Corinne Haioun

Bone marrow histologic and immunohistochemical findings in peripheral. T-cell lymphoma: A study of 38 cases.

The histologic and immunohistochemical findings in bone marrow (BM) biopsies from 38 patients with peripheral T-cell lymphoma (PTCL) are reported. Routine light microscopy showed that BM involvement was unequivocal in 12 cases and questionable in 14 cases. There was no histologic evidence of lymphoma in the remaining 12 cases. Immunohistochemistry performed on BM frozen sections demonstrated the T-cell origin of the infiltrating lymphoid cells in 24 of the 26 patients with unequivocal or questionable involvement. The malignant nature of these cells was suggested by demonstration of an aberrant T-cell phenotype identical to that observed in the other sites of involvement. In addition, in four of the 12 cases with apparently normal BM at routine light microscopy, immunohistochemistry revealed a minimal but phenotypically abnormal T-cell population, suggesting mild infiltration by lymphoma. These combined histologic and immunohistochemical data documented a high incidence (73%) of BM involvement by PTCL. In addition, a very peculiar sinusal pattern of BM involvement was found in five patients who presented an unusual type of hepatosplenic T-cell lymphoma expressing the gamma delta T-cell receptor. The present study demonstrates the high incidence of BM involvement by PTCL and emphasizes the value of frozen section immunohistochemistry to establish this diagnosis, especially when routine light microscopy findings are questionable.

Recurrent mutations of the exportin 1 gene (XPO1) and their impact on selective inhibitor of nuclear export compounds sensitivity in primary mediastinal B-cell lymphoma.

Primary mediastinal B‐cell lymphoma (PMBL) is an entity of B‐cell lymphoma distinct from the other molecular subtypes of diffuse large B‐cell lymphoma (DLBCL). We investigated the prevalence, specificity, and clinical relevance of mutations of XPO1, which encodes a member of the karyopherin‐β nuclear transporters, in a large cohort of PMBL. PMBL cases defined histologically or by gene expression profiling (GEP) were sequenced and the XPO1 mutational status was correlated to genetic and clinical characteristics. The XPO1 mutational status was also assessed in DLBCL, Hodgkin lymphoma (HL) and mediastinal gray‐zone lymphoma (MGZL).The biological impact of the mutation on Selective Inhibitor of Nuclear Export (SINE) compounds (KPT‐185/330) sensitivity was investigated in vitro. XPO1 mutations were present in 28/117 (24%) PMBL cases and in 5/19 (26%) HL cases but absent/rare in MGZL (0/20) or DLBCL (3/197). A higher prevalence (50%) of the recurrent codon 571 variant (p.E571K) was observed in GEP‐defined PMBL and was associated with shorter PFS. Age, International Prognostic Index and bulky mass were similar in XPO1 mutant and wild‐type cases. KPT‐185 induced a dose‐dependent decrease in cell proliferation and increased cell‐death in PMBL cell lines harboring wild type or XPO1 E571K mutant alleles. Experiments in transfected U2OS cells further confirmed that the XPO1 E571K mutation does not have a drastic impact on KPT‐330 binding. To conclude the XPO1 E571K mutation represents a genetic hallmark of the PMBL subtype and serves as a new relevant PMBL biomarker. SINE compounds appear active for both mutated and wild‐type protein. Am. J. Hematol. 91:923–930, 2016.

Rituximab, alkylating agents or combination therapy for gastric mucosa-associated lymphoid tissue lymphoma: a monocentric non-randomised observational study.

There is no consensus on the standard treatment of gastric mucosa‐associated lymphoid tissue (MALT) lymphoma for Helicobacter pylori‐negative patients and for patients with persistent disease despite H. pylori eradication.

Long-term course of precancerous lesions arising in patients with gastric MALT lymphoma

BACKGROUND AND AIMS To evaluate the prevalence and the long-term course of gastric precancerous lesions in patients with GML. PATIENTS AND METHODS In this retrospective single-centre study, we included 179 patients with GML, 70 with gastric diffuse large B-cell lymphoma (GDLBCL) and 152 with Helicobacter pylori-associated gastritis (HpG), from January 1995 to January 2014. The presence of atrophic gastritis, intestinal metaplasia and neoplastic lesion has been assessed at baseline and during follow-up. RESULTS Atrophic gastritis was more frequent in the GML group whereas there was also a trend for intestinal metaplasia and gastric dysplasia. In patients with GML, atrophic gastritis, intestinal metaplasia and gastric dysplasia were more frequent in the GML area than in other part of the stomach. During follow-up, the prevalence of atrophic gastritis remained stable overtime whereas intestinal metaplasia and dysplasia tend to increase overtime. In multivariate analysis, the occurrence of dysplasia or carcinoma was associated with the presence of intestinal metaplasia at baseline and male gender. CONCLUSION GML is associated with gastric precancerous lesion to a higher extent than GDLBCL and HpG. Those precancerous lesions do not regress despite achievement of complete remission of GML and tend to increase overtime.