Plasmablastic Lymphoma of Head and Neck: Report of Two New Cases and Correlation with c-myc and IgVH Gene Mutation Status

Abstract

Plasmablastic lymphoma (PBL) is a rare acquired immunodeficiency syndrome-associated nonHodgkin's lymphoma (AIDS-NHL), with predilection for the mucosa of oral cavity. It usually has a plasmablastic morphology, expressing plasma cell-associated antigens with weak or absent expression of B-cell-associated markers. To further define the immunophenotypic and molecular genetics of these tumors, we investigated two cases of plasmablastic lymphomas of the head and neck for c-myc gene rearrangement and immunoglobulin heavy chain (IgV H ) hypermutation status. For the first time we report a case of AIDS-related PBL that, by fluorescence in situ hybridization (FISH), shows a c-myc gene rearrangement. Although current literature suggests that most cases of c-myc gene rearranged AIDS-NHL are Burkitt's lymphoma, our case has an immunophenotype characteristic for PBL. In this case, IgV H hypermutation analysis showed a somatic hypermutation, indicative of germinal center transit. The concurrent B-cell immunophenotype of BCL-6 -/CD138 + /MUM-1 + also suggests a post-germinal center B-cell origin of this lymphoma. The immunophenotype of our second case (BCL-6 -/CD138 + /MUM-1 + ) also suggests a post-germinal center B-cell origin. However, IgV H hypermutation analysis was not possible in this case.

High incidence of MYC rearrangement in human immunodeficiency virus‐positive plasmablastic lymphoma

“…After an extensive search of the English‐language literature, we found 85 PBL cases with available MYC rearrangement information . The detailed clinicopathological data of the 85 cases from the literature are shown in Table .…”

“…described the first reported cytogenetic abnormality in PBL, an IGH – MYC translocation. In the past few years, several other studies have reported MYC translocations in PBL . However, these reports have included only isolated cases or a small series of tumours.…”

“…More recently, MYC rearrangements have been identified in approximately half of PBL cases, and have been reported as the main cytogenetic alterations in PBL . As PBL is a rare disease, very few studies concerning MYC rearrangement in PBL have been published, and these studies have mainly been presented as case reports or small series . The clinicopathological features of PBL with MYC rearrangement and the prognostic significance of MYC rearrangement in PBL are not well characterised.…”

Concurrent plasmablastic lymphoma with malignant external otitis in the external auditory canal

“…Se trata de un subtipo de linfoma células B caracterizado por un comportamiento clínico agresivo. Este tipo de linfoma se observa con mayor frecuencia en la cavidad oral de pacientes VIH-positivos6, aunque también se puede observar en sitios extra-orales en pacientes VIH-negativos, donde el virus de Epstein-Barr (EBV) puede estar estrechamente relacionado con su patogénesis (2). El PBL representa un reto diagnóstico dada su morfología muy característica y la falta de expresión de CD20, y también un desafío terapéutico, con primeras respuestas a la terapia, pero con altas tasas de recaída y mal pronóstico (3).…”

Extranodal hematopoietic neoplasms and mimics in the head and neck: an update

“…t(8;14)(q24;q32)/MYC-IGH has been described in a subset of plasmablastic lymphomas, but their prevalence needs better definition[54]. Human herpes virus type 8 (HHV8) is absent.Molecular analysis of plasmablastic lymphomas has shown that most cases have monoclonal IGH rearrangements, but a subset show somatic mutations of the IGH variable regions, indicating derivation from post-germinal center B-cells.…”