前言：子宮內膜基質惡性腫瘤為少見的子宮體惡性腫瘤。源發於子宮外如陰道和骨盆腔的病例 則鮮少被報告。子宮體外內膜基質惡性腫瘤主要治療以手術切除為主，而放射線治療之角色仍 不明確。我們期望發展放射線治療對於低惡性度之子宮內膜基質惡性腫瘤，特別於治療子宮體 外之病灶。以下提出兩位病患報告，第一例為手術切除加輔助性放射線治療於原發陰道處腫 瘤，第二例為原發於骨盆腔內並使用放射線治療。 病例報告：第一例病例報告：39 歲女性，症狀表現為大量陰道出血，檢查發現陰道壁靠近子宮 頸開口有一息肉狀腫瘤。經手術切除後病理報告為低惡性度子宮內膜基質惡性腫瘤。術後輔助 性治療使用體外照射劑量 50.4 Gy 分別照射 28 次，加上 2 次近接治療每次劑量為 3 Gy。第二例 病例：59 歲女性，在病患45 歲時因子宮壁內平滑肌瘤接受子宮卵巢切除術。病患現因幾天來 的下腹疼痛和無尿而求診。經電腦斷層檢查後，報告顯示出大小 8 x 5 cm的軟組織腫塊，位於 骨盆腔鄰近左側膀胱三角和輸尿管處，並且侵犯至陰道穹窿頂。切片報告為低惡性度子宮內膜 基質惡性腫瘤。此病患未接受手術而單獨使用放射線治療，劑量為 72 Gy 分別照射 40 次。 結論：放射線治療有較低的復發率。對於提高存活率卻仍有爭議性。然而，放射線治療仍可用 於不適合手術的病患。我們的兩位病例分別在 1 年與 12 年追蹤時間內都顯示無復發。但是受限 於較少的病例數，放射線治療於子宮體外內膜基質惡性腫瘤的效用仍需要進一步的研究來確認。

Background : Endometrial stromal sarcoma (ESS) is a rare malignant tumor of the uterus. Few extrauterine ESS cases arising in vagina and pelvic cavity were reported. The main treatment for extrauterine ESS is surgical resection; however the role of radiotherapy in extrauterine ESS remained unclear. We aimed to explore the value of radiotherapy treating low-grade endometrial stromal sarcoma (LGESS), especially in extrauterine. We presented one case of extrauterine LGESS arising in vaginal wall with surgical treatment and adjuvant radiotherapy and the second case arising from pelvic cavity treated with tumor-directed radiotherapy alone. Case Presentation : Case 1: A 39-year-old woman presented with symptom of excessive vaginal bleeding. A polyp tumor protruding from the vagina wall near cervical os was found on speculum examination. She underwent surgical removal of the mass. The microscopic examination revealed LGESS. Adjuvant radiotherapy was performed using external beam radiotherapy (EBRT) with a dose of 50.4 Gy in 28 fractions and brachytherapy with a dose of 3 Gy x 2 fractions. Case 2: A 59-year-old woman had a past history of abdominal total hysterectomy with bilateral salpingo-oophorectomy due to intramural leiomyoma at age 45 years. She presented with progressive lower abdominal pain and anuria for days. Contrast-enhanced CT scan showed a 8x5 cm soft tissue mass over left pelvic cavity close to trigone of urinary bladder and left ureter, with involvement of vaginal vault apex. Biopsy revealed LGESS. She received tumor-directed radiotherapy with a dose of 72 Gy in 40 fractions without surgical resection. Conclusions : Radiotherapy provide lower recurrence rate, but the result of overall survival was still in controversy. It can be considered in patients who are unsuitable for surgical resection. Our 2 cases had no evidence of recurrence in 1 year and 12 years of follows-up. Because of the paucity of extrauterine ESS, further investigation is needed to determine the benefit of radiotherapy.