Secondary Cutaneous Diffuse Large B-cell Lymphoma has a Higher International Prognostic Index Score and Worse Prognosis Than Diffuse Large B-cell Lymphoma, Leg Type.

Diffuse large B-cell lymphoma (DLBCL) can be separated into 2 groups: nodal and extranodal disease. The aim of this study was to analyse the clinical features of skin lesions and survival outcomes of cutaneous DLBCL according to the primary tumour site. A total of 44 patients with cutaneous DLBCL were classified as primary cutaneous DLBCL, leg type or cutaneous DLBCL secondary to primary disease. Although skin lesion characteristics did not differ significantly between groups, extensive cutaneous lesions were more often observed in secondary cutaneous DLBCL compared with DLBCL, leg type. Secondary cutaneous DLBCL was more commonly associated with an advanced stage and higher International Prognostic Index score than DLBCL, leg type. DLBCL, leg type demonstrated a better survival outcome than secondary cutaneous DLBCL. The multiplicity of skin lesions and time-point of cutaneous involvement were associated with prognosis in secondary cutaneous DLBCL. Survival outcomes and prognostic factors differ depending on the primary tumour site of cutaneous DLBCL.