Figure 1.

Intravital videomicroscopic views of B16F1 melanoma cells in mouse liver. a: Intravascular melanoma cell (*) arrested due to size restriction within a sinusoid (S), shown 45 minutes after injection. Blood flow is blocked (→) in the region immediately downstream from the cell; sinusoids further downstream are being supplied by collateral flow. b: Micrometastasis (M) at the liver surface 3 days after cell injection, displaying melanin. A microsphere (→), slightly below the plane of focus, is also visible. Scale bars, 20 μm.