Ultrastructural Study on the Histogenesis of Alveolar Soft Part Sarcoma

本文对6例腺泡状软组织肉瘤进行了超微结构观察，以了解肿瘤中是否含有与浆膜内陷有关的光滑管状结构。两种不同的光滑管状结构被确定为：聚集型和分散型。前者在质膜附近有许多细长的光滑小管的明显聚集体，而后者则在细胞质中散在一些不明显的光滑小管束。两种类型的共同组成部分是光滑小管。因此，很可能这两种类型有相同的起源，尽管在数量，外观和分布之间存在一些差异。根据管腔内含物的不同，将两种类型的光滑小管分为三个不同的亚型。经细胞膜示踪法观察，两型中有3例光滑小管的细胞膜连续性，提示管状结构起源于细胞膜。由于6例均见管状结构，故肿瘤多为管状结构。分型和亚型的建立有助于鉴别肿瘤的结构。目前尚不清楚这些结构是否是T小管的残余。

The smooth tubular structures associated with plasmalemmal invaginations were made an ultrastructural search for in 6 alveolar soft part sarcomas to known whether the tumor s usually contained them or not. Two different smooth tubular structures were identified : the aggregated type and the dispersed one. The former had marked aggregates of many elongated smooth tubules without ribosomes close to plasmalemma whereas the latter showed inconspicuous bundles of a few smooth tubules scattered in the cytoplasm. The common components of both types were smooth tubules. Therefore, it is likely that both types had the same origin although there were some differences in number, appearance, and distribution between the types. The smooth tubules of both types were classified into three different subtypes on the basis of inclusive materials in the lumen. A plasmalemmal continuity of smooth tubules in both types was found in 3 cases after intensive observation and using a plasmalemmal tracer-method, suggesting that the tubular structures originated from plasmalemma. Since the tubular structures were found in all 6 cases, the tumors might usually have the tubular structures. The establishment of types and subtypes was helpful to identify the structures in the tumors. It has remained unclear whether the structures are the remnants ot T-tubules ornot.