Hemangiosarcoma cells induce M2 polarization and PD-L1 expression in macrophages.

Hemangiosarcoma (HSA) is a malignant tumor derived from endothelial cells. Tumor-associated macrophages are one of the major components of tumor microenvironment and crucial for cancer development. The presence and function of macrophages in HSA have not been studied because there is no syngeneic model for HSA. In this study, we evaluated two mouse HSA cell lines and one immortalized mouse endothelial cell line for their usefulness as syngeneic models for canine HSA. Our results showed that the ISOS-1 cell line developed tumors with similar morphology to canine HSA. ISOS-1 cells highly expressed KDM2B and had similar KDM2B target expression patterns with canine HSA. Moreover, we determined that in both ISOS-1 and canine HSA tumors, macrophages were present as a major constituent of the tumor microenvironment. These macrophages were positive for CD204, an M2 macrophage marker, and express PD-L1, an immune checkpoint molecule. Canine HSA with macrophages expressing PD-L1 had a smaller number of T-cells in tumor tissues than tumors with PD-L1 negative macrophages. ISOS-1-conditioned medium could induce M2 polarization and PD-L1 expression in RAW264.7 mouse macrophage cell line and mouse peritoneal macrophages. These results show that ISOS-1 can be used as a syngenic model for canine HSA and suggest that macrophages play an important role in immune evasion in HSA. Using the syngeneic mouse model for canine HSA, we can further study the role of immune cells in the pathology of HSA.

Clinical features and treatment outcomes of 14 patients with hepatosplenic γ δ T-cell lymphoma.

BACKGROUND: Hepatosplenic γ δ T-cell lymphoma (HSTCL) is a rare subtype of peripheral T-cell lymphoma (PTCL) with aggressive clinical behavior. To date, no standard therapy for HSTCL has been established. This study analyzed the clinical features, treatment, and prognosis for patients with HSTCL to determine the best therapeutic approach. METHODS: We reviewed the clinical characteristics, treatments, and responses to treatment of patients in our center between January 2001 and June 2021, and also reviewed related literature. RESULTS: Median patient age was 38 years (range 16-60 years) and the patients included eight males and six females. HSTCL in these patients typically presented with B symptoms (71.4%), splenomegaly (100%), and hepatomegaly (50.0%), but lymphadenopathy was extremely rare. In these patients, routine laboratory testing showed elevated lactate dehydrogenase (71.4%), liver dysfunction (42.9%), and decreased fibrinogen (35.7%). In the induction phase, five of the 14 patients received chemotherapy regimens containing anthracycline (CHOP, or CHOP plus bortezomib or Chidamide), and six were treated with non-CHOP chemotherapy. Seven patients responded to induction treatment, four of whom received allogeneic hematopoietic cell transplantation and then achieved a complete response in the consolidation phase. survival time of patients who received alloHCT range from 10 to 27 months. CONCLUSION: Hepatosplenic γ δ T-cell lacks a standard therapy and is often refractory to conventional chemotherapy regimens. Intensive induction chemotherapy followed by hematopoietic cell transplantation may improve the prognosis of HSTCL.

Immune remodeling triggered by photothermal therapy with semiconducting polymer nanoparticles in combination with chemotherapy to inhibit metastatic cancers.

Photothermal therapy (PTT) based on semiconducting polymer nanoparticles (SPNs) is a promising strategy to treat solid tumors, but its ability to combine with chemotherapy for immune remodeling to efficiently suppress metastatic cancers has rarely been studied. Here, we demonstrate that PTT combined with chemotherapy can efficiently elicit immunity to suppress metastatic tumor growth. Specifically, we rationally designed a new SPN (PDPSe NPs) as a photothermal agent for PTT with a large mass extinction coefficient in the near-infrared region (e.g., 44.9 L g-1 cm-1 at 808 nm), high photothermal conversion efficiency (62.5%) and excellent biocompatibility. A hypoxia-activated anti-tumor drug, tirapazamine (TPZ), was selected for chemotherapy. Strikingly, the combination therapy not only induced tumor cell death in the primary tumor, but also effectively suppressed the growth of distant tumors (mimicking metastatic tumors) without PTT. Importantly, the combined therapies exhibit synergistic effects on immune remodeling. Immunofluorescence data suggest that the inhibition of metastatic tumor growth is attributed to the immune remodeling triggered by PTT and chemotherapy. This work demonstrates a new paradigm of utilizing PTT together with hypoxia-activated drugs to effectively retard metastatic tumor growth.

IGHV mutational status of nodal marginal zone lymphoma by NGS reveals distinct pathogenic pathways with different prognostic implications.

The precise B cell of origin and molecular pathogenesis of nodal marginal zone lymphoma (NMZL) remain poorly defined. To date, due to the rarity of NMZL, the vast majority of already-published studies have been conducted on a limited number of samples and the technical approach to analyze the immunoglobulin genes was of amplifying rearranged variable region genes with the classical direct sequencing of the PCR products followed by cloning. Here, we studied the B cell Ig heavy-chain repertoires by next-generation sequencing (NGS) in 30 NMZL cases. Most of the cases were mutated (20/28; 71.5%) with homologies to the respective germ line genes ranging from 85 to 97, 83%, whereas 8/28 (28.5%) were unmutated. In addition, our results show that NMZL cases have a biased usage of specific immunoglobulin heavy-chain variable (IGHV) region genes. Moreover, we documented intraclonal diversity in all (100%) of the mutated cases and ongoing somatic hypermutations (SHM) have been confirmed by hundreds of reads. We analyzed the mutational pattern to detect and quantify antigen selection pressure and we found a positive selection in 4 cases, whereas in the remaining cases there was an unspecific stimulation. Finally, the disease-specific survival and the progression-free survival were significantly different between cases with mutated and unmutated IGHV genes, pointing out mutational status as a possible new biomarker in NMZL.

Hepatosplenic γ-δ T-Cell Lymphoma: Who Is on Your Speed Dial?

Hepatosplenic γ-δ T-cell lymphoma, an exceptionally uncommon subtype of peripheral T-cell lymphomas, commonly presents with advanced-stage disease manifesting with hepatosplenomegaly, cytopenias, and constitutional symptoms. Management of this subset is challenging as a result of the unique presentation and refractory nature to conventional treatment approaches. There is a lack of consensus guidelines for up-front induction strategies, and the role of consolidative autologous or allogeneic stem-cell transplantation is controversial. Prospective studies are lacking, and treatment is often guided by literature on the basis of case series or single-institution studies, lending to expert opinions influencing treatment paradigms.

Immunophenotypic Characterization of Canine Splenic Follicular-Derived B-Cell Lymphoma.

Marginal zone lymphoma (MZL) and mantle cell lymphoma (MCL) belong to a subgroup of indolent B-cell lymphomas most commonly reported in the canine spleen. The goal of this study was to characterize the immunophenotype of splenic MZL and MCL in comparison to their human counterparts. Ten MCLs and 28 MZLs were selected based on morphology. A tissue microarray was generated, and expression of CD3, CD5, CD10, CD45, CD20, CD79a, Pax-5, Bcl-2, Bcl-6, cyclin D1, cyclin D3, MCL-1, MUM-1, and Sox-11 was evaluated. Neoplastic cells in all MCLs and MZLs were positive for CD5, CD20, CD45, CD79a, and BCL2 and negative for CD3, CD10, Bcl-6, cyclin D1, and cyclin D3. Positive labeling for Pax-5 was detected in 8 of 10 MCLs and 26 of 28 MZLs. Positive labeling for MUM-1 was detected in 3 of 10 MCLs, and 27 of 28 MZLs were positive for MUM-1. No MCLs but 8 of 24 MZLs were positive for MCL-1. Canine splenic MZL and MCL have a similar immunophenotype as their human counterparts. However, human splenic MCL overexpresses cyclin D1 due to a translocation. A similar genetic alteration has not been reported in dogs. In addition, in contrast to human MZL, canine splenic MZL generally expresses CD5. Following identification of B vs T cells with CD20 and CD3, a panel composed of BCL-2, Bcl-6, MUM-1, and MCL-1 combined with the histomorphological pattern can be used to accurately diagnose MZL and MCL in dogs. Expression of Bcl-2 and lack of MCL-1 expression in MCL may suggest a therapeutic benefit of BCL-2 inhibitors in canine MCL.

Hepatosplenic T-Cell Lymphoma in an Immunocompetent Male with Central Nervous System Invasion: A Rare Clinical Entity.

Hepatosplenic T-cell lymphoma (HSTCL) is a very rare non-Hodgkin lymphoma with an aggressive clinical course and poor prognosis. Patients of this disease usually presented with hepatosplenomegaly, which can be misdiagnosed or delayed. Bone marrow (BM) and peripheral blood (PB) are frequently involved, however, central nervous system (CNS) involvement is less common. Here, we are reporting an unusual case of hepatosplenic γδ T-cell lymphoma in a 64-year-old man with CNS involvement. Flow cytometry immunophenotyping was proved of great diagnostic contribution. © 2018 International Clinical Cytometry Society.

A rare case of hepatosplenic γδ T-cell lymphoma expressing CD19 with ring chromosome 7 and trisomy 8.

Hepatosplenic T-cell lymphoma (HSTL) is a rare subtype of peripheral T-cell lymphoma predominantly seen in young males. This disease presents with isolated hepatosplenomegaly and thrombocytopenia with sinusoidal infiltration of liver and sinusal infiltration of spleen. Immunophenotype shows positivity for CD3, CD7, TCRγδ or TCRαß, CD38 and double negative for CD4, CD8, TdT, CD5, and CD56. Isochromosome 7q with or without trisomy 8 is seen in HSTL. Recently, ring chromosome 7 has also been identified as a new abnormality. We describe the clinical, immunophenotypic and cytogenetic analysis in a 24-year-old woman. We present an unusual case of TCRγδ positive T-cell lymphoma with aberrant expression of CD19, which is a B-cell lymphoid marker, with amplification of 7q region and subsequent formation of ring chromosome 7 and trisomy 8. This is the second case of HSTL, positive for CD19 and first case presenting with ring chromosome 7 and trisomy 8 in a CD19 positive HSTL which is a rare finding in T-cell lymphoma and needs to be explored further.

Effective management strategies for patients with marginal zone lymphoma.

Marginal zone lymphoma (MZL) is an uncommon indolent lymphoma classified into subtypes based on primary site of involvement: splenic, nodal and extranodal. MZLs' relative rarity has largely precluded adoption of a standard management strategy. Here, we provide an overview of the epidemiology, clinical behavior and therapeutic approaches for each subtype. Biologic insights into lymphomagenesis have identified B-cell receptor signaling as a rational therapeutic target. Recent clinical data suggest that novel agents targeting this pathway, including the Bruton's tyrosine kinase inhibitor, ibrutinib, show significant promise in treatment of relapsed MZL. More work is needed to evaluate these agents' activity in the front-line setting, possible combination regimens and the impact of resistance to B-cell receptor-targeted agents in order to optimize therapy in MZL.

Modeling of Lymphogenous and Hematogenous Metastasizing from Murine В16 Melanoma in Rats.

We developed a model of experimental melanoma. Intralienal xenogeneic transplantation of a suspension of melanoma cells B16 in physiological saline (0.1 ml; 1:10) was conducted to outbred male rats. In 6 months, histologically confirmed melanoma B16 in the spleen and its metastases in the liver, intestine, pancreas, adrenal glands, and lungs (hematogenous metastasis), as well as in the thymus and lymph nodes (lymphogenous metastasis) were revealed in rats. The proposed rat model of melanoma B16 metastasizes by the hematogenous and lymphogenous pathways, develops over 6 months, and allows receiving sufficient volume of material for analysis.

[13 cases of littoral cell angioma in spleens].

OBJECTIVE: To investigate the clinicopathological features, morphological characteristics, immunophenotypes of littoral cell angioma (LCA) in spleen, and to provide new evidence for making diagnosis and avoiding misdiagnosis. METHODS: Clinicopathological data, histological characteristics of 13 cases of LCA were retrospectively studied and immunohistochemical staining was imposed on the paraffi-nembedded specimens, and 5 cases of cavernous hemangioma, 4 cases of normal littoral cells of spleens were used as control groups, simultaneously. RESULTS: All the 13 LCA patients included 7 males and 6 females, aged from 39 to 70 years with an average of 54. 2 years and a median age of 55 years. Among these tumor patients, 6 cases were accompanied by malignances, benign tumors or inflammation states at abdominal cavities, and 7 cases were accidentally discovered by physical examinations. Grossly, spleens contained solitary or multiple gray red nodules ,which ranged from 0.5 to 6.2 cm in diameter. Histologically, tumors were composed by anastomosing vascular spaces which were lining by plump, rounded to cuboidal littoral cells that extended into vascular lumens. Usually, papillary frameworks that were covered by these cells were also seen extending into the lumens in some areas. Other types of histiocytoid cells were identified in lumens and the sizes were larger than the littoral cells. Both types of cells absented cytologic atypia. Immunohistochemical study demonstrated that the littoral cells in all cases were positive for vascular endothelial and histiocyte markers, such as CD21, CD31, CD68, polyclone FVIII RAg and ERG, while these cells were negative for CD8, CD34, and WT-1. These findings manifested that immunophenotype of littoral cell in LCA distinctive from that in controls. CONCLUSION: LCA is a benign lesion, which frequently occurs in the elderly. Its etiology remains confusion, however, immune dysregulation may associate with it because of the concomitance with other tumor or inflammation in some cases. The littoral cells in LCA show a hybrid endothelial-histiocytic phenotype on immunohistochemistry, therefore these cells may have features that intermediate between those of endotheliocytes and histiocytes. Emphasizing the histological findings and immunophenotypes is significant for diagnosis and differential diagnosis.

Clinicopathological analysis of primary splenic diffuse large B-cell lymphoma.

Splenic infiltration is often seen in diffuse large B-cell lymphoma (DLBCL). However, primary splenic DLBCL is rare and studies on its clinicopathological features are limited. We assessed 66 cases of primary splenic DLBCL and 309 control DLBCL, not otherwise specified. Hepatitis C virus antibody prevalence, B symptoms, poor performance status and CD5 positivity differed significantly between the primary splenic DLBCL and control DLBCL groups. Primary splenic DLBCL cases were classified histopathologically into two groups [white pulp pattern (n = 46), red pulp pattern (n = 20)]. Survival analysis showed no difference in overall survival between the primary splenic DLBCL and the control group, but the former had a more favourable progression-free survival. In the examination of primary splenic DLBCL, the white pulp pattern was statistically associated with a lower performance status (2-4), and a lower CD5 positivity than the red pulp pattern. In the survival analysis, the red pulp pattern demonstrated poorer overall survival. Multivariate analysis of overall survival in primary splenic DLBCL cases identified CD5 positivity as an indicator of poor prognosis. Classifying primary splenic DLBCL into white and red pulp patterns was useful in terms of clinicopathological features and overall survival.

Florid splenic γ/δ T-cell proliferation in patients with splenomegaly and cytopenias: a "high stakes" diagnostic challenge.

Splenic γ/δ T-cell proliferation is rare, and correct diagnosis is critical for adequate clinical management. Two splenectomy cases from patients with splenomegaly and cytopenias were studied by morphological evaluation, extensive immunophenotyping, FISH and molecular studies. The clinicopathologic findings were compared with splenic T γ/δ neoplasia, notably hepatosplenic T-cell lymphoma (HSTL) and T-cell large granular lymphocytic leukemia (TLGL) of the variety T γ/δ. The enlarged spleens showed expanded red pulp with markedly increased γ/δ T cells, which share significant to complete overlapping morphology and immunophenotype with the neoplastic γ/δ T cells in HSTL and γ/δ TLGL. However, they were polyclonal by molecular study and showed no evidence of isochromosome 7q. Splenectomy alone led to long-term clinical remission in both patients. Two florid reactive splenic γ/δ T-cell proliferations mimicking γ/δ T-cell neoplasia were reported for the first time in English literature. Recognition of this exceedingly rare phenomenon is critical in prevention of misdiagnosis with potentially catastrophic consequences.

Morphology and immunoreactivity of canine and feline extramedullary plasmacytomas.

The aim of the study was the evaluation of morphology and immunophenotype of canine (19 cases) and feline (7 cases) extramedullary plasmacytomas. Tumours, located in skin, oral cavity and spleen were surgically excised, fixed and processed for histopathology and immunohistochemistry (CD79α, CD18, proliferating cell nuclear antigen, metallothionein). Histologically, tumours were classified into mature, cleaved, asynchronous, polymorphous blastic, hyalin, or monomorphous blastic type. All evaluated tumours showed cytoplasmic expression of CD79α antigen. The expression of CD18 was observed in canine cutaneous and splenic tumours. In canine tumours expression of metallothionein was low to moderate, while in feline plasmacytomas - absent or low. In canine tumours, the mitotic index and proliferating cell nuclear antigen index were positively correlated with the expression of metallothionein. In feline tumours no correlation between mitotic index, proliferating cell nuclear antigen and metallothionein was found. This is the first study describing expression of metallothionein in canine and feline extramedullary plasmacytoma.