孤発性直腸神経節細胞腫の1例

Sporadic Rectal Ganglioneuroma, Report of a Case

要旨●患者は60歳代，男性．背景に遺伝性疾患なし．結腸憩室出血後の大腸内視鏡検査にて，上部直腸（Ra）に径40mm大の境界不明瞭な上皮下腫瘍様の扁平隆起性病変を認めた．病変内には結節状小隆起を伴っていた．NBIでは拡張した血管が観察され，クリスタルバイオレット染色では不均一に疎に分布するI型のpitが観察された．EUSで第2〜3層にかけて，壁肥厚を伴う境界不明瞭な軽度低エコー領域として描出された．診断的加療目的にESDで切除し，病理組織学的所見にて上皮直下の粘膜固有層〜粘膜下層にかけて神経線維と紡錘形細胞がびまん性に増生し，内部に神経節細胞が散見され，神経節細胞腫と診断した．

　A male patient in his 60s with no hereditary disease underwent colonoscopy, which revealed a flattened, submucosal tumor-like lesion of 40mm in diameter with indistinct borders in the upper rectum. The lesion was accompanied by a small nodular ridge. Narrow band imaging revealed dilated blood vessels, and crystal violet staining demonstrated heterogeneous sparse nonneoplastic pits. Endoscopic ultrasonography detected a mildly hypoechoic area with indistinct borders in layers 2-3 with wall thickening. Diagnostic treatment included endoscopic submucosal dissection. Histopathological examination indicated a diffuse proliferation of nerve fibers and spindle-shaped cells from the mucosal intrinsic layer just below the epithelium to the submucosal layer, with scattered ganglion cells in the interior, leading to the diagnosis of ganglioneuroma.