Reference
Medical Dictionary
300 ENT terms selected from a 3,008-entry working corpus. Entries are readable; organic publication requires documented medical review.
Medical review is in progress
These 300 entries are accessible for information. Entries without documented medical sign-off remain excluded from search indexing and entry-level medical structured data.
Thyroid & Parathyroid
78 selected termsThyroglobulin Monitoring in Thyroid Cancer
Recurrence marker used in differentiated thyroid cancer follow-up after total thyroidectomy and RAI ablation; interpretation complicated by TgAb presence, stimulated Tg is superior to suppressed Tg.
Read more →Whole-Body Scintigraphy (WBS)
Nuclear medicine method using I-131 or I-123 to evaluate residual thyroid tissue and suspected distant involvement during differentiated thyroid malignancy review.
Read more →PET-CT in Thyroid Cancer Follow-up
The role of FDG-PET/CT in interpreting suspected RAI-resistant disease and dedifferentiation in differentiated thyroid malignancy; one advanced imaging option when Tg is high but WBS is negative.
Read more →Thyroid Cancer Staging
Thyroid cancer classification according to the AJCC/TNM staging system; age threshold, different T/N/M criteria by pathological subtype and critical role in prognosis prediction.
Read more →Neck Dissection in Thyroid Cancer
Surgical removal of central or lateral neck lymph nodes in metastatic or high-risk thyroid cancer, planned according to confirmed nodal disease and risk level.
Read more →TSH Suppression Therapy
Levothyroxine strategy that suppresses TSH in differentiated thyroid cancer to reduce recurrence risk while balancing cardiac and bone side effects.
Read more →Thyroid Molecular Testing
Molecular diagnostic platforms helping determine malignancy risk with BRAF, RAS, RET/PTC, PAX8/PPARG mutations and gene expression classifiers (Afirma, ThyroSeq) in Bethesda III-IV indeterminate thyroid nodules.
Read more →RET Proto-Oncogene
RET proto-oncogene mutations strongly associated with medullary thyroid carcinoma and MEN 2A/2B syndromes; germline RET results influence family screening and prophylactic-surgery timing.
Read more →BRAF V600E Mutation in Thyroid Cancer
BRAF V600E mutation can be seen in papillary thyroid carcinoma; it may be associated with more aggressive histology, extrathyroidal extension and RAI resistance and is a target for inhibitor therapy.
Read more →Parathyroid Glands
Four small endocrine glands located on the posterior surface of the thyroid gland, secreting PTH to regulate calcium-phosphate balance; their preservation is critically important in thyroid surgery.
Read more →Hyperparathyroidism
Endocrine disorder developing from excessive PTH secretion from parathyroid glands, causing hypercalcemia, kidney stones, bone erosion and neuropsychological symptoms; primary, secondary and tertiary types exist.
Read more →Parathyroid Adenoma
Benign tumor of a single parathyroid gland and one of the most common causes of primary hyperparathyroidism; localization imaging and surgical options are reviewed together.
Read more →Secondary Hyperparathyroidism
Reactive PTH increase developing due to chronic kidney disease, vitamin D deficiency or malabsorption; surgical options may be discussed in advanced cases resistant to medical therapy.
Read more →Thyroid Ultrasound and TI-RADS Classification
Thyroid ultrasound categorises nodules by the ACR TI-RADS 2017 system into risk categories TR1–TR5; TR4 (≥3 points) and TR5 (≥7 points) nodules are evaluated against size-based biopsy thresholds.
Read more →Medullary Thyroid Carcinoma
Medullary thyroid carcinoma (MTC) is a neuroendocrine tumour arising from parafollicular C cells that secretes calcitonin, representing 3–5% of thyroid cancers; 25% of cases are hereditary (MEN2A/2B or familial MTC).
Read more →Thyroid Fine-Needle Aspiration Biopsy — Technique
Ultrasound-guided thyroid fine-needle aspiration biopsy (FNA) uses a 25G needle to obtain cellular specimens from nodules; diagnostic adequacy is approximately 90%, and it is the standard diagnostic method per ATA 2015 and ETA guidelines.
Read more →Thyroid Scintigraphy
Thyroid scintigraphy using Tc-99m pertechnetate or I-123 provides functional thyroid imaging; it identifies 'hot' (hyperfunctioning) nodules, differentiates Graves' disease from toxic multinodular goitre, and is used for RAI treatment dose calculation.
Read more →Complications of Thyroid Surgery
Major complications of thyroid surgery include recurrent laryngeal nerve (RLN) palsy (0.5–2% permanent), hypoparathyroidism (1–3% permanent), and haemorrhage (<1%); surgeon experience is the dominant determinant of these rates.
Read more →Reoperative Thyroid Surgery
Reoperative thyroid surgery is performed in patients with prior thyroid operations for residual or recurrent disease and carries complication rates 2–3 times higher than primary surgery.
Read more →Total Thyroidectomy vs. Lobectomy: Decision Criteria
ATA 2015 guidelines state that lobectomy is an acceptable alternative to total thyroidectomy for 1–4 cm papillary or follicular carcinoma without contralateral involvement, extrathyroidal extension, RAI requirement, or nodule >4 cm.
Read more →Thyroid Hormone Replacement Therapy
Thyroid hormone replacement targets TSH within the reference range (0.5–4.5 mIU/L) using synthetic levothyroxine (LT4) as standard therapy for hypothyroidism; dosing must be individualised by age, weight, and comorbidities.
Read more →Radioiodine-Refractory Differentiated Thyroid Cancer
Radioiodine-refractory DTC (RAI-refractory DTC) is defined by loss of I-131 uptake or lack of response to RAI therapy; kinase inhibitors such as sorafenib or lenvatinib are the standard of care in this setting.
Read more →Thyroid Nodule Surveillance Protocol
ATA 2015 and ACR TI-RADS 2017 guidelines define thyroid nodule surveillance by risk category: TR5/high suspicion annually, TR4/intermediate 1–2 yearly, TR3/low suspicion every 2–3 years, and TR1–2/very low suspicion may not need follow-up beyond 5 years.
Read more →Types and Classification of Thyroiditis
Thyroiditis is a heterogeneous group of inflammatory thyroid conditions encompassing autoimmune (Hashimoto's, Graves'), subacute granulomatous (De Quervain's), silent/postpartum, drug-induced (amiodarone, lithium, checkpoint inhibitors), and acute suppurative thyroiditis subtypes.
Read more →Autoimmune Thyroiditis
Autoimmune thyroiditis describes a group of diseases characterised by chronic lymphocytic inflammation of the thyroid mediated by thyroid antibodies (TPOAb and/or TgAb); Hashimoto's thyroiditis (atrophic or goitrous) and Graves' disease are the primary forms.
Read more →TSH Interpretation
Thyroid-stimulating hormone (TSH) is the single most sensitive indicator of thyroid function; the reference range is 0.4–4.0 mIU/L, but interpretation varies by age, pregnancy, and clinical context.
Read more →Free T4 and T3 Interpretation
Free T4 (FT4) reference range is 0.8–1.8 ng/dL (10–23 pmol/L) and free T3 (FT3) is 2.3–4.2 pg/mL (3.5–6.5 pmol/L); interpreted alongside TSH they differentiate pathology at all levels of the thyroid axis.
Read more →Thyroid Antibody Interpretation
Thyroid antibodies are evaluated in three main groups — TPOAb (thyroid peroxidase antibody), TgAb (thyroglobulin antibody), and TRAb (TSH receptor antibody) — and guide diagnosis, risk stratification, and treatment decisions in autoimmune thyroid disease.
Read more →Thyroglobulin — Thyroid Cancer Surveillance Marker
Thyroglobulin (Tg) is the primary surveillance biomarker for differentiated thyroid cancer (DTC) after total thyroidectomy and RAI ablation; stimulated Tg >1 ng/mL or basal Tg >0.2 ng/mL (under LT4 suppression) raises suspicion of structural recurrence.
Read more →Thyroid Cancer Recurrence
Recurrence in differentiated thyroid cancer (DTC) occurs cumulatively in 10–30% over 20 years after surgery and RAI; cervical lymph node recurrence is most common (80%), distant metastasis recurrence (20%) is less frequent but demands aggressive management.
Read more →Neck Dissection in Thyroid Cancer
In differentiated thyroid cancer, neck dissection is planned as compartment-based central (Level VI) or lateral (Level II–V) based on the spread pattern; prophylactic central dissection remains controversial while therapeutic dissection is standard for imaging-positive lymph nodes.
Read more →Pharmacology of Hyperthyroidism
Pharmacological treatment of hyperthyroidism uses thionamides (methimazole, propylthiouracil) to block thyroid hormone synthesis; beta-blockers provide symptomatic control and serve as bridging therapy until definitive treatment (RAI or surgery) is planned.
Read more →Parathyroid Adenoma
Parathyroid adenoma is the most common cause of primary hyperparathyroidism (85–90% of cases); it is defined by elevated PTH and calcium, and parathyroidectomy is recommended in symptomatic patients or when calcium exceeds ULN by >1 mg/dL.
Read more →Parathyroid Hormone (PTH) Interpretation
Intact PTH (iPTH) reference range is 15–65 pg/mL (1.6–6.9 pmol/L); interpreted alongside calcium levels, it differentiates parathyroid axis disorders including hyperparathyroidism, hypoparathyroidism, and pseudohypoparathyroidism.
Read more →Calcium Regulation
Normal serum calcium range is 8.5–10.5 mg/dL (2.12–2.62 mmol/L); it is tightly regulated through a negative feedback mechanism involving PTH, calcitriol (active vitamin D), and calcitonin.
Read more →Treatment of Hypoparathyroidism
The cornerstone of hypoparathyroidism treatment is oral calcium (1.5–3 g/day) combined with active vitamin D (calcitriol 0.25–2 mcg/day); serum calcium is maintained at 8.0–9.0 mg/dL with urinary calcium <300 mg/day to prevent nephrocalcinosis.
Read more →Thyroid Volume Calculation
Thyroid volume is calculated by ultrasound using the ellipsoid formula: length × width × depth × 0.479 for each lobe (Brunn formula); normal adult thyroid volume is <25 mL in men and <18 mL in women.
Read more →Endoscopic Ultrasound of the Thyroid Nodule
Endoscopic ultrasound (EUS) is an advanced imaging and sampling technique that enables diagnostic biopsy of thyroid nodules or lymph nodes with retrooesophageal or mediastinal extension where transcervical access is limited.
Read more →Thyroglossal Duct Cyst
A thyroglossal duct cyst is a congenital cystic lesion arising from a persistently patent duct remaining from embryonic thyroid migration (from the foramen caecum to the thyroid bed); it is the most common midline neck cyst (75%) in children and young adults.
Read more →ENT — General
80 selected termsSinusitis
Inflammation of the paranasal sinuses; it may present in acute, subacute or chronic clinical forms.
Read more →Allergic Rhinitis
IgE-mediated inflammation of the nasal mucosa triggered by allergen exposure; may be seasonal or perennial.
Read more →Functional Endoscopic Sinus Surgery (FESS)
Minimally invasive endoscopic surgery aimed at widening sinus ostia and removing diseased tissue to treat chronic sinusitis or nasal polyposis.
Read more →Nasal Polyp
Soft, painless growths developing from the nasal or sinus mucosa that can cause nasal obstruction and loss of smell.
Read more →Adenoid
A mass of lymphoid tissue in the nasopharynx that, when enlarged, can cause nasal obstruction, sleep apnoea and recurrent ear infections.
Read more →Tonsil
Lymphoid tissue on each side of the throat; surgery may be needed in cases of recurrent tonsillitis or hypertrophy causing obstruction.
Read more →Epistaxis (Nosebleed)
Bleeding from the nasal mucosa; most episodes originate from the anterior area at the Kiesselbach plexus.
Read more →Obstructive Sleep Apnoea (OSA)
A syndrome in which the upper airway repeatedly collapses during sleep, causing oxygen desaturation and sleep fragmentation.
Read more →Snoring
Sound produced by vibration of the soft palate and throat tissues during sleep; may be a symptom of sleep apnoea.
Read more →Have a question about your condition?
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