Spindle B-cell lymphoma: a rare variant of follicle center lymphoma

Primary cutaneous follicle center lymphoma (PCFCL) is a common subtype of primary cutaneous B-cell lymphoma (PCBCL). The prognosis of this subtype is favorable and recurrence is observed in up to 50% of patients. The dissemination to lymph nodes or internal organs is rare. In this study, two cases of rare variant of PCFCL are reported. Both cases presented with multiple erythematous nodules, plaques and some annular configurations. Histopathological examination revealed dermal lymphocytic infiltrates consisting of admixed centrocytes and centroblasts. Interestingly, spindle-shaped cells with elongated nuclei, dispersed chromatin and scant cytoplasm were also detected. Immunohistochemical analysis revealed that all cells including the spindle cells were positive for CD20 and negative for CD3, CD43, CD10, CD34, CD68 and CD138. They were also negative for desmin and S-100. They consistently expressed nuclear bcl-6, but did not express bcl-2. The histopathological and immunohistochemical examination suggest a rare case of primary cutaneous spindle cell B-cell lymphoma (PCSBCL). Although few data is published about this rare subtype, PCSBCL is recently considered as a rare subtype of PCFCL. The prognosis and the nature of this peculiar subtype are not yet cleared. This indicates a great need for more investigations.