Spindle-cell variant of primary cutaneous follicle center lymphoma spreading to the hepatobiliary tree, mimicking Klatskin tumor

Primary cutaneous follicle center lymphoma (pcFCL) is an indolent type of primary cutaneous B-cell lymphoma (pcBCL) rarely disseminating to other organs. PcBCL with spindle-cell morphology has been described as a rare variant of pcFCL but the prognosis data of this variant is sparse. We report a rare case of spindle-cell pcFCL with CD20⁺, CD79a⁺, CD3⁺, Bcl-6⁺, Mum-1^- and CD10^-tumor cells that infiltrated the hepatic hilum, mimicking a Klatskin tumor. On the basis of the sparse published data on spindle-cell morphology of pcBCL, this growth pattern should elicit awareness of an increased risk of systemic involvement in the otherwise indolent pcFCL.