悪性血管内皮細胞腫について

MALIGNANT ANGIOENDOTHELIOMA

症例

　患者　74歳，女，郵便局員家族。

　初診　昭和41年7月21日。

A 74-year-old woman noted a red tumor on the scalp 9 months ago, which enlarged gradually and developed into an ulcer at the center.

The tumor was composed mainly of a solid mass of undifferentiated mesenchymal cells with numerous vascular tubes. The peripheral part of the mass showed large sinuses anasto-mosing with one another, surrounded by less atypical cells.

There are three theories on the histogenesis of malignant angioendothelioma ; that is, ( 1 ) dedifferentiation of hemangioblasts derived from the area vasculosa on the yolk sac, ( 2 ) uncontrolled local growth of undifferentiated mesenchymal cells which are normally distrib-uted systemically, and ( 3 ) an anaplastic change of the pre-existing mature capillaries.

Although the analysis of this disorder located on the scalp and face of the aged in the lite-rature indicates the similar clinical and pathological characteristics as have been stressed by Wilson Jones and favors the anaplastic theory of the capillaries, the author is conserva-tive in regarding it as a special type of malignant hemangioendothelioma.