Dual diagnosis of a cutaneous T cell lymphoma type mycosis fungoides combined with a B cell chronic lymphocytic leukaemia. A case report Abstract: The coexistence of two distinct, B and T, lymphocytic clones is very rare. We report the case of a 68-year-old woman who was presenting simultaneously a cutaneous T cell lymphoma, type mycosis fungoides, and a B cell chronic lymphocytic leukaemia.