Secondary cutaneous lymphoma: comparative clinical features and survival outcome analysis of 106 cases according to lymphoma cell lineage.

BACKGROUND: The relative frequency, clinical features and survival outcomes of secondary cutaneous lymphoma remain poorly understood. OBJECTIVES: To determine the clinical characteristics and survival outcomes of secondary cutaneous lymphoma. MATERIALS AND METHODS: The present retrospective cohort study included all 106 patients who presented with secondary cutaneous lymphoma. Patient medical records were reviewed to determine the clinical features, survival outcomes and prognostic factors. Survival outcomes were analysed by using the Kaplan-Meier method and comparisons between lymphoma cell lineages [T or natural killer (T-/NK)-cell vs. B-cell lymphoma] were performed using the log-rank test. RESULTS: Secondary cutaneous lymphomas consisted of mature T-/NK-cell lymphomas (56%), mature B-cell lymphomas (35%), immature haematopoietic malignancies (8%) and Hodgkin lymphoma (1%). The T-/NK-cell lineage lymphoma cases were more likely to have multiple and disseminated skin lesions than the B-cell lineage lymphoma cases. The lymphoma cell lineage did not significantly influence survival outcomes. Patients who showed cutaneous involvement within 6 months of the initial diagnosis of primary disease had a poorer overall survival (OS) outcome than patients who developed cutaneous dissemination 6 or more months after the initial diagnosis (P < 0.001). Patients with disseminated skin lesions had a poorer OS than patients with localized skin lesions (P = 0.028). The two lymphoma cell lineages differed in terms of prognostic factors that influenced survival. CONCLUSIONS: Skin lesion characteristics such as time point of appearance and extent affect the survival outcomes of secondary cutaneous lymphoma. Cell lineage did not influence survival outcomes but the two lineages are associated with different prognostic factors.