[Morphology of syncytiotrophoblast cells in testicular tumors]

Syncytiotrophoblastic cells were identified in a teratocarcinoma of the testis by light microscopy using the semi-thin sectioning technique. An electron microscope study confirmed them to be syncytial. Many irregularly shaped nuclei lying in a honeycombed cytoplasm were observed, while the free margins contained microvilli. These cells are morphologically similar to syncytiotrophoblasts of the normal placenta. The presence of syncytiotrophoblastic cells in testicular tumours means a worse prognosis than would otherwise be concluded on the basis of the particular tumour concerned.