Periorbital Subcutaneous EmphysemaMistaken for Unilateral AngioedemaDuring Dental CrownPreparation

Discussion | In 1995, Benchikhi et al4 reported the first case of cutaneous B-cell lymphoma associated with follicular mucinosis in a patient with bone-marrow and peripheral blood infiltration.4We report the first caseof primary cutaneous follicle center lymphoma with follicular mucinosis. Cutaneous lymphomascanusuallybedistinguishedbyarchitectural features, where most atypical lichenoid infiltrates implicate cutaneousT-cell lymphoma, especiallywhen areas of epidermotropism are present; cutaneous B-cell lymphomas often appear with a nodular to diffuse lymphoid infiltrate and relative sparing of the epidermis. However, B-cell lymphomas can sometimes show atypical lymphoid infiltrates mainly limited to the papillary dermis, epidermotropism, interstitial involvement,andabsenceofgrenzzone,mimickingmycosis fungoides.5,6 Todate, at least 3 caseshavebeen reportedof epidermotropicmarginal zoneB-cell lymphoma.6 Immunohistochemical studies demonstrating B-cell phenotype (CD20, and CD79α positivity) with marginal zone differentiation (BCL2 positivity, and BCL6, CD10 and CD5 negativity) for the epidermotropic cells, aswell as themajority of the dermal cells, confirmed the diagnosis in these cases. In our case, the tumor cells testeddiffuselypositive forBCL-6,which rather suggested a follicular center differentiation. Insummary,ourcase represents the first case toourknowledge of primary cutaneous follicle center lymphomawith follicular mucinosis and a very unusual miliary clinical presentation.Morphologic findings, oftenused todistinguish among different types of cutaneous lymphomas, can sometimes be misleading,andmolecularcharacterization is important tosupport the diagnosis.