Detection of Thyroid Isthmus Agenesia during Diagnostic Lobectomy: A Case Report.

The thyroid gland is an endocrine organ comprising two lobes connected by an isthmus. Thyroid isthmus agenesia (TIA) is a rare anatomical anomaly, which has only been documented in a limited number of case reports. This report presents the case of a 49-year-old female patient who was diagnosed with intraoperative TIA during diagnostic thyroid lobectomy. The patient was arranged for a diagnostic lobectomy of the right thyroid lobe after identifying an atypical nodule of undetermined significance, in the right lobe, which had been confirmed with two distinct biopsies. The patient was discovered to have isthmus agenesia during a neck exploration performed under general anesthesia. Owing to its rarity, the precise clinical and anatomical characteristics of TIA have not been defined, and its underlying cause is still not completely understood. The detection of TIA warrants the considerations of any other accompanying diseases. Prior identification and assessment of surgical approach are crucial for ensuring a secure surgical procedure and mitigating the risk of surgical complications. Nevertheless, caution must be exercised if TIA is detected during operation because preoperative identification is not always feasible. In summation, additional patient reports and studies are required to uncover the underlying cause of this pathological condition.

The thyroid foramen: a systematic review and meta-analysis.

PURPOSE: To systematically review published studies on the prevalence of the thyroid foramen (TF), perform a meta-analysis to generate pooled prevalence estimates, and identify factors associated with its presence. METHODS: A systematic literature search was conducted in Google Scholar, PubMed, and Journal Storage databases. Studies reporting the prevalence of the thyroid foramen were included without language or date restrictions. Quality assessment was performed using AQUA tool. A random-effects meta-analysis was performed with subgroup analyses. Heterogeneity was assessed using Higgins' I2 statistics, and publication bias was evaluated using funnel plots and Egger's test. RESULTS: Out of 271 entries, 38 studies met the inclusion criteria, comprising 3,030 subjects from various continents. The overall TF prevalence was 24.5% (95% CI: 19.2-29.8%, I2 = 93.44%), with unilateral TF present in 16.9% and bilateral TF in 6.2%. Prevalence was highest in North America (31.4%,) and lowest in Africa (12.3%). No significant prevalence difference was found between adults and younger populations (p = 0.15). Publication bias, or the small-study effect, was detected (p < 0.01). CONCLUSION: This meta-analysis reveals a 24.5% overall prevalence of TF, with significant heterogeneity primarily explained by geographical differences. The TF's clinical relevance necessitates awareness among surgeons and radiologists to avoid complications during laryngeal surgeries and prevent misdiagnosis in imaging studies.

An ectopic thyrolingual trunk arising from the common carotid artery: a rare variant.

The common carotid artery (CCA) typically bifurcates into the external and internal carotid arteries (ECA and ICA). In the head and neck area, the ECA gives off a few anterior branches from proximal to distal: the superior thyroid artery (STA), the lingual artery (LA), and the facial artery (FA). Occasionally, these branches can fuse into trunks, with the linguofacial trunk being the most common. During a computed tomography angiography (CTA) of a 67-year-old patient, a common arterial trunk, 11.3 mm proximal (prior) to the CCA bifurcation was recorded. The trunk was formed by the STA and the LA fusion and was characterized as a thyrolingual trunk (TLT). These trunks have been reported with a prevalence ranging between 0.3 and 1% and correspond to one of the rarest variants of the ECA anterior branches. Knowledge of the typical and variant anatomy of the carotid arteries and their branches is of paramount importance to surgeons and interventional radiologists.

Thyroid hemiagenesis with compensatory hypertrophy of the remaining lobe: A case report.

Thyroid hemiagenesis is defined as a failure of one thyroid lobe development. This condition predominantly manifests as an incidental finding during radiological investigation. This paper repor ts the case o f a 53-year-ol d female, a known case of hypertension, who visited the ENT clinic at AKU, a ter tiary ca re centre in Karachi, Pak istan and was hospi talized from 12 th to 1 5th Septembe r 202 1. The patient presented with hemiagenesis of the right thyroid lobe with enlargement of the contralateral lobe resulting in airway compression. She was subjected to excision of the thyroid gland without any intra-operative or postoperative com plicati ons. There were n o complaints o f dyspnoea, stridor or hoarseness during the hospital stay. The patient was discharged and was found to be well on subsequent follow-ups.

Superior laryngeal artery originating from the lingual artery.

In most cases, the superior laryngeal artery (SLA) branches from the superior thyroid artery, which, in turn, leaves the external carotid artery. Few dissection studies found previously that the SLA could originate from the lingual artery. We report here probably the first evidence of such a rare anatomical variation found unilaterally in a retrospectively evaluated by computed tomography angiography adult male case. The left SLA left a suprahyoid coil of the lingual artery and continued over the greater hyoid horn to enter the larynx through the thyrohyoid membrane. On both sides, thyroid foramina were found, but only the right one used for the entry of the right SLA. Therefore, the rare SLA origin from the lingual artery can be documented on computed tomography angiograms, which could help during preoperative evaluations and prevent unwanted surgical complications.

Prognostic evaluation models for primary thyroid lymphoma, based on the SEER database and an external validation cohort.

PURPOSE: Primary thyroid lymphoma (PTL) is a rare malignancy, and the literature is limited to small case series and case reports. This study aimed to assess the epidemiologic characteristics, survival, and prognostic factors of patients with PTL. METHODS: We analyzed 2215 PTL patients from the Surveillance, Epidemiology, and End Results database medical records, between 1983 and 2015, as the training cohort. We enrolled 105 patients from the Cancer Hospital, Chinese Academy of Medical Sciences, for the external validation cohort. The nomograms for predicting the 1-, 5-, and 10-year overall survival (OS) and lymphoma-specific survival (LSS) were constructed. RESULTS: PTL incidence steadily increased from 1977 to 1994, with an annual percentage change of 3.2% (95% confidence interval [CI]: 1.2-5.2, P < 0.05). The 1-, 5-, and 10-year OS and LSS rates were 84.66%, 71.61%, and 55.95%; and 90.5%, 85.7%, and 82.2%, respectively. Multivariate Cox regression analysis revealed that shorter OS association with age ≥ 60 years (hazard ratio [HR], 3.94; 95% CI 3.31-4.69; P < 0.001), unmarried status (HR, 1.55; 95% CI 1.37-1.75; P < 0.001), Ann Arbor stage III-IV (HR, 1.55; 95% CI 1.37-1.75; P = 0.020), diffuse large B-cell lymphoma (HR, 2.60; 95% CI 1.15-5.87; P = 0.022), and T cell non-Hodgkin lymphoma (HR, 3.53; 95% CI 1.12-11.10; P = 0.031). In the multivariate competing-risk analyzes, age, stages III-IV, year of diagnosis, surgery, radiation, chemotherapy, and histology were strongly predictive of PTL-specific risk of death. To estimate the 1-, 5-, and 10-year LSS and OS rates, respectively, nomograms were built. In the validation cohort, the results also confirmed the utility. CONCLUSIONS: This study presents the first prognostic model with an external validation that could help clinicians identify patients with high-risk PTL to improve their prognosis.

Three-dimensional microscopy and image fusion reconstruction analysis of the thyroid gland during morphogenesis.

Thyroid dysgenesis (TD) is a major cause of primary congenital hypothyroidism; however, the molecular mechanism underlying this process is unclear. Current knowledge regarding the morphogenesis of the thyroid gland and vascular anomalies affecting thyroid development is limited. To monitor the early stages of thyroid gland development, we generated double transgenic zebrafish embryos Tg(tg:mCherry/flk1:EGFP). We described the volume of the thyroid from 2 days postfertilization (dpf) to 5 dpf using 3D reconstruction images. We treated zebrafish embryos with the fibroblast growth factor (FGF) inhibitor PD166866 to better understand the impact of vascular defects on thyroid development and the effects of drug administration at specific time periods on different stages of thyroid development. The 3D reconstruction data revealed that the thyroid glands underwent significant transformation at critical time points. PD166866 treatment from 48 to 72 hours postfertilization (hpf) and from 72 to 96 hpf did not cause obvious reductions in thyroid volume but did result in observable abnormalities in thyroid morphology. The treatment also affected thyroid volume from 36 to 48 hpf, thus indicating that there are time-point-specific effects of drug administration during thyroid development. Three-dimensional image reconstruction provides a comprehensive picture of thyroid anatomy and can be used to complement anatomical fluorescence information. The effects of an FGF pathway inhibitor on thyroid development were determined to be time-point-dependent.

Enhanced Canonical Wnt Signaling During Early Zebrafish Development Perturbs the Interaction of Cardiac Mesoderm and Pharyngeal Endoderm and Causes Thyroid Specification Defects.

Background: Congenital hypothyroidism due to thyroid dysgenesis is a frequent congenital endocrine disorder for which the molecular mechanisms remain unresolved in the majority of cases. This situation reflects, in part, our still limited knowledge about the mechanisms involved in the early steps of thyroid specification from the endoderm, in particular the extrinsic signaling cues that regulate foregut endoderm patterning. In this study, we used small molecules and genetic zebrafish models to characterize the role of various signaling pathways in thyroid specification. Methods: We treated zebrafish embryos during different developmental periods with small-molecule compounds known to manipulate the activity of Wnt signaling pathway and observed effects in thyroid, endoderm, and cardiovascular development using whole-mount in situ hybridization and transgenic fluorescent reporter models. We used the antisense morpholino (MO) technique to create a zebrafish acardiac model. For thyroid rescue experiments, bone morphogenetic protein (BMP) pathway induction in zebrafish embryos was obtained by manipulation of heat-shock inducible transgenic lines. Results: Combined analyses of thyroid and cardiovascular development revealed that overactivation of Wnt signaling during early development leads to impaired thyroid specification concurrent with severe defects in the cardiac specification. When using a model of MO-induced blockage of cardiomyocyte differentiation, a similar correlation was observed, suggesting that defective signaling between cardiac mesoderm and endodermal thyroid precursors contributes to thyroid specification impairment. Rescue experiments through transient overactivation of BMP signaling could partially restore thyroid specification in models with defective cardiac development. Conclusion: Collectively, our results indicate that BMP signaling is critically required for thyroid cell specification and identify cardiac mesoderm as a likely source of BMP signals.

Influence of triphenyltin on morphologic abnormalities and the thyroid hormone system in early-stage zebrafish (Danio rerio).

In the present study, we assessed the negative effects of triphenyltin (TPT) on zebrafish (Danio rerio) by exposing embryos and early-stage larvae to various concentrations of TPT from 2 h after fertilization (haf) until 30 days after hatching (dah). Whether test groups were fed or fasted during ecotoxicity studies using fish models has varied historically, and whether this experimental condition influences test results is unknown. Here, we confirmed that the lethal concentration of TPT to embryo and early-stage larvae (i.e., 3 dah or younger) showed in fed (lowest observed effect concentration (LOEC); 6.34 µg/L) and fasted (LOEC; 6.84 µg/L) groups. In addition, 84% and 100% of the larvae in the 2.95 and 6.64 µg/L exposure groups, respectively, had uninflated swim bladders; all affected larvae died within 9 dah. This finding suggests that morphologic abnormalities in early larval zebrafish are useful as endpoints for predicting the lethality of chemical substances after hatching. We then assessed the expression of several genes in the thyroid hormone pathway, which regulates swim bladder development in many fish species, including zebrafish. Larvae exposed to 6.64 µg/L TPT showed significant increases in the mRNA expression levels of thyroid hormone receptor α (trα) and trß but not of thyroid stimulating hormone ß subunit. These findings suggest that TPT disrupts the thyroid system in zebrafish.

Giant epidermal inclusion cyst of the thyroid: a rare occurrence

Epidermal inclusion cyst (EIC) of the thyroid is extremely rare in the clinical practice. A handful of cases have been documented in the past in the world literature. A giant EIC of the thyroid is hitherto unreported. This lesion may arise from the squamous metaplasia of the thyroid follicular cells. Though non-neoplastic, giant forms can cause compression of the vital structures of the neck. In the present case, we have described a giant epidermal inclusion cyst successfully managed with surgical management.

Genetic testing of PAX8 mutations associated with thyroid dysgenesis in Chinese congenital hypothyroidism patients.

INTRODUCTION: Thyroid dysgenesis (TD) is the main cause of congenital hypothyroidism (CH), affecting nearly 1 in 2000-3000 newborns worldwide, as the most common neonatal endocrine disorder. Paired box gene 8 (PAX8), expressed during all stages of thyroid follicular cell, plays a key role in thyroid morphogenesis by a complex regulatory network. In conclusion, the genetic mechanism of PAX8 mutant in TD is still ambiguous; therefore, further research is needed. MATERIAL AND METHODS: Blood samples were collected from 289 TD patients in Shandong Province, China. Genomic DNA was extracted from peripheral blood. All the exons of PAX8 along with their exon-intro boundaries were amplified by PCR and analysed by Sanger sequencing. RESULTS: We identified three novel PAX8 nonsense mutations in three patients by sequence analysis of PAX8: Patient 1 (c.285C>G, p.Tyr95Ter), Patient 2 (c.747T>G, p.Tyr249Ter), and Patient 3 (c.786C>A, p.Tyr262Ter). All the three patients carrying PAX8 variants had obvious clinical phenotypes of thyroid anomaly, such as hypoplasia and athyreosis. CONCLUSION: We conducted the largest worldwide PAX8 mutation screening so far in TD patients. Three presumably pathogenic PAX8 mutations were detected in 289 TD cases for the first time, showing the mutation rate of PAX8 is 1.04% in Chinese TD patients. In addition, our study expands the gene mutation spectrum of TD.

Molecular defects in thyroid dysgenesis.

Congenital hypothyroidism (CH) is a neonatal endocrine disorder that might occur as itself or be associated to congenital extra-thyroidal defects. About 85% of affected subjects experience thyroid dysgenesis (TD), characterized by defect in thyroid gland development. In vivo experiments on null mice paved the way for the identification of genes involved thyroid morphogenesis and development, whose mutation has been strongly associated to TD. Most of them are thyroid-specific transcription factors expressed during early thyroid development. Despite the arduous effort in unraveling the genetics of TD in animal models, up to now these data have been discontinuously confirmed in humans and only 5% of TD have associated with known null mice-related mutations (mainly PAX8 and TSHR). Notwithstanding, the advance in genetic testing represented by the next-generation sequencing (NGS) approach is steadily increasing the list of genes whose highly penetrant mutation predisposes to TD. In this review we intend to outline the molecular bases of TD, summarizing the current knowledge on thyroid development in both mice and humans and delineating the genetic features of its monogenetic forms. We will also highlight current strategies to enhance the insight into the non-Mendelian mechanisms of abnormal thyroid development.

Study of the relationship between vitamin D deficiency, sunlight incidence and skeletal/extra skeletaldiseases

It is estimated that more than 1 billion people worldwide have vitamin D insufficiency or deficiency. Vitamin D participates in bone mineralization, and is therefore important in osteoporosis, osteomalacia and rickets prevention. However, vitamin D deficiency could also be associated with several other pathologies. The present study aimed to investigate the relationships between vitamin D deficiency and vitamin D deficiency-related disorders in patients. In addition, this study aims to verify if countries with low solar incidence have higher extraskeletal disease death rates when compared to countries with high solar incidence. The vitamin D concentrations were obtained from the Heart Hospital database (Natal/Brazil). The relationship between solar incidenceand death rate for vitamin D deficiency-related disorders was verified. Death rate data were extracted from the 'World Life Expectancy' repository and data about solar incidence were obtained from NASA's Surface Meteorology and Solar Energy project. Thesedata were statistically processed with IBM SPSS v23.0 software and R programming language. Our results showed that patients with vitamin D insufficiency/deficiency showed significantly more bone diseases, thyroid diseases, hypercholesterolemy, hypertriglyceridemia, cancers, diabetes, hepatobiliary diseases, and urinary system diseases. Moreover, countries with high solar incidence have low cancer and multiple sclerosis death rates. This work suggests the participation of vitamin D and sunlight incidence inseveral diseases.

Double knock-out of Hmga1 and Hipk2 genes causes perinatal death associated to respiratory distress and thyroid abnormalities in mice.

The serine-threonine kinase homeodomain-interacting protein kinase 2 (HIPK2) modulates important cellular functions during development, acting as a signal integrator of a wide variety of stress signals, and as a regulator of transcription factors and cofactors. We have previously demonstrated that HIPK2 binds and phosphorylates High-Mobility Group A1 (HMGA1), an architectural chromatinic protein ubiquitously expressed in embryonic tissues, decreasing its binding affinity to DNA. To better define the functional role of HIPK2 and HMGA1 interaction in vivo, we generated mice in which both genes are disrupted. About 50% of these Hmga1/Hipk2 double knock-out (DKO) mice die within 12 h of life (P1) for respiratory failure. The DKO mice present an altered lung morphology, likely owing to a drastic reduction in the expression of surfactant proteins, that are required for lung development. Consistently, we report that both HMGA1 and HIPK2 proteins positively regulate the transcriptional activity of the genes encoding the surfactant proteins. Moreover, these mice display an altered expression of thyroid differentiation markers, reasonably because of a drastic reduction in the expression of the thyroid-specific transcription factors PAX8 and FOXE1, which we demonstrate here to be positively regulated by HMGA1 and HIPK2. Therefore, these data indicate a critical role of HIPK2/HMGA1 cooperation in lung and thyroid development and function, suggesting the potential involvement of their impairment in the pathogenesis of human lung and thyroid diseases.

Small-Molecule Screening in Zebrafish Embryos Identifies Signaling Pathways Regulating Early Thyroid Development.

Background: Defects in embryonic development of the thyroid gland are a major cause for congenital hypothyroidism in human newborns, but the underlying molecular mechanisms are still poorly understood. Organ development relies on a tightly regulated interplay between extrinsic signaling cues and cell intrinsic factors. At present, however, there is limited knowledge about the specific extrinsic signaling cues that regulate foregut endoderm patterning, thyroid cell specification, and subsequent morphogenetic processes in thyroid development. Methods: To begin to address this problem in a systematic way, we used zebrafish embryos to perform a series of in vivo phenotype-driven chemical genetic screens to identify signaling cues regulating early thyroid development. For this purpose, we treated zebrafish embryos during different developmental periods with a panel of small-molecule compounds known to manipulate the activity of major signaling pathways and scored phenotypic deviations in thyroid, endoderm, and cardiovascular development using whole-mount in situ hybridization and transgenic fluorescent reporter models. Results: Systematic assessment of drugged embryos recovered a range of thyroid phenotypes including expansion, reduction or lack of the early thyroid anlage, defective thyroid budding, as well as hypoplastic, enlarged, or overtly disorganized presentation of the thyroid primordium after budding. Our pharmacological screening identified bone morphogenetic protein and fibroblast growth factor signaling as key factors for thyroid specification and early thyroid organogenesis, highlighted the importance of low Wnt activities during early development for thyroid specification, and implicated drug-induced cardiac and vascular anomalies as likely indirect mechanisms causing various forms of thyroid dysgenesis. Conclusions: By integrating the outcome of our screening efforts with previously available information from other model organisms including Xenopus, chicken, and mouse, we conclude that signaling cues regulating thyroid development appear broadly conserved across vertebrates. We therefore expect that observations made in zebrafish can inform mammalian models of thyroid organogenesis to further our understanding of the molecular mechanisms of congenital thyroid diseases.

A case of PHACE syndrome with growth hormone deficiency and abnormal thyroid functions.

Background PHACE syndrome is a rare vascular neurocutaneous disorder characterized by posterior fossa anomalies, hemangioma, arterial anomalies, cardiac anomalies and eye anomalies. Growth hormone deficiency (GHD) has been infrequently described. Case presentation We report a girl with PHACE syndrome. Endocrine abnormalities including abnormal thyroid functions and GHD have recently been described in similar cases. Conclusions This case suggests the necessity to screen pituitary functions in all patients with PHACE syndrome with abnormal hypothalamus and pituitary (HP) anatomy. Likewise, growth parameters and thyroid function test (TFT) should be monitored in all patients with PHACE syndrome at regular intervals.

Fetal Sinus Bradycardia Is Associated with Congenital Hypothyroidism: An Infant with Ectopic Thyroid Tissue.

Hypothyroidism is rarely included in the differential diagnosis for fetal sinus bradycardia. We report an infant with congenital hypothyroidism caused by ectopic thyroid tissue, who showed antenatal bradycardia. The baseline fetal heart rate was 100-110 bpm at 30 weeks of gestation, and fetal echocardiography revealed sinus bradycardia but no cardiac anomalies. Maternal thyroid function was normal (thyroid-stimulating hormone [TSH] 2.03 µIU/ml, free T3 2.65 pg/ml, and free T4 0.99 ng/dl) when measured at 31 weeks of gestation. Her serum anti SS-A and SS-B antibodies, anti-thyroglobulin, and microsomal antibodies were negative. A male infant without cardiac anomalies was delivered at 35 weeks and 4 days of gestation and admitted for prematurity and respiratory distress syndrome. The infant's heart rate was 70-110 bpm (normal: 120-160 bpm) on admission. On 8 days of age, thyroid function tests revealed that the infant had severe hypothyroidism (TSH 903.3 µIU/ml, free T3 1.05 pg/ml, and free T4 0.26 ng/dl). The prolonged jaundice assumed to be due to hypothyroidism. Oral levothyroxine sodium hydrate (10 µg/kg/day) was immediately started on day 8. After the treatment, the heart rate was gradually increased to 130-140 bpm as the infant's thyroid function was improved (TSH 79.8 µIU/ml, free T3 2.95 pg/dl, and free T4 1.66 ng/dl on day 22). The infant was diagnosed ectopic thyroid tissue because of the high thyroglobulin level (85.9 µg/l). In conclusion, congenital hypothyroidism should be included in the differential diagnosis in cases of fetal bradycardia without cardiac anomalies or maternal autoimmune diseases.

Congenital hypothyroidism in preterm infants: a 3- to 8-year longitudinal study in southern Thailand.

Background Preterm infants are at high risk of developing congenital hypothyroidism (CH) due to the immaturity of the hypothalamic-pituitary-thyroid (HPT) axis, loss of iodine supply from the mother and preterm health problems. Objectives To study the incidence and etiologies of CH in preterm infants who were born or admitted in our institute during 2010-2015. Methods The medical records of preterm infants diagnosed with CH as defined by the thyroid-stimulating hormone (TSH) level at the time of the first or second screening >10 mU/L and/or free T4 < 1.00 ng/dL were reviewed. Results Of 2777 preterm infants, 73 cases (2.6%) were diagnosed as CH. The average TSH levels at the first and second screenings were 20.85 and 15.42 mU/L, respectively. The patients were treated with thyroxine at an average initial dosage of 15 µg/kg/day. At 2-3 years of age, after thyroxine discontinuation for 6-10 weeks and regular thyroid function tests for 2 years, 58 patients (79.5%) were diagnosed as having transient CH and 15 patients (20.5%) were diagnosed as having permanent CH. We found no clinical or laboratory parameters in the neonatal period that could differentiate permanent from transient CH. Thyroid scintigraphy (99 m pertechnetate) revealed two patients (13.3%) with ectopic thyroid, one with thyroid hypoplasia (6.7%), eight with normal thyroid (53.3%) and four with enlarged thyroid (26.7%). Conclusions CH was common in preterm infants with an estimated incidence of 2.6%. Thyroxine should be given to preterm infants with higher initial values of TSH >10 mU/L in order to prevent delayed treatment of permanent CH that could be confirmed later.

Why Central Neck Dissection Works (and Fails) for Recurrent Thyroglossal Duct Remnants.

OBJECTIVE: To review the patient characteristics and outcomes for children and undergoing central neck dissection for control of recurrent thyroglossal duct cysts and fistula following prior Sistrunk procedures and children requiring surgery for refractory infection. METHODS: We performed a computerized review of all children who were evaluated for thyroglossal duct cysts during the years 1999-2018 by a single surgeon operating at an urban children's hospital and an outpatient surgical center. Those requiring a central neck dissection for control of recurrent disease or intractable infection were identified. Age at time of surgery, sex, surgical procedure, and postoperative complications were recorded. These data were combined with similar data from a published report by the same surgeon in the years 1990-1998 to complete a 28-year review. RESULTS: 18 central neck dissections were performed including 13 for recurrent thyroglossal duct remnants after Sistrunk procedures and 5 primary surgeries for intractable infection. Ages ranged from 3 to 19 years (median = 10 years) and 13 of 18 were girls (72%). Four children had their first Sistrunk surgery performed by the senior author. Three children operated elsewhere had intact hyoid bones at the time of revision surgery, suggesting less-than-Sistrunk primary surgeries. Central neck dissection controlled disease in the lower neck in all cases. One child re-fistulized at the level of the hyoid. CONCLUSIONS: Central neck dissection in combination with a Sistrunk-type dissection of the tongue base is effective in the control of recurrent infection following unsuccessful Sistrunk surgery and aids in dissection for children with intractable infection. Although this technique reliably controls infrahyoid disease and improves access to the hyoid and posterior hyoid space, it does nothing to address the difficulties of following the thyroglossal tract into the tongue base.