Classification and challenges in the histopathological diagnosis of peripheral T-cell lymphomas, emphasis on the WHO-HAEM5 updates

Implementation of the recommended immunohistochemistry algorithm for classification of peripheral T-cell lymphoma, not otherwise specified into the prognostically significant GATA3 and TBX21 subtypes

INTRODUCTION

Current molecular research has shown the several oncogenic pathways that give rise to the peripheral T-cell lymphoma, not otherwise defined (PTCL, NOS) subtypes, which alter prognosis and might have predictive value. This study was conducted to assess the immunohistochemistry (IHC) algorithm by Amador et al for the subtyping of PTCL, NOS and determine its applicability in relation to the clinicopathological profile.

METHODS

This study included 43 patients with PTCL, NOS diagnosis. Following the use of IHC for the transcription factors GATA3, TBX21, CCR4, and CXCR3, two pathologists subtyped the samples. Comprehensive clinicopathological correlation was carried out.

RESULTS

Applying the algorithm of Amador et al., cases were classified into GATA3 (20), TBX21 (15), and unclassified (8) subtypes. No significant association with clinical parameters of subtypes or CD4/ CD8 positivity was observed. Although a higher proportion of cases in the TBX21 subgroup showed a polymorphic population compared with the GATA3 subgroup, which had a monomorphic population, no significant p-value (0.111) was observed. Two Lennert lymphomas were classified into the GATA3 subgroup. Multivariate analysis showed no significant difference in overall survival (p-value = 0.105) and progression-free survival (p-value = 0.0509) between IHC-defined subtypes; trends indicate that overall survival and progression-free survival are worse in the GATA3 subgroup.

CONCLUSION

Although the algorithm is reproducible, a proportion of cases remains unclassifiable and may require additional investigation and gene expression profiling. The GATA3 subgroup was found to have a monomorphic population with a poor overall prognosis and thus requires a larger sample size for validation.

Intestinal T-cell lymphomas NOS presenting as a polypoidal lesion: A case report

RATIONALE

Intestinal T-cell lymphomas are exceedingly rare diseases. Intestinal T-cell lymphoma NOS, as a "wastebasket" category, is difficult to diagnosis. Endoscopy can identify abnormal mucosa in most patients at a reasonably early stage. Therefore, it is crucial to increase the understanding of endoscopists in terms of the endoscopic characteristics of ITCL.

PATIENT CONCERNS

A 74-year-old male alone with wasting as the major complaint, had multiple polypoid lesions in the large intestine. The patient then had endoscopic care.

DIAGNOSES

Only 1 polypoid lesion on white-light endoscopy in the sigmoid colon was pathologically diagnosed as intestinal T-cell lymphomas, not otherwise specified (ITCL-NOS).

INTERVENTIONS

The patient underwent intensity-reduced CHOP therapy.

OUTCOMES

The patient is still with controlled disease but developed chemotherapy-related side effects.

LESSONS

In the individual with unexplained anemia and waste, endoscopy should not be delayed. For each of polypoid lesion on white-light endoscopy, the endoscopist need to remain cautious, because every lesion in the same patient can exhibit the independence of histopathological features. Meanwhile, we suggest that endoscopists should routinely observe the terminal ileum, even take biopsy samples if necessary.

Cutaneous Intravascular Hematolymphoid Entities: A Review

Intravascular lymphomas are rare disease conditions that exhibit neoplastic lymphoid cells that are confined mainly to the lumens of small capillaries and medium-sized vessels. The majority of the intravascular lymphomas are of B-cell origin, but they can include NK/T-cell and CD30+ immunophenotypes. In the histologic differential diagnosis are benign proliferations such as intralymphatic histiocytosis and intravascular atypical CD30+ T-cell proliferation. In this review, we discuss the clinical, histopathologic, and molecular findings of intravascular B-cell lymphoma, intravascular NK/T-cell lymphoma, intralymphatic histiocytosis, and benign atypical intravascular CD30+ T-cell proliferation.

Therapeutic challenges in peripheral T-cell lymphoma

Peripheral T-cell lymphoma (PTCL) is a rare and heterogeneous group of hematological malignancies. Compared to our knowledge of B-cell tumors, our understanding of T-cell leukemia and lymphoma remains less advanced, and a significant number of patients are diagnosed with advanced stages of the disease. Unfortunately, the development of drug resistance in tumors leads to relapsed or refractory peripheral T-Cell Lymphomas (r/r PTCL), resulting in highly unsatisfactory treatment outcomes for these patients. This review provides an overview of potential mechanisms contributing to PTCL treatment resistance, encompassing aspects such as tumor heterogeneity, tumor microenvironment, and abnormal signaling pathways in PTCL development. The existing drugs aimed at overcoming PTCL resistance and their potential resistance mechanisms are also discussed. Furthermore, a summary of ongoing clinical trials related to PTCL is presented, with the aim of aiding clinicians in making informed treatment decisions.

SOHO State of the Art Updates and Next Questions | New Pathways and New Targets in PTCL: Staying on Target

While the peripheral T-cell lymphomas (PTCL) remain a therapeutic challenge, and increasingly account for a disproportionate number of lymphoma-related deaths, improved understanding of disease pathogenesis and classification, and the development of novel therapeutic agents over the past decade, all provide reasons for a more optimistic outlook in the next. Despite their genetic and molecular heterogeneity, many PTCL are dependent upon signaling input provided by antigen, costimulatory, and cytokine receptors. While gain-of-function alterations effecting these pathways are recurrently observed in many PTCL, more often than not, signaling remains ligand-and tumor microenvironment (TME)-dependent. Consequently, the TME and its constituents are increasingly recognized as "on target". Utilizing a "3 signal" model, we will review new-and old-therapeutic targets that are relevant for the more common nodal PTCL subtypes.