Electron microscopic observations of lymphangiosarcoma arising from chronic lymphedema

Lymphangiosarcoma, so-called Stewart-Treves syndrome, originating from the edematous left leg after hysterectomy in a 53-year-old woman has been studied by light and electron microscopy. Histologically the tumor was composed of either vascular channels or solid nests of the neoplastic cells having a large hyperchromatic nucleus with a single or multiple prominent nucleoli. The inner surface of the vascular channels was lined by either single or several layers of identical cells. Erythrocytes were occasionally observed in the lumina of the vascular channels. By electron microscopy the maturation of the neoplastic cells differed considerably from one area to another even in the same section. The immature cells were clustered in groups and consisted of scanty cytoplasm and a large nucleus with prominent nucleoli, whereas some of the mature cells lining the lumina had rod-shaped tubulated bodies (Weibel-Palade bodies). Desmosomes were frequently observed between the neoplastic cells. Basal lamina was generally not continuous or not present although some vascular structures were completely surrounded by a basal lamina. An autopsy was performed but revealed no metastatic lesions in any organs or lymph nodes.