Not palsas. Palsas are formed on bogs, as peat is necessary for summertime insulation. Because all vegetation (if there ever was any)—and with that all the peat—has long since left Mars, any former palsas shouldn't really leave that visible marks.
Palsa formation usually requires not just a peat bog, but also snow cover. Ice lenses are formed underneath the peat layer on spots where winter freezing occurs unusually rapidly e.g. due to a thin spot in snow cover. (Palsas have been deliberately created by plowing snow off from certain spots on a bog in wintertime.) Palsas are also relatively short-term formations; they will eventually melt when they grow so much that their sheer size will cause the isolating peat layer to crack, thus withdrawing the insulation that prevents ice lenses from melting during summertime.
Solifluctations are a more plausible explanation, and perhaps also collapsed pingos. AFAIK pingos have a much longer lifetime than palsas, and when they collapse they also leave around much more visible evidence of their former existence.