This dual-panel educational graphic illustrates thyroglossal duct anatomy and the embryological descent of the thyroid gland. On the left is a sagittal anatomical diagram showing the path of descent (indicated by a red arrow) from the foramen cecum at the base of the tongue, passing through the hyoid bone, to its final position at the thyroid gland anterior to the trachea. Key labeled structures include the tongue, lingual tonsil, foramen cecum, hyoid, and thyroid gland. The right panel displays a corresponding sagittal contrast-enhanced CT image of the neck. The CT scan highlights the radiologic appearance of these landmarks: the hyoid bone appears as a high-attenuation U-shaped structure, and the thyroid gland exhibits homogenous enhancement inferior to the thyroid cartilage. This comparison demonstrates the clinical relevance of embryological pathways in understanding the location of thyroglossal duct cysts, which can occur anywhere along this midline tract.

A composite medical visual consisting of a clinical intraoperative photograph (left) and a corresponding anatomical diagram (right) illustrating the anatomy of the neck and larynx. The content focuses on the anatomical variations of the External Branch of the Superior Laryngeal Nerve (EBSLN) in relation to the Superior Thyroid Artery (STA) and the thyroid gland, specifically representing Cernea Type IIb and Kierner Type III classifications. In the diagram, the EBSLN is shown descending alongside the STA and crossing it at a level below the upper pole of the thyroid gland, terminating in the cricothyroid muscle. Key labeled structures include the hyoid bone, thyrohyoid membrane/muscle, sternothyroid muscle, and cricothyroid membrane. The intraoperative photo displays the surgical field during thyroid surgery, with tissue retracted to expose the EBSLN in a clinical context. This material is designed for surgical education, highlighting the high-risk positioning of the nerve during the ligation of superior thyroid vessels.

This composite educational graphic details the cross-sectional anatomy of the human neck for Finite Element (FE) thyroid simulation. (a) A 2D schematic diagram presents a simplified semicircular model of the neck. It labels the layers concentrically: skin (outermost), fat, and muscle. Inside the muscle layer, the thyroid gland is depicted in pink, containing an elliptical dark grey thyroid nodule. Boundaries are marked as Γ1 (skin surface), Γ2 (trachea boundary), and Γ3 (prescribed temperature base). (b) A corresponding axial CT scan image shows the actual anatomical cross-section, with labels identifying the skin, fat, muscle, thyroid gland, trachea (central air-filled void), and an internal nodule. The CT highlights varying tissue densities, from the dark fat layer to the intermediate density of muscle and thyroid tissue. (c) A sagittal CT view of the head and neck shows a red horizontal line indicating the anatomical plane of the axial slice in (b), positioned at the level of the thyroid gland. This visual serves as a reference for modeling heat transfer and infrared thermography in patients with thyroid nodules.

This composite figure illustrates a modified en-bloc resection technique for thyroid lobectomy and central neck dissection (CND). Panel A is an anatomical diagram showing the surgical area, including the thyroid (TH), trachea (TR), common carotid artery (CCA), and Level VI central compartment lymph nodes. Panel B displays a clinical photograph of a resected gross specimen, showing a thyroid lobe attached to a stalk of Level VI fibro-fatty tissue, demonstrating en-bloc removal. Panels C and D provide intraoperative endoscopic views during thyroidectomy. Panel C shows the surgical manipulation of the thyroid lobe (TH) in proximity to the recurrent laryngeal nerve (RLN) and the CCA. Panel D highlights the preservation of critical structures post-resection, including the RLN, parathyroid gland (PG), and trachea (TR) relative to the common carotid artery (CCA). The figure demonstrates the surgical anatomy and the objective of maintaining structural integrity of vital nerves and glands during oncologic resection of papillary thyroid carcinoma.

Imaging modality: Light microscopy of Hematoxylin and Eosin stained thyroid tissue. The section displays a diffuse, multilocular thyroid parenchyma with numerous round to oval follicles of varying diameter. Follicles are lined by a single layer of cuboidal to flattened epithelium, separating abundant eosinophilic colloid within expansive lumens. The colloid appears as homogenous pink material; some follicles are dilated with scant luminal epithelium, while others are more compact, creating a cobblestone-like appearance. The surrounding stroma is minimally fibrous, with occasional vascular spaces and sparse interfollicular connective tissue. There is no evident cellular atypia or overt inflammatory infiltrate in this field. Overall architecture shows a benign-appearing follicular pattern with preserved polarity and uniform follicle distribution, though follicle sizes vary, suggesting a multinodular or hyperplastic process. The image illustrates classical thyroid histology, showcasing normal thyroid parenchyma or a mild nodular change characterized by colloid-rich follicles. Diagnostic significance lies in identifying thyroid tissue with intact colloid-filled follicles, helping to differentiate benign thyroid tissue from neoplastic lesions such as follicular adenoma or follicular carcinoma when clinical data and adjunct studies are available. This image is applicable for educational demonstrations of thyroid histology, goiter pathology, and comparative endocrine pathology.

Imaging modality and technique: Bright-field light microscopy of a hematoxylin and eosin–stained thyroid tissue section. Specimen is a thyroid parenchymal biopsy/resection showing multinodular goiter with heterogenous follicle sizes. The micrograph reveals variably sized, dilated follicles interspersed with smaller hypercellular follicles; cells lining some follicles are flattened to cuboidal with scant colloid, while other follicles are large and colloid-rich, producing a biphasic appearance. The stroma is not heavily fibrotic; nodular architecture creates broad fibrous separations. Notable features include very large colloid-containing follicles, uneven distribution, and thickened septa in some areas. Overall thyroid architecture shows nodular hyperplasia without cytologic atypia; there is no invasion or malignant features evident. The image is representative of benign nodular goiter, reflecting long-standing iodine deficiency in some cases or chronic compensatory hyperplasia. Diagnostic significance: demonstrates classic histologic spectrum of multinodular goiter with variable follicle size and colloid content; important to distinguish from follicular neoplasms and inflammatory thyroid disease. Clinical correlation: correlates with clinically enlarging neck mass; usually euthyroid; histology informs management and follow-up. Feature set aligns with common teaching examples for medical education and pathology atlases, enabling search queries for terms such as multinodular goiter, colloid-rich follicles, flattened follicular epithelium, and nodular hyperplasia.

Imaging modality: light microscopy of hematoxylin and eosin–stained thyroid tissue sections. Primary subject: thyroid follicular epithelium with colloid-filled follicles. Anatomical context: thyroid gland parenchyma in the cervical region, showing follicles lined by tall columnar epithelium. Morphology: hypercellular epithelium with marked nuclear crowding creates papillary infoldings that protrude into the glandular lumens. Pale colloid is present within the follicles and margins appear scalloped. In architectural detail, papillary projections resemble papillary thyroid carcinoma but lack true fibrovascular cores, a key differentiator on histology. The follicular lumens vary in size, and colloid shows scalloping margins, consistent with benign activity rather than malignant invasion. Cytologic features include elongated nuclei with ovoid contours and scant cytoplasm; mitotic activity is not conspicuous. Immunophenotype is not assessed in this image; histology alone raises diagnostic considerations of benign hyperplastic changes including nodular hyperplasia or benign follicular adenoma with papillary-like infoldings. Diagnostic significance: recognition of papillary-like architecture without fibrovascular cores reduces the likelihood of classic papillary thyroid carcinoma, and highlights the need for correlating with nuclear features and ancillary studies. This image is relevant for surgical pathology reference, education, and differential diagnosis training in endocrine pathology. These considerations are essential for resident education, diagnostic conundrums, and interdisciplinary tumor boards.

This line graph illustrates a joinpoint analysis of time trends for the age-standardized incidence of non-papillary thyroid cancer (including follicular, medullary, and anaplastic histological types) in Israel from 1980 to 2012. The data is stratified by gender within the Jewish population. The y-axis represents the rate per 100,000, while the x-axis denotes the calendar years. The visual demonstrates a statistically significant downward trend in the incidence for both Jewish women and Jewish men over the 32-year period. Jewish women (indicated by the upper green line) started with a higher incidence rate in 1980 compared to Jewish men (indicated by the lower blue line). Both groups show fluctuations year-over-year but exhibit a clear overall decline, with incidence rates narrowing and approaching lower, more similar values by 2012. This epidemiological data highlights shifting patterns in thyroid cancer pathology, contrasting the decreasing incidence of non-papillary types with the concurrent rise of papillary carcinoma observed in the same period.

This is a histopathology slide of thyroid tissue prepared by hematoxylin and eosin staining, examined under brightfield light microscopy at high magnification. The specimen demonstrates epithelial neoplasm consistent with papillary thyroid carcinoma (PTC). The neoplastic cells are arranged in sheets and, where present, papillary fronds with fibrovascular cores are recognizable. The predominant cytoplasm is finely reticular and eosinophilic, with blander nuclear features. The nuclei show characteristic raisinoid appearance with nuclear grooves, giving an Orphan Annie eye look; the nuclear membranes are distinct and often thickened. Perinuclear halos, i.e., clear nuclear clearing around the chromatin, are evident. Some tumor cells exhibit voluminous cytoplasm, and in the plane of section, nuclei may be absent in those cells, a phenomenon of sectioning rather than true anuclear cells. The cytoplasmic clearing and grooves are diagnostic, aiding differentiation from benign nodules. The histology carries diagnostic significance, with PTC carrying generally favorable prognosis but potential for lymphatic metastasis; differential includes follicular carcinoma, medullary carcinoma, Hashimoto-related changes, and benign adenomas. Clinically, presence of these features correlates with occult metastasis risk and guides surgical planning, post-operative radioiodine therapy considerations, and molecular testing (e.g., BRAF V600E). This image is relevant for medical education, pathology teaching files, digital atlases, and research on thyroid cancer morphology.

This diagnostic image displays two B-mode ultrasound scans (longitudinal view in A, axial view in B) of a human thyroid gland, demonstrating a focal nodule in the left lobe. The visual content showcases a solid, markedly hypoechoic nodule relative to the surrounding hyperechoic thyroid parenchyma. Key morphological features include an irregular shape and ill-defined margins. In the longitudinal scan (A), the nodule exhibits a 'taller-than-wide' orientation (anteroposterior diameter greater than the transverse diameter), which is a significant ultrasound finding in thyroid risk stratification. No posterior acoustic enhancement or shadowing is clearly evident. The surrounding thyroid tissue displays a heterogeneous echotexture, consistent with the patient's background of chronic lymphocytic thyroiditis. In the axial scan (B), the relationship of the thyroid lobe to adjacent cervical vascular structures is visible. This image serves as an educational example of TIRADS-based risk assessment (C-TIRADS 4C/K-TIRADS 5/ACR-TIRADS 5) for thyroid malignancies, despite the histopathological diagnosis of benign lymphocytic thyroiditis.

Diagnostic ultrasound imaging of the thyroid gland demonstrating characteristic TIRADS 3 thyroid incidentalomas. Panel (a) and (b) show a predominantly hyperechoic solid nodule located in the left thyroid lobe. The lesion features sharp, well-defined margins and is encircled by a peripheral hypoechoic halo. Color Doppler imaging in panel (b) reveals significant peripheral vascularization, appearing as a 'basket-weave' pattern of blood flow around the nodule's edge. Panel (c) illustrates a second nodule characterized as isoechogenic relative to the surrounding parenchyma, also exhibiting a peripheral hypoechoic halo and peripheral Doppler signals. These sonographic findings represent low-risk nodules (TIRADS 3) typically characterized by benign growth patterns, intended for medical education regarding thyroid cancer risk stratification and ultrasonographic morphological assessment.

This set of grayscale ultrasound images (Figures A, B, and C) provides a diagnostic assessment of bilateral thyroid nodules in a patient with suspected medullary thyroid carcinoma (MTC). Image A displays the right thyroid lobe containing a large, dominant nodule (35 x 29 x 41 mm) characterized by heterogeneous echogenicity and internal macrocalcifications, which appear as bright echogenic foci with posterior acoustic shadowing. This lesion is classified as EU-TIRADS 4. Image B shows a second, smaller hypoechoic nodule (22 mm) in the right lobe, also classified as EU-TIRADS 4. Image C depicts the left thyroid lobe containing a 9 x 7 x 9 mm hypoechoic nodule with irregular margins, assigned a higher risk category of EU-TIRADS 5. These findings illustrate the sonographic presentation of multifocal thyroid lesions in the context of MEN2A syndrome. The variations in echogenicity, calcification patterns, and margin definition are key diagnostic features used for risk stratification and determining the necessity for fine-needle aspiration (FNA) biopsy.

A multi-panel fetal ultrasound series demonstrating the diagnosis and monitoring of a fetal goiter associated with hyperthyroidism. Panel (a) shows a transverse view of the fetal neck utilizing color Doppler, revealing marked hypervascularity (the 'thyroid inferno' sign) within an enlarged thyroid gland. Panel (b) illustrates transverse biometry of the fetal thyroid, with calipers measuring an enlarged gland (dimensions approximately 0.72 cm to 0.96 cm). Panel (c) shows a fetal orbital view with a blue arrowhead pointing to retro-orbital tissue enlargement, indicative of fetal exophthalmos. Panel (d) displays a follow-up transverse ultrasound at 26 weeks, showing calipers measuring a reduced thyroid size (8.9 mm to 9.6 mm) following maternal propylthiouracil (PTU) treatment. The series illustrates the clinical management of fetal Graves' disease, highlighting key diagnostic markers: fetal goiter, increased vascularity, and associated signs like exophthalmos, as well as the utility of serial biometry for assessing therapeutic response in utero.

Imaging modality and technique: Gross autopsy photograph of the thyroid gland. The view is a frontal, macroscopic examination of the neck showing diffuse enlargement of both lobes with smooth surfaces and no discrete nodules. The tissue is pink to tan with subtle lobular architecture preserved. This gross appearance corresponds to diffuse hyperplasia and hypertrophy of thyroid follicles seen in Graves disease, producing a diffusely enlarged, symmetric goiter. There are no focal masses or inflammatory lesions evident in this specimen. Clinically, Graves disease is an autoimmune thyrotoxicosis characterized by endogenous hyperthyroidism, ophthalmopathy (exophthalmos), and dermopathy; the autopsy image reflects the thyroid component of that syndrome. Pathophysiology involves stimulation by thyroid-stimulating immunoglobulins that drive diffuse follicular hyperplasia and increased thyroid hormone synthesis. The gross findings support laboratory and clinical data such as suppressed TSH and elevated free T4/T3. Epidemiology notes peak incidence in females aged 20–40 years, with female-to-male ratio ≈10:1. This photograph is valuable for teaching gross pathology, correlating macroscopic thyroid changes with endocrinologic manifestations, and differentiating Graves disease from nodular goiters or thyroiditis in educational and research settings. It also highlights the importance of autopsy correlations in endocrine pathology. Educational utility.

Summary : This figure presents an algorithmic flowchart for the evaluation and management of patients with suspected thyroid nodules, based on ultrasound (US) pattern and fine-needle aspiration (FNA) cytology, referencing the Bethesda system and specific recommendations.

This diagnostic ultrasound image presents two views—transverse (a) and sagittal (b)—of a thyroid nodule, illustrating key features for TIRADS (Thyroid Imaging Reporting and Data System) risk stratification. In both planes, the nodule is characterized as mildly hypoechoic relative to the surrounding brighter (more echogenic) thyroid parenchyma. The nodule possesses a well-defined, ovoid-to-slightly-irregular shape without evidence of macrocalcifications. View (a) demonstrates the nodule's relationship to adjacent vascular structures, appearing as anechoic circular lumens. View (b) shows the nodule in its longitudinal axis, clearly depicting a biopsy needle positioned within the lesion, characteristic of a real-time ultrasound-guided fine needle aspiration (FNA) procedure. The image serves as an educational example of differentiating nodule echogenicity and performing diagnostic interventional procedures. Clinically, this nodule was classified as TIRADS 4A (Kwak system) and TIRADS 3 (M-TIRADS), with a subsequent Bethesda II cytology result indicating a benign process.

Imaging modality: Light microscopy of thyroid tissue; Hematoxylin and eosin stained; 400x magnification. The specimen shows thyroid parenchyma with dense mononuclear inflammatory infiltrate. There are well-developed germinal centers within lymphoid follicles indicating lymphoid folliculopathy; the normal thyroid follicles are small and atrophic and exhibit prominent Hurthle cell (oxyphilic) change with abundant granular eosinophilic cytoplasm. The interface between infiltrate and residual follicles is irregular; the architecture is disrupted with loss of colloid and follicular cell atrophy. The infiltrate is predominantly lymphocytic with plasma cells; occasionally macrophages; formation of organized lymphoid follicles suggests autoimmune thyroiditis. Clinically Hashimoto's disease is associated with anti-thyroid antibodies (anti-TPO, anti-thyroglobulin); this histology correlates with autoimmune hypothyroidism in adults, typically female, around age 60; pediatric cases occur. The diagnostic significance lies in identifying chronic lymphocytic thyroiditis and distinguishing from acute or granulomatous thyroiditis; Hashimoto's increases risk for thyroid lymphoma (MALT, diffuse large B-cell). Differential considerations include subacute thyroiditis, de Quervain's granulomatous thyroiditis, and radiation-induced changes. This image exemplifies classic Hashimoto histopathology: lymphoid follicle formation, Hurthle cell metaplasia, and thyroid parenchymal destruction. Potential clinical applications include educational reference for medical students and residents, differential diagnosis practice, and correlation with serologic autoimmune markers (anti-TPO, anti-Tg) and hypothyroid management.

This histopathology image shows thyroid parenchyma with dense lymphocytic infiltration in the interstitium and prominent germinal center formation, captured on a hematoxylin and eosin stained section. The infiltrate is predominantly CD3+ T cells, with a minority of CD20+ B cells and scattered mature plasma cells. Hyperplastic follicles and well-developed germinal centers are evident in the top-center region, accompanied by preserved thyroid parenchyma interspersed with lymphoid aggregates. The histology demonstrates features consistent with autoimmune thyroiditis, classically seen in Graves disease: chronic lymphocytic infiltration with follicular hyperplasia and organized lymphoid architecture. There may be mild disruption of thyroid follicles, with colloid depletion? In Graves, hyperplasia and lymphoid infiltration; However, the image emphasizes lymphoid follicle formation and interstitial T-cell predominance. Diagnostic significance: correlates with autoimmune thyroid disease activity, supports a diagnosis of Graves-related thyroiditis or Hashimoto-like lymphocytic thyroiditis; appropriate differential considerations include Hashimoto thyroiditis with germinal centers, follicular lymphoma should be considered in unusual clonal proliferation, and other inflammatory processes. This image is valuable for education on thyroid histology, autoimmune pathology, and the morphologic spectrum of lymphoid-rich thyroiditis. Potential clinical use cases include medical education, pathology exam review, and correlation with thyroid function tests and autoantibody profiles to evaluate disease activity and treatment response.