Primary cutaneous follicle center cell lymphoma

The exact classification of primary cutaneous follicle center cell lymphoma s (FCCLs) has been the subject of ongoing debate. In the classification of cutaneous lymphomas proposed by the European Organization for Research and Treatment of Cancer (EORTC)-Cutaneous Lymphoma Project Group, cutaneous fol licle center cell lymphoma (FCCL) is defined as a proliferation of centrocy tes and centroblasts showing a diffuse pattern of growth in the great major ity of cases, and presenting only rarely a true follicular pattern. CD10 an d Bcl-2 are usually not expressed by neoplastic cells, and the t(14; 18) is absent. By contrast, nodal follicular lymphoma is a tumor with a follicula r pattern, characterized by the proliferation of CD10+, Bcl-2+ follicular c ells, and by the presence of the t(14;18) in most cases. In this review we outline the clinicopathologic, phenotypic, and molecular features of primar y cutaneous FCCL, reviewing criteria for diagnosis and differential diagnos is of this peculiar variant of cutaneous B-cell lymphoma.