title: Lack of efficacy of imiquimod in patients with basal cell carcinoma previously treated with rituximab for B cell lymphoma: two case reports.
abstract: BACKGROUND
  Non-Hodgkin lymphomas are a heterogeneous group, which involve either B or T lymphocytes. The most used treatment is a chemotherapy regimen, which includes cyclophosphamide, hydroxydaunorubicin, oncovin and prednisone combined with rituximab - a monoclonal antibody specific for CD20 - an antigen expressed on B lymphocyte membrane. Nonmelanoma skin cancers are the most common forms in patients who have lymphomas.
  
  
  METHODS
  We reported the cases of two Caucasian men affected by non-Hodgkin disease, treated with chemotherapy and rituximab. After treatment, they both presented superficial basal cell carcinoma and we prescribed imiquimod 5 % cream. Unfortunately, the drug was not effective in either patient and the tumors were excised.
  
  
  CONCLUSIONS
  We speculated about the effect of rituximab on B lymphocytes, on a particular population of T cells and on antigen-presenting dendritic cells that may have determined a lower expression of some surface antigens involved in antigen presentation. These cells are the specific targets of imiquimod to promote skin cancer cells apoptosis. A lack of action by imiquimod on skin cancer after treatment with rituximab is likely due to its transitory inhibitory effects on lymphocytes and Langherans cells. Further studies could be useful to understand the mechanism behind the lack of response.
authors.affiliation: Department of Dermatology, University of Rome Tor Vergata, Viale Oxford 81, 00133, Rome, Italy. campioneelena@hotmail.com.
authors.forename: Elena
authors.initials: E
authors.lastname: Campione
authors.affiliation: Department of Dermatology, University of Rome Tor Vergata, Viale Oxford 81, 00133, Rome, Italy.
authors.forename: Monia
authors.initials: M
authors.lastname: Di Prete
authors.affiliation: Department of Hematology, University of Rome Tor Vergata, Viale Oxford 81, 00133, Rome, Italy.
authors.forename: Ilaria
authors.initials: I
authors.lastname: Del Principe
authors.affiliation: Department of Dermatology, University of Rome Tor Vergata, Viale Oxford 81, 00133, Rome, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Diluvio
authors.affiliation: Royal London Hospital, Whitechapel Road, London, E1 1BB, UK.
authors.forename: Luigi
authors.initials: L
authors.lastname: Citarella
authors.affiliation: Department of Pathology, University of Rome Tor Vergata, Viale Oxford 81, 00133, Rome, Italy.
authors.forename: Augusto
authors.initials: A
authors.lastname: Orlandi
authors.affiliation: Department of Dermatology, University of Rome Tor Vergata, Viale Oxford 81, 00133, Rome, Italy.
authors.forename: Sergio
authors.initials: S
authors.lastname: Chimenti
authors.affiliation: Department of Dermatology, University of Rome Tor Vergata, Viale Oxford 81, 00133, Rome, Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: Bianchi
mesh_terms: D000634:Aminoquinolines / Q000008:administration & dosage*; D000911:Antibodies, Monoclonal / Q000008:administration & dosage*; D000971:Antineoplastic Combined Chemotherapy Protocols; D003520:Cyclophosphamide; D004317:Doxorubicin; D004334:Drug Administration Schedule; D006801:Humans; D000077271:Imiquimod; D008213:Lymphocyte Activation / Q000187:drug effects / Q000276:immunology; D016393:Lymphoma, B-Cell / Q000188:drug therapy* / Q000276:immunology / Q000473:pathology; D008228:Lymphoma, Non-Hodgkin / Q000188:drug therapy* / Q000276:immunology / Q000473:pathology; D008297:Male; D008875:Middle Aged; D011241:Prednisone; D000069283:Rituximab / Q000008:administration & dosage*; D033581:Stem Cell Transplantation; D016896:Treatment Outcome; D014750:Vincristine
chemical_list: D000634:Aminoquinolines; D000911:Antibodies, Monoclonal; D000069283:Rituximab; D014750:Vincristine; D004317:Doxorubicin; D003520:Cyclophosphamide; D000077271:Imiquimod; D011241:Prednisone
keywords: Anti-CD20 monoclonal antibodies; Immunomodulant therapy; Skin cancer