腫瘍核出術を施行した骨盤内神経鞘腫の1例

Abstract

36歳男性.患者は頻尿にて近医を受診し, 超音波検査にて骨盤内の腫瘤を指摘され, 紹介入院となった.所見では, 下腹部に可動性のない手拳大の腫瘤を触知し, 血中S100蛋白の軽度高値を認めた.超音波断層法では下腹部に嚢胞状の腫瘤を, CTでは骨盤内の仙骨前面に一部石灰化を伴った内部不均一な16×12×11cmの腫瘤を認め, MRIでは実質部分はT1強調像で低信号, T2強調像で不均一な高信号を示した.更に血管造影では正中仙骨動脈から腫瘍への栄養血管を認め, 生検ではS100免疫染色陽性の良性神経鞘腫で, 開腹下に腫瘍摘出術を行った.腫瘍の骨盤内占拠で術中操作困難のため腫瘍被覆切開で内容を核出し, 強固な仙骨癒着部の一部を残して腫瘍を摘出した.病理診断はAntoni A型の良性神経鞘腫であった.術後血中S100蛋白は低下し, 術後1年6ヵ月経過で再発の徴候はない

A 36-year-old man with a complaint of pollakisuria visited our hospital. A non-displaceable, palm-sized tumor was palpable in the lower abdomen. Laboratory data were normal except for slightly high serum S100 protein. Intravenous pyelography revealed hydronephrosis on the right side and deviation of the bladder to the left. Computed tomogaphy revealed a heterogenous tumor in the pelvis with a cystic lesion and calcification. The tumor was 16 x 12 x 11 cm in size and in contact with the sacrum. The tumor was extirpated following diagnosis as a benign schwannoma by needle biopsy. The pelvic cavity was occupied by the tumor rigidly adhered to the sacrum. Although serious complications, such as bleeding and nerve injury were apprehended, we incised the tumor capsule and enucleated the contents as much as possible. The histopathological diagnosis of the resected specimen was benign schwannoma, type Antoni A. In the last 10 years, 37 cases of pelvic schwannoma have been reported in the Japanese literature. In most of them, surgical extirpation was difficult to perform because of adhesion to the sacrum. If the tumor is confirmed benign from histopathologic findings preoperatively, tumor enucleation may become a therapeutic option.