The Screw modifier allows one to revolve a profile curve around an axis to generate geometry. However, there is no such Geometry Node type. Instead, Curve to Mesh is supposed to be a more general solution, accepting generic profile and curve inputs.
A ticket on the blender dev-site even rejects the idea of a "screw node" as something that can be accomplished using existing geometry node types. However, it seems that neither curve-to-mesh, nor any existing geometry node type, can accomplish the axial extrusion that screw accomplishes. Am I missing something?
Specifically, the issue is that curve-to-mesh takes a curve as input, but to emulate the screw function, one would need that curve to be a zero-radius circle, or a zero-length line with non-zero twist. Obviously, this can be worked around by using an extremely small radius (1e-9 seems to work fine) or applying a negative offset to the profile equal to the radius of the curve, but these both feel like hacks and introduce edge cases for certain geometries.
When I try using an actual zero-radius curve, arc, or spiral node, the geometry disappears, with the output vertices having all zeros for one or more axes.