To identify the clinical features of malignancy mimic vasculitis(MMV), and to increase the knowledge and alertness of MMV to avoid misdiagnosis and mistreatment.

Clinical records and laboratory index with test results were collected and retrospective study was employed to analyze twentyfour MMV patients, who were admitted to the department of Rheumatology of Peking Union Medical College Hospital during the period from January 2001 to January 2015. All data were analyzed by Fisher exact probability test.

① Twenty-four MMV took up to 2.5%(24/927) of all the systemic vasculitis, and 0.15‰ (24/157 883) of all the malignancy diagnosed during the same period. ② The average age at the diagnoses being established was (43±19) years and the male to female was 3∶1. ③ Skin lesions (16/24), mucous injury (12/24), pulmonary involvement (10/24), thrombosis (7/24) and neurological involvement (7/24) were the mose common clinical manifestations that could mimic systemic vasculitis; Behçet's disease (6/24), granulomatous with polyangiitis (6/24) and polyarteritis nodosa (5/24) were types of systemic vasculitis that MMV most frequently mimic. ④ Among 22 MMV with definite pathological evidence, there were sixteen hematological malignancies and fourteen non-Hodgkin's lymphoma (NHL). ⑤ For hematological malignancies mimic vasculitis patients, skin lesions (P=0.023), elevated LDH (P=0.046), leukocyte disorder (P=0.015) were more common than those nonhematological malignancy patients. ⑥ Those with long disease duration (>12 months) (n=6) tended to present more skin lesions(P=0.024) especially skin ulcers P=0.038) were than short course patients.

MMV should be proposed for those "systemic vasculitis" patients with atypical manifestations and poor response to routine therapy. Even if the disease duration is as long as more than 12 months, MMV should not be excluded imprudently as hematological malignancies could have long disease durations.

Systemic vasculitis; Mimic vasculitis; Malignancy