組織診断困難な皮膚腫瘍の1例（Histiocytoma ?）

HISTIOCYTOMA ?

I．はじめに

　私達は最近，29歳，女性の右膝蓋骨外上方皮膚に生じ，組織診断上非常に難解であつた軟部組織腫瘍の1例を経験したので報告する。

A case with a skin tumor on the right patellar region in a 29-year-old woman, whose histolo-gical diagnosis was difficult to make, was reported.

It was situated in the deeper layer of the dermis, and composed of mesenchymal cells, small number of foam cells, mast cells and lymphatic vessels. The nuclei of the tumor cells were round or oval, but some were kidney-spindle-shaped, or indented. They showed some irregularity in size containing moderate to small amount of chromatin, with fine nuclear structure and small nucleolus.

Their cytoplasm was faint acidphilic, not so well demarcated, and finely reticulated.

Scatteredly or massively arranged foam cells containing sudanophilic substance were mixed with the main tumor cells.

Lymphatic vessels and cavities (?) were scattered in the tumor, which contained eosinophilic homogeneous substance. Hemosiderin deposition was proved in and around the blood vessels.

Although inflammatory reaction in the tumor was scarcely seen, many mast cells were disseminated.

Specimen stained with Van-Gieson's method showed partly diffuse fine fibrous structure inbetween the tumor cells, irregular mosaic pattern of bundles composed of fine fibers around the small or large tumor cell nests, or areas without any fibrous component.

These fibers were argyrophilic and showed PAS positive reaction.