周邊許旺氏細胞瘤之診斷與治療

Diagnosis and Treatment of Peripheral Schwannoma

許旺氏細胞瘤是一種非侵襲性、邊界清楚的良性腫瘤，是成人最常見的良性神經鞘腫瘤。通常發生在周邊神經鞘，好發於30至50歲的成年人。雖然腫瘤生長緩慢，不過腫塊效應可能會壓迫神經束，形成疼痛或是感覺異常等症狀。影像診斷以超音波和磁振造影為主，超音波上的表現為低回聲，且有後方回音增強；磁振造影的T1加權成像(T1-weighted)影像為一般強度或是低強度訊號，在T2加權成像(T2-weighted)影像為高強度訊號。且有一點異質性表現。組織病理切片會發現Antoni A和Antoni B的型態，且免疫染色可見S-100蛋白。因為腫瘤生長緩慢．若無症狀保守觀察且定時追蹤即可；若出現會影響日常的疼痛或感覺異常，可以接受手術切除腫瘤，術後長期追蹤並無明顯的後遺症，且幾乎不會復發。

Schwannoma is a benign, noninvasive and well-defined tumor. It`s also the most common type of benign nerve sheath tumors. Schwannoma originates from the nerve sheath and has a peak incidence in adult between 30 and 50 years old. Despite slow growth of the schwannoma, pain and paresthesia would be emerged secondary to nerve compression and local mass effect. Ultrasonography and MRI are helpful in diagnosis. Schwannoma is a hypoechoic mass and has the posterior acoustic reinforcement on ultrasonography. MRI showed iso- or hypointense in T1-weighted images with mildly heterogeneous hyperintense in T2-weighted images. Antoni A and Antoni B tissue would be presented in histopathology with positive S-100 protein in immunohistochemistry. Conservative treatment and routine follow up are recommended due to its slow progression. Surgical excision with intracapsular enucleation can be performed if it is causing pain, paresthesia or growing quickly. No apparent sequelae was noted in long-term follow-up with low recurrence rate.