Primary central nervous system lymphoma and subcutaneous metastases.

Primary central nervous system lymphoma (PCNSL) is a rare disease with a poor prognosis. It usually remains confined to central nervous system (CNS). Reports of metastases outside of the CNS are rare. We report a patient with well-documented PCNSL who responded to treatment, but subsequently developed a histologically confirmed subcutaneous metastasis to the left leg without local failure.