Intravascular Large B-Cell Lymphoma Complicated by Anti-Neutrophil Cytoplasmic Antibody-Associated Vasculitis that was Successfully Treated with Rituximab-Containing Chemotherapy.

A 64-year-old woman had suffered from painful livedo reticularis for 2 years and was referred to us due to fever, anasarca and paresthesia of the lower limbs. Serum proteinase-3-anti-neutrophil cytoplasmic antibody (ANCA) was positive. Abnormal lymphocytes were found in the cerebrospinal fluid and bone marrow. Skin biopsy revealed large atypical lymphoid cells with CD20 positivity lodged in the small vessels and neutrophilic infiltration into the arterial vascular wall with fibrinoid degeneration. A diagnosis of intravascular large B-cell lymphoma complicated by ANCA-associated vasculitis was made, and rituximab-containing chemotherapy followed by prednisolone was quite effective for both lymphoma and ANCA-associated vasculitis.