A case of diffuse large B-cell lymphoma misdiagnosed as an erysipelas of the face

We report a case of a woman with diffuse large B-cell lymphoma (DLBCL). Primary cutaneous lymphomas (PCLs) represent distinct clinical and histopathologic subtypes of extranodal T- and B-cell lymphomas. Cutaneous B-cell lymphomas comprise 20–25% of all primary cutaneous lymphomas. The patient presented an erythematous tumour mass of the left nasolabial fold, nose and left cheek as well as disseminated infiltrative plagues on the trunk, arms and left lower leg. Skin biopsy revealed a diffuse infiltrate of lymphocytes around hair follicles and blood vessels within dermis and subcutaneous tissue. An immunohistochemistry showed a diffuse infiltrate of large non-cleaved B-cells, with a high proportion of centroblast-like cells within dermis. Tumor cells expressed CD20, bcl-2 protein and did not express CD10. The patient was misdiagnosed as the erysipelas of the face and unsuccessfully treated with long-term antibiotic therapy by a laryngologist and a dermatologist. The correct diagnosis was delayed and established after 6 months’ history of DLBCL lesions. Therefore, we would like to strongly stress the importance of considering diagnosis of cutaneous lymphomas in chronic skin lesions non-responsive to adequate therapies.