Vasculitis associated with nonhematological malignancies.

[PURPOSE OF REVIEW] There is a complex relationship between nonhematological malignancies and vasculitis Paraneoplastic vasculitis may present in many different forms. Cancer risk is high in patients with some types of vasculitis. Also, immune checkpoint inhibitors (ICIs) used in treatment of many solid tumors may cause vasculitis.

[RECENT FINDINGS] Vasculitis associated with solid tumors is less frequently seen when compared to vasculitis associated with hematological malignancies. Cutaneous leukocytoclastic vasculitis (vasculitis of small vessels) is the most frequently encountered paraneoplastic vasculitis type. Paraneoplastic vasculitis is usually seen in patients with lung, genitourinary and gastrointestinal system tumors. The timing of paraneoplastic vasculitis varies as before, after or concurrently with the diagnosis of malignancy. Vasculitis is usually considered to be paraneoplastic when time gap between the onset of vasculitis and diagnosis of cancer is within 12 months. ICIs used frequently in treatment of many solid tumors may cause vasculitis by stimulating T cell activation. They usually cause large vessel (temporal arteritis and single organ vasculitis), central nervous system vasculitis or small vessel vasculitis.

[SUMMARY] Close monitoring of patients with vasculitis is essential for early recognition of an underlying malignancy and directing treatment options towards cancer specific treatments. Vasculitis due to ICIs should be recognized as early as possible when ICIs should be stopped, and immunosuppressives should be started to avoid severe complications of immune adverse events diagnosed to with- hold ICIs and start immunosuppressive treatments precluding severe complications of immune adverse events.