Knölstruma

Knölstruma, also known as multinodular goiter (MNG), is a thyroid enlargement characterized by the growth of multiple nodules within the gland. It typically develops over years and is more common in women and in areas with iodine deficiency, though the exact cause is often multifactorial, including aging and genetic predisposition. The nodules may vary in function, leading to a spectrum from euthyroid to hypothyroid or hyperthyroid states.

Clinical presentation ranges from a visibly enlarged neck to a palpable goiter. Many cases are asymptomatic. Large nodular goiters can cause compressive symptoms such as difficulty swallowing, breathing problems, or hoarseness, and may be associated with cosmetic concerns.

Diagnosis starts with physical examination and thyroid function tests (TSH, free T4, and sometimes T3) to assess hormone production. Ultrasound is the primary imaging method and typically shows multiple nodules of varying sizes. Fine-needle aspiration biopsy is performed for nodules that are suspicious for malignancy or larger than about 1 cm. Radionuclide thyroid scintigraphy can help determine whether nodules are functioning (hot) or non-functioning (cold), especially if hyperthyroidism is suspected. Cancer risk in multinodular goiter is present but generally low; any suspicious nodule warrants evaluation.

Management depends on symptoms, function, and cancer risk. Small, asymptomatic MNGs may be observed with regular follow-up. Large or symptomatic goiters, or those with suspicious nodules, are often treated surgically (hemithyroidectomy or total thyroidectomy). Hyperfunctioning nodules may be treated with radioiodine therapy or anti-thyroid drugs. Post-treatment, some patients require lifelong thyroid hormone replacement. Prognosis is usually favorable with appropriate management.