| disease | Thyroid Adenoma |
Thyroid adenoma originates from the thyroid follicular tissue and is the most common benign tumor of the thyroid. This disease is sporadically distributed nationwide and is slightly more prevalent in areas endemic for goiter.
bubble_chart Pathological Changes
Thyroid gland tumor diseases can be pathologically divided into two types: follicular adenoma and papillary cystic adenoma. The former is more common. The cut surface appears pale yellow or dark red and has a complete membrane. The latter is less common than the former and is characterized by the formation of papillary projections. Most are single nodules, with slow development and a long course of disease.
bubble_chart Clinical Manifestations
The majority of patients are women, typically under the age of 40, and usually present with a single nodule within the thyroid gland, with multiple nodules being rare. The tumor is round or oval in shape, confined to one lobe of the gland, slightly firmer in texture than the surrounding thyroid tissue, with a smooth surface and well-defined borders, non-tender, and moves up and down with swallowing. It grows slowly, and most patients experience no symptoms. Papillary cystic adenomas may occasionally develop intratumoral hemorrhage due to rupture of the cystic wall blood vessels. In such cases, the tumor size can rapidly increase within a short period, accompanied by a sensation of local distending pain.
The diagnosis of thyroid adenoma is primarily determined based on medical history, physical examination, isotope scanning, and "B"-mode ultrasound, among other tests.
1. A painless neck mass in the anterior region, asymptomatic in the early stages, with occasional swallowing discomfort or a choking sensation. More common in middle-aged women.
2. A single round nodule can be palpated within the thyroid gland, occasionally multiple. The surface is smooth, boundaries are clear, not adherent to the skin, and moves up and down with swallowing. The texture varies: solid nodules are soft, while cystic ones are hard. Some patients experience sudden enlargement due to tumor hemorrhage, accompanied by local distending pain and tenderness, along with transient hyperthyroidism symptoms. As the tumor grows, it may cause compression symptoms in adjacent organs and tissues.3. Radionuclide scanning may reveal a "warm nodule," while cystic nodules appear as "cold nodules." Thyroid uptake of 131 iodine is generally normal.
4. B-mode ultrasound can distinguish whether the adenoma is solid or cystic.
bubble_chart Treatment Measures
Given that approximately 10-15% of thyroid adenomas are pathologically confirmed as malignant, and about 20% can lead to secondary hyperthyroidism, surgical treatment should be performed as early as possible once the diagnosis is confirmed. Clinically, it is often difficult to distinguish thyroid adenomas from stony goiter (thyroid carcinoma), especially in the early stages. Therefore, simple adenoma enucleation is generally not recommended; instead, subtotal or total lobectomy of the affected side should be performed. The excised specimen should be immediately sent for frozen section examination to determine the presence of malignancy. If malignancy is confirmed, it should be managed as stony goiter (thyroid carcinoma).
Thyroid adenoma should be differentiated from other thyroid nodules.
Clinically, it is sometimes difficult to distinguish between thyroid adenoma and the solitary nodule of nodular goiter. The following two points may serve as references for differentiation: ① Thyroid adenoma remains solitary for many years, whereas the solitary nodule of nodular goiter often progresses to multiple nodules over time. ② The intraoperative distinction is clear: adenomas have a complete capsule with normal surrounding tissue and well-defined boundaries, whereas the solitary nodule of nodular goiter lacks a complete capsule and is surrounded by abnormal thyroid tissue.
The following points may serve as references for differentiation from stony goiter (thyroid carcinoma): ① The possibility of stony goiter (thyroid carcinoma) should be considered in children or male patients over 60 years old, whereas thyroid adenoma is more common in female patients under 40. ② The nodule of stony goiter (thyroid carcinoma) has an irregular surface, is hard in texture, shows limited mobility during swallowing, and grows rapidly within a short period. Sometimes, even if the thyroid nodule is small, enlarged lymph nodes may be palpable on the same side of the neck. In contrast, thyroid adenoma has a smooth surface, is soft in texture, shows significant mobility during swallowing, grows slowly, and usually does not present with cervical lymphadenopathy. ③ 131 Iodine scanning or radionuclide γ imaging often reveals a cold nodule in stony goiter (thyroid carcinoma), whereas thyroid adenoma may present as a warm, cool, or cold nodule. Cold nodules often appear cystic on "B" ultrasound. ④ During surgery, stony goiter (thyroid carcinoma) typically lacks a capsule and shows adhesion or infiltration into surrounding tissues, whereas thyroid adenoma usually has a complete capsule with normal surrounding thyroid tissue.
