PTEN Deficiency Induces an Extrahepatic Cholangitis-Cholangiocarcinoma Continuum via Aurora kinase A in Mice.

BACKGROUND & AIMS: The PTEN-AKT pathway is frequently altered in extrahepatic cholangiocarcinoma (eCCA). We aim to evaluate the role of PTEN in the pathogenesis of eCCA and find novel therapies for this disease. METHODS: The Pten gene in the biliary epithelial cells were genetically deleted using the Cre-loxp system. The pathologies were evaluated both macroscopically and histologically. The characteristics were further analyzed by immunohistochemistry (IHC), RT-PCR, cell culture, and RNAseq. Some features were compared to those in human eCCA samples. Further mechanistic studies utilized the conditional knockout of Trp53 and Aurora kinase A (Aurka) genes. Experimental therapy was tested using an Aurka inhibitor. RESULTS: We observed that genetic deletion of the Pten gene in the extrahepatic biliary epithelium and peri-ductal glands initiated sclerosing cholangitis-like lesions in mice, resulting in enlarged and distorted extrahepatic bile ducts in mice as early as one month old. Histologically, these lesions exhibited increased epithelial proliferation, inflammatory cell infiltration, and fibrosis. With aging, the lesions progressed from low-grade dysplasia to invasive carcinoma. Trp53 inactivation further accelerated the disease progression, potentially through downregulating senescence. Further mechanistic studies showed that both human and mouse eCCA showed high expressions of AURKA. Notably, the genetic deletion of Aurka completely eliminated Pten deficiency-induced extrahepatic bile duct lesions. Furthermore, pharmacological inhibition of Aurka alleviated disease progression. CONCLUSIONS: Pten deficiency in extrahepatic cholangiocytes and peribiliary glands led to a cholangitis-to-cholangiocarcinoma continuum through an Aurka-dependent manner. These findings offer new insights into preventive and therapeutic interventions for extrahepatic CCA. IMPACT AND IMPLICATIONS: The aberrant PTEN-PI3K-AKT signaling pathway is commonly observed in human extrahepatic cholangiocarcinoma (eCCA), a disease with a poor prognosis. In our study, we developed a mouse model mimicking cholangitis to eCCA progression by conditionally deleting the Pten gene via Pdx1-Cre in epithelial cells and peribiliary glands of the extrahepatic biliary duct. The conditional Pten deletion in these cells led to cholangitis, which gradually advanced to dysplasia, ultimately resulting in eCCA. The loss of Pten heightened Akt signaling, cell proliferation, inflammation, fibrosis, DNA damage, epigenetic signaling, epithelial-mesenchymal transition (EMT), cell dysplasia, and cellular senescence. Genetic deletion or pharmacological inhibition of Aurka successfully halted the disease progression. This model shall be valuable for testing novel therapies and unraveling the mechanisms of eCCA tumorigenesis.

Clinical characteristics, molecular aberrations, treatments, and outcomes of malignant histiocytosis.

Malignant histiocytosis (MH) is an extremely rare neoplasm of the macrophage-dendritic cell lineage. We report the clinical characteristics, molecular aberrations, treatments, and outcomes of patients with MH seen at two referral centers from January 2000 to May 2023. We identified 43 patients with MH, of which 26 had histiocytic sarcoma (MH-H), 9 interdigitating dendritic cell sarcoma (MH-IDC), and 8 Langerhans cell sarcoma (MH-LC). The median age at diagnosis was 61 years (range, 3-83). Thirty-three patients (77%) had multifocal disease, while 10 had unifocal involvement. Tumor specimens from 22 patients (51%) underwent targeted next generation sequencing, and 19 of 22 (86%) had at least one pathogenic mutation, including mutations in MAPK pathway genes (73%). The median overall survival (OS) among the entire cohort was 16 months (95% CI: 8-50). The outcomes of those with multifocal disease were significantly shorter than their unifocal counterpart: median OS of 10 months versus 50 months (p = .07). Patients with risk organ involvement (bone marrow, spleen, or liver) had significantly inferior outcomes. Chemotherapy and surgery were the most common first-line treatments for multifocal and unifocal disease, respectively. While the outcome for patients with multifocal disease was poor, there was a subset of patients who had durable responses to treatment. Our study highlights that MH has heterogeneous clinical presentation, frequent oncogenic mutations, and prognosis, which is strongly tied to disease extent and type of organ involvement.

Submucosal Epstein-Barr Virus Positive Polymorphic B-cell Lymphoproliferative Disorder of the Larynx: A Case Report.

Epstein-Barr virus (EBV) belongs to the group of human herpes virus and can cause clinical and subclinical infections. Although EBV-related disease presentations are similar, they can lead to oncogenic transformation with various clinical manifestations. A thorough workup with morphology, immunohistochemistry, and molecular studies is crucial for the diagnosis of EBV-positive polymorphic B-cell lymphoproliferative disorder, not otherwise specified (NOS), which is a new entity introduced by International Consensus Classification in 2022. We describe an interesting presentation of EBV-positive polymorphic B-cell lymphoproliferative disorder with laryngeal involvement to bring awareness to this entity and we would like to address the need for more accessible treatment options.

Evaluation of Novel Targets, Including CC-Chemokine Receptor 4, in Adult T-Cell Acute Lymphoblastic Leukemia/Lymphoma: A Mayo Clinic Clinical and Pathologic Study.

CONTEXT.­: Unlike B-cell acute lymphoblastic leukemia/lymphoma (ALL/LBL), there have been few therapeutic advances in T-cell ALL (T-ALL)/LBL, an aggressive ALL/LBL subtype. OBJECTIVE.­: To perform a focused tissue array study to elucidate tumor markers of therapeutic potential in T-ALL/LBL. DESIGN.­: Using immunohistochemistry, we evaluated expression of leukemic antigens of interest, specifically CC-chemokine receptor 4 (CCR4), among others, on available remnant diagnostic material, including tumor tissue slides obtained from formalin-fixed, paraffin-embedded preserved tissues. RESULTS.­: Our analysis identified, for the first time, expression of CCR4 in T-ALL/LBL in 11 of 27 cases (40.7%) and confirmed common expression of BCL2, CD38, and CD47, as reported previously. We also identified the expression of CD123 in 4 of 26 cases (15.4%), whereas BCL6 and PDL1 were expressed in a small number of T-ALL/LBL cases. The potential novel target CCR4 was significantly more common in the Pre/Pro-T immunophenotypic subtype, 6 of 9 (66.7%, P = .01). No additional differences in clinical and epidemiologic variables were noted among positive or negative CCR4 cases. CONCLUSIONS.­: These findings support preclinical and clinical testing of therapies targeting CCR4, CD47, BCL2, CD38, and CD123 in T-ALL/LBL, and may help guide the development of targeted clinical trials in T-ALL/LBL, a rare disease in urgent need of novel therapies.

Hyperviscosity Syndrome Induced Bilateral Visual and Auditory Impairment in Therapy Resistant Waldenström Macroglobulinemia with MYD88 and CXCR4 Mutations.

Hyperviscosity syndrome (HVS) is an emergent complication of Waldenström macroglobulinemia (WM) characterized by visual, neurologic, and rarely auditory impairment. We report a 69-year-old female with MYD88 and CXCR4-mutant WM who developed HVS resulting in bilateral blindness and deafness associated with neurologic manifestations including confusion, severe generalized weakness, and imbalance. Ophthalmologic evaluation revealed bilateral central retinal vein occlusion (CRVO), diffuse retinal hemorrhages, macular edema, and serous macular detachments (SMD). Magnetic resonance imaging of the brain showed bleeding in the inner ears. Management was challenging as her WM was resistant to systemic therapies including bendamustine + rituximab (BR) and rituximab + bortezomib + dexamethasone (RVD). Bruton's tyrosine kinase inhibitors could not be used initially due to ongoing lower gastrointestinal bleeding. She required five total sessions of plasma exchange and was finally initiated on zanubrutinib, achieving a partial response. She also received intravitreal bevacizumab with rapid resolution of the retinal hemorrhages but with little improvement of the SMD. She had partial restoration of her hearing in the right ear and only slight improvement in her bilateral visual deficits. The management of HVS in frail, elderly patients with therapy-resistant WM can be challenging. In these cases, plasma exchange is required until an effective systemic therapy can be safely instituted. Genomic profiling is important in the management of WM as it can predict treatment resistance and guide therapeutic decisions.

Successful Anatomy Adapted Therapeutic Management and Genetic Profiling of Primary Pituitary Diffuse Large B-Cell Lymphoma.

Primary pituitary diffuse large B-cell lymphoma (PPL) has been regarded as a subtype of primary central nervous system lymphoma (PCNSL); however, the pituitary gland is located outside the blood brain barrier (BBB) with neural and vascular connections to the brain. Given its unique anatomic location, a combination of non-central nervous system (CNS)-penetrating and CNS-penetrating therapeutic agents can be employed to treat PPL. We report a female patient with PPL who was successfully managed with anatomy-adapted therapy incorporating non-CNS penetrating chemoimmunotherapy [rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP)] alternating with CNS-penetrating chemoimmunotherapy [rituximab, high-dose methotrexate, and high-dose cytarabine (RMA)]. She received a total of eight cycles of treatment with four cycles of each regimen following partial transsphenoidal resection. She achieved a complete response after two cycles and has remained in complete remission for the last eight years. To our knowledge, this is the longest documented survival in a patient with PPL. Targeted genomic profiling with Next-Generation Sequencing (NGS) was recently performed on the lymphoma tissue. The genomic profile of PPL in this patient is quite different from the findings typically associated with PCNSL. We suggest that PPL may be biologically distinct from PCNSL and should be treated with an anatomy adapted approach. Additional research is necessary to confirm our findings.

Detection of an MN1::ETV6 Gene Fusion in a Case of Acute Myeloid Leukemia with Erythroid Differentiation: A Case Report and Review of the Literature.

The MN1::ETV6 gene fusion resulting from t(12;22)(p13;q12) has been rarely reported in myeloid neoplasms. We describe a 69-year-old male with newly diagnosed acute myeloid leukemia (AML) with erythroid differentiation and t(12;22)(p13;q12) demonstrated by conventional chromosome studies. Subsequent fluorescence in situ hybridization studies demonstrated a balanced ETV6 gene rearrangement (at 12p13). To further characterize this translocation, whole-genome sequencing was performed which confirmed t(12;22) with breakpoints involving the MN1 and ETV6 genes. Herein, we describe our case and review the literature to summarize the clinical and laboratory findings in patients with this rare but recurrent MN1::ETV6 gene fusion observed in myeloid neoplasms. Importantly, this case expands the clinical spectrum associated with the MN1::ETV6 gene fusion to include AML with erythroid differentiation. Lastly, this case demonstrates the importance of moving toward more comprehensive molecular testing to fully characterize the driver events in neoplastic genomes.

Yttrium-90 Ibritumomab Tiuxetan is Cost-Effective Compared to Bendamustine + Rituximab in Low-grade Lymphomas.

BACKGROUND: Yttrium-90 ibritumomab tiuxetan [(90)Y-IT] is a CD20-targeted radio-immunotherapeutic agent. It has shown an excellent therapeutic activity with high tolerability against previously untreated follicular lymphoma (FL) and marginal zone B cell lymphoma (MZL). It is an attractive therapeutic option as the treatment schedule is short and convenient. The aim of our study is to determine the cost-effectiveness of (90)Y-IT in comparison to the standard-of-care bendamustine + rituximab (BR) in the first-line treatment of low-grade FL (LG-FL) and MZL in the real world. PATIENTS AND METHODS: We included all patients who were treated with standard-dose (90)Y-IT for previously untreated LG-FL and MZL at the Mayo Clinic Cancer Center (N = 51). A comparator arm with a historical cohort of previously untreated LG-FL and MZL patients who received BR was used (N = 92). RESULTS: Inverse propensity weighting was utilized to balance the 2 study arms. There were no differences in terms of overall response rate (100% vs. 98%, P = .18), complete response rate (94% vs. 95%, P = .91), or 5 years progression-free survival (76% vs. 75%, P = .63) between patients who received (90)Y-IT and BR, respectively. Within the first year, patients who received (90)Y-IT required an average of 4.5 fewer oncology clinic visits (P < .001), an average of 10 fewer days of therapeutic use (P < .001), and 40% less use of growth factors (P < .001) as compared to the BR group. The direct therapeutic cost of (90)Y-IT treatment was 54% less than that of 6 cycles of BR. CONCLUSION: The findings suggest that (90) Y-IT is more cost-effective than BR and is a viable alternative in up-front management of LG-FL and MZL.

Successful CNS-Centric Therapeutic Management and Genomic Profiling of Primary Cranial Vault Diffuse Large B-Cell Lymphoma.

Primary cranial vault lymphoma (PCVL) is a rare lymphoma involving the skull with or without extra- and intracranial extension. Most cases of PCVL are diffuse large B-cell lymphoma (DLBCL). We report a case of primary cranial vault diffuse large B-cell lymphoma (PCV-DLBCL) that was successfully treated with anthracycline-based chemoimmunotherapy (CIT) alternating with central nervous system (CNS)-directed CIT with high-dose methotrexate and high-dose cytarabine. CNS-centric therapy was given for suspected cerebral cortical involvement and presumed elevated risk of CNS recurrence. The patient has remained in complete remission for 4.25 years following treatment. We suggest that PCV-DLBCL is potentially curable with CNS-directed therapy. Additionally, we provide genomic profiling results indicating an indeterminate cell of origin and multiple genetic mutations which are not frequently seen in DLBCL.

Poly-lymphomatous Syndrome With Concurrent or Sequential Hodgkin and Non-Hodgkin lymphoma.

INTRODUCTION: The development of Hodgkin lymphoma (HL) and non-Hodgkin lymphoma (NHL) concurrently or sequentially in the same patient is a rare clinical scenario and can be labeled as a poly-lymphomatous syndrome (PLS). METHODS: We report clinico-pathologic characteristics and survival outcomes of 7 such cases from our institution. In concurrent PLS, HL is present with NHL in the same location (composite PLS) or in separate locations (discordant PLS). Sequential presentations were seen with HL following NHL or vice versa (sequential PLS). CONCLUSIONS: It is essential to perform adequate biopsies in supposedly relapsed or refractory settings to diagnose PLS. We suggest that the incidence of PLS is likely underestimated due to the under-utilization of repeat biopsies. In patients with concurrent PLS, the treatment should ideally cover both types of lymphoma with an emphasis on tailoring the treatment towards the more aggressive lymphoma. In patients with sequential PLS, the treatment should target the new lymphoma. Consolidation treatments such as autologous hematopoietic cell transplant should be considered when there is a component of relapsed cHL or aggressive NHL. Based on our experience, PLS does not appear to be associated with a poor prognosis. Further research is necessary for better understanding of the biology and management of PLS.

Primary Bone Marrow Lymphoma: De Novo and Transformed Subtypes.

Diffuse large B-cell lymphoma (DLBCL) is well known for selectively involving certain extranodal locations such as the central nervous system (CNS), testes, and skin. DLBCL or high-grade B-cell lymphoma selectively involving the bone marrow is rare and has been sparsely reported in the medical literature. We report two cases of lymphoma presenting with primary bone marrow involvement without evidence of involvement of any other sites. The first case represents de novo DLBCL. The patient achieved complete remission with initial treatment, had a bone marrow-only relapse three years later, and achieved a second complete remission following non-transplant salvage therapy. The second case had findings consistent with "double hit" Richter's transformation of chronic lymphocytic leukemia with translocation of c-MYC and BCL-2. This patient had an aggressive clinical course characterized by rapid progression with CNS involvement within three months resulting in the demise of the patient. These two cases represent two distinct subtypes of primary bone marrow lymphoma: de novo and transformed. Further research is necessary to gain a better understanding of this rare lymphoma entity and develop novel therapies.

Intravascular Large B Cell Lymphoma with CNS Involvement Successfully Treated with High-Dose Methotrexate and High-Dose Ara-C Based CNS-Directed Chemoimmunotherapy Alternating with Anthracycline Based Chemoimmunotherapy.

Intravascular large B cell lymphoma (IVL) is a rare subtype of diffuse large B cell lymphoma confined to small blood vessels with a predilection for CNS involvement. The prognosis of IVL with CNS involvement (CNS-IVL) is extremely poor. The optimal treatment for CNS-IVL is not well defined. Thus, we report three patients with CNS-IVL successfully treated with a CNS-centric approach consisting of high-dose methotrexate (HDMTX) and high-dose Ara-C (HiDAC) based CNS-directed chemoimmunotherapy (CIT) alternating with anthracycline-based CIT. Our rationale for intensifying the CNS-directed therapy is the presence of intracerebral bleeding in two of our patients which would result in extravasation of lymphoma cells into the cerebral parenchyma with the development of CNS lymphoma. All three patients have achieved excellent therapeutic outcomes. Two patients with intracerebral bleeding have been in complete remission (CR) for about 11 years and 4 years. One patient was successfully induced into CR about 10 months ago and currently is in CR. This unique therapeutic approach should be further explored for CNS-IVL.

Clinical characteristics, prognostic indicators, and survival outcomes in intravascular lymphoma: Mayo Clinic experience (2003-2018).

Intravascular lymphoma (IVL) is a rare extranodal non-Hodgkin lymphoma. We performed a retrospective analysis of 55 IVL patients who were treated at our institution 2003-2018. Median age at diagnosis was 68 years, and 64% were males. The most frequent presenting symptoms were skin rash 43% and weight loss 30%. MRI brain on IVL patients with CNS involvement (CNS-IVL) showed multifocal involvement in 76% (13/17). 89% (17/19) of non-CNS-IVL patients with abnormal FDG-PET had biopsy of an avid lesion resulting in definitive diagnosis. The top diagnostic biopsy site was the bone marrow (45%). 56% had multiorgan involvement. Based on CNS involvement, 36.5% (20/55) had CNS-IVL and 63.5% (35/55) had non-CNS-IVL. CNS-IVL group consists of clinically isolated CNS involvement (CNS-only IVL) (22%;12/55) and mixed clinical CNS and peripheral site involvement (M-IVL) (14.5%; 8/55). Non-CNS-IVL group consists of clinically isolated skin involvement (skin-only IVL) (9%; 5/55) and peripheral IVL with or without skin involvement (P-IVL); (54.5%; 30/55). Skin involvement was predominantly in the lower extremities. Pathologically, 89% (48/54) were B-cell IVL. Rituximab + high-dose methotrexate-based regimen were used in 75% (12/16) of CNS-IVL patients and RCHOP in 60% (17/28) of non-CNS-IVL patients. Estimated 5-year progression free survival (PFS) and overall survival (OS) for the entire cohort were 38.6% and 52%, respectively. Skin-only IVL was associated with excellent survival. Platelet count <150x109 /L, age > 60Y, and treatment without Rituximab were poor prognostic factors. Further research is necessary to identify novel therapies.

Leukemic High Grade B Cell Lymphoma is Associated With MYC Translocation, Double Hit/Triple Hit Status, Transformation, and CNS Disease Risk: The Mayo Clinic Experience.

INTRODUCTION: Leukemic involvement in high grade B cell lymphoma (L-HGBL) is rare and has been sparsely described in the literature. We report our experience in a large single institution multicenter academic setting. MATERIALS AND METHODS: Medical records of patients with HGBL who received care at Mayo Clinic between 2003 and 2020 were reviewed. L-HGBL was confirmed by peripheral blood smear and flow cytometry with corroboration from tissue and bone marrow biopsy findings. RESULTS: Twenty patients met inclusion criteria. All patients had significant bone marrow involvement by HGBL. Leukemic involvement presented in 11 of 20 (55%) in the de novo and 9 of 20 (45%) in the relapsed setting. Seven of 20 patients had DLBCL, NOS, 6 of 20 had transformation (t-DLBCL), 3 of 20 had transformed double/triple hit lymphoma (t-DHL/THL), 2 of 20 had double hit lymphoma (DHL), and 2 of 20 had HGBL with intermediate features between DLBCL and Burkitt lymphoma. Nine of 15 patients had MYC translocation. Based on Hans criteria, 11 of 20 had germinal center B-cell (GCB) cell of origin (COO) and 9/20 had non-GCB COO. Five of 11 de novo patients experienced CNS relapse/progression. All de novo patients received anthracycline-based chemoimmunotherapy. Eighteen of 20 patients died of progressive disease. Median overall survival was significantly better in the de novo compared to relapsed group (8.9 months vs. 2.8 months, P = .01). COO, MYC status, DHL/THL status, HGBL subtype, or treatment group did not demonstrate a significant effect on overall survival. CONCLUSION: L-HGBL carries a poor prognosis and is associated with MYC translocation, DHL/THL status, transformation, and high CNS risk. Novel therapeutic approaches are needed for L-HGBL.

Long-Term Survival with Ibrutinib Therapy in Elderly Patients with Newly Diagnosed Primary Central Nervous System Lymphoma.

Primary central nervous system lymphoma (PCNSL) carries a dismal prognosis in elderly patients above 70 years of age with a median overall survival of 6 months. Novel therapeutic agents are urgently needed to improve survival outcomes in this age group. We describe the clinical presentation, diagnostic workup, and treatment outcome in two 80-year-old patients diagnosed with PCNSL who were treated with ibrutinib therapy. Both patients remain in complete remission following treatment with ibrutinib therapy. One patient is currently 4 years and the other is 2 years and 9 months from the time of initial diagnosis. We suggest that ibrutinib therapy has significant therapeutic activity against PCNSL in the newly diagnosed setting and should be evaluated in a clinical trial as part of front-line therapy, especially in elderly patients.

Polarization of Macrophages in Granulomatous Cutaneous T Cell Lymphoma Granulomatous Mycosis Fungoides Microenvironment.

Polarization of tumor associated macrophages (TAMs) has been shown to have prognostic significance in different cancer types. This study evaluates the macrophage subtypes that predominates in GMF. Cases of GCTCL from 2007-2020 were identified (n = 6), clinical data was extracted from the electronic medical record, and all pathology slides were reviewed to confirm the diagnosis. Immunohistochemistry (IHC) studies were performed to characterize M1 and M2 macrophage polarization. CD68 (PGM1), pSTAT1, and CD163 were used as pan macrophage, M1, and M2 markers, respectively. The macrophages with positive staining at hot spot per high power field were counted and recorded for data analysis. The average age of patients was 60.5 years [range, 21-78], five patients (83%) were women and 1 (17%) was a man. Five patients were Caucasian (83%), and 1 was Black/African American (17%). Two patients had late stage GMF with M2 (CD163) predominance and the other three had early stage GMF with M1 (pSTAT1) predominance. Our study suggests that macrophage polarization present in GMF tends to be M1 in early stages and M2 in advanced stages. Additional studies are needed to further elucidate the microenvironment of macrophages present in GMF. Such findings may lead to prognostic and therapeutic advances in GMF.

Myelomatous ascites and pleural effusion in relapsed multiple myeloma.

Extramedullary multiple myeloma is seen in advanced and aggressive disease and occurs due to plasma cell infiltration of sites other than the bone marrow. Myelomatous ascites or pleural effusion is seen in less than 1% of cases and can be differentiated from infectious etiologies based on fluid cytology.

A 71-Year-Old Man With Diffuse Waxing and Waning Multifocal Lung Lesions, Empyema, and Episodic Fevers Reveals a Rare Diagnosis.

CASE PRESENTATION: A 71-year-old man with history of gastroesophageal reflux disease, chronic sinusitis, arthritis, hypothyroidism, and anemia of chronic disease initially sought treatment with a recurrent left pleural effusion along with other abnormal lung findings on chest CT scan. Before his referral, he was being managed for 3 years at his local hospital for waxing and waning fevers, fatigue, productive cough, chills, and night sweats. He did not report any hemoptysis or chest pain, but reported weight loss of 13 kgs in 15 months. During those 3 years, he was treated with multiple courses of antibiotics and steroids with temporary relief of symptoms. At that time, his chronic sinusitis was suspected to be the cause of his symptoms and he underwent balloon sinuplasty. He was receiving daily sublingual immunotherapy for inhaled respiratory allergens for the previous year after showing positive test results for 17 inhaled allergens. The patient had no other known immunologic workup before our evaluation.