title: Atypical IgM multiple myeloma with deletion of c-MAF.
abstract: IgM multiple myeloma (MM) is a rare subtype of myeloma that shares clinical and pathological features with Waldenström's macroglobulinaemia. These are two separate entities that differ both in therapy and prognosis. We report a 57-year-old male, who presented with anaemia, hypercalcaemia, acute renal failure and several vertebral fractures that clinically suggested a multiple myeloma. Further investigations revealed a serum monoclonal component of IgM lambda type and a bone marrow infiltrated by small, lymphoplasmocytic cells. IgM MM was finally diagnosed by means of both inmunophenotypic and immunohistochemistry techniques, stressing the importance of inmunophenotypic evaluation when clinical and morphological features are discordant. Fluorescence in situ hybridization (FISH) studies disclosed a particular combination of deletion 13q14, t(11;14) and monoallelic deletion C-MAF without t(14;16). The clinical evolution after a Bortezomib-containing polychemotherapy and autologous stem cell transplantation (ASCT) conditioned with busulphan and melphalan is also presented. This very uncommon case highlights the impact of immunophenotyping on the differential diagnosis between IgM MM and WM, to choose the best treatment and establish an appropriate outcome.
authors.affiliation: Division of Hematology, Hospital Universitario Príncipe de Asturias, Madrid, Spain.
authors.forename: L M
authors.initials: LM
authors.lastname: Juárez Salcedo
authors.affiliation: Division of Hematology, Hospital Universitario Príncipe de Asturias, Madrid, Spain.
authors.forename: M
authors.initials: M
authors.lastname: López Rubio
authors.affiliation: Division of Hematology, Hospital Universitario Príncipe de Asturias, Madrid, Spain.
authors.forename: J J
authors.initials: JJ
authors.lastname: Gil Fernández
authors.affiliation: Division of Hematology, Hospital Universitario Príncipe de Asturias, Madrid, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Garcia-Suarez
authors.affiliation: Division of Hematology, Hospital Universitario Príncipe de Asturias, Madrid, Spain.
authors.forename: E
authors.initials: E
authors.lastname: Magro
authors.affiliation: Division of Cytogenetic, Hospital Universitario La Princesa, Madrid, Spain.
authors.forename: E
authors.initials: E
authors.lastname: Arranz
authors.affiliation: Division of Hematology, Hospital Universitario Príncipe de Asturias, Madrid, Spain.
authors.forename: I
authors.initials: I
authors.lastname: Gutiérrez Jomarrón
authors.affiliation: Division of Hematology, Hospital Universitario Príncipe de Asturias, Madrid, Spain.
authors.forename: S
authors.initials: S
authors.lastname: Marcellini Antonio
authors.affiliation: Division of Pathological Anatomy, Hospital Universitario Príncipe de Asturias, Madrid, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Blasco
authors.affiliation: Division of Hematology, Hospital Universitario Príncipe de Asturias, Madrid, Spain.|Medicine Departament, Universidad de Alcalá de Henares, Madrid, Spain.
authors.forename: C
authors.initials: C
authors.lastname: Burgaleta
mesh_terms: D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D001706:Biopsy; D001853:Bone Marrow / Q000473:pathology; D003937:Diagnosis, Differential; D017353:Gene Deletion; D006801:Humans; D007075:Immunoglobulin M / Q000097:blood*; D016130:Immunophenotyping; D008297:Male; D008875:Middle Aged; D009101:Multiple Myeloma / Q000097:blood* / Q000175:diagnosis / Q000188:drug therapy / Q000235:genetics*; D051257:Proto-Oncogene Proteins c-maf / Q000235:genetics*; D016896:Treatment Outcome; D008258:Waldenstrom Macroglobulinemia
chemical_list: D007075:Immunoglobulin M; D051257:Proto-Oncogene Proteins c-maf
keywords: C-MAF; Multiple myeloma; Waldenström's macroglobulinemia