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benigne Schilddrüsenknoten
Schilddrüsenknoten Radiopaedia • CC-by-nc-sa 3.0 • de
Thyroid nodules are any discrete lesion that can be delineated on imaging studies from the adjacent thyroid parenchyma. They can represent a range of benign or malignant conditions.
Epidemiology
They are more common in females (4:1 F: M) and have an increasing prevalence with increasing age and reduced iodine intake . The incidence is estimated at 0.1% with a lifetime prevalence of 10% .
Clinical presentation
Thyroid nodules are a common incidental finding on imaging (see: incidental thyroid nodules), present in ~10% of CT and MRI neck examinations, ~50% (range 20-76%) of ultrasound neck ultrasound, and 55% (range 50-65%) of autopsies . They can also be found on clinical examination as palpable lesions in the neck, although this clinical finding does not represent a thyroid nodule if there is no imaging correlate.
When symptomatic, patients may present with thyroid dysfunction or rarely compressive symptoms .
Pathology
Thyroid nodules are typically benign. The prevalence of malignancy (based on biopsy) in thyroid nodules is ~10% (range 4-6-15%) .
Etiology
There are many causes of thyroid nodules, some of the more common causes are listed below:
- benign nodules
- follicular adenoma
- Hurthle cell adenoma
- thyroid cyst: simple, hemorrhagic
- focal/asymmetrical thyroiditis
- malignant nodules
- primary thyroid cancer
- papillary thyroid carcinoma
- follicular thyroid carcinoma
- Hurthle cell carcinoma
- poorly differentiated carcinoma
- medullary thyroid carcinoma
- anaplastic thyroid carcinoma
- thyroid lymphoma: primary or secondary
- metastases to the thyroid
- primary thyroid cancer
Radiographic features
Ultrasound is the modality of choice for diagnostic assessment of thyroid nodules . It also allows for ultrasound-guided fine-needle aspiration of selected nodules.
Treatment and prognosis
As thyroid nodules are commonly incidental, there are numerous classification systems to help with risk stratification. See article: Incidental thyroid nodules for further detail.