In a patient with recurrent episodes of GCA that flare shortly after steroid tapering, how do you differentiate between steroid-dependent inflammatory relapse, an alternative autoimmune vasculitic process, and a paraneoplastic phenomenon?

Paraneoplastic disease rarely behaves like GCA with ischemic manifestations. If a non-GCA vasculitis is suspected, perhaps repeat biopsy or serologic testing for other markers could be done. I'm not sure of the value of these tests, however, given that the treatment approach with immunosuppression w...

This could certainly be worrisome for a paraneoplastic phenomenon. GCA is associated disproportionately with myeloid lineage mutations (CHIP - clonal hematopoiesis of indeterminate significance). TET2 is think is the best studied mutation but in my experience any other CHIP mutation such as asxl1, ...