM from single-institution experiences. A retrospective analysis of patients surgically treated for CNM in a 12-year period was performed. Altogether, 117 patients (female/male ratio, 1:1.05) were diagnosed with CNM. The mean age at presentation was 26.91 years (range, 0.01-84 years). Within the study population, 120 CNMs were identified: 52 (43.33%) thyroglossal duct remnants, 48 (40.00%) branchial cleft anomalies, 7 (5.83%) epidermoid/dermoid cysts, 4 (3.33%) hemangiomas, 3 (2.50%) lymphangiomas, 1 (0.83%) hemangiolymphangioma, 1 (0.83%) hemangioendothelioma, 1 (0.83%) internal laryngocele, 1 (0.83%) external laryngocele, 1 (0.83%) ectopic thyroid gland, and 1 (0.83%) parathyroid cyst. The lateral neck region was the most frequently affected anatomical site, followed by the midline neck location and mediastinum (54%, 45%, and 1%, respectively). Surgical excision was performed in all cases. Recurrence was recorded in 5 (4.17%) patients. The results of this study provide comprehensive information regarding the clinical spectrum of CNM. Successful management of these lesions depends on a thorough understanding of neck embryology and anatomy. Misdiagnosis and improper treatment increase the morbidity and recurrence rate of CNM.

Thyroglossal duct surgery. What is the acceptable recurrence rate?

OBJECTIVES: To present experiences of different specialties in the treatment of thyroglossal duct cysts (TGDCs) and subsequent complications in multiple centers.  Methods: A retrospective cross-sectional study of all cases of TGDC for a period of 11 years from 2008-2019 by different departments from 3 different centers in Jeddah, Kingdom of Saudi Arabia (King Faisal Specialist Hospital and Research Centre, Bakhsh Hospital and International Medical Center). Results: Forty-nine patients were included. The type of surgery performed plays a significant role in recurrence (p less than 0.001). The Sistrunk procedure had a lower recurrence rate (0%) than simple excision (70%) and has showed a significantly long recurrence-free interval (p less than 0.001). Higher recurrence rates are associated with higher postoperative complications (p=0.002). Patients who underwent pre-operative fine needle aspiration did not have any recurrence during the follow-up period. Conclusion: The Sistrunk procedure is the gold standard technique with the highest recurrence-free interval rate. Fine needle aspiration could be recommended as a less invasive procedure to exclude malignancy.

Prevalence and Features of Thyroglossal Duct Cyst on Ultrasonography, According to Radioactive Iodine Therapy: A Single-Center Study.

Objective: The relationship between radioactive iodine therapy (RIT) and prevalence of thyroglossal duct cysts (TGDC) on ultrasonography (US) has not been reported. We assessed the prevalence and US features of TGDC according to RIT. Methods: From July 2017 to June 2018, 3,146 subjects underwent thyroid or neck US at our center. The presence or absence of TGDCs was prospectively investigated based on real-time US examination. Among the 3,146 subjects, 261 subjects were excluded because of <18 years of age, unclear information of RIT, or the presence of a radiation therapy history to the neck. Eventually, 2,885 subjects were included in this study. Results: Of the 2,885 subjects finally included, 126 (4.4%) showed a TGDC on US. Those with RIT history showed a higher prevalence of TGDCs than those without (no statistical difference, p = 0.062). In 697 male subjects, there were statistical differences in type of surgery, RIT history, and session number of RIT between those with or without TGDCs (p < 0.0001). In 126 subjects with TGDCs, only sex showed a significant difference between those with or without RIT history (p = 0.015). However, there were no significant differences in the location, size, and shape of TGDCs (p > 0.05). The common US features of TGDC were suprahyoid location, ~1 centimeter, and flat-to-ovoid or round shape. Conclusions: RIT may increase the prevalence of TGDCs, particularly in men.

Neck masses in children: a 10-year single-centre experience in Northwest China.

Neck masses in children are a common clinical concern but there is a paucity of published information about them. We organised this retrospective study to analyse their prevalence and treatment in Northwest China. The records of 207 children who presented with neck masses between 2008 and 2017 were retrieved from the Department of Oral and Maxillofacial Surgery, Lanzhou University Second Hospital, and age, sex, clinical presentation, preoperative investigation, surgical procedure, histopathological diagnosis, and complications were recorded. Their mean (range) age was 10 years (6 months to 21 years), and the male:female ratio was 1.23:1. In total 128 patients (62%) had congenital lesions, 35 (17%) had inflammatory lesions, and 44 (21%) had neoplastic lesions. The most common mass was a thyroglossal cyst (31%), followed by plunging ranula (17%) and lymphangioma (16%). Temporary injury to the facial nerve and wound infection were the major complications of surgical treatment. The types of neck masses in Northwest China differ from those previously reported, which may be attributed to genetic alterations in people of this race. The present report adds to the knowledge of diagnosis and treatment of neck masses in children in Northwest China, and brings out the demographic differences between races.

Management outcome of thyroglossal cyst in a tertiary health center in Southwest Nigeria.

Thyroglossal duct cyst is a non-odontogenic congenital developmental cyst. It is predominantly a midline anterior neck swelling in children and total excision of the tracts prevents recurrence. Retrospective hospital record analysis of patients managed with histopathology results of thyroglossal cyst between 2003 and 2018. Comparing outcomes and technique of thyroglossal cyst excision in a resource challenged environment. A total of 37 patients comprising 22(59.5%) males and 15(40.5%) females (M:F 1.4:1) with age range of 13 days to 55 years (median 6 years) were managed. The majority were children less than 10 years of age. They all presented with a fluctuant midline progressive anterior neck swelling, in addition to anterior neck ulcer 1(2.7%), discharging sinuses 3(8.1%) and thyroglossal cyst duct infections, which were managed successfully with antibiotics. Central compartment neck dissection with excision of mid-portion of the hyoid bone was performed in all the patients. Rupture of thyroglossal duct cysts was observed in 7(18.9%) at surgery, but there was no recurrence. Surgical drain was not used and most patients were discharged within 48 hours postoperatively. Thyroglossal duct cyst was confirmed at histology without any evidence of mitotic changes. There was no recurrence for the Sistrunk's procedure in all specialties. The modification of the Sistrunk's procedure with mid-anterior neck dissection is effective in excising a thyroglossal duct cyst, hence preventing recurrence. Non-usage of wound drains and short hospital stay are cost effective.

The incidence of microscopic thyroglossal duct tissue superior to the hyoid bone.

OBJECTIVE: Despite the success of the Sistrunk procedure, persistence of a thyroglossal duct cyst (TGDC), sinus, or remnant following excision remains a clinical problem. This is most likely due to the presence of microscopic disease that was not excised at the time of surgery. The purpose of this study is to determine the incidence of microscopic disease superior to the hyoid bone in children who have had either a primary or revision procedure for a TGDC. METHODS: A prospective review of pathologic specimens was conducted of all consecutive patients undergoing TGDC excision by pediatric otolaryngologists at the Children's Hospital Los Angeles beginning March 2014 through July 2017 in both primary and revision procedures. RESULTS: Microscopic disease was present superior to the hyoid bone in 25 of the 34 (74%) specimens and in 100% (6) of the specimens from a revision procedure. CONCLUSION: The majority of persons who have a TGDC will have microscopic disease superior to the hyoid bone. In order to minimize the incidence of persistence following a primary procedure, tissue superior to the hyoid bone should be removed routinely even if no gross disease is noted at the time of surgery. When performing a revision procedure, special attention should be given to the suprahyoid area as a likely site of persistent disease. LEVEL OF EVIDENCE: 2b Laryngoscope, 129:1215-1217, 2019.

Long-Term Ultrasound Follow-Up of Incidentally Detected Thyroglossal Duct Cysts in Adults.

BACKGROUND AND PURPOSE: There has been no previous study that used ultrasonography for longitudinal changes of thyroglossal duct cysts, to our knowledge. We assessed the prevalence and interval changes in incidentally detected thyroglossal duct cysts in adults. MATERIALS AND METHODS: From January 2010 to December 2016, we identified 796 ultrasonography radiologic reports from 513 subjects that contained the words "thyroglossal" or "TGDC" among 54,369 participants. Of 513 subjects, 172 (M/F = 103:69, mean age, 53 ± 11 years) who underwent ≥2 sonography studies were enrolled. Two reviewers determined ultrasonography features, including maximal diameter, location, internal echogenicity, wall thickness, and the presence of posterior enhancement, internal septa, and solid components. RESULTS: The mean follow-up time of total 172 lesions was 2.01 ± 1.13 years. Thyroglossal duct cysts ranged from 2 to 32 mm (mean, 8.77 ± 3.83 mm) on the initial ultrasonography examination. On follow-up ultrasonography studies, 14 lesions (8.2%) increased by >2 mm, while most thyroglossal duct cysts (133 lesions, 77.3%) remained stable in size. During the follow-up period, 31 lesions (18.0%) showed interval changes in ultrasonography features. There was no significant relationship between the presence of ultrasonography feature changes and size changes (P = .12). CONCLUSIONS: On ultrasonography, 0.9% of adults had incidental thyroglossal duct cysts. Most did not increase in size with time despite changes in various ultrasonography features. Therefore, we recommend performing an observation at long intervals of 2-3 years for asymptomatic thyroglossal duct cysts, and we suggest that fine-needle aspiration can be suspended unless suspicious findings of malignancy are detected.

Thyroid cancer in lingual thyroid and thyroglossal duct cyst.

Ectopy is the most common embryogenetic defect of the thyroid gland, representing between 48 and 61% of all thyroid dysgeneses. Persistence of thyroid tissue in the context of a thyroglossal duct remnant and lingual thyroid tissue are the most common defects. Although most cases of ectopic thyroid are asymptomatic, any disease affecting the thyroid may potentially involve the ectopic tissue, including malignancies. The prevalence of differentiated thyroid carcinoma in lingual thyroid and thyroglossal duct cyst is around 1% of patients affected with the above thyroid ectopies. We here review the current literature concerning primary thyroid carcinomas originating from thyroid tissue on thyroglossal duct cysts and lingual thyroid.

Incidental radiographic findings of thyroglossal duct cysts: Prevalence and management.

OBJECTIVES/HYPOTHESIS: To determine the epidemiology of incidental thyroglossal duct cysts (TGDC) discovered on imaging studies obtained in the head and neck area in children and to discuss subsequent management. METHODS: A retrospective chart review was performed at Texas Children's Hospital of all computed tomography (CT) and magnetic resonance (MR) imaging studies obtained in the head and neck region between July 2011 and July 2014. Images obtained for the purpose of evaluating a neck or lingual mass were excluded from the study, as were patients with previously known TGDCs. Data including age, sex, location of TGDC, size, presence of symptoms, referral to Otolaryngology, and intervention were recorded. RESULTS: A total of 60,663 CT and MR studies of the head, brain, sinus, neck, and C-spine during this time period were reviewed; of these 69 (0.1%) cases contained incidental discovery of probable TGDCs with more males (40) than females (29). Ages ranged from 3 days to 17 years old, with the mean age at 5 years. Locations varied, with majority at base of tongue (83%) followed by hyoid (13%) then infrahyoid straps (4%). Sizes ranged from 2 to 28 mm with average size at 8 mm. 11 of these patients were referred to an Otolaryngologist; 9 were asymptomatic and decision was made to observe, the other two subsequently underwent surgical excision secondary to mass effect and dysphagia with histologic confirmation of diagnosis. CONCLUSION: TGDCs commonly present as an anterior neck mass, however the majority of incidentally discovered TGDCs on imaging are located at the base of tongue. Management of these findings should include referral to an Otolaryngologist for further evaluation with the decision to intervene surgically based on development of clinical symptoms.

A Clinicopathologic Series of 685 Thyroglossal Duct Remnant Cysts.

The clinical features of thyroglossal duct remnant cysts (TGDC) have been well described, however the histopathologic aspects of these lesions have not been addressed in a detailed manner. In particular, there has been no large community practice based series evaluating TGDC histologically compared with management outcomes. A retrospective review of all TGDC diagnosed between 2005 and 2015 was performed. Six hundred eighty-five patients were identified (344 males; 341 females). Age at presentation was bimodal (first and fifth decades) and ranged from 0.8 to 87 years (mean 31.3 years). Males predominate in children (150:111); females in adults (230:194). Patients presented most frequently with a mobile midline neck mass in an infrahyoid location. An associated skin fistula (n = 67) was twice as common in pediatric as adult patients. The average cyst size was 2.4 cm (range 0.4-9.9 cm) by imaging studies and 2.6 cm (range 0.2-8.5 cm) by pathologic examination; pediatric patients had smaller cysts (mean 2.1 cm) than adults (mean 2.8 cm). Histologically, 257 (38 %) TGDC were lined by respiratory epithelium alone, 68 (10 %) squamous epithelium alone, 347 (51 %) exhibited both respiratory and squamous epithelium, and 13 (1 %) had no identifiable epithelial lining. Four hundred eighty-four (71 %) TGDC had associated thyroid gland tissue present within the cyst wall (n = 282), skeletal muscle (n = 71), adipose tissue (n = 34), or a combination of these sites (n = 97). The hyoid bone was identified in 647 (grossly and/or histologically), and absent in 38. Surgical management consisted of Sistrunk procedure (n = 647), cystectomy (n = 31), or thyroidectomy/thyroid lobectomy (n = 7). Treatment related complications were observed in 6 patients, which included vocal cord damage, seroma, and hematoma. Recurrences developed in 20 (3 %) patients, 14 of whom were managed initially by cystectomy. Papillary thyroid carcinoma was identified in 22 (3.2 %) TGDC. In summary, TGDC show a bimodal peak in the 1st and 5th decades, commonly presenting as a midline cervical lesion below the hyoid bone, associated with a skin fistula in 10 %. Histologically TGDC are most commonly lined by a combination of respiratory and squamous epithelium. Thyroid gland tissue is identified in 71 % of cases (0.45 cm mean size), although not limited to the cyst wall, but present in the surrounding soft tissues. Rare TGDC may harbor malignancy (3.2 %). TGDC are most effectively managed by Sistrunk procedure rather than excision, which carries low rates of complications (1 %) and recurrence (3 %).

Branchial cleft anomalies and thymic cysts.

Branchial cleft anomalies are a common cause of congenital neck masses and can present as a cyst, sinus, or fistula. A comprehensive understanding of the embryologic basis of these anomalies aids in diagnosis and surgical excision. Fistulas tend to present at an earlier age than sinuses or cysts, with most lesions presenting as either a neck mass, draining sinus, or recurrent infections. The eventual management of each is complete surgical excision, which is curative. A history of recurrent preoperative infections leads to a higher rate of recurrence.

Thyroglossal surgery in Scotland 1981-2010.

BACKGROUND AND AIMS: Thyroglossal surgery is not common in Scotland with 0.013 procedures performed per 1000 population in 2010. There is a growing practice in surgery to consolidate service providers to ensure a minimum 'case volume', with the belief that this will raise standards and improve co-ordination of services. We investigated thyroglossal surgery to see if this had occurred. METHODS AND RESULTS: Data on thyroglossal surgery performed in Scotland from 1981 to 2010 were obtained from the Information Services Division of NHS Scotland. This was analysed to investigate the number of procedures involving thyroglossal tissue, the surgical speciality of operating surgeon and the health board in which the procedure was performed. Whilst the number of thyroglossal operations has remained essentially static over the study period, there has been a steady trend of consolidation of the surgical speciality performing the procedure. In 1981, 58% of thyroglossal surgery was performed by general surgeons, 18% by paediatric surgeons and 15% by ENT surgeons nationally. In 2010, ENT surgeons are performing 81%. CONCLUSIONS: Our data suggest that the provision of thyroglossal surgery is being consolidated in Scotland by speciality and that ENT surgeons are providing this service in the majority of cases.

Recurrences after thyroglossal duct cyst surgery: Results in 207 consecutive cases and review of the literature.

BACKGROUND: A thyroglossal duct cyst is the most common form of congenital anomaly in the neck. Surgical removal is very effective. However, in some cases, a cyst recurs. The purpose of this study was to identify factors that predispose to recurrence of a thyroglossal duct cyst. METHODS: A retrospective study was conducted of consecutive patients who underwent surgical resection for histologically confirmed thyroglossal duct cysts between 1998 and 2013 in a tertiary referral center. RESULTS: Two hundred seven patients were included. The overall recurrence rate was 9.7%. The most important factor predicting recurrence was the type of resection: recurrence rate was 5.3% after the Sistrunk procedure, and 55.6% after plain excision (p < .001). The only other factor that was significantly associated with chance of recurrence was postoperative infection. CONCLUSION: The Sistrunk procedure is the treatment of choice for thyroglossal duct cysts because it yields low recurrence and morbidity. Postoperative infections, rather than preoperative infections, are associated with recurrence.

Neck masses: diagnostic analysis of 630 cases in Turkish population.

Neck masses can be classified into three main categories: congenital, inflammatory and neoplastic. Our aim was to determine the distribution of diagnosis in patients who were followed-up for a neck mass and had undergone surgery for diagnostic indications. Six hundred and thirty cases referred to the Otorhinolaryngology and Head Neck Surgery Department of Haseki Research and Training Hospital between January 2005 and February 2012 with a neck mass who underwent excisional or incisional biopsy to establish a histopathologic diagnosis were retrospectively evaluated. Patients with a diagnosis of upper aerodigestive tract malignancy were excluded from the study. As well as the patients with thyroid masses were excluded. Only unknown primary neck masses were included in the study. The neck masses were categorized as inflammatory (33.49 %), congenital (18.9 %) or neoplastic (47.6 %). Neoplastic masses were either benign (51 %) or malignant (49 %) tumors. The most common causes were tuberculous lymphadenitis (40.28 %) among inflammatory masses, thyroglossal duct cysts (32.77 %) among congenital masses, pleomorphic adenoma (22.33 %) among benign neoplastic masses, and lymphoma (20 %) among malignant neoplastic masses. The most common types of mass were congenital in the 0-20 year age group, benign neoplastic in 21-40-year-old and malignant neoplastic in the >40-year group. Any neck mass, especially in an elderly patient, should be managed with caution as a considerable proportion may be malignant. In children and adolescents, a neck mass requiring surgery is most likely to be congenital. Tuberculosis should be considered as a cause of a neck mass due to a long-term inflammatory process in a developing country.

Thyroglossal duct cyst carcinomas: is there a need for thyroidectomy?

OBJECTIVE: Thyroglossal duct cyst (TGDC) carcinoma is a rare entity and its management is controversial. The aim of this retrospective study was to: (a) identify patients with TGDC carcinoma followed up in our clinic and (b) study specific characteristics of the disease and their association with thyroid carcinoma. DESIGN: Medical files of patients with TGDC carcinoma were reviewed and tumour characteristics, lymph node metastases, treatment and follow-up were evaluated. RESULTS: A total of 6 patients, 4 females and 2 males, mean age 39.3 years (median 33.5), were treated for papillary thyroid carcinoma arising in a TGDC. Carcinoma of the thyroid gland was found simultaneously in 4 of these patients, while in one patient thyroid carcinoma developed 10 years after the diagnosis of TGDC carcinoma. A variable clinical picture and presentation was recorded. The most aggressive manifestation of the disease in terms of local infiltration, local recurrence and lymph node metastases was observed in our youngest patients. CONCLUSIONS: Long-term follow-up is necessary for patients with thyroid carcinoma arising in a TGDC. In view of the frequent co-existence of thyroid cancer in these patients, we would recommend detailed thyroid evaluation and, eventually, total thyroidectomy at initial diagnosis of TGDC carcinoma.