Paraneoplastic necrotising myopathy (Q84065)

Paraneoplastic necrotising myopathy is an acute or subacute myopathy with proximal weakness, and facultative myalgia and muscle pain. CK can be markedly elevated. The onset and clinical pattern resembles DM and PM, it is rapidly disabling within 2-3 months. Histology shows scattered muscle necrosis, macrophages and scarce focal T cell infiltrates. C5b-9 complement deposition can appear in muscle fibres. It occurs in several cancer types in particular lung, breast and gastrointestinal cancers.