Prognostic factors in primary cutaneous large B-cell lymphomas: a European multicenter study

Most primary cutaneous B-cell lymphomas have an excellent prognosis. However, primary cutaneous large B-cell lymphomas (PCLBCLs) of the leg have been recognized as a distinct entity with a poorer prognosis in the European Organization for Research and Treatment of Cancer (EORTC) classification. This distinction on the basis of site has been debated. Our aim was to identify independent prognostic factors in a large European multicenter series of PCLBCL.

The clinical and histologic data of 145 patients with PCLBCL were evaluated. According to the EORTC classification, 48 patients had a PCLBCL of the leg and 97 had a primary cutaneous follicle center-cell lymphoma (PCFCCL). Data from both groups were compared. Univariate and multivariate analyses of specific survival were performed using a Cox proportional hazards model.

Compared with PCFCCL, PCLBCL-leg were characterized by an older age of onset, a more recent history of skin lesions, a more frequent predominance of tumor cells with round nuclei and positive bcl-2 staining, and a poorer 5-year disease-specific survival rate (52% v 94%; P <.0001). Univariate survival analysis in the entire study group showed that older age, a more recent onset of skin lesions, the location on the leg, multiple skin lesions, and the round-cell morphology were significantly related to death. In multivariate analysis, the round-cell morphology (P <.0001), the location on the leg (P =.002), and multiple skin lesions (P =.01) remained independent prognostic factors. The round-cell morphology was an adverse prognostic factor both in PCLBCL-leg and in PCFCCL, whereas multiple skin lesions were associated with a poor prognosis only in patients with PCLBCL-leg.

With site, morphology, and number of tumors taken into account, guidelines for the management of PCLBCL are presented.