Overview of thyroid adenocarcinoma

Why does thyroid cancer occur? In fact, there is still no accurate answer so far! But if we want to prevent and treat thyroid cancer, we must understand some relevant knowledge about this disease! So today we will learn about the overview of thyroid cancer!

1. Cause: The cause of thyroid cancer is still unknown. Some people believe that its occurrence is related to chronic thyroid-stimulating hormone stimulation.

2. Pathological classification and biological characteristics: Different pathological types of thyroid cancer have very different development processes and metastatic pathways, and their treatments are also different. Pathologically, they can be divided into:

① Papillary carcinoma: It accounts for about 60% of thyroid cancers. It is more common in young people. It grows slowly and is of low grade malignancy. It often metastasizes to the deep cervical lymph nodes. Some people also believe that papillary carcinoma is multicentric or has contralateral metastasis.

② Follicular carcinoma: It accounts for about 20% of thyroid cancers, mostly in middle-aged people, with moderate malignancy, rapid development, and early metastasis to cervical lymph nodes. However, it mainly metastasizes to bones and lungs through blood.

③ Medullary carcinoma: Occurs in parafollicular cells (C cells) outside the follicular epithelium. There are two types: scattered and familial, accounting for about 5% to 10%. The cells are arranged in bands or bundles, without papillae or follicular structures, and there are amyloid deposits in the stroma. It secretes a large amount of serotonin and calcitonin. Histologically, it is undifferentiated, but its biological characteristics are different from those of undifferentiated carcinoma. It is moderately malignant, with early cervical lymph node metastasis and distant metastasis in the late stage. Familial medullary carcinoma often affects both lobes at the same time.

④ Undifferentiated carcinoma: It accounts for about 10% to 15% of thyroid cancers. It can be divided into small cell and giant cell types according to its cell morphology. It mostly occurs in the elderly. This type develops rapidly and is highly malignant. It metastasizes to the cervical lymph nodes in the early stage, can invade the recurrent laryngeal nerve, trachea or esophagus, and can metastasize to the bones and lungs through the blood.

⑤ Squamous cell carcinoma: rare, accounting for about 0.8% to 2.2%, more common in the elderly, no obvious relationship with gender, it may be derived from squamous thyroid follicular epithelial metaplasia, or embryonic residual squamous epithelial tissue. Generally, it is of unifocal origin, the tumor cells are highly invasive, grow faster, and have a shorter doubling time. Lymph node metastasis can be seen, and blood metastasis is rare.

3. Clinical manifestations: There are usually no obvious symptoms in the early stage of the disease, except for the appearance of a hard and uneven nodule in the thyroid tissue. In the late stage, it often compresses the recurrent laryngeal nerve, trachea, and esophagus, causing hoarseness, dyspnea, or dysphagia. If the cervical sympathetic nerve is compressed, Horner syndrome may occur (manifested by constriction of the pupil on the same side, ptosis of the upper eyelid, enophthalmos, and anhidrosis on the head and face on the same side). When the superficial branches of the cervical plexus are damaged, the patient may have pain in the ear, occipital bone, shoulder, etc. Local metastasis is often in the neck, with hard and fixed lymph nodes. Distant metastasis is often seen in dry flat bones (such as the skull, vertebrae, and pelvis) and lungs.

Some patients have no obvious thyroid tumors, but metastatic cancer in the neck, lungs, and bones is the prominent symptom. Therefore, when there is metastatic cancer of unknown primary focus in the neck, lungs, and bones, the thyroid should be carefully examined.