PAN is a vasculitis that affects medium sized vessels, which play a large role in the blood supply of muscles. The transmural inflammation and fibrinoid necrosis of the vessels can lead to an interrupted blood supply and ischemic necrosis in the muscles. The necrosis would be segmental since other parts of the muscle are still perfused.
Correct me if I'm wrong, but you can rule out the other answers simply because they are more related to glycogen storage diseases and similar metabolic etiologies. Segmental ischemic necrosis is pretty much the only answer available that could be caused by a vascular lesion of any kind.
submitted by โcassdawg(1780)
Polyarteritis nodosa is a medium vessel vasculitis associated with different stages of transmural inflammation with fibrinoid necrosis of vessels. [FA2020 p314]
Because this is a vasculitis that affects medium vessels, it can affect the arteries supplying the muscles and thus cause segmental ischemic necrosis from loss of blood supply.