A Double Hit CD10-Negative B-Cell Lymphoma with t(3;8)(q27;q24) Leading to Juxtaposition of the BCL6 and MYC Loci Associated with Good Clinical Outcome

Gene Transactivation and Transrepression in MYC-Driven Cancers

MYC is a proto-oncogene regulating a large number of genes involved in a plethora of cellular functions. Its deregulation results in activation of MYC gene expression and/or an increase in MYC protein stability. MYC overexpression is a hallmark of malignant growth, inducing self-renewal of stem cells and blocking senescence and cell differentiation. This review summarizes the latest advances in our understanding of MYC-mediated molecular mechanisms responsible for its oncogenic activity. Several recent findings indicate that MYC is a regulator of cancer genome and epigenome: MYC modulates expression of target genes in a site-specific manner, by recruiting chromatin remodeling co-factors at promoter regions, and at genome-wide level, by regulating the expression of several epigenetic modifiers that alter the entire chromatin structure. We also discuss novel emerging therapeutic strategies based on both direct modulation of MYC and its epigenetic cofactors.

Double-Hit Lymphoma (MYC and BCL6) with Involvement of Skull and Adnexal Lesions: A Case Report and a Review of the Literature

BACKGROUND Double-hit lymphomas (DHL) belong to a category of very aggressive lymphomas characterized by MYC translocation and either BCL2, or less commonly, BCL6 translocations. Those with BCL6 translocations have a predilection for rare extranodal sites such as the gastrointestinal tract, nasopharynx, and tonsils. Involvement of the skull and adnexal structures is rare. Here we report a case of a young female with both skull and adnexal involvement. CASE REPORT A 20-year-old female who presented with hypercalcemia was found to have adnexal, skull, and jaw masses. Workup revealed a stage IV high grade B-cell lymphoma (HGBL) with MYC and BCL6 rearrangements. She was subsequently treated with R-EPOCH and attained complete remission 9 months after her initial presentation. To the best of our knowledge, our patient represents the first reported case of skull and adnexal involvement in HGBL with MYC and BCL6 rearrangement. CONCLUSIONS Rare extranodal presentations of HGBL with MYC and BCL6 rearrangement should be considered in the differential diagnosis of masses found in unusual sites such as the skull and adnexa. Due to their aggressive nature, early and prompt recognition of these lymphomas is essential for timely administration of appropriate therapy.

[Diffuse large B-cell lymphoma with concomitant c-MYC and BCL6 gene rearrangements with primary skin involvement: A case report and a review of literature]

Double-hit lymphoma (DHL) is a rare aggressive B-cell lymphoma with concomitant c-MYC, BCL2 or BCL6 gene rearrangements, which is characterized by the high frequency of extranodal lesions and by resistance to chemotherapy. The median survival does not exceed 18 months in patients with this disease. The majority of DHL is represented by с-MYC/BCL2 cases. The combination of c-MYC/BCL6 occurs rarely (5-8%). The paper describes a case of DHL with concomitant c-MYC and BCL6 gene rearrangements, which mimics diffuse large B-cell lymphoma, leg-type.