Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0268596 (EMA)
 2,520 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

CD20-negative diffuse large B-cell lymphomas (DLBCLs) constitute a rare and heterogeneous group of aggressive lymphomas. Known well-documented variants include plasmablastic lymphomas, primary effusion lymphomas, anaplastic kinase-positive large B-cell lymphomas, and large B-cell lymphomas arising in human herpesvirus 8 (HHV8)-associated multicentric Castleman disease. They impose diagnostic challenges for pathologists and therapeutic confrontations for clinicians. CD20 loss in B-cell lymphomas is a well-known phenomenon after rituximab therapy. De novo loss of CD20 has been reported in human immunodeficiency virus (HIV)-positive patients. Rare cases of primary CD20-negative DLBCLs that did not meet the criteria of the well-established subtypes of CD20-negative DLBCLs have been reported. This might expand the spectrum of unclassifiable CD20-negative DLBCLs with aberrant genetic and immunophenotypes. This imposes further diagnostic and therapeutic challenges. We report a case of a primary CD20-negative DLBCL in an HIV-infected female patient with an Epstein Barr virus (EBV) coinfection, who presented with generalized lymphadenopathy and fever. The nodal neoplastic immunoblasts were positive for LCA, PAX5, CD30, OCT2, BOB1, MUM1, CD79a, and CD19. Ki67 proliferation index was 100%. They were negative for CD20, CD3, ALK, EMA, CD138, CD38, EBV, and HHV8. Our case did not meet the criteria of the known variants of CD20-negative DLBCLs. The aim of this study is to highlight the diagnostic challenges associated with CD20-negative DLBCLs. De novo unclassifiable CD20-negative DLBCLs might raise an insight into the complex genetic mechanisms of CD20 concealment with variable immunoprofiles and resistance to conventional chemotherapies.
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PMID:De Novo Unclassifiable CD20-Negative Diffuse Large B-Cell Lymphoma: A Diagnostic and Therapeutic Challenge. 2898 64

Plasmablastic lymphoma (PBL) is an aggressive malignancy that usually occurs in the setting of immunosuppression. The immunohistochemical profile of PBL is that of terminally differentiated B lymphocytes. CD138, CD38, and MUM1 are usually immunopositive. However, pan B-cell markers such as CD20 and PAX-5 are usually negative. MYC rearrangement is the most commonly encountered genetic alteration, with immunoglobulin (IG), especially immunoglobulin heavy (IGH) chain, being the most frequent partner. We report a case of PBL in a 48-year-old human immunodeficiency virus- (HIV-) positive male who was admitted to the hospital with signs and symptoms suspicious for tumor lysis syndrome. Bone marrow examination revealed hypercellular marrow with trilineage hypoplasia and sheets of intermediate to large neoplastic cells with basophilic vacuolated cytoplasm comprising the majority of cellular elements of the bone marrow. The neoplastic cells were negative for conventional B-cell, T-cell, plasma cell, and myeloid markers, while flow cytometric analysis revealed an abnormal CD45-dim population that was partially weakly positive for CD71 and CD79b. The diagnosis was initially thought to be a high-grade primitive hematopoietic neoplasm, possibly an acute undifferentiated leukemia. BOB-1, however, was immunopositive in the neoplastic cells, confirming its B-cell origin. MYC was positive by immunohistochemistry and break-apart FISH, as were CD45, MUM-1, and EMA immunostains. There was immunoglobulin kappa (IGK) light chain gene rearrangement by polymerase chain reaction (PCR). Additionally, Epstein-Barr virus- (EBV-) encoded small RNAs (EBER) were positive by in situ hybridization (ISH). The tumor proliferation index by Ki-67 immunostaining approached 95%. Although the tumor cells were negative for CD38 and CD138, the diagnosis of PBL was still rendered. We recommend using a broad spectrum of B-cell markers, including BOB-1 and OCT-2, in such challenging cases of B-cell lymphomas with no expression of conventional B-cell markers. We also emphasize that the negative CD38 and CD138 should not exclude PBL from the differential diagnosis.
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PMID:Plasmablastic Lymphoma, a Rare Entity in Bone Marrow with Unusual Immunophenotype and Challenging Differential Diagnosis. 3156 47

Lymphoepithelial-like carcinoma (LEC) is a rare malignant neoplasm, which can be associated with Epstein-Barr virus (EBV) infection. Histologically, LEC is an undifferentiated carcinoma with an intermixed reactive lymphoplasmacytic infiltrate. LEC appears to be an uncommon tumor type of lip carcinoma. An 82-year-old white woman presented a lesion on her lower lip that developed over the last year. The lesion was characterized by ulceration with flat edges, hardened base, painful, and absence of regional lymphadenopathy. Microscopical analysis evidenced an intense inflammatory infiltrate, composed of lymphoplasmacytic cells, associated with scarce pleomorphic epithelial cells. Immunohistochemistry highlighted the LEC cells with strong expression of pan-CK AE1/AE3, EMA, p63, and p53. CD138 was also faintly positive. Ki-67 was >85%. In situ hybridization analysis did not show evidence of EBV. A diagnostic of EBV-negative LEC was made. We present an uncommon type of lip carcinoma, which can represent a diagnostic challenge for clinicians and pathologists.
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PMID:EBV-negative lymphoepithelial-like carcinoma of the lower lip. 3203 67


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