Primary cutaneous follicle-center lymphoma

We present a 64-year-old man with a three-year history of pruritic, pink papules and nodules of the face who was found to have a clonal lymphoproliferative B-cell disease that was characterized by a clonal IGH rearrangement. Although morphologic features present in the biopsy specimen were consistent with a reactive process, additional clinicopathologic correlation (anatomic presentation of lesions on the face, the absence of t(14:18) translocation, and bcl-2 and MUM1 expression) reinforced suspicion of a cutaneous B-cell lymphoma. Systemic work-up with CT/PET and a bone marrow biopsy ultimately excluded systemic disease and primary cutaneous follicle-center lymphoma (PCFCL) was a strong diagnostic consideration. The patient was treated with systemic rituximab with a partial resolution of the facial lesions. The case demonstrates both clinical and pathologic challenges to the diagnosis of primary cutaneous B-cell lymphoma (PCBCL). Furthermore, despite a newly refined classification system, the case also specifically highlights the persistent requirement for flexible clinical reasoning and pathologic correlation. Such reasoning is necessary to generate individualized strategies for diagnosis and treatment when cutaneous B-cell lymphoma is suspected.