The authors agree that this surname derives from the term cascina (farm or rural estate), and that its original meaning alludes to the place of dwelling of the one who bore it. E. Rossoni notes that it could indicate a settler residing on a farm, although he also admits a toponymic derivation from places such as Cassina De Pecchi, in the Milan area. Rossoni documents its transformation into a surname in the Diplomatic Code of medieval Lombardy, in a deed of sale of the year 1168 drafted in Milan, where a certain Anselmo called Cassina appears.

R. Brondolo broadens the early geographical distribution: he places the surname from the 12th century in Milan, in the Val Veddasca and in the Malcantone, an area of Italian Switzerland belonging to the canton of Ticino. For its part, Surnames in Italy distinguishes two independent clusters: one in Milan and another in the Brianza. Of the Milanese nucleus it highlights its presence in the political life of the city, with references to Arderico Cassina, who in 1162 swore fidelity to Frederick Barbarossa in Lodi, and to the registration of the family in 1377 among the noble lineages with the right to the election of canons of the Duomo of Milan.