良性後腹腔神經俏劉為較罕見及難於診斷之病變。本文報告兩病例，患者住院前均主訴下腹疼痛及觸摸到硬塊。超音波及電腦斷層除可發現囊腫變化外，對於腫瘤無法提供更準確之診斷。手術切除是唯一治療方法。

Benign retroperitioneal schwannomas are relatinely rare tumors and are difficultto diagnose. Two cases of such tumors are presented. Both patients suffered from abdominal pain and palpable mass before admission. Sonography and computerized tomography(CT) can help to localize the lesion but cannetprovide enough informations to reach a specific pre-operative diagnosis. Cystic change in the tumor may be one of the preoperative features. Complete surgical excision is thetreatment of choice.