Clinicopathologic features of a case of lymphoblastic lymphoma (LyL) with the classic 14;18 translocation are described in this article. The patient had prominent splenomegaly with numerous splenic nodules, exhibiting a homogeneous blast cell infiltrate and occasional cells with cleft nuclei, a picture suggestive of high-grade non-Hodgkin lymphoma (NHL) possibly lymphoblastic. Early B-cell features were detected immunologically, thus confirming the diagnosis of LyL. The presence of primary splenic involvement and of the t(14;18)(q32;q21) are unusual in this histologic subset of B-cell NHL, these cytogenetic and clinicopathologic characteristics being typically associated with low- or intermediate-grade NHL of follicle center origin. These features, along with the presence of some centrocytelike cells in the biopsy sections, suggest that an unusual pattern of histologic evolution from a follicle center cell NHL may have occurred in this case of LyL.