Its the nature of the trophoblast cells that largely determines the form, the fungal moiety is fairly constant.
If trophoblast is of lung, you get one form of lichen in the body. If trophoblast is of kidney, you get a different form of lichen in the body. If trophoblast is of neural or lymphatic tissue, you get a different form of lichen in the body for each, and so on. For every type of trophoblast, there is a different cancer lichen for the body. Do you see it now ?