Predictive factors and scoring system for intravascular large B-cell lymphoma among suspected cases: a single-center retrospective analysis.

BACKGROUND: Although the utility of random skin biopsies in the diagnosis of intravascular large B-cell lymphoma (IVLBCL) has been confirmed, the patients who should undergo random skin biopsies remain unclear.

OBJECTIVES: To assess predictive factors for IVLBCL and establish a scoring system for the applicability of random skin biopsies.

METHODS: We conducted a retrospective case-control study of IVLBCL-suspected patients who underwent random skin biopsies between April 2010 and March 2022. We compared the general symptoms, imaging findings, and laboratory findings between IVLBCL and non-IVLBCL cases.

RESULTS: Fifty-three patients were enrolled in this study. Eight patients were diagnosed with IVLBCL, and 35 patients were diagnosed with other diseases. The final diagnosis was unclear in 10 patients. There were no significant differences in the frequency of general symptoms and imaging findings between IVLBCL and non-IVLBCL cases. Among laboratory findings, IVLBCL cases showed significantly higher serum lactate dehydrogenase (LDH) and soluble IL-2 receptor (sIL-2R) levels and lower platelet counts than non-IVLBCL cases. We established a scoring system to predict IVLBCL by using these three parameters. The cut-off values were as follows: serum LDH level, 256 IU/l; serum sIL-2R level, 2011 U/ml; and platelet count, 107 × 109 /l. IVLBCL was not included in patients with scores of <2. The probabilities of IVLBCL in patients with scores 2 and 3 were 18% and 86%, respectively.

CONCLUSIONS: Our simple scoring system can help clinicians determine the applicability of random skin biopsies in IVLBCL-suspected cases.