粘液状基質を伴った後腹膜線維肉腫の1例

Abstract

54歳男.右腰背部痛を主訴とした.右上腹部に弾性硬, 可動性に乏しい腫瘤を触知し, 超音波検査で肝の下部に径13cm大の腫瘤を認めた.腹部CT検査では後腹膜腔右側に肝臓を後下方より圧排する腫瘍を認め, 腰部MRIでは腫瘍辺縁と内部は不均一な造影増強効果を示した.腎細胞癌, 後腹膜腔由来の粘液型肉腫, 副腎癌などが考えられ腫瘍摘出および右腎合併切除術を施行したが, 腫瘍は癒着が強く根治切除はできなかった.病理組織学的所見では豊富な粘液様基質を背景に紡錘形の腫瘍細胞が束状, 錯綜性の配列を示して密に増殖していた.免疫組織学的にはビメンチンのみ陽性であり, 後腹膜原発線維肉腫と診断した.術後40日目に肝内の再発を認め, CYVADIC療法変法を2コース施行したが, 166日目に癌死した

A 54-year-old male visited a local physician with right dorsolumbar pain as the chief complaint. Ultrasonography revealed a tumor mass 13 cm in diameter at the lower part of the liver, and the patient was referred to our hospital. On abdominal computed tomography, uneven contrast-enhanced effects were recognized in the tumor. On magnetic rescmance imaging studies, T1-weighted images showed a hypoechoic pattern from the kidney and a weak hyperechoic pattern from the muscle. T2-weighted images showed uneven hyperecoic patterns. Uneven contrast-enhanced effects were recognized inside and on the margin of the tumor. A diagnosis of retroperitoneal tumor was made, and surgery was performed. Histopathological examination revealed a fascicular alignment of spindle cells in the area in which the myxoid matrix is seen. On the immunological special test, only vimentin was positive, which led to the diagnosis of fibrosarcoma. Fibrosarcoma originating from retroperitoneal tumor is relatively rare.