ACR Appropriateness Criteria® Staging and Post-Therapy Assessment of Head and Neck Cancer.

Imaging of head and neck cancer at initial staging and as part of post-treatment surveillance is a key component of patient care as it guides treatment strategy and aids determination of prognosis. Head and neck cancer includes a heterogenous group of malignancies encompassing several anatomic sites and histologies, with squamous cell carcinoma the most common. Together this comprises the seventh most common cancer worldwide. At initial staging comprehensive imaging delineating the anatomic extent of the primary site, while also assessing the nodal involvement of the neck is necessary. The treatment of head and neck cancer often includes a combination of surgery, radiation, and chemotherapy. Post-treatment imaging is tailored for the evaluation of treatment response and early detection of local, locoregional, and distant recurrent tumor. Cross-sectional imaging with CT or MRI is recommended for the detailed anatomic delineation of the primary site. PET/CT provides complementary metabolic information and can map systemic involvement. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

ACR Appropriateness Criteria® Tinnitus: 2023 Update.

Tinnitus is abnormal perception of sound and has many subtypes. Clinical evaluation, audiometry, and otoscopy should be performed before ordering any imaging, as the choice of imaging will depend on various factors. Type of tinnitus (pulsatile or nonpulsatile) and otoscopy findings of a vascular retrotympanic lesion are key determinants to guide the choice of imaging studies. High-resolution CT temporal bone is an excellent tool to detect glomus tumors, abnormal course of vessels, and some other abnormalities when a vascular retrotympanic lesion is seen on otoscopy. CTA or a combination of MR and MRA/MRV are used to evaluate arterial or venous abnormalities like dural arteriovenous fistula, arteriovenous malformation, carotid stenosis, dural sinus stenosis, and bony abnormalities like sigmoid sinus wall abnormalities in cases of pulsatile tinnitus without a vascular retrotympanic lesion. MR of the brain is excellent in detecting mass lesions such as vestibular schwannomas in cases of unilateral nonpulsatile tinnitus. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

Relationship of Bern Score, Spinal Elastance, and Opening Pressure in Patients With Spontaneous Intracranial Hypotension.

BACKGROUND AND OBJECTIVES: Existing tools to diagnose spontaneous intracranial hypotension (SIH), namely spinal opening pressure (OP) and brain MRI, have limited sensitivity. We investigated whether evaluation of brain MRI using the Bern score, combined with calculated craniospinal elastance, would aid in diagnosing SIH and provide insight into its pathophysiology. METHODS: A retrospective chart review was performed of patients who underwent brain MRI and pressure-augmented dynamic CT myelography (dCTM) for suspicion of SIH. Two blinded neuroradiologists assigned Bern scores for each brain MRI. OP and incremental pressure changes after intrathecal saline infusion were recorded to calculate craniospinal elastance. The relationship between Bern score, OP, and elastance and whether a leak was found were analyzed. RESULTS: Seventy-two consecutive dCTMs were performed in 53 patients. Twelve CSF-venous fistulae, 2 ruptured meningeal diverticula, 2 dural defects, and 1 dural bleb were found (17/53, 32%). Among patients with imaging-proven CSF leak/fistula, OP was normal in all but 1 patient and was not significantly different in those with a leak compared with those without (15.1 vs 13.6 cm H2O, p = 0.24, A = 0.40). The average Bern score in individuals with a leak was significantly higher than that in those without (5.35 vs 1.85, p < 0.001, A = 0.85), even when excluding pachymeningeal enhancement from the score (3.77 vs 1.57, p = 0.001, A = 0.78). The average elastance in those with a leak was higher than that in those without, but this difference was not statistically significant (2.05 vs 1.20 mL/cm H2O, p = 0.19, A = 0.40). Increased elastance was significantly associated with an increased Bern score (95% CI -0.55 to 0.12, p < 0.01) and was significantly associated with venous distention, pachymeningeal enhancement, prepontine narrowing, and subdural collections, but not a narrowed mamillopontine or suprasellar distance. DISCUSSION: OP is not an effective predictor for diagnosing CSF leak and if used in isolation would result in misdiagnosis of 94% of patients in our cohort. The Bern score was associated with a higher diagnostic yield of dCTM. Elastance was significantly associated with certain components of the Bern score.

Structured Reporting for Findings of Spontaneous Intracranial Hypotension on Brain MRI.

A voluntary structured reporting template (based on the Bern score) for brain MRI examinations performed for suspected spontaneous intracranial hypotension (SIH) was associated with an increase in reporting of intracranial MRI findings of SIH and a reduction in discordant assessments with respect to a reference reader.

Diagnostic performance of computed tomography features in detecting oropharyngeal squamous cell carcinoma extranodal extension.

OBJECTIVES: Accurate pre-treatment imaging determination of extranodal extension (ENE) could facilitate the selection of appropriate initial therapy for HPV-positive oropharyngeal squamous cell carcinoma (HPV + OPSCC). Small studies have associated 7 CT features with ENE with varied results and agreement. This article seeks to determine the replicable diagnostic performance of these CT features for ENE. METHODS: Five expert academic head/neck neuroradiologists from 5 institutions evaluate a single academic cancer center cohort of 75 consecutive HPV + OPSCC patients. In a web-based virtual laboratory for imaging research and education, the experts performed training on 7 published CT features associated with ENE and then independently identified the "single most (if any) suspicious" lymph node and presence/absence of each of the features. Inter-rater agreement was assessed using percentage agreement, Gwet's AC1, and Fleiss' kappa. Sensitivity, specificity, and positive and negative predictive values were calculated for each CT feature based on histologic ENE. RESULTS: All 5 raters identified the same node in 52 cases (69%). In 15 cases (20%), at least one rater selected a node and at least one rater did not. In 8 cases (11%), all raters selected a node, but at least one rater selected a different node. Percentage agreement and Gwet's AC1 coefficients were > 0.80 for lesion identification, matted/conglomerated nodes, and central necrosis. Fleiss' kappa was always < 0.6. CT sensitivity for histologically confirmed ENE ranged 0.18-0.94, specificity 0.41-0.88, PPV 0.26-0.36, and NPV 0.78-0.96. CONCLUSIONS: Previously described CT features appear to have poor reproducibility among expert head/neck neuroradiologists and poor predictive value for histologic ENE. KEY POINTS: • Previously described CT imaging features appear to have poor reproducibility among expert head and neck subspecialized neuroradiologists as well as poor predictive value for histologic ENE. • Although it may still be appropriate to comment on the presence or absence of these CT features in imaging reports, the evidence indicates that caution is warranted when incorporating these features into clinical decision-making regarding the likelihood of ENE.

ACR Appropriateness Criteria® Cranial Neuropathy: 2022 Update.

Cranial neuropathy can result from pathology affecting the nerve fibers at any point and requires imaging of the entire course of the nerve from its nucleus to the end organ in order to identify a cause. MRI with and without intravenous contrast is often the modality of choice with CT playing a complementary role. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer-reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances in which peer-reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

ACR Appropriateness Criteria® Sinonasal Disease: 2021 Update.

This article presents guidelines for initial imaging utilization in patients presenting with sinonasal disease, including acute rhinosinusitis without and with suspected orbital and intracranial complications, chronic rhinosinusitis, suspected invasive fungal sinusitis, suspected sinonasal mass, and suspected cerebrospinal fluid leak. CT and MRI are the primary imaging modalities used to evaluate patients with sinonasal disease. Given its detailed depiction of bony anatomy, CT can accurately demonstrate the presence of sinonasal disease, bony erosions, and anatomic variants, and is essential for surgical planning. Given its superior soft tissue contrast, MRI can accurately identify clinically suspected intracranial and intraorbital complications, delineate soft tissue extension of tumor and distinguish mass from obstructed secretions.The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

ACR Appropriateness Criteria® Imaging of Facial Trauma Following Primary Survey.

Maxillofacial trauma patients comprise a significant subset of patients presenting to emergency departments. Before evaluating for facial trauma, an emergency or trauma physician must perform a primary survey to ensure patient stabilization. Following this primary survey, this document discusses the following clinical scenarios for facial trauma: tenderness to palpation or contusion or edema over frontal bone (suspected frontal bone injury); pain with upper jaw manipulation or pain overlying zygoma or zygomatic deformity or facial elongation or malocclusion or infraorbital nerve paresthesia (suspected midface injury); visible nasal deformity or palpable nasal deformity or tenderness to palpation of the nose or epistaxis (suspected nasal bone injury); and trismus or malocclusion or gingival hemorrhage or mucosal hemorrhage or loose teeth or fractured teeth or displaced teeth (suspected mandibular injury). The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Cooperative effects of RIG-I-like receptor signaling and IRF1 on DNA damage-induced cell death.

Properly responding to DNA damage is vital for eukaryotic cells, including the induction of DNA repair, growth arrest and, as a last resort to prevent neoplastic transformation, cell death. Besides being crucial for ensuring homeostasis, the same pathways and mechanisms are at the basis of chemoradiotherapy in cancer treatment, which involves therapeutic induction of DNA damage by chemical or physical (radiological) measures. Apart from typical DNA damage response mediators, the relevance of cell-intrinsic antiviral signaling pathways in response to DNA breaks has recently emerged. Originally known for combatting viruses via expression of antiviral factors including interferons (IFNs) and establishing of an antiviral state, RIG-I-like receptors (RLRs) were found to be critical for adequate induction of cell death upon the introduction of DNA double-strand breaks. We here show that presence of IRF3 is crucial in this process, most likely through direct activation of pro-apoptotic factors rather than transcriptional induction of canonical downstream components, such as IFNs. Investigating genes reported to be involved in both DNA damage response and antiviral signaling, we demonstrate that IRF1 is an obligatory factor for DNA damage-induced cell death. Interestingly, its regulation does not require activation of RLR signaling, but rather sensing of DNA double-strand breaks by ATM and ATR. Hence, even though independently regulated, both RLR signaling and IRF1 are essential for full-fledged induction/execution of DNA damage-mediated cell death programs. Our results not only support more broadly developing IRF1 as a biomarker predictive for the effectiveness of chemoradiotherapy, but also suggest investigating a combined pharmacological stimulation of RLR and IRF1 signaling as a potential adjuvant regimen in tumor therapy.

Algorithmic Multimodality Approach to Diagnosis and Treatment of Spinal CSF Leak and Venous Fistula in Patients With Spontaneous Intracranial Hypotension.

Spontaneous intracranial hypotension (SIH) is a disorder of CSF dynamics that causes a complex clinical syndrome and severe disability. SIH is challenging to diagnose because of the variability of its presenting clinical symptoms, the potential for subtle imaging findings to be easily overlooked, and the need for specialized diagnostic testing. Once SIH is suggested by clinical history and/or supported by initial neuroim-aging, many patients may undergo initial nontargeted epidural blood patching with variable and indefinite benefit. However, data suggest that precise localization of the CSF leak or CSF-venous fistula (CVF) can lead to more effective and durable treatment strategies. Leak localization can be achieved using a variety of advanced diagnostic imaging techniques, although these may not be widely performed at nontertiary medical centers, leaving many patients with the potential for inadequate workup or treatment. This review describes imaging techniques including dynamic fluoroscopic and CT myelography as well as delayed MR myelography and treatment options including percutaneous, endovascular, and surgical approaches for SIH. These are summarized by an algorithmic framework for radiologists to approach the workup and treatment of patients with suspected SIH. The importance of a multidisciplinary approach is emphasized.

SARS-CoV-2 infection induces a pro-inflammatory cytokine response through cGAS-STING and NF-κB.

SARS-CoV-2 is a novel virus that has rapidly spread, causing a global pandemic. In the majority of infected patients, SARS-CoV-2 leads to mild disease; however, in a significant proportion of infections, individuals develop severe symptoms that can lead to long-lasting lung damage or death. These severe cases are often associated with high levels of pro-inflammatory cytokines and low antiviral responses, which can cause systemic complications. Here, we have evaluated transcriptional and cytokine secretion profiles and detected a distinct upregulation of inflammatory cytokines in infected cell cultures and samples taken from infected patients. Building on these observations, we found a specific activation of NF-κB and a block of IRF3 nuclear translocation in SARS-CoV-2 infected cells. This NF-κB response was mediated by cGAS-STING activation and could be attenuated through several STING-targeting drugs. Our results show that SARS-CoV-2 directs a cGAS-STING mediated, NF-κB-driven inflammatory immune response in human epithelial cells that likely contributes to inflammatory responses seen in patients and could be therapeutically targeted to suppress severe disease symptoms.

ACR Appropriateness Criteria® Parathyroid Adenoma.

Hyperparathyroidism is defined as excessive parathyroid hormone production. The diagnosis is made through biochemical testing, in which imaging has no role. However, imaging is appropriate for preoperative parathyroid gland localization with the intent of surgical cure. Imaging is particularly useful in the setting of primary hyperparathyroidism whereby accurate localization of a single parathyroid adenoma can facilitate minimally invasive parathyroidectomy. Imaging can also be useful to localize ectopic or supernumerary parathyroid glands and detail anatomy, which may impact surgery. This document summarizes the literature and provides imaging recommendations for hyperparathyroidism including primary hyperparathyroidism, recurrent or persistent primary hyperparathyroidism after parathyroid surgery, secondary hyperparathyroidism, and tertiary hyperparathyroidism. Recommendations include ultrasound, CT neck without and with contrast, and nuclear medicine parathyroid scans. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

"Knobology" in Doppler Ultrasound.

Ultrasonography is a ubiquitous and indispensable diagnostic and therapeutic tool in medicine. Due to modern equipment and automatic image optimization, nowadays the introduction of ultrasound imaging requires only little technical and physical knowledge. However, profound knowledge of the device function repertoire and underlying mechanisms are essential foroptimal image adjustment and documentation. From a medical as well as an aesthetic point of view, the goal should always be to achieve the best possible image quality. This article provides an overview of handling of ultrasound systems, fundamental adjustments and their optimization in Doppler ultrasound.

Ultrasound Image Optimization ("Knobology"): B-Mode.

Ultrasound is a ubiquitous and indispensable diagnostic and therapeutic tool in medicine. Due to modern equipment and automatic image optimization, the introduction of ultrasound imaging currently requires only little technical and physical knowledge. However, in-depth knowledge of the device functions and underlying mechanisms is essential for optimal image adjustment and documentation. From a medical as well as an aesthetic point of view, the goal should always be to achieve the best possible image quality. The first part of this article provides an overview of the handling of ultrasound systems, fundamental adjustments, and their optimization in B-mode ultrasound.

Chemistry, pharmacology, and cellular uptake mechanisms of thiometallate sulfide donors.

BACKGROUND AND PURPOSE: A clinical need exists for targeted, safe, and effective sulfide donors. We recently reported that ammonium tetrathiomolybdate (ATTM) belongs to a new class of sulfide-releasing drugs. Here, we investigated the cellular uptake mechanisms of this drug class compared to sodium hydrosulfide (NaHS) and the effects of a thiometallate tungsten congener of ATTM, ammonium tetrathiotungstate (ATTT). EXPERIMENTAL APPROACH: In vitro H2 S release was determined by headspace gas sampling of vials containing dissolved thiometallates. Thiometallate and NaHS bioactivity was assessed by spectrophotometry-derived sulfhaemoglobin formation. Cellular uptake dependence on the anion exchange protein (AE)-1 was investigated in human red blood cells. ATTM/glutathione interactions were assessed by LC-MS/MS. Rodent pharmacokinetic and pharmacodynamic studies focused on haemodynamics and inhibition of aerobic respiration. KEY RESULTS: ATTM and ATTT both exhibit temperature-, pH-, and thiol-dependence of sulfide release. ATTM/glutathione interactions revealed the generation of inorganic and organic persulfides and polysulfides. ATTM showed greater ex vivo and in vivo bioactivity over ATTT, notwithstanding similar pharmacokinetic profiles. Cellular uptake mechanisms of the two drug classes are distinct; thiometallates show dependence on AE-1, while hydrosulfide itself was unaffected by inhibition of this pathway. CONCLUSIONS AND IMPLICATIONS: The cellular uptake of thiometallates relies upon a plasma membrane ion channel. This advances our pharmacological knowledge of this drug class, and further supports their utility as cell-targeted sulfide donor therapies. Our results indicate that, as a more stable form, ATTT is better suited as a copper chelator. ATTM, a superior sulfide donor, may additionally participate in intracellular redox recycling. LINKED ARTICLES: This article is part of a themed section on Hydrogen Sulfide in Biology & Medicine. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v177.4/issuetoc.

ACR Appropriateness Criteria® Neuroendocrine Imaging.

Neuroendocrine dysfunction includes suspected hyper- and hypofunction of the pituitary gland. Causative lesions may include primary masses of the pituitary such as pituitary microadenomas and macroadenomas, as well as extrinsic masses, typically centered in the suprasellar cistern. Clinical syndromes related to hormonal dysfunction can be caused by excessive hormonal secretion or by inhibited secretion due to mass effect upon elements of the hypothalamic-pituitary axis. Additionally, complications such as hemorrhage may be seen in the setting of an underlying mass and can result in hormonal dysfunction. MRI with high-resolution protocols is the best first-line test to evaluate the sella turcica and parasellar region. CT provides complementary information regarding bony anatomy, and may be appropriate as a first-line test in certain instances, but it provides less detail and lesion characterization when compared to MRI. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Frequency and Morbidity of Temporomandibular Joint Involvement in Adult Patients With a History of Juvenile Idiopathic Arthritis.

PURPOSE: Most patients with juvenile idiopathic arthritis (JIA) have temporomandibular joint (TMJ) involvement, but little is known about the natural history of TMJ disease as these children enter adulthood. The purpose of this study was to evaluate adults with a history of JIA to document the frequency and severity of TMJ abnormalities and morbidity. The authors hypothesized that most would have persistent TMJ disease as adults. MATERIALS AND METHODS: This cross-sectional study included adults (>19 years of age) with JIA who were managed at Boston Children's Hospital (BCH) as children and at Brigham and Women's Hospital (BWH) as adults. History of a TMJ problem was not considered for enrollment. Patients completed a questionnaire and underwent physical examination and maxillofacial cone-beam computed tomography (CBCT). Additional data were obtained from medical records. Associations between TMJ abnormalities at CBCT and arthritis history, TMJ pain and function, facial asymmetry, malocclusion, and cephalometric analysis were examined. RESULTS: Of 129 eligible patients contacted, 21 (42 TMJs) were enrolled. Mean age was 26.0 ± 6.1 years and mean duration of care for JIA at the BCH and BWH was 13.7 ± 6.5 years. TMJ pain was present in 62% of patients (n = 13); 43% (n = 9) had a TMJ functional limitation and 76% (n = 16) had lower facial asymmetry. Abnormalities were found in the TMJs on 55% of CBCT scans, with 79% showing bilateral deformities. There was at least 1 cephalometric measurement of mandibular size or position that was more than 1 standard deviation beyond normal in 81% of patients (n = 17). Only 4 patients (19%) had previously been evaluated for a TMJ problem. CONCLUSION: TMJ abnormalities and related morbidity are common in adult patients with a history of JIA. Therefore, an early screening protocol for TMJ involvement in children with a new diagnosis of JIA would be beneficial and long-term follow-up into adulthood should be routine.

Use of the submental vessels for free gracilis muscle transfer for smile reanimation.

BACKGROUND: Free muscle transfer is an important in dynamic facial reanimation; however, suitable donor vessels in this population can be inadequate. In this case series, the submental vessels were used as donors to free gracilis muscle in vessel-depleted patients. METHODS: Five patients underwent free gracilis muscle transfer for smile reanimation, 2 with a prior failed free gracilis transfer, 2 with vascular anomalies, and 1 with previous distal ligation of the facial vessels. The submental artery was used as a donor in all cases, and the submental vein was used in 3 cases. RESULTS: There were no complications or flap failure. Postoperative arterial and venous blood flow was confirmed in all patients using Doppler color flow imaging above and below the anastomoses. CONCLUSION: The submental vessels are suitable for microvascular anastomosis for free flaps having short pedicles, such as the free gracilis muscle flap, in the vessel-depleted hemiface. © 2016 Wiley Periodicals, Inc. Head Neck 38: First-E2503, 2016.

Imaging of ectopic thyroid tissue and thyroglossal duct cysts.

When a child or young adult presents with a mass in the anterior portion of the neck, diagnostic considerations include a thyroglossal duct cyst and ectopic thyroid tissue. These entities are often suspected clinically, and imaging provides an opportunity to evaluate the extent, confirm the diagnosis, and evaluate for complications. Imaging characteristics of a thyroglossal duct cyst as a simple cyst and of ectopic thyroid tissue as a hyperattenuating soft-tissue mass can help identify these lesions at computed tomography (CT); however, intrinsic magnetic resonance, CT, and ultrasonographic imaging characteristics alone cannot be used to confirm the diagnosis. Rather, knowledge of the typical course of the thyroid primordium during embryologic development is essential to understand the variant locations along this path where thyroid tissue can be found. The migration of thyroid primordium begins at the foramen cecum at the base of the tongue and then loops around the hyoid bone anteriorly and inferiorly and descends anteriorly to the thyrohyoid membrane into the orthotopic location in the infrahyoid portion of the neck. Thyroid ectopia is categorized into one of four typical locations with respect to this embryologic course: (a) the base of the tongue, (b) adjacent to the hyoid bone, (c) the midline infrahyoid portion of the neck, and, rarely, (d) the lateral part of the neck. The differential diagnosis includes metastatic thyroid carcinoma, branchial cleft cyst, lymphatic malformation, abscess, saccular cyst, epidermoid cyst, and squamous cell carcinoma. The relationship of a mass to landmarks such as the foramen cecum, hyoid bone, strap muscles, thyrohyoid membrane, and thyroid cartilage can help differentiate a thyroglossal duct cyst and ectopic thyroid tissue from other anterior neck masses when the embryologic thyroid course is considered.