Brentuximab-induced splinter nail haemorrhages in a patient with Sézary syndrome: A case report.

Sézary syndrome is a systemic variant of cutaneous T-cell lymphoma characterized by erythroderma, lymphadenopathy and circulating atypical lymphocytes (Sézary cells). It may present with nonspecific lesions on multiple digits. We describe an atypical case of brentuximab-induced splinter nail haemorrhages in a patient with Sézary syndrome, associated with a poor prognosis during follow-up. Concomitantly with the appearance of nail lesions, significant lymphocytosis was detected as well as infiltration of bone marrow and nail matrices. The lesions followed a precise sequence, which can be traced back to the monthly application of brentuximab and its direct cytotoxic effect on CD30+ T lymphocytes in the nail matrix. Brentuximab-induced nail lesions might be associated with decreased efficacy of brentuximab in this patient with advanced cutaneous T-cell lymphoma.