Breathing-mode measurements in Sn isotopes and isospin dependence of nuclear incompressibility

T. Li et al. [Phys. Rev. C 81, 034309 (2010)] have analyzed the measured breathing-mode energies of some tin isotopes in terms of a first-order leptodermous expansion and found the value of -550 +/- 100 MeV for the symmetry-incompressibility coefficient Kt. Removing an approximation that they made, we find that the first-order estimate of Kt shifts to -661 +/- 144 MeV. However, taking into account higher-order terms in the leptodermous expansion shows that the data are compatible with the significantly lower magnitudes indicated by both another experiment and some theoretical estimates. In particular, there does not appear to be any conflict between the breathing-mode data and a value of Kt consistent with most Skyrme forces.