Journal of Clinical and Experimental Hematopathology最新文献

Histiocytic neoplasms (HNs) include juvenile xanthogranuloma, Erdheim-Chester disease, Rosai-Dorfman disease, ALK-positive histiocytosis, and histiocytic sarcoma in the 5th edition of the World Health Organization Classification of Haematolymphoid Tumours. These entities are clinicopathologically distinctive, and typical histological findings have been established. However, the common feature of a proliferation of histiocytic cells often leads to morphological overlap among HNs, and also necessitates a differential diagnosis from several non-HNs or non-neoplastic conditions. In this review, we provide a brief summary of the clinical findings, molecular features, histopathologies, and immunophenotypes of HNs, as well as to discuss their differential diagnosis.

Cytokine release syndrome (CRS) is the most common adverse event of chimeric antigen receptor T (CAR-T) cell therapy and is usually characterized by systemic symptoms such as fever, hypotension, and hypoxia. However, there have been several recent reports of local CRS characterized by cervical swelling. This localized syndrome can cause life-threatening laryngeal edema and requires early diagnostic treatment. Here we report 3 cases of local CRS where bilateral salivary gland swelling emerged following anti-CD19 CAR-T cell therapy for relapsed or refractory diffuse large B-cell lymphoma. Following tocilizumab treatment for systemic CRS, all patients exhibited cervical swelling. Physical examinations revealed significant swelling of the bilateral submandibular glands, and computed tomography scans showed substantial enlargement of the bilateral parotid and submandibular glands. Immediate treatment with dexamethasone effectively managed the potentially life-threatening laryngeal or pharyngeal edema, thereby preventing severe airway obstruction. This study has demonstrated, for the first time to our knowledge, that salivary gland enlargement is a common finding in local CRS. This observation suggests that physicians should continue to closely monitor the risk of developing cervical edema leading to life-threatening airway obstruction after systemic CRS, even in patients treated with tocilizumab. If salivary gland swelling is observed, it would be better to consider prompt evaluation and dexamethasone administration.

Since the identification of the TTMV::RARA fusion in pediatric cases resembling acute promyelocytic leukemia (APL) by Astolfi et al. in 2021, several similar cases have been reported worldwide. In this report, we present a case of relapsed APL in an adolescent patient, who exhibited the TTMV::RARA fusion gene. This patient exhibited extensive central nervous system involvement and experienced bone marrow necrosis during disease recurrence. Despite achieving complete remission after re-induction chemotherapy, the patient experienced a rapid second relapse, highlighting the extremely aggressive nature of this subtype. These clinical manifestations contribute to the growing recognition of this rare disease.

Duodenal type follicular lymphoma (DFL), a rare entity of follicular lymphoma (FL), is clinically indolent and is characterized by a low histological grade compared with nodal follicular lymphoma (NFL). Our previous reports revealed that DFL shares characteristics of both NFL and mucosa-associated lymphoid tissue (MALT) lymphoma in terms of clinical and biological aspects, suggesting its pathogenesis may involve antigenic stimulation. In contrast to NFL, the genomic methylation status of DFL is still challenging. Here, we determined the methylation profiles of DNAs from patients with DFL (n = 12), NFL (n = 10), duodenal reactive lymphoid hyperplasia (D-RLH) (n = 7), nodal reactive lymphoid hyperplasia (N-RLH) (n = 5), and duodenal samples from normal subjects (NDU) (n = 5) using methylation specific PCR of targets previously identified in MALT lymphoma (CDKN2B/P15, CDKN2A/P16, CDKN2C/P18, MGMT, hMLH-1, TP73, DAPK, HCAD). DAPK1 was frequently methylated in DFL (9/12; 75%), NFL (9/10; 90%), and D-RLH (5/7; 71%). CDKN2B/P15 sequences were methylated in six DFL samples and in only one NFL sample. Immunohistochemical analysis showed that p15 expression inversely correlated with methylation status. Genes encoding other cyclin-dependent kinase inhibitors (CDKN2A/P16, CDKN2C/P18) were not methylated in DFL samples. Methylation of the genes of interest was not detected in DNAs from D-RLH, except for DAPK1, and the difference in the extent of methylation between NDU and D-RLH was statistically significant (P = 0.013). Our results suggest that D-RLH serves as a reservoir for the development of DFL and that methylation of CDKN2B/P15 plays an important role in this process.

In the new WHO classifications of haematolymphoid tumours (WHO-HAEM5), classic Hodgkin lymphoma (cHL) is categorized into B-cell lymphoid proliferations and lymphomas. Although the majority of Hodgkin Reed-Sternberg (HRS) cells are of germinal center B-cell origin with some defects of B-cell transcription factors, they rarely express T-cell antigens or cytotoxic molecules. Clonality analyses on cHL samples using BIOMED-2 have been reported by several groups; however, those studies were only focused on Ig regions, including IgH, Ig-kappa, and Ig-lambda, and TCR-γ clonality analysis of cHL has not yet been explored. Here, we investigated TCR-γ gene rearrangement for one hundred cases using a PCR-based method. Four of one hundred (4%) cases showed TCR-γ clonal peaks. Of these, three were at an advanced stage and one patient died of the disease. To clarify whether HRS cells showed T-cell clonality or not, we performed PCR analysis using DNAs of microdissected HRS cells. Three samples showed identical clonal peaks with bulk specimens. Our results indicate that cHL is a heterogeneous disease of mainly B-cell and rarely T-cell origin with a special phenotype. Further molecular studies are warranted.

Patients with refractory or relapsed (R/R) large B-cell lymphoma (LBCL) refractory to first-line chemotherapy or with early relapse have poor outcomes. While chimeric antigen receptor (CAR) T-cell therapy has impressive efficacy after two or more lines of chemotherapy, it's still uncertain if these outcomes remain consistent in the context of third-line CAR T-cell therapy. We conducted a retrospective study of 107 R/R LBCL patients. Patients with relapse 12 months or more after their first-line chemoimmunotherapy (late failure: n = 25) had significantly longer overall survival (OS) than patients with refractory disease or relapse within 12 months (early failure: n = 82) (median OS: not achieved vs. 18.4 months; P < 0.001). Among patients who proceeded to autologous hematopoietic stem-cell transplantation (auto-HSCT), those with late failure had significantly longer event-free survival (EFS) than those with early failure (median EFS: 26.9 vs. 3.1 months; P = 0.012). However, no significant difference in EFS was detected among patients who underwent CAR T-cell therapy (median EFS: not reached vs. 11.8; P = 0.091). Cox regression with restricted cubic spline demonstrated that timing of relapse had significant impact on EFS in patients with auto-HSCT but not in patients with CAR T-cell therapy. Of patients who were scheduled for CAR T-cell therapy, those with late failure were significantly more likely to receive CAR T-cell therapy than those with early failure (90% vs. 57%; P = 0.008). In conclusion, patients with early failure still experienced poor outcomes after the approval of third-line CAR T-cell therapy.

Primary diffuse large B-cell lymphoma of the central nervous system (CNS-DLBCL) can be difficult to diagnose because of the limited amount of biopsy tissue. Here, we analyzed the utility of insulin-like growth factor II mRNA binding protein 3 (IMP3) immunohistochemistry (IHC) as an adjunctive diagnostic tool for CNS-DLBCL. IHC was performed on 57 biopsy samples (55 brain biopsy samples and two vitreous cell blocks) from 54 patients with CNS-DLBCL, including three biopsy samples initially diagnosed as negative or indeterminate for CNS-DLBCL. Additionally, IMP3 IHC was performed on 68 DLBCLs other than CNS-DLBCL and 12 inflammatory brain diseases. Cytoplasmic IMP3 expression was noted in ≥50% of tumor cells in 100% (57/57) of CNS-DLBCLs and 88.2% (60/68) of non-CNS-DLBCLs. In contrast, no IMP3-positive CD20-positive B cells were observed in the inflammatory brain disease (P < 0.0001). In conclusion, IMP3 is highly expressed in CNS-DLBCL. However, it is also expressed in other types of DLBCLs, making it less specific. Most CNS-DLBCL cases can be diagnosed without performing IHC for IMP3 expression, but it may be a useful adjunctive tool to differentiate from reactive lesions when tumor cells are few or deformed.

Mature B-cell acute lymphoblastic leukemia (ALL) is defined by the expression of light chain-restricted surface immunoglobulin (sIg) and usually has features of the leukemic phase of Burkitt lymphoma including FAB-L3 morphology and MYC rearrangement. Recently, another distinct entity in childhood mature B-cell ALL has been characterized as non-L3 morphology and KMT2A rearrangement. Here we report an unusual case of mature B-cell ALL that presented with RUNX1 rearrangement. A 65-year-old male was admitted to our department for thorough examination of leukocytosis and thrombocytopenia. The patient's bone marrow was hypercellular and infiltrated with 97.8% myeloperoxidase-negative, medium-to-large-sized blasts without cytoplasmic vacuoles. Immunophenotypes were characterized by the presence of light chain-restricted sIg and the lack of immature markers, indicating a diagnosis of mature B-cell ALL with L2 morphology: sIg-κ+, CD19+, CD20+, CD22+, CD79a+, TdT-, and CD34-. G-banding combined with spectral karyotyping showed the following complex karyotype: 45,X,der(Y;10)(p10;q10),del(13)(q?),inv(21)(p13q22.1). Fluorescence in situ hybridization revealed separated signals of RUNX1 at 21q22.1, whereas rearrangements of MYC and KMT2A were not found. To our knowledge, inv(21)(p13q22.1) involving RUNX1 is a novel cytogenetic aberration and this is the first case of mature B-cell ALL that presented with RUNX1 rearrangement. Thus, RUNX1 may be implicated in the pathogenesis of mature B-cell ALL showing non-L3 morphology without MYC rearrangement.