Clinical characteristics, prognostic indicators, and survival outcomes in intravascular lymphoma: Mayo Clinic experience (2003-2018).

Intravascular lymphoma (IVL) is a rare extranodal non-Hodgkin lymphoma. We performed a retrospective analysis of 55 IVL patients who were treated at our institution 2003-2018. Median age at diagnosis was 68 years, and 64% were males. The most frequent presenting symptoms were skin rash 43% and weight loss 30%. MRI brain on IVL patients with CNS involvement (CNS-IVL) showed multifocal involvement in 76% (13/17). 89% (17/19) of non-CNS-IVL patients with abnormal FDG-PET had biopsy of an avid lesion resulting in definitive diagnosis. The top diagnostic biopsy site was the bone marrow (45%). 56% had multiorgan involvement. Based on CNS involvement, 36.5% (20/55) had CNS-IVL and 63.5% (35/55) had non-CNS-IVL. CNS-IVL group consists of clinically isolated CNS involvement (CNS-only IVL) (22%;12/55) and mixed clinical CNS and peripheral site involvement (M-IVL) (14.5%; 8/55). Non-CNS-IVL group consists of clinically isolated skin involvement (skin-only IVL) (9%; 5/55) and peripheral IVL with or without skin involvement (P-IVL); (54.5%; 30/55). Skin involvement was predominantly in the lower extremities. Pathologically, 89% (48/54) were B-cell IVL. Rituximab + high-dose methotrexate-based regimen were used in 75% (12/16) of CNS-IVL patients and RCHOP in 60% (17/28) of non-CNS-IVL patients. Estimated 5-year progression free survival (PFS) and overall survival (OS) for the entire cohort were 38.6% and 52%, respectively. Skin-only IVL was associated with excellent survival. Platelet count <150x10 /L, age > 60Y, and treatment without Rituximab were poor prognostic factors. Further research is necessary to identify novel therapies.