Carcinoma arising in median ectopic thyroid (including thyroglossal duct tissue)

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.

Isolated poorly differentiated cancer (insular) in a thyroglossal cyst: a case report

A 23-year-old young man presented with a painless neck mass that he noticed slowly growing over the past 4 years. Neck imaging showed an irregular 5 x 5 cm mixed solid and cystic mass in mid neck that looked suspicious but normal looking thyroid and no neck lymphadenopathy. Thyroid uptake scan was within normal also. Fine needle biopsy (FNA) from thyroglossal cyst (TGC) was malignant, Bethesda VI. Multi-disciplinary meeting discussed the case and advised for removal of both the TGC cancer and total thyroidectomy. After patient counseling, he underwent Sistrunk procedure for excision of the TGC mass and total thyroidectomy. histopathological examination revealed a poorly differentiated carcinoma of insular type in TGC with unremarkable thyroid gland. Patient recovery was uneventful. Post-operative multi-disciplinary meeting discussed the histopathology results and advised for post-operative radioactive iodine therapy (RAI) and thyroxine suppression followed by serum thyroid stimulating hormone (TSH) and thyroglobulin (TG). We shall review the diagnostic and management considerations of our case having this rare cancer.

Thyroid tissue outside the thyroid gland: Differential diagnosis and associated diagnostic challenges

The presence of thyroid tissue outside of the thyroid gland may occur in various clinical settings and anatomic locations and includes both benign and malignant differential diagnoses. Some of these entities include thyroglossal duct cyst, lingual thyroid, parasitic nodule, thyroid tissue within a lymph node and struma ovarii. In routine daily practice, these entities do pose diagnostic challenges for the pathologists. Differential diagnostic considerations depend largely on the location of lesion and the histologic features. A definitive diagnosis may remain unclear in some cases while knowledge is still evolving in others i.e., incidentally detected bland appearing thyroid follicles in a lateral neck lymph node. This article aims to elaborate on the various entities characterized by thyroid tissue outside of the thyroid gland, both benign and malignant, and the relevant differential diagnostic considerations.

Occult Papillary Thyroid Carcinoma without Detection of the Primary Tumor on Preoperative Ultrasonography or Postoperative Pathological Examination: A Case Report

Herein, we report a case of an occult thyroid cancer that was not detected as a primary tumor on preoperative ultrasonography or postoperative pathological examination, although a diagnosis of papillary thyroid carcinoma metastasis was made owing to the presence of a mass in the right upper neck. Needle biopsy of the mass in the right upper neck revealed positive results for thyroglobulin and TTF-1 on immunostaining, and a papillary thyroid carcinoma was observed with papillary and follicular patterns. We suspected papillary thyroid carcinoma (T0N1bM0) or ectopic papillary thyroid carcinoma. Accordingly, we performed total thyroidectomy, central lymph node dissection, right lateral neck dissection, and resection of the superficial lobe of the right parotid. A postoperative pathological examination of 5-mm slices of the specimen revealed no primary tumor in the thyroid. However, a hyalinized image of the thyroid indicated that a micropapillary thyroid carcinoma might have spontaneously disappeared. As there was no normal thyroid tissue in the metastasis to the superior internal jugular lymph node, the tumor was unlikely to be an ectopic papillary thyroid carcinoma. Therefore, we made a diagnosis of a papillary thyroid carcinoma (pT0N1bM0). After surgery, we determined that the tumor belonged to a high-risk group of papillary thyroid carcinomas and a poor-prognosis group of symptomatic papillary thyroid microcarcinomas; accordingly, ablation was performed with 30 mCi iodine-131. There was no recurrence or metastasis 24 months after the first surgery.

Educational Case: Developmental Neck Masses and Other Neck Tumors

The following fictional case is intended as a learning tool within the Pathology Competencies for Medical Education (PCME), a set of national standards for teaching pathology. These are divided into three basic competencies: Disease Mechanisms and Processes, Organ System Pathology, and Diagnostic Medicine and Therapeutic Pathology. For additional information, and a full list of learning objectives for all three competencies, see http://journals.sagepub.com/doi/10.1177/2374289517715040.¹

Papillary Thyroid Carcinoma with Cervical Lymph Node Metastasis Arising from Lingual Thyroid

Although lingual thyroid is the most common site for ectopic thyroid gland but carcinomas originating from lingual thyroid are extremely rare, accounting only for 1% of all ectopic thyroids. Here we represent a young female with a bleeding mass at the base of her tongue and review the diagnostic approach towards papillary thyroid carcinoma of lingual thyroid. The surgical treatment and follow up are discussed. A combination of radiological studies and histological evaluation should be deployed to investigate suspicious lingual thyroids. The perspective of diagnostic and therapeutic approaches for carcinomas of lingual thyroid is the same as orthotopic thyroid tissue.

Papillary Thyroid Carcinoma Identified after Sistrunk Procedure: Report of Two Cases and Review of the Literature

Thyroglossal duct cysts represent the most common congenital cervical malformations. Carcinomas arising in the thyroglossal duct cysts are rare neoplasms characterized by a relatively non aggressive behavior with rare lymph node spread. Approximately 1% of thyroglossal cysts contain a carcinoma. The most frequent histological type is papillary carcinoma, accounting for about 80% of cases. Currently, most authors agree about their primary origin ex novo from ectopic thyroid tissue in the cyst. In most cases the diagnosis of thyroglossal duct carcinoma (TDC) is not made until histopathological examination has been performed on a resected cyst without any suspected clinical sign of malignancy. The definition of the correct surgical treatment for these carcinomas is still controversial; most authors maintain that resection of a TDC with the Sistrunk procedure can be considered oncologi-cally adequate when dealing with a differentiated carcinoma without extracapsular invasion and/or lymph node metastases and with a normal thyroid.

We present two cases of papillary thyroid carcinoma identified after resection of a thyroglossal cyst according to the Sistrunk procedure and managed with different surgical approaches according to the different sites of the tumors. In addition, we discuss appropriate therapeutic strategies in light of the most recent data in the literature.

Squamous cell carcinoma arising from a thyroglossal duct cyst: A case report and review of the literature

Objectives:

Squamous cell carcinoma in a thyroglossal duct cyst is exceedingly rare with only 26 reported cases in the literature so far, which only account for 6% of the patients.

Methods:

We report a unique case of squamous cell carcinoma arising from a thyroglossal duct cyst in a 49-year-old male who was primarily diagnosed as a thyroglossal duct cyst with inflammation. The patient underwent Sistrunk procedure with wide local excision and radiation therapy as well as chemotherapy post-operatively and had no evidence of recurrence or metastasis for 24 months. In addition, we reviewed the relevant literatures.

Results:

Whether squamous cell carcinoma actually arises from thyroglossal duct cyst is still controversial; however, carcinoma originating from metaplasia of columnar and squamous epithelium in thyroglossal duct cyst has been well accepted. The gold-standard diagnostic method is fine needle aspiration biopsy with ultrasound guidance. Sistrunk procedure alone or with wide excision is likely to be beneficial. Neck dissection is necessary in patients with positive cervical lymphadenopathy. Radiation therapy and chemotherapy have not yet been clearly defined.

Conclusion:

Squamous cell carcinoma arising from thyroglossal duct cyst is really a rare disease, whose origin, treatments and prognosis still remain uncertain. These are solely based on case reports, case series and expert opinions. Hence, more investigations about squamous cell carcinoma will be conducted in the near future.

Papillary Thyroid Carcinoma within Thyroglossal Duct Cyst: Case Series and Literature Review

Introduction  Thyroglossal duct cyst (TGDC) is the most common congenital anomaly of the neck, and approximately 7% of all the adult population presents it. Ectopic thyroid tissue is found in the thyroglossal duct cyst wall in up to 65% of cases. This thyroid tissue has the potential to develop some type of malignancy, the most common of which is the papillary carcinoma of the thyroid. There are just over 270 cases of thyroglossal duct cyst malignancy reported in the literature.

Objectives  We aimed to study our population of patients in order to identify cases with thyroglossal duct cyst malignancy.

Methods  A retrospective chart review was conducted in the section of otolaryngology/head and neck surgery at a hospital in Karachi, Pakistan, from January of 2004 to December of 2014 on patients with the diagnosis of thyroglossal duct cyst.

Results  Fifty-eight patients were diagnosed with TGDC, two of whom also presented with thyroglossal duct cyst carcinoma. Both patients revealed papillary thyroid carcinoma on histopathology. Case 1 had an open biopsy before undergoing definitive surgery. Both patients underwent subsequent total thyroidectomy after Sistrunk procedure, and case 2 had selective neck dissection revealing lymph node metastasis.

Conclusion  Thyroglossal duct cyst carcinoma is a rare finding that comes as a surprise to both the patient and the surgeon. We report 2 out of 58 cases diagnosed with thyroglossal duct cyst carcinoma.

Can Medullary Thyroid Carcinoma Arise in Thyroglossal Duct Cysts? A Search for Parafollicular C-cells in 41 Resected Cases

Thyroglossal duct cysts (TGDCs) are present in ~7% of adults and develop from the midline migratory tract between the foramen cecum and anatomic location of the thyroid. Thyroid tissue can be identified in 2/3 of TGDCs, and up to 1% develop associated malignancy, 90% of which are papillary thyroid carcinoma. Cases of follicular and anaplastic carcinoma have been documented, but there are no reports of medullary thyroid carcinoma arising in a TGDC. This is presumably due to the distinct embryologic origin of parafollicular C-cells, from which medullary carcinoma arises. The goal of this study is to determine whether parafollicular C-cells are present in TGDCs. H&E sections from 41 TGDC cases were examined for thyroid tissue, thyroglossal duct remnants, ultimobranchial remnants, and parafollicular C-cells. Immunohistochemistry was performed for TTF-1 and calcitonin. Eighty three percent (34/41) of cases contained thyroid tissue on H&E and by TTF-1. No cases (0/41) had ultimobranchial remnants or parafollicular C-cells on H&E or with calcitonin. One case of papillary carcinoma in a TGDC was identified. These cases illustrate that although TGDCs often contain thyroid tissue, parafollicular C-cells are absent. Therefore, unlike other thyroid neoplasms, there is no evidence to support the possibility of medullary carcinoma arising in a TGDC.

Thyroglossal Duct Cyst Carcinomas in Pediatric Patients: Report of Two Cases with a Comprehensive Literature Review

Thyroglossal duct cyst (TGDC) carcinomas are rarely encountered in the pediatric population. The clinical behavior of these tumors in the pediatric setting is unclear and management is not well defined. Two cases of pediatric thyroglossal duct cyst carcinoma were identified in a review of all thyroglossal duct cysts diagnosed over a ten year period. These two cases were analyzed along with 57 cases of thyroglossal duct cyst carcinoma affecting patients less than 21 years of age compiled from the English literature. Fifty-nine patients (36 females, 23 males) aged 6-20 years (mean 15.0 years) were identified. All presented with an anterior midline neck mass, which was typically mobile and non-tender. The average tumor size was 2.6 cm. Histologically, all tumors were papillary thyroid carcinomas arising in a background of a thyroglossal duct cyst. The tumors exhibited a papillary, follicular, or mixed architecture with classical papillary thyroid carcinoma nuclear features. Soft tissue extension was present in 16 cases. All patients were managed surgically with a Sistrunk procedure, with additional thyroidectomy performed in 29 patients, combined with a lymph node dissection (n = 15), or a Sistrunk and lymph node dissection (n = 5). All patients were stage I at presentation, with 11 showing lymph node metastases. Postoperative radioactive iodine was employed in 20 patients. A papillary carcinoma of the thyroid gland was reported in four of the patients who had concurrent/subsequent thyroidectomies. Recurrences were reported in four patients, with distant metastases in one patient, who died of disease (13 months). Follow up data was available for 45 patients, with an overall mean follow-up of 54.5 months. All patients were alive, with the exception of one who died with disease. TGDC carcinomas in pediatric patients is associated with a good overall prognosis, best managed by Sistrunk procedure alone, with selected lymph node dissection if clinically indicated.

Thyroglossal Duct Cyst Carcinomas: A Clinicopathologic Series of 22 Cases with Staging Recommendations

Carcinomas arising from thyroglossal duct remnant cysts (TGDCs) are rare, without well-defined management and staging criteria. All TGDCs (n = 685) diagnosed between 2005 and 2015 were retrospectively reviewed, with 22 carcinomas identified (3.2 % incidence). Twenty-two patients (17 females, 5 males), aged 12-64 years (mean 39.9 years; median 39 years) were identified. An anterior, superior midline neck mass was the presenting symptom in all patients. A cancer diagnosis [all papillary thyroid carcinoma (PTC)] was made after the Sistrunk procedure (SP), with a Bethesda Category V or VI classification preoperatively by fine needle aspiration in 5 of 12 cases tested. A SP was performed in all patients, with total thyroidectomy concurrently (n = 4) or subsequently (n = 12). A selected neck dissection was performed in 5 patients, with metastases found in 3. Of the patients who had a thyroidectomy, synchronous PTC was identified in 6 (thus, 6 of 22 patients had synchronous thyroid gland primaries). This supports an origin from extra-thyroidal remnants (cyst origin) rather than metastatic tumor from a thyroid gland primary. Follow-up radioactive iodine therapy was performed in 13 patients. Metastatic disease to local lymph nodes 57 months after presentation was seen in 1 patient, with all others alive and disease free (mean 3.8 years; range 0.4-10.8 years). The TGDCs ranged from 0.8 to 5 cm (mean 2.3 cm), while the PTCs ranged from 0.1 to 3.8 cm (mean 1.4 cm). All of the tumors were classical PTC, showing a sclerotic and infiltrative pattern, with a capsule present in 11. Lymphovascular invasion was detected in 11; margins were positive in 6. Using currently defined criteria, the patients were separated into AJCC stage group I (n = 21) or II (n = 1). However, if extension into the adipose tissue (n = 11), skeletal muscle (n = 10), or perineural/perivascular tissues (n = 10) were used to stage the patients, interpreted to represent the equivalent of "extrathyroidal extension" (n = 13) as defined for thyroid gland primaries, there would be 15 group I and 7 group III cases. All seven group III patients were ≥45 years. Three of four patients with lymph node metastasis also showed soft tissue extension. In conclusion, TGDC carcinomas (TGDCCa) are uncommon, with all classical PTC. For "microcarcinomas" (≤1 cm), conservative management can be used for patients <45 years (i.e., Sistrunk procedure only); for >1 cm tumors, and due to the high incidence of concurrent papillary carcinoma and higher stage at presentation in older patients, completion thyroidectomy is recommended for patients ≥45 years. Thus, even though a good prognosis can be expected for PTC developing in TGDCs, staging is advocated to more appropriately match therapeutic interventions.

Adult Thyroglossal Duct Carcinoma of Thyroid Epithelial Origin: A Retrospective Observational Study

Thyroglossal duct or cyst carcinoma (TGDCCa) is uncommon. Current treatments follow those of thyroid cancer but controversy exists over the extent of thyroid and lymph node surgery. Our aim was to study the presentation, treatment strategies and clinical outcomes in patients presenting with TGDCCa. Of 637 patients diagnosed with thyroid cancer over 15-years, 4 patients (0.6 %) with TGDCCa were identified. Two patients were diagnosed outside this time period. Details of demographics, presentation, diagnosis, management and outcomes of all 6 patients were reviewed. 5 females and 1 male with a median (range) age of 41 (21-70) years were treated for TGDCCa. Five patients were diagnosed after initial surgery for thyroglossal cyst-cyst excision (n = 2) and Sistrunk's procedure (n = 3). This was followed by a total thyroidectomy (TT) in 4 of these patients. One patient underwent Sistrunk's operation, total thyroidectomy and central neck dissection at the first operation. I131 therapy was used in patients who had TT. Three patients had additional tumour foci in the thyroid. However, lymph node recurrence occurred in 2 patients at 6 and 16 months. At a median follow up of 55 months, all 6 patients were disease free. All patients had papillary TGDCCa and did well with conventional treatment as for thyroid cancer. The extent of treatment required is debatable as half the patients had additional thyroid foci and no patient had clinically or radiologically involved lymph nodes at presentation. A systematic review of published cases will help summarise the existing knowledge base.

The extent of surgery in thyroglossal cyst carcinoma

PURPOSE

The optimal management of thyroglossal cyst carcinoma, particularly the extent of surgery required is controversial. The aim of this study was to evaluate the need for routinely adding total thyroidectomy to Sistrunk's operation in the management of this condition.

METHODS

The clinical records of 19 patients with a diagnosis of thyroglossal cyst carcinoma encountered in an 11-year period (2004-2015) were reviewed. All patients underwent total thyroidectomy in addition to Sistrunk's procedure. The rate of concomitant thyroglossal cyst and thyroid carcinomas was calculated and cancers were staged according to the AJCC-TNM staging system. Patients were divided into two groups: those with thyroglossal cyst carcinoma only (group A) and those with a synchronous or metachronous thyroid carcinoma as well (group B). The need for radioactive iodine ablation in group A was assessed. The ability to omit total thyroidectomy based on thyroglossal cancer size and a negative thyroid ultrasound was also evaluated.

RESULTS

The rate of concomitant thyroid cancer was 63.2 % (12/19). Based on stage, three out of the seven patients in group A required radioactive iodine ablation. Total thyroidectomy was ultimately justifiable in 78.9 % (15/19) of cases. Omitting total thyroidectomy in T1 thyroglossal cyst cancers or based on a sonographically normal thyroid was associated with a 43 % risk of missing thyroid malignancy.

CONCLUSION

The routine addition of total thyroidectomy to Sistrunk's procedure seems to be appropriate for comprehensive loco-regional control especially that selecting a subset of patients in which it could be omitted is a difficult task.

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 %).

Risk-reduction surgery in pediatric surgical oncology: A perspective

OBJECTIVE

A small percentage of pediatric solid cancers arise as a result of clearly identified inherited predisposition syndromes and nongenetic lesions. Evidence supports preemptive surgery for children with genetic [multiple endocrine neoplasia type 2 (MEN2), familial adenomatous polyposis syndrome (FAP), hereditary nonpolyposis colorectal cancer (HNPCC), and hereditary diffuse gastric cancer (HDGC) and nongenetic [thyroglossal duct cysts (TGDC), congenital pulmonary airway malformations (CPAM), alimentary tract duplication cysts (ATDC), and congenital choledochal cysts (CCC)] developmental anomalies. Our aim was to explore the utility of risk reduction surgery to treat and prevent cancer in children.

METHODS

A systematic review of the available peer-reviewed literature on PubMed was performed using a PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) search strategy, where possible. Search items included "risk reduction surgery", "hereditary cancer predisposition syndrome", "multiple endocrine neoplasia type 2", "familial adenomatous polyposis", "hereditary nonpolyposis colorectal cancer", "hereditary diffuse gastric cancer", "thyroglossal duct cysts", congenital pulmonary airway malformations", "alimentary tract duplication cysts", "malignant transformation", and "guidelines".

RESULTS

We identified 67 articles that met the inclusion criteria describing the indications for prophylactic surgery in surgical oncology. For the genetic predisposition syndromes, 7 studies were related to professional endorsed guidelines, 7 were related to surgery for MEN2, 11 were related to colectomy for FAP, 6 were related to colectomy for HNPCC, and 12 related to gastrectomy for HDGC. Articles for the nongenetic lesions included 5 for techniques related to TGDC resection, 9 for surgery for CPAMs, and 10 for resection of ATDCs. Guidelines and strategies varied significantly especially related to the extent and timing of surgical intervention; the exception was for the timing of thyroidectomy in children with MEN2.

CONCLUSION

Current evidence supporting prophylactic surgery in the management of pediatric cancer predisposition syndromes and nongenetic lesions is best delineated for thyroidectomy to prevent medullary thyroid cancer in children with MEN2 (Strength of Recommendation Grade B/C). Despite the lack of pediatric specific evidence-based recommendations regarding the appropriate extent and timing for risk-reduction surgery for FAP, HNPCC, HDGC and nongenetic anomalies, our review represents an opportunity towards understanding the postgenomic development of these lesions and provides current indications and techniques for preemptive cancer prevention surgery in children.

Differentiated thyroid carcinoma in lingual thyroid

The lingual thyroid is the most common form of thyroid ectopy. The ectopic tissue may display any disease affecting the thyroid, including malignancies, which have an estimated incidence of less than 1%. To date only 51 cases of lingual thyroid cancer were reported. Analogously to what observed in orthotopic thyroid, papillary carcinoma is the predominant histotype in lingual thyroid carcinoma. The higher frequency of lingual follicular thyroid carcinoma previously reported is possibly related to histological misclassification in some early reports, prior to the standardization of histological typing of differentiated thyroid carcinomas. Nonetheless, the frequency of the follicular histotype is not negligible, accounting for about one-third of the reported cases. Both natural history and prognosis of lingual thyroid carcinoma are poorly known, likely because of the rarity of the disease and the heterogeneity in the therapeutic approach. However, among the cases more recently reported, surgical excision of the mass, either alone or followed by radioiodine ablation, is the first-line approach, with only two cases treated by radioiodine alone. The nonsignificant rate of neoplastic transformation in lingual thyroid should encourage efforts to obtain a widely accepted consensus for the management of this rare condition, along with standardization of either diagnostic or therapeutic handling of malignancies arising in ectopic thyroid.

Pathology of thyroglossal duct: an institutional experience

Thyroglossal duct (TGD) is a developmental anomaly in which a remnant of the thyroid anlage is left in the neck during its descent from the foramen cecum of tongue to final pretracheal position. A persistent duct can lead to thyroglossal duct cyst (TGDC). Histologically, TGDC contains an epithelial lining of squamous or pseudostratified ciliated columnar epithelium and ectopic thyroid gland tissue in the duct wall. TGD-associated malignancy is rare, and the majority is papillary thyroid carcinoma (PTC). A total of 242 patients with a diagnosis of TGD-associated lesions were identified in our institute. Two hundred and seventeen cases were diagnosed as TGDC. Sixty-eight of 217 (31.3 %) cases of TGDC had ectopic thyroid tissue in the cystic wall. Thirty-nine cases had preoperative fine needle aspiration (FNA). Of these cases, 37 of 39 (94.9 %) demonstrated macrophages and 19 (48.7 %) also showed cells of squamous and/or columnar epithelial lining. Only two cases showed rare thyroid follicular cells. Thyroid carcinoma was identified in 18 of 242 (7.4 %) cases. All cases were diagnosed as PTC including 12 cases of classic PTC (66.7 %), 3 cases of follicular variant (16.7 %), 2 cases of tall cell variant (11.1 %), and 1 case of classic PTC with focal tall cell features (5.6 %). Nine cases had TGD component (either epithelial lining cysts or ectopic thyroid tissue). Ten patients also underwent total thyroidectomy (67 %). Of these patients, four had no tumor and one had an incidental medullary carcinoma. Five of 10 (50 %) cases had incidental PTC with a size range of 0.1-0.3 cm. Five patients had follow-up by imaging studies; no suspicious or nodular lesions were found in the thyroid. In conclusion, we report an institutional case cohort of 242 patients with TGD-associated lesions, including 217 TGDC and 18 cases of PTC. Only seven cases fulfilled the diagnostic criteria of TGD-associated PTC, i.e., the presence of components of TGD and a normal thyroid. In the remaining 11 cases, we could not differentiate with certainty between pyramidal primary thyroid PTC/Delphian node metastasis or TGD-associated PTC.

Papillary carcinoma in median aberrant thyroid (ectopic) - case report

Median ectopic thyroid may be encountered anywhere from the foramen caecum to the diaphragm. Non lingual median aberrant thyroid (incomplete descent) usually found in the infrahyoid region and malignant transformation in this ectopic thyroid tissue is very rare. We report an extremely rare case of papillary carcinoma in non lingual median aberrant thyroid in a 25-year-old female. The differentiation between a carcinoma arising in the median ectopic thyroid tissue and a metastatic papillary carcinoma from an occult primary in the main thyroid gland is also discussed.

Thyroglossal duct remnant carcinoma: beyond the Sistrunk procedure

Thyroglossal duct remnants (TGDRs) account for more than 70% of anterior neck masses in children and 7% in adults; however, cancer is identified in only 1-2% of the cases. The diagnosis of a TGDR is based on clinical manifestation of a painless, anterior neck swelling, which elevates with swallowing. Cytological evaluation with fine needle aspiration and biopsy (FNAB) may facilitate the pre-operative diagnosis of malignancy, as the majority of TGDR cancers are of papillary histotype. The recommended treatment for symptomatic TGDR without evidence of malignancy is a Sistrunk procedure, which entails en bloc resection of the remnant and the mid-portion of the hyoid bone. The optimal management of patients with diagnosed malignancy is controversial, and in the past, additional total thyroidectomy was recommended for all of these patients. The purpose of this study is to review the literature on TGDR carcinomas, present the evidence on the available diagnostic tools, identify the surgical and post-operative medical management strategies, discuss current controversies, and conclude with a management algorithm.

An adolescent with a rare midline neck tumor: thyroid carcinoma in a thyroglossal duct cyst

Occurrence of malignancy in a thyroglossal duct cyst (TDC) in children and adolescents is very rare, preoperative diagnosis is a challenge, and appropriate management is still debated. We report a 19-year-old male patient referred for a midline neck mass diagnosed as an atypical TDC after initial and subsequent investigations. Ultrasound-guided fine-needle aspiration (FNA) of the mass was diagnostic for papillary thyroid carcinoma. Sistrunk procedure and total thyroidectomy were performed. Histologic analysis confirmed the presence of papillary thyroid carcinoma within TDC, infiltrating surrounding soft tissues. Postoperatively, radioiodine ablation treatment was administered, followed by TSH suppression therapy.

Thyroglossal duct cyst cancer most likely arises from a thyroid gland remnant

Thyroglossal duct cancer is a rare entity, occurring in 1.5 % of all thyroglossal duct cysts (TDC). A definitive consensus about its neoplastic origin has not been established as two contrasting theories exist, one proposing an origin in extra-thyroid remnants and the other a metastatic localization of a primary thyroid cancer. We compare morphological and molecular characteristics of both thyroglossal and thyroid carcinomas in a case series from our institute. We evaluated histology of 80 TDC. In 12 cases, prior cytological evaluation had been performed by liquid-based cytology (LBC). The BRAF gene was examined for mutations, and the histology of both thyroglossal duct and synchronous thyroid carcinoma was reevaluated. In 9 out of 80 (11 %) TDC cases, a papillary thyroid cancer (PTC) was diagnosed. In five out of nine (56 %) thyroglossal carcinomas, a synchronous thyroid cancer was diagnosed: 3 PTC and 2 follicular variant PTC (FVPC). In five thyroglossal carcinomas, mutated BRAF (V600E) was found, three in PTC and in thyroglossal as well as in the synchronous tumor in the thyroid. All the patients are in a disease-free status and still alive. Our results suggest that the majority of thyroglossal carcinomas most likely develop as a primary malignancy from a thyroid remnant. Neither the presence of V600E BRAF mutations nor that of a well-differentiated thyroid carcinoma changed the outcome or disease-free survival. We suggest that a diagnosis of thyroglossal carcinoma should be followed by a detailed evaluation of the thyroid gland. In the absence of clinical and radiological thyroid alterations, follow-up as for thyroid cancer is the correct management.

Thyroglossal duct papillary carcinoma in a 15-year old female and review of pediatric cases of thyroglossal duct carcinoma

Thyroglossal duct carcinoma is rare, occurring in approximately 1% of thyroglossal duct cysts. Excluding this case report there have been 25 cases of adolescent thyroglossal duct carcinoma reported in the English literature thus far. Most of the pathology reported has been papillary or follicular carcinoma, leading to the question of whether or not to perform concurrent thyroidectomy. Based on our review of the pediatric cases of thyroglossal duct carcinoma we elected not to perform a concurrent thyroidectomy and recommend close follow-up to monitor for signs of future thyroid involvement.

Papillary carcinoma arising in thyroglossal duct cyst in the lateral neck

The patient presented here, a 74-year-old female, had a 3-year history of a gradually enlarging painless nodule in the right submental lateral region of the neck. A neck CT scan showed a well-demarcated cystic lesion, measuring 25mm in diameter, but without any definite evidence of neoplastic foci in the lymph nodes, thyroid gland, or lung. Clinicians first interpreted it as branchial cleft cyst, and a cystectomy was performed. Gross examination revealed a unilocular cystic lesion filled with yellowish clear fluids, containing a markedly thinned fibrous wall with smooth inner surface, partly coexisting with tiny solid and papillary-like components. On microscopic examination, the cystic tumor was lined by mono-layered ciliated columnar or metaplastic stratified squamous epithelium with underlying ectopic thyroid follicles or lymphocytic infiltrate, reminiscent of thyroglossal duct cyst (TDC), partly adjacent to the compressed lymph node tissue. Its solid parts were composed of a proliferation of atypical cuboidal to columnar epithelial cells with occasional nuclear grooves or intranuclear inclusions, arranged in a papillary growth pattern with supporting delicate fibrovascular cores. Immunohistochemically, these atypical cells were positive for thyroid transcription factor 1, thyroglobulin, and cytokeratin 19. Therefore, we finally made a diagnosis of papillary carcinoma (PC) arising in TDC in the lateral neck. Although metastatic thyroid PC of cervical lymph node was an important differential diagnosis owing to various overlapping clinicopathological features, coexistent benign lining epithelium or thyroid follicles, a histological hallmark of TDC, were present in the current case.

Papillary carcinoma arising from thyroglossal duct cyst with thyroid and lateral neck metastasis

INTRODUCTION

Thyroglossal duct carcinomas (TGDC) are rare, with approximately 274 reported cases since the first report in 1915. The prevalence of carcinomas in surgically removed thyroglossal duct cyst (TGD) is less than 1%. The usual recommended treatment for this condition is the Sistrunk operation, but controversies remain regarding the need for total or partial thyroidectomy.

PRESENTATION OF CASE

A 28-year-old woman was admitted to our hospital with the symptoms of painless midline neck swelling and growing mass. A preoperative computed tomography (CT) showed a 4cm sized heterogeneous mass at the infrahyoid anterior neck. Ultrasonography of the neck additionally showed suspicious metastatic lymph node at right level VI, both level VI. The patient underwent a Sistrunk operation. The frozen section revealed papillary carcinoma arising from TGDC and also revealed metastatic papillary carcinoma in the right thyroid, at right level III and level VI. Total thyroidectomy, right modified radical neck dissection and central neck dissection were performed. The thyroid gland and TGD were confirmed papillary carcinoma. The dissected neck lymph nodes revealed metastatic papillary carcinoma.

DISCUSSION

The usual recommended treatment for TGD is the Sistrunk procedure. There is controversy regarding whether total or partial thyroidectomy should be performed.

CONCLUSION

Physicians should be aware of extended operation, including thyroidectomy and/or neck node dissection for TGDC with metastatic lesion of thyroid and neck node.

Delayed diagnosis of hypothyroidism following excision of a thyroglossal duct cyst

Thyroglossal duct cysts can contain ectopic thyroid tissue, and in some cases this tissue may be the only functional thyroid gland. We present the case of a 6-year-old girl with delayed diagnosis of iatrogenic hypothyroidism that developed after excision of a thyroglossal duct cyst.

Robot-assisted Sistrunk's operation, total thyroidectomy, and neck dissection via a transaxillary and retroauricular (TARA) approach in papillary carcinoma arising in thyroglossal duct cyst and thyroid gland

BACKGROUND

Carcinomas arising in the thyroglossal duct cysts are rare, accounting only for about 0.7-1.5 % of all thyroglossal duct cysts. Synchronous occurrence of thyroglossal duct carcinoma and thyroid carcinoma is reported to be even rarer. Traditionally, surgical treatments of such coexisting thyroglossal duct cyst carcinoma (TGDCa) and papillary thyroid carcinoma (PTC) were typically performed through a single transverse or double incisions on the overlying skin. A longer, extended cervical incision might be required if neck dissection is necessary. Though this method provides the operator with the optimal surgical view, the detrimental cosmetic effect on the patient of possessing a scar cannot be avoided, despite the effort of the surgeon to camouflage the scar by placing the incision in natural skin creases. Recently, the authors have previously reported the feasibility of robot-assisted neck dissections via a transaxillary and retroauricular ("TARA") approach or modified face-lift approach in early head and neck cancers. On the basis of the forementioned surgical technique, we demonstrate our novel technique for robot-assisted Sistrunk's operation via retroauricular approach as well as robot-assisted neck dissection with total thyroidectomy via transaxillary approach.

METHODS

This is a case presentation of a 22-year-old woman with synchronous TGDCa and PTC with minimal lymph node metastasis who underwent resection of TGDCa and total thyroidectomy with left neck level III and IV lymph node dissection as well as central compartment lymph node dissection (CCND) via TARA approach with a robotic surgery system after approval from the institutional review board at Severance Hospital, Yonsei University College of Medicine. The incision was just like the TARA approach in head and neck cancer, which has been reported by our institute. The operation was proceeded as follows. First, excision of the TGDCa through the retroauricular incision was done followed by total thyroidectomy with CCND via transaxillary approach. Finally, neck dissection of left level III, IV was conducted via transaxillary approach. The da Vinci surgical system (Intuitive Surgical, Sunnyvale, CA) was introduced via retroauricular or transaxillary port. A 30° dual-channel endoscope was used, and the two instrument arms were equipped with 5 mm Maryland forceps and a 5 mm spatula monopolar cautery for TGDCa excision via retroauricular approach. When conducting total thyroidectomy and neck dissection via transaxillary approach, three instrument arms were utilized, each equipped with 5 mm Maryland forceps, ProGrasp forceps and a 5 mm spatula monopolar cautery or Harmonic curved shears. The rest of the surgery was completed with the robotic system (see Video).

RESULTS

The operative procedure was successfully completed utilizing the robotic surgical system with no conversion to open surgery. The operation time for TGDCa excision was 97 min, including the time for skin flap elevation (15 min), setting up the robotic system (5 min), and console time using the robotic system (77 min). Also, the total operation time for the consecutive total thyroidectomy with CCND and level III, IV dissection was 142 min including the time for skin flap elevation (27 min), setting up the robotic system (3 min), and console time using the robotic system (112 min). There were no intraoperative complications. The retroauricular approach for the removal of the TGDCa allowed for an excellent magnified surgical view revealing important structures of the local anatomy. It also created sufficient space for the cutting of the relevant portion of the hyoid bone. Handling of the robotic instruments through the incision was technically feasible and safe without any mutual collisions throughout the operation. The patient's postoperative parathyroid hormone (PTH) level was within normal range and functions of her both vocal cords were intact. The histopathologic results of the specimens revealed thyroglossal duct cyst with internal papillary carcinoma measuring 1.1 cm with infiltrative tumor margins and papillary microcarcinoma measuring 0.9 cm within the left thyroid lobe with extrathyroidal soft tissue extension. There was no evidence of tumor in the right lobe and the pyramidal lobe of the thyroid gland. As for the lymph nodes resected, 7 out of 9 paratracheal nodes and 2 out of 7 left level III, IV nodes revealed metastatic carcinomas. The patient was discharged on the 8th day after the operation with no complications. The patient was extremely satisfied with the cosmetic results. The patient has received high-dose radioiodine ablation (RAI) therapy and is currently doing well with no evidence of recurrence.

DISCUSSION

Although there is still a great deal of controversy regarding the treatment of TGDCa, there is little debate that for the cases of synchronous TGDCa and PTC, total thyroidectomy in addition to the Sistrunk procedure must be performed. As for the patient in our case where left level IV lymph node metastasis was detected under preoperative ultrasonography (USG), if the usual method of surgical procedure was to be selected, double incisions or a single extended transverse incision must be adopted for the Sistrunk's operation and total thyroidectomy with lateral neck dissection. The conventional method to remove neck masses was to do so by placing an incision on the overlying skin. This 'open' approach to viewing the lesion has an advantage of providing the operator with the best surgical view, but the recognizable surgical scar that results from the surgery can be displeasing for patients. Therefore the surgeon can try to make a small incision and camouflage the scar by placing the incision in natural skin creases, yet the cosmetic results can still be displeasing for the patient due to its visibility and permanence. This can be an even greater problem if the patient is young and an active member of his/her society and if the lesion is benign or low-grade malignancy which can be simply dissected and excised. Therefore it is the surgeon's best interest to perform an operation successfully with a 'least obvious' or 'hidden' scar whenever possible. Accordingly, we have adopted a novel approach, the transaxillary and retroauricular approach, in view of our increasing surgical experience with various indications such as submandibular gland (SMG) resections and neck dissections in head and neck cancer or thyroid papillary carcinoma. Some investigators have demonstrated that robot-assisted neck dissections performed on patients with thyroid cancer and lateral neck node metastasis are feasible and safe. We conducted total thyroidectomy with bilateral CCND and level III and IV dissection using the same approach. Although the technical feasibility and safety of neck dissection or SMG resection via retroauricular approach has already been reported previously at our institute, Sistrunk's operation via retroauricular approach will be challenging. In spite of that, we were able to demonstrate successfully Sistrunk's operation including the hyoid bone resection through the retroauricular approach. There are however, certain areas of potential difficulties which must be considered with caution during the operation procedure. First, when removing the TGDCa through the retroauricular port, identification of the ipsilateral hyoid bone is primarily important and it is also crucial that dissection along the capsule must be done carefully so as not to rupture the tumor. It is essential that sufficient working space must be created for the comfortable movement of the robotic arms through the retroauricular port and in order to do so, sufficient skin flap elevation in both superior and inferior directions must be performed. It is necessary to elevate the superior skin flap up to the level of the inferior border of the mandible but during this process, the platysma muscle must be identified and meticulous dissection along the subplatysmal plane must be carried out so as not to damage the marginal mandibular branch of the facial nerve. Another area of potential pitfalls concerns the total thyroidectomy with neck dissection through the transaxillary port. Sufficient amount of working space must be secured in order to perform comfortably the contralateral thyroidectomy and neck dissection and in order to do so, skin flap elevation must be done at least 2 cm further based on the ipsilateral omohyoid muscle and the contralateral thyroid gland must be adequately exposed. Using the robotic surgical system in removing the thyroglossal duct cyst, the free movement of wristed instrumentation through the retroauricular incision allowed for efficient dissection and easy handling of the tissue. In this particular case we could not identify the tract beyond the hyoid and up to the foramen cecum, but we anticipate that there would be no technical problems of dissection and excision had it been so. To our knowledge, Sistrunk's operation and total thyroidectomy with lateral neck dissection via TARA approach utilizing the robotic surgical system has never been attempted before. It has some advantages over the conventional surgery in terms of cosmesis. However, careful consideration in selecting appropriate cases is required and prospective trials should be conducted to recognize long-term outcomes and to overcome potential limitations.

Synchronous occurrence of papillary carcinoma in the thyroid gland and thyroglossal duct in an adolescent with congenital hypothyroidism

Thyroid carcinoma (TC) combined with congenital hypothyroidism is rare. The synchronous occurrence of these two conditions is even rarer. We describe a patient with congenital hypothyroidism in whom hyperthyroglobulinemia and nodules developed despite adequate replacement therapy. Papillary TC was detected at age 19 years. Postoperative diagnostic scintigraphy showed increased uptake in the thyroglossal duct region. Repetitive imaging of the thyroid gland can be useful in the early detection of TC in patients with congenital hypothyroidism. Moreover, this rare situation can be complicated by a synchronous thyroglossal duct carcinoma. Thyroglossal duct carcinoma can be detected if diagnostic scintigraphy is performed after total thyroidectomy.

Surgical management of primary thyroid carcinoma arising in thyroglossal duct cyst: an experience of a single institution in Serbia

Thyroglossal duct cyst (TDC) carcinoma is a comparable rare entity and treatment strategies have not been standardized. Here, we report a favorable outcome of TDC carcinoma patients based on our therapeutic strategy. Twelve patients with TDC carcinoma treated in our department from 1986 to 2012 were enrolled. Ten patients underwent Sistrunk's procedure in other institutions and referred to our institution for re-operation after the diagnosis of TDC carcinoma and the remaining two underwent initial surgery in our institution. Eleven patients were diagnosed as papillary and one as follicular carcinoma originating from TDC. We performed total thyroidectomy for 11, and limited thyroidectomy for one patient. Three patients (25%) had carcinoma lesions in the thyroid. We routinely dissected level I bilaterally and 6 of 11 patients (55%) with papillary carcinoma-type TDC carcinoma had metastasis. Level II/III nodes were biopsied and if positive, we performed level II-IV dissection. Of the 5 patients positive for level II/III, 2 were also positive for level IV. For the 3 patients with synchronous carcinoma in the thyroid, we performed level VI dissection and two had metastasis in this level. To date, 1 patient showed a recurrence to the lung, but none of the patients in our series died of carcinoma. For surgery of TDC carcinoma, Sistrunk's procedure, total thyroidectomy with level I dissection is mandatory. Whether level II-IV dissection is performed depends on pathology of biopsied level II/III nodes. Level VI dissection is also recommended especially when carcinoma lesions are pre/intra operatively detected in the thyroid.

Utilization of three-dimensional computed tomography for papillary thyroid carcinoma arising in the thyroglossal duct remnant: report of a case

This report presents a rare and interesting case of papillary thyroid carcinoma arising in a thyroglossal duct remnant (TDR) that was diagnosed by three-dimensional computed tomography (3DCT). The patient, a 61-year-old woman, presented with a painless mass in the anterior suprahyoid region that had gradually enlarged over a 2-year period. Three-dimensional CT successfully revealed the thyroglossal duct (TD) descending from the tumor to the isthmus of the thyroid. An ultrasonography-guided fine-needle aspiration biopsy of the tumor was positive for carcinoma. A total thyroidectomy was performed in addition to the Sistrunk procedure. The histological findings indicated papillary thyroid carcinoma arising in the TDR and thyroid papillary microcarcinoma in the left thyroid lobe. The patient underwent radioactive iodine ablation and thyroid suppression therapy. This is apparently the first reported case of papillary thyroid carcinoma arising in a TDR evaluated using 3DCT. Three-dimensional CT was able to clarify the relative locations of the tumor, TD, and thyroid in the present case, and visualization of the TD allowed a definitive preoperative diagnosis that would not otherwise have been possible using conventional imaging techniques. This case suggests that 3DCT may therefore play an important role in providing definitive information on patients with anterior neck masses that are difficult to diagnose.

Ectopic thyroid papillary carcinoma presenting as bilateral neck masses

Ectopic thyroid papillary carcinoma presenting as bilateral neck lymph nodes metastasis is very rare. We report a 42-year-old male with midline submental ectopic thyroid papillary carcinoma presenting as bilateral progressively growing neck masses for 3 months. A right neck mass excisional biopsy was carried out and the pathology revealed metastatic papillary carcinoma. Total thyroidectomy, submental "ectopic thyroid tissue" excision and bilateral neck dissection were then performed. No primary lesions were found in the thyroid gland. Therefore, the differential diagnosis of bilateral neck masses should include cervical metastasis of ectopic papillary carcinoma.

Papilläres Schilddrüsenkarzinom in einer medianen Halszyste

Thyroglossal duct cysts are the most common anomaly in thyroid development. The occurrence of carcinoma in a cyst is reported to be about 1% of cases. Histopathological examinations reveal a papillary thyroid carcinoma in about 94% of these. We report the case of 38-year-old female having a massive, cervical cystic mass over a period of 18 months. An ectopic papillary thyroid carcinoma was diagnosed. A total thyoidectomy and bilateral neck dissection were performed. This revealed a small thyroid carcinoma and three positive lymphatic nodes. Whether the cystic carcinoma is the primary or a metastasis of the thyroid carcinomais discussed.

High rate of multifocality and occult lymph node metastases in papillary thyroid carcinoma arising in thyroglossal duct cysts

BACKGROUND

The incidence of cancer in thyroglossal duct cysts (TDC) is low and management is controversial. The objective was to report the rate of multifocality, lymph node metastases, and long-term results for TDC carcinomas in adults.

MATERIALS AND METHODS

Files from 1979 to 2008 were reviewed for tumor stage, multifocality in the lobes, lymph node metastases, treatment, and follow-up.

RESULTS

A total of 18 patients (13 females, 5 males, average age 41.5 years) were treated for papillary carcinoma arising in a TDC. Of these, 15 underwent total thyroidectomy, 1 isthmusectomy and 2 a Sistrunk procedure only. Also, 16 patients underwent neck dissection of the central and/or lateral compartments. Tumors were staged pT1 (n = 15), pT3 (n = 3), pN0 (n = 4), pN1a (n = 3), pN1b (n = 9), Nx (n = 2), M0 (n = 17), and M1 (n = 1, lung metastases). Tumor foci were found in the thyroid lobes in 9 of 16 patients(56%). Lymph node metastases were found in 12 of 16 (75%). Nodes were positive in 6 of 15 central compartment dissections (40%) and in 9 of 15 lateral neck dissections (60%). Metastases to the lateral compartment, with no central compartment metastasis, were found in 6 of 15 patients (40%). Radioiodine was administered to 12 patients. Median follow-up was 12 years (range 1-22 years). All had negative ultrasound. Stimulated Tg levels available for 11 patients were undetectable for 10 and 2 ng/mL for the remaining patient.

CONCLUSIONS

This series shows a high rate of thyroid lobe foci and lymph node metastases but an excellent long-term outcome, characteristics shared with classic papillary carcinoma. Lateral neck metastases seem to be more frequent. These findings are in favor of following the current guidelines for differentiated thyroid cancer in general for the treatment of these rare tumors.

The imperative of the Sistrunk operation: review of 160 thyroglossal tract remnant operations

OBJECTIVE

Analysis of the pre- and postoperative features, long-term follow-up, and complications.

STUDY DESIGN AND METHODS

Case series with chart review of 160 thyroglossal tract remnant excisions over a 20-year period (1988-2007).

RESULTS

The mean age of diagnosis was 10.9 +/- 14.2 years with 63.8 percent male predominance. There was a prior history of thyroglossal tract remnant infections in 70 percent of patients, and 30 percent presented with cutaneous fistulas. The majority had ultrasound imaging that identified cysts mainly (66.7%) in the infrahyoid region. Preoperative fine-needle aspirations in 18 patients were benign. On pathological reevaluation, 26.5 percent had thyroid tissue inside the remnant, with one case of papillary carcinoma. After the Sistrunk operation, postoperative complications occurred in 7.5 percent including a 1.9 percent recurrence rate.

CONCLUSIONS

All age groups had similar clinical presentations and outcomes. Ultrasound is a reliable and appropriate imaging modality for most patients. Surgery must effectively incorporate the tract and cyst to allow low recurrence rates (<2%). Clinically diagnosed thyroglossal tract remnant may, in fact, be other pathologies in 10 percent of cases. Nevertheless, our recommendation is a Sistrunk procedure for all midline neck lesions suspected to be a thyroglossal tract remnant.

Papillary carcinoma of a thyroglossal duct cyst in a patient with thyroid hemiagenesis: effectiveness of conservative surgical treatment

OBJECTIVE

To describe a case of thyroglossal duct cyst carcinoma that arose in a patient with right thyroid lobe hemiagenesis.

METHODS

We present the imaging, physical examination findings, treatment, and clinical course of the study patient.

RESULTS

A 35-year-old woman was evaluated for a neck mass that had been present for 6 months and was slowly growing. She reported a previous diagnosis of right hemithyroid agenesis. The patient's preoperative workup included ultrasonography of the neck and head and neck T1- and T2-weighted magnetic resonance imaging, which showed right hemithyroid agenesis and a cystic lesion in the median region of the neck below the hyoid bone. Findings from chest x-rays and thyroid function tests were normal. The patient underwent a modified Sistrunk procedure that included removal of the median portion of the hyoid bone. Histologic findings showed a 2.5-cm thyroglossal duct cyst with a 0.6-cm focus of follicular variant of papillary carcinoma with invasion of the cyst wall. Total thyroidectomy was not performed because of the absence of tumoral invasion of the parenchyma around the thyroglossal duct cyst and because the patient was at low risk for aggressive disease. Cervical ultrasonography examinations were performed 6, 12, and 24 months after treatment, and all findings were normal. Presently, the patient is symptom-free after 4 years of follow-up and has no evidence of disease.

CONCLUSION

Incidentally discovered, well-differentiated thyroid cancer that is confined to a thyroglossal duct cyst in a patient at low risk for aggressive disease can be adequately treated by a modified Sistrunk procedure that includes the median portion of the hyoid bone.

[A diagnostic pitfall: papillary adenocarcinoma arising in ectopic thyroid tissue within a branchial cyst]

A case of thyroid papillary carcinoma arising in ectopic thyroid tissue within a branchial cleft cyst is described. Complete dissection of the thyroid gland was necessary to rule out the differential diagnosis of primary thyroid carcinoma. The thyroglossal duct tract is an unusual localization for thyroid carcinomas in ectopic thyroid tissue. Thyroid carcinoma arising in ectopic thyroid tissue within a branchial cyst is extremely rare. Complete thyroidectomy may be necessary to eliminate an occult thyroid carcinoma.

A Case of Papillary Carcinoma Arising in Ectopic Thyroid Tissue within a Branchial Cyst with Neck Node Metastasis

We describe the interesting case of a young man who presented with a lateral neck node that was diagnosed as a branchial cyst. Histopathology of the excised node revealed that a papillary carcinoma was located within thyroid tissue, which in turn was located within a branchial cyst. A total thyroidectomy with local lymph node clearance was performed. Histology identified a normal thyroid gland, but a papillary carcinoma in one of the excised lymph nodes was consistent with a metastasis. To our knowledge, this is only the second reported case of a thyroid carcinoma arising in ectopic thyroid tissue that metastasized in the neck.

Management of well-differentiated thyroglossal remnant thyroid carcinoma: time to close the debate? Report of five new cases and proposal of a definitive algorithm for treatment

BACKGROUND

Thyroid carcinoma is diagnosed in approximately 1% to 2% of thyroglossal duct remnants (TGDR). No definite agreement exists concerning the management of TGDR carcinoma, especially regarding the role of total thyroidectomy and postoperative adjuvant therapy. We report five new cases of TGDR carcinoma and review relevant articles in an attempt to clarify this issue.

METHODS

We studied the demographic, clinical, tumor-related, treatment, pathologic, and outcome data on five patients treated at our institution for a TGDR carcinoma and compared the results with the four most important series published.

RESULTS

All five patients were women, and diagnosis occurred after surgery in four. The sizes of the papillary tumors were 40, 38, 25, 23, and 15 mm (mean, 28.2 mm; range, 15-40 mm). Fine-needle aspiration biopsy of the TGDR had a low sensitivity (positive for one in four). A Sistrunk procedure was performed for resection of the TGDR in four patients, and plain TGDR resection was performed for the other patient. Three patients underwent repeat surgery; total thyroidectomy was performed in all cases, and cervical bilateral node dissection was performed in one case. With a median follow-up of 123.8 months (range, 8-284 months), all the patients are alive and free of disease, with no recurrences.

CONCLUSIONS

TGDR carcinoma is a rare malignant tumor that is usually diagnosed after surgery; papillary carcinoma is the most common type. The currently recommended treatment is a Sistrunk procedure, with a tendency to deferred total thyroidectomy in selected cases (similar criteria exist for papillary carcinoma of the thyroid gland). The prognosis is excellent, with a good long-term survival.

Thyroglossal duct carcinoma in children: case presentation and review of the literature

Carcinoma within the thyroglossal duct (TGDCa) is a very rare pediatric tumor. This report presents the case of a 15-year-old girl with TGDCa, reviews the previously published pediatric cases of this tumor, and provides diagnostic and therapeutic considerations in TGDCa in children. Twenty one cases of TGDCa have been reported, 12 of them in females. Mean age at presentation was approximately 13 years for females and approximately 12 years for males. The duration of a midcervical mass prior to the diagnosis of TGDCa varied from 3 weeks to 8 years. The size of the neck mass at presentation averaged 2 cm-4 cm. All masses were asymptomatic, and the diagnosis of TGDCa was incidental following surgery. All pediatric cases of TGDCa reported thus far were of the papillary type, except for 3 patients who presented with a mixed papillary-follicular carcinoma. Capsular invasion was detected in 10 (45%) patients. Local invasive disease was found in 5 (23%) patients, but all removed thyroid glands (12) were free of carcinoma. One patient had lung metastases. Thyroidectomy with subsequent radioiodine ablation was the treatment of choice in the majority of the cases. The reported prognosis for TGDCa in children was favorable, with only one reported death.

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.