  The fact that a magnetic field in a fermion system breaks the spherical
symmetry suggest that the intrinsic geometry of this system is axisymmetric
rather than spherical. In this work we analyze the impact of anisotropic
pressures, due to the presence of a magnetic field, in the structure equations
of a magnetized quark star. We assume a cylindrical metric and an anisotropic
energy momentum tensor for the source. We found that there is a maximum
magnetic field that the star can sustain, closely related to the violation of
the virial relations.
