摘要
背景：對於偶爾出現於門診之舌根異位甲狀腺，病人除了表現出吞嚥及呼吸困難之情形外，經常是沒有特別之病史可供追溯；更由於一般認為病例稀少，往往易因經驗不足而造成診斷上之失誤，所以準確的流行病學及觀念應該被建立。本篇即利用迴溯性的病歷研究以供臨床之參考。 方法：我們收集本院自1992年8月至1998年8月曾接受甲狀腺掃描之病例，共有2439人次，在其中找出異位甲狀腺有61例並分析之。 結果：61例病例中，舌根或舌下異位甲狀腺共有51例，全部都沒有正常位置之甲狀腺。男女比例1比2，其中46例為1個月內之新生兒。颌下異位甲狀腺共有2例，皆為男性，2名病例則有1名具有正常位置的甲狀腺。胸內異位甲狀腺有8名，皆至少有一邊正常位置之甲狀腺。甲狀腺功能則顯示即使甲狀腺荷爾蒙處於正常狀態，大部分病人依然有高濃度促甲狀腺分泌激素。 結論：異位甲狀腺最常見的位置為舌根或舌下，通常無法在正常位置上發現甲狀腺，也就是說舌根異位甲狀腺為唯一的甲狀腺組織。是故當發現舌根或舌下腫瘤時，應該與異位甲狀腺做鑑別診斷，以防經由手術切除病人唯一之甲狀腺。對於已經造成呼吸困難之病人，部份切除或全切除後再移植它處是必需的。由本篇之數據看來，TSH對於異位甲狀腺，不失為一種有效之篩選工具。
並列摘要
BACKGROUND:Ectopic thyroid is a rare disease causing a lump sensation and airway obstruction. Clinicians may misdiagnose it due to lack of experience. To better under-stand the clinical presentation of ectopic thyroid, we conducted this retrospective study to obtain more reliable data on the prevalence and characteristics of ectopic thyroid. METHODS:We reviewed images from 2439 patients who had a thyroid scan(Tc 99m or I-131)from July 1992 to July 1998. There were 61 cases of ectopic thyroid among these patients. The distribution, age, and results of thyroid function tesrs were collected and analyzed. RESULTS:Of the 61 patients, 51 had a lingual or sublingual ectopic thyroid, with a male to female ratio of 1:2(17:34). Among them 46 patients were newborns less than 1 month old. In this group, no isotope uptake at the normal site could be found. The second group with submandibular ectopic thyroid, included two men. One of these two patients had one lobe of normal thyroid. In the third group with intrathoracic thyroid, there were 8 patients and they all had at least one lobe of normal thyroid at the normal site. The thyroid function tests showed that 82% of these hypothyroidic patients had persistent high TSH levels even though their T3, T4 were within normal levels after hormonal replacement therapy. CONCLUSIONS:The most common site of ectopic thyroid was the tongue base or sublin-gual area. The patients had no thyroid tissue at the normal site. This type of ectopic thyroid gland sometimes presents as a mass due to compensatory enlargement. Clinicians should differentiate it from a tumor in the tongue base or sublingual area and avoid remov-ing the thyroid by mistake. If breathing difficulties caused by an enlarged thyroid are noted, partial resection or replantation is preferred. These results also suggest that measurement of the TSH level is useful for screening this not-so-rare disorder.