Epstein-Barr Virus-Positive Mucocutaneous Ulcer: A Unique and Curious Disease Entity

Epstein-Barr virus (EBV)-positive mucocutaneous ulcer (EBVMCU) was first described as a lymphoproliferative disorder in 2010. EBVMCU is a unifocal mucosal or cutaneous ulcer that often occurs after local trauma in patients with immunosuppression; the patients generally have a good prognosis. It is histologically characterized by proliferating EBV-positive atypical B cells accompanied by ulcers. On the basis of conventional pathologic criteria, EBVMCU may be misdiagnosed as EBV-positive diffuse large B-cell lymphoma or other lymphomas. However, its prognosis differs from that of EBV-associated lymphomas, in that patients with EBVMCU frequently show spontaneous regression or complete remission without chemotherapy. Therefore, EBVMCU is now recognized as a low-grade malignancy or a pseudo-malignant lesion. Avoiding unnecessary chemotherapy by distinguishing EBVMCU from other EBV-associated lymphomas will reduce the burden and unnecessary harm on patients. On the basis of these facts, EBVMCU was first described as a new clinicopathological entity by the World Health Organization in 2017. In this review, we discuss the clinicopathological characteristics of previously reported EBVMCU cases, while focusing on up-to-date clinical, pathological, and genetic aspects

Upregulated Expression of Activation-Induced Cytidine Deaminase in Ocular Adnexal Marginal Zone Lymphoma with IgG4-Positive Cells

Immunoglobulin G4-related disease (IgG4-RD) is a systemic disorder characterized by tissue fibrosis and intense lymphoplasmacytic infiltration, causing progressive organ dysfunction. Activation-induced cytidine deaminase (AID), a deaminase normally expressed in activated B-cells in germinal centers, edits ribonucleotides to induce somatic hypermutation and class switching of immunoglobulin. While AID expression is strictly controlled under physiological conditions, chronic inflammation has been noted to induce its upregulation to propel oncogenesis. We examined AID expression in IgG4-related ophthalmic disease (IgG4-ROD; n = 16), marginal zone lymphoma with IgG4-positive cells (IgG4+ MZL; n = 11), and marginal zone lymphoma without IgG4-positive cells (IgG4- MZL; n = 12) of ocular adnexa using immunohistochemical staining. Immunohistochemistry revealed significantly higher AID-intensity index in IgG4-ROD and IgG4+ MZL than IgG4- MZL (p < 0.001 and = 0.001, respectively). The present results suggest that IgG4-RD has several specific causes of AID up-regulation in addition to inflammation, and AID may be a driver of oncogenesis in IgG4-ROD to IgG4+ MZL

Clinicopathological analysis of 34 Japanese patients with EBV-positive mucocutaneous ulcer

Epstein–Barr virus (EBV)-positive mucocutaneous ulcer (EBVMCU) is a unifocal mucosal or cutaneous ulcer that is histologically characterized by proliferating EBV-positive atypical B cells. While EBVMCU demonstrates a histology similar to that of EBV-positive diffuse large B-cell lymphoma (DLBCL), their clinical behavior differs. Thus, characterizing distinguishing features of EBVMCU and EBV-positive DLBCL is critical. To identify unique characteristics between EBVMCU and lymphoma, we analyzed the clinicopathological and genetic features of 34 Japanese patients with EBVMCU and compared them to those of 24 EBV-positive DLBCL patients and 25 EBV-negative DLBCL patients. All patients with EBVMCU had localized ulcerative lesions, and 31 patients (91%) were using immunosuppressants, such as methotrexate (MTX) or hydroxycarbamide. All patients that were followed up with exhibited good prognosis following immunosuppressant reduction or chemotherapy. In addition, 17 EBV-positive DLBCL patients, and 15 EBV-negative DLBCL patients, received chemotherapy (P < 0.001, P < 0.001, respectively). Our data showed that EBVMCU did not increase indicators associated with lymphoma prognosis, such as soluble interleukin 2 receptor (sIL-2R) and lactate dehydrogenase (LDH) compared to those in the EBV-positive DLBCL or EBV-negative DLBCL groups (sIL-2R, P < 0.001, P = 0.025; LDH, P = 0.018, P = 0.038, respectively). However, histologically, EBVMCU exhibited EBV-positive, variable-sized, atypical B-cell proliferation. Thus, EBVMCU was histologically classified as: (1) polymorphous; (2) large cell-rich; (3) classic Hodgkin lymphoma-like; and (4) mucosa-associated lymphoid tissue lymphoma-like. Moreover, genetic analysis showed that immunoglobin heavy chain (IGH) gene rearrangement did not differ significantly between EBVMCU and EBV-positive DLBCL (44% vs. 32%; P = 0.377), or between EBVMCU and EBV-negative DLBCL (44% vs. 58%; P = 0.280). Therefore, it is difficult to distinguish EBVMCU from EBV-positive DLBCL using only pathological and genetic findings, suggesting that clinical information is important in accurately distinguishing between EBVMCU and EBV-positive DLBCL

PD-L1 expression is associated with the spontaneous regression of patients with methotrexate-associated lymphoproliferative disorders

Background Most patients with methotrexate-associated lymphoproliferative disorder (MTX-LPD) show diffuse large B-cell lymphoma (DLBCL) or classic Hodgkin lymphoma (CHL) types. Patients with MTX-LPD often have spontaneous remission after MTX discontinuation, but chemotherapeutic intervention is frequently required in patients with CHL-type MTX-LPD. In this study, we examined whether programmed cell death-ligand 1 (PD-L1) expression levels were associated with the prognosis of MTX-LPD after MTX discontinuation. Methods A total of 72 Japanese patients diagnosed with MTX-LPD were clinicopathologically analyzed, and immunohistochemical staining of PD-L1 was performed in 20 DLBCL-type and 24 CHL-type MTX-LPD cases to compare with the clinical course. Results PD-L1 was expressed in 5.0% (1/20) of patients with DLBCL-type MTX-LPD, whereas it was expressed in 66.7% (16/24) of the patients with CHL-type MTX-LPD in more than 51% of tumor cells. Most CHL-type MTX-LPD patients with high PD-L1 expression required chemotherapy owing to exacerbations or relapses after MTX discontinuation. However, no significant differences in clinicopathologic findings at diagnosis were observed between PD-L1 high- and low-expression CHL-type MTX-LPD. Conclusion PD-L1 expression was significantly higher in patients with CHL-type than DLBCL-type MTX-LPD, suggesting the need for chemotherapy in addition to MTX discontinuation in CHL-type MTX-LPD patients to achieve complete remission. No association was observed between PD-L1 expression levels and clinical findings at diagnosis, suggesting that PD-L1 expression in tumor cells influences the pathogenesis of CHL-type MTX-LPD after MTX discontinuation

The Kiloparsec-scale Neutral Atomic Carbon Outflow in the Nearby Type-2 Seyfert Galaxy NGC 1068: Evidence for Negative AGN Feedback

Active galactic nucleus (AGN) feedback is postulated as a key mechanism for regulating star formation within galaxies. Studying the physical properties of the outflowing gas from AGN is thus crucial for understanding the co-evolution of galaxies and supermassive black holes. Here we report 55 pc resolution ALMA neutral atomic carbon [CI] $^3P_1\text{-}^3P_0$ observations toward the central 1 kpc of the nearby type-2 Seyfert galaxy NGC 1068, supplemented by 55 pc resolution CO($J=1\text{-}0$) observations. We find that [CI] emission within the central kpc is strongly enhanced by a factor of $>$5 compared to the typical [CI]/CO intensity ratio of $\sim$0.2 for nearby starburst galaxies (in units of brightness temperature). The most [CI]-enhanced gas (ratio $>$ 1) exhibits a kpc-scale elongated structure centered at the AGN that matches the known biconical ionized gas outflow entraining molecular gas in the disk. A truncated, decelerating bicone model explains well the kinematics of the elongated structure, indicating that the [CI] enhancement is predominantly driven by the interaction between the ISM in the disk and the highly inclined ionized gas outflow (which is likely driven by the radio jet). Our results strongly favor the "CO dissociation scenario" rather than the "in-situ C formation" one which prefers a perfect bicone geometry. We suggest that the high [CI]/CO intensity ratio gas in NGC 1068 directly traces ISM in the disk that is currently dissociated and entrained by the jet and the outflow, i.e., the "negative" effect of the AGN feedback.Comment: 12 pages, 5 figures, accepted for publication in The Astrophysical Journal Letter