Colloid cystの組織起源について—Immunoperoxidase study

ORIGIN OF COLLOID CYST:IMMUNOPEROXIDASE STUDY

　抄録　Colloid cystの組織起源を明らかにする目的でcolloid cyst 8例，および類似の上皮性のう腫2例のパラフィン包埋組織を使用してepithelial membrane antigen （EMA），　tissue polypeptide antigen（TPA），epidermal keratin （EK），およびS−100蛋白のperoxidase anti-peroxidase （PAP）染色を行った。全例がS−100陰性で，colloid cystは上皮表層がEMA陽性，中間の立方状，または円柱状上皮がTPA陽性，基底部の細胞がEK陽性であった。脈絡叢はS−100陽性で，EMA, TPA, EK陰性であった。従ってcolloid cystは免疫組織学的に内胚葉由来であることが示唆される。

Despite their consistent anatomic location and histological features, the histogenesis of colloid cysts has remained obscure. We report immuno-histochemical data on surgically excised cysts in attempt to define the origin of the lining epithelial cells.

Paraffin-embedded tissues from colloidal cysts (7 in the 3rd ventricle and one in the sella) and two similar epithelial cysts (one in the cerebellopontine angle and one in the sella) were investigated.

After examination by conventional stains, im-munoperoxidase studies were carried out using primary antisera against epithelial membrane antigen (EMA), tissue polypeptide antigen (TPA), epidermal keratin (EK) and S-100 protein.

The apical plasma membrane, surface micro-structures were consistently EMA positive. Colum-nar cells demonstrated cytoplasmic staining for TPA. Basal cells of lining epithelia expressed EK. All epithelia studied were negative for S-100 protein. These findings suggest an endodermal origin of colloid cysts.