Autonomous hyperfunctioning thyroid adenoma

Introduction to autonomous hyperfunctional thyroid adenoma Autonomous hyperfunctioning adenoma (autonomous hyperfunctioning adenoma), also known as toxic adenoma (toxicadenoma), or hyperactive hyperthyroid adenoma, refers to hyperthyroidism caused by a single or multiple high-functioning adenoma in the thyroid gland. A type of disease, the disease progresses slowly, more than when the doctor or other people find it, women over 40 years old are more common, when the tumor is small, it can be asymptomatic. When the tumor is large, there may be typical hyperthyroidism symptoms. Rarely, the number of cases discovered has increased since the application of thyroid imaging technology. Because thyroid nucleus imaging is a "hot nodule" at the adenoma or nodule (131I concentration at the nodule), and this nodule is not regulated by TSH, it is called autonomous high-function thyroid adenoma. . basic knowledge The proportion of illness: the incidence rate is about 0.004% - 0.009% Susceptible people: no specific population Mode of infection: non-infectious Complications: hyperthyroidism

The cause of autonomic hyperfunctional thyroid adenoma

Cause

This disease is different from toxic nodular goiter, the exact cause is not very clear, mainly for thyroid nodules (adenomas) partial function increase, and autonomy, that is, not regulated by TSH of the pituitary, and extranodal thyroid tissue Still maintain normal feedback, but when the adenoma is larger (more than 3cm), excessive secretion of thyroxine can cause hyperthyroidism. Most pathological examinations of toxic solitary nodules are follicular adenomas, and a few are cancers.

Pathogenesis

This disease is different from toxic nodular goiter, mainly for thyroid nodules (adenomas), and has autonomy, that is, it is not regulated by TSH of the pituitary, and the extranodal thyroid tissue still maintains normal feedback, but When the adenoma is large (more than 3cm), excessive secretion of thyroxine can cause hyperthyroidism. Most pathological examinations of toxic solitary nodules are follicular adenomas, and a few are cancers.

Pathological examination showed adenoma changes in the nodules. Under the microscope, there were hyperplastic follicles in the nodules. The nucleus was large, and the central position contained less gelatinous tissue. The epithelium was cuboidal and could absorb vacuoles.

Autonomic hyperfunctional thyroid adenoma prevention

Prognosis:

1. The remaining thyroid tissue in most patients after surgery can restore function, no need to supplement thyroid hormone.

2. For patients without surgical conditions or with multiple nodules, radiotherapy after 131I treatment is usually satisfactory.

Prevention: To avoid radiation damage, dry thyroid tablets can be taken several days before 131I treatment.

Autonomic hyperfunctional thyroid adenoma complications Complications

Can be complicated by T3 type hyperthyroidism: clinical manifestations similar to the common type, may be associated with goiter, eye disease, but the symptoms are mild, check T4, FT4 normal or low, and T3, FT3 increased, treatment is the same as hyperthyroidism.

Autonomic hyperfunctional thyroid adenoma symptoms Common symptoms Vascular murmur gaze ectopic nodules weight loss diarrhea

The onset of this disease is quite slow. It is more common in middle-aged and elderly patients aged 40-60 years. Most of them have neck nodules, which gradually increase. The symptoms of hyperthyroidism appear only a few years later. The symptoms of hyperthyroidism are generally mild. Most patients have only tachycardia. Fast or weak, thin or diarrhea, no skin lesions of the eye and Graves' disease, but may have cleft palate and gaze.

The thyroid palpation can be smooth and smooth oval nodules, the boundary is clear, the texture is solid, and it can move up and down with swallowing. The auscultation of the neck has no vascular murmur. The longer the course of disease, sometimes the adenoma sometimes has its own degenerative changes during the course of the disease. It can be necrotic, atrophic, degenerative or disappearing, or the degenerative changes of individual cases after TSH stimulation can cause the adenoma to disappear.

Examination of autonomous hyperfunctional thyroid adenoma

In the early stage of the disease, the level of thyroid hormone in the serum is normal. Only when the symptoms of hyperthyroidism are more obvious, the T3 and T4 in the serum will increase. The disease often manifests as T3 type hyperthyroidism. Conversely, the T3 type hyperthyroidism Toxic adenomas are common, TRH stimulation test or T3 inhibition test, in the early stage of the disease, there is no abnormality, only after the occurrence of hyperthyroidism symptoms have a corresponding positive performance, so these tests for the diagnosis of this disease only Partial reference meaning.

1. The 131I rate of thyroid can be normal or slightly elevated.

2. The T3 inhibition test showed that 131I was not inhibited by exogenous T3 (or no response by TRH stimulation test), indicating autonomy of thyroid nodules.

3. Serum thyroid hormone (T3, T4) determination Most patients with T3, T4 increased, some patients only have T3 increased, that is, T3 type hyperthyroidism, so combined determination of blood T3, T4 can better reflect the thyroid function status, there are Helps determine if the patient has hyperthyroidism.

4. Fine needle aspiration cytology excludes malignant lesions, providing a basis for treatment options.

The 131I or 99mTc thyroid imaging examination is most meaningful for the diagnosis of this disease. The vast majority of patients have a single "hot nodule", the nodular part is a radioactive concentrated "hot nodule", and the surrounding atrophic thyroid gland The tissue is only partially displayed (Fig. 2). Even if H is excited, the surrounding thyroid tissue can be redeveloped. Very few patients can have multiple "hot nodules", and the thyroid tissue outside the nodule is sucked. Iodine function is inhibited.

Diagnosis and differentiation of autonomous hyperfunctional thyroid adenoma

Mainly relying on clinical manifestations and radionuclide imaging, determination of T3 and T4 in serum can help to determine whether patients have hyperthyroidism, thyroid nodules in middle-aged and elderly people, clinical tachycardia, weight loss, fatigue or diarrhea, accompanied by With or without symptoms of hyperthyroidism, serum T3, T4 increased, or only T3 increased, T4 normal, TSH can be decreased, TSH low response or no reaction, 131I rate is normal or elevated, for thermal nodule inhibition test The negative person was diagnosed as the disease.

When radioactive thyroid imaging is performed, the thyroid tissue around the nodule is atrophied due to feedback inhibition by TSH. It can be completely undeveloped or developed very lightly. It should be differentiated from congenital one-leaf thyroid deficiency when it is not developed. Exogenous TSH 10U, then repeated scans, re-developed suppressed atrophic thyroid tissue, can be diagnosed as autonomous high-function thyroid adenoma.

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