High throughput sequencing reveals high specificity of TNFAIP3 mutations in ocular adnexal marginal zone B-cell lymphomas.

The majority of ocular adnexal (OA) lymphomas (OAL) are extranodal marginal zone lymphomas (MZL). First high throughput sequencing (HTS) studies on OA-MZL showed inconsistent results and the distribution of mutations in reactive lymphoid lesions of this anatomic region has not yet been sufficiently addressed. We characterized OAL and lymphoid lesions of the OA by targeted HTS. The study included 34 OA-MZL, 11 chronic conjunctivitis, five mature small cell B-cell lymphomas spreading to the OA, five diseases with increase of IgG4+ plasma cells, three Burkitt lymphomas (BL), three diffuse large B-cell lymphomas (DLBCL), three mantle cell lymphomas, three idiopathic orbital inflammations/orbital pseudo tumors (PT), and three OA lymphoid hyperplasia. All cases were negative for Chlamydia. The mutational number was highest in BL and lowest in PT. The most commonly (and exclusively) mutated gene in OA-MZL was TNFAIP3 (10 of 34 cases). Altogether, 20 out of 34 patients harbored mutually exclusive mutations of either TNFAIP3, BCL10, MYD88, ATM, BRAF, or NFKBIE, or nonexclusive mutations of IRF8, TNFRSF14, KLHL6, and TBL1XR1, all encoding for NK-κB pathway compounds or regulators. Thirteen patients (38%) had, to a great part, mutually exclusive mutations of chromatin modifier-encoding genes: KMT2D, CREBBP, BCL7A, DNMT3A, EP300, or HIST1H1E. Only four patients harbored co-occurring mutations of genes encoding for NK-κB compounds and chromatin modifiers. Finally, PTEN, KMT2D, PRDM1, and HIST1H2BK mutations were observable in reactive lymphoid lesions too, while such instances were devoid of NF-κB compound mutations and/or mutations of acetyltransferase-encoding genes. In conclusion, 80% of OA-MZL display mutations of either NK-κB compounds or chromatin modifiers. Lymphoid lesions of the OA bearing NF-κB compound mutations and/or mutations of acetyltransferase-encoding genes highly likely represent lymphomas.

Bone Marrow Infiltration of Angioimmunoblastic T-Cell Lymphoma: Identification and Prognostic Impact of Histologic Patterns and Diagnostic Application of Ancillary Phenotypic and Molecular Analyses.

CONTEXT.­: Angioimmunoblastic T-cell lymphomas originate from T follicular helper cells and express respective markers (BCL6, CD10, CXCL13, ICOS, and PD-1). Although commonly present, bone marrow involvement by angioimmunoblastic T-cell lymphoma can be diagnostically challenging. Additionally, only little is known about the distribution of T follicular helper cells in healthy and reactively changed bone marrows or in samples affected by other lymphomas. OBJECTIVE.­: To establish a diagnostic approach to reliably identify bone marrow infiltration of angioimmunoblastic T-cell lymphoma. DESIGN.­: We analyzed the morphologic infiltration pattern and the expression of T follicular helper-cell markers in 42 matched paired lymph node and bone marrow samples and applied comparative clonality testing. Furthermore, we studied the expression of BCL6 and PD-1 in a control cohort of healthy, reactively changed, and otherwise affected bone marrows. RESULTS.­: We identified 3 different bone marrow infiltration patterns correlating with overall survival (interstitial/micronodular infiltration with or without eosinophilia and diffuse infiltration with eosinophilia). The matched pairs showed a consistent (co)expression of PD-1 and BCL6 with a generally weaker expression in the bone marrow than in the lymph nodes. Comparative clonality testing was helpful in only a minority of cases. Infiltrates of the most important differential diagnoses contained either PD-1- or BCL6-positive tumor-infiltrating cells, but no coexpressing cells. CONCLUSIONS.­: Bone marrow infiltration by angioimmunoblastic T-cell lymphoma displays 3 different patterns that correlate with prognosis. BCL6 and PD-1 can be reliably used to identify lymphoma infiltrates and to help rule out several differential diagnoses. Comparative clonality testing rarely provides additional value and cannot replace morphologic and phenotypic analyses.

Single and combined BTK and PI3Kδ inhibition with acalabrutinib and ACP-319 in pre-clinical models of aggressive lymphomas.

The B-cell receptor and the phosphatidylinositol 3-kinase (PI3K) signalling pathways, together with their downstream partners, represent important therapeutic targets for B-cell lymphomas. Here, we evaluated the activity of acalabrutinib (ACP-196) and ACP-319 (AMG-319), second generation inhibitors of Bruton tyrosine kinase (BTK) and PI3Kδ inhibitor, respectively, in lymphoma pre-clinical models. The two compounds showed activity in activated B-cell-like diffuse large B-cell lymphoma (ABC DLBCL), mantle cell lymphoma and marginal zone lymphoma. Two in vivo experiments with ABC DLBCL and MCL xenografts confirmed the effect of the single agents. Benefit was achieved by exposing the lymphoma cell lines to both acalabrutinib and ACP-319. Two cell lines presented a discordant response to first and second generation BTK inhibitors, probably due to the inhibition by ibrutinib of kinases other than BTK. In conclusion, our data sustain the on-going current trials with acalabrutinib and ACP-319 as single agents and provide the basis for the investigation of their combination as well.

Possible pulmonary Rhizopus oryzae infection in a previously healthy child after a near-drowning incident.

This article reports on a previously healthy 17-month-old boy who developed pulmonary mucormycosis after a near-drowning incident in a goose pond. The patient survived without neurological sequelae and recovered, under treatment with amphotericin B, from the rare and often invasive fungal infection with Rhizopus spp., usually occurring in immunodeficient patients.