Systemic mastocytosis (SM) with associated hematological neoplasia (SM-AHN) is a rare and aggressive condition characterized by abnormal clonal proliferation of mast cells and the concurrent occurrence of hematologic malignancies, such as acute myeloid leukemia (AML). We present a 41-year-old female diagnosed with SM-AML, who underwent allogeneic hematopoietic stem cell transplantation (allo-HSCT). Despite an initial favorable response to chemotherapy and transplantation, the patient later experienced an AML relapse five years post-transplant, without concurrent recurrence of SM. This discrepancy may be attributed to the differential immune responses to AML and SM, where AML cells are more susceptible to graft-versus-leukemia (GVL) effects, while mast cells in SM may exhibit resistance to immune-mediated elimination. The absence of SM relapse raises important questions regarding the pathophysiology and treatment of SM-AML. This case underscores the complexity of managing SM with AML, highlighting the need for further research to optimize therapeutic strategies and improve patient outcomes.

Objectives: Primary and post-primary tuberculosis (TB) are distinct entities. The aim of this study was to study the histopathology of primary and post-primary TB by using the unique human autopsy material from the pre-antibiotic era, 1931–1947. Material and Methods: Autopsy data were collected from the autopsy journals, and the human tissue was collected from the pathology archives at the Department of Pathology, the Gades Institute. Results: Histological presentations of TB lesions showed great diversity within a single lung. Post-primary TB starts as a pneumonia forming early lesions, characterized by the infiltration of foamy macrophages containing mycobacterial antigens within alveoli, and progressing to necrotic pneumonias with an increasing density of mycobacterial antigens in the lesions. These necrotic pneumonic lesions appeared to either resolve as fibrocaseous lesions or lead to cavitation. The typical granulomatous inflammation, the hallmark of TB lesions, appeared later in the post-primary TB and surrounded the pneumonic lesions. These post-primary granulomas contained lesser mycobacterial antigens as compared to necrotic pneumonia. Conclusions: Immunopathogenesis of post-primary TB is different from primary TB and starts as pneumonia. The early lesions of post-primary TB may progress or regress, holding the key to understanding how a host can develop the disease despite an effective TB immunity.

Mantle cell lymphoma (MCL) is an aggressive B-cell non-Hodgkin lymphoma having a poor overall survival that is in need for the development of new therapeutics. In this study, we report the identification and expression of a new isoform splice variant of the tyrosine kinase receptor AXL in MCL cells. This new AXL isoform, called AXL3, lacks the ligand-binding domain of the commonly described AXL splice variants and is constitutively activated in MCL cells. Interestingly, functional characterization of AXL3, using CRISPR inhibition, revealed that only the knock down of this isoform leads to apoptosis of MCL cells. Importantly, pharmacological inhibition of AXL activity resulted in a significant decrease in the activation of well-known proproliferative and survival pathways activated in MCL cells (ie, β-catenin, Ak strain transforming, and NF-κB). Therapeutically, preclinical studies using a xenograft mouse model of MCL indicated that bemcentinib is more effective than ibrutinib in reducing the tumor burden and to increase the overall survival. Our study highlights the importance of a previously unidentified AXL splice variant in cancer and the potential of bemcentinib as a targeted therapy for MCL.

BACKGROUND While standard blood tests are often sufficient for an anaemia workup, sometimes more invasive diagnostic testing is required to exclude rare conditions. CASE PRESENTATION A man in his forties contacted his general practitioner because of increasing functional dyspnoea. He had completed a course of dicloxacillin a few months previously for a skin abscess on his abdomen. Bloodwork revealed severe anaemia (haemoglobin 5.4 g/dL), which required transfusion. Subsequent testing excluded iron and vitamin deficiency anaemia, haemolysis and malignancy. Initial bone marrow biopsy was of suboptimal quality. However, repeat tissue sample supported a diagnosis of pure red cell aplasia. The patient improved with ciclosporin treatment, which was gradually tapered. INTERPRETATION Pure red cell aplasia should be considered in patients with new onset isolated anaemia with severe reticulocytopenia. Diagnosis depends on obtaining representative tissue from bone marrow biopsy. It is difficult to conclude for this patient whether the aetiology of his pure red cell aplasia was idiopathic or secondary to recent dicloxacillin use.

Background and aimsAcute myeloid leukemia (AML) is a heterogeneous malignant condition characterized by massive infiltration of poorly differentiated white blood cells in the blood stream, bone marrow, and extramedullary sites. During leukemic development, hepatosplenomegaly is expected to occur because large blood volumes are continuously filtered through these organs. We asked whether infiltration of leukemic blasts initiated a response that could be detected in the interstitial fluid phase of the spleen and liver. Material and MethodsWe used a rat model known to mimic human AML in growth characteristics and behavior. By cannulating efferent lymphatic vessels from the spleen and liver, we were able to monitor the response of the microenvironment during AML development. Results and DiscussionFlow cytometric analysis of lymphocytes showed increased STAT3 and CREB signaling in spleen and depressed signaling in liver, and proteins related to these pathways were identified with a different profile in lymph and plasma in AML compared with control. Additionally, several proteins were differently regulated in the microenvironment of spleen and liver in AML when compared with control. ConclusionInterstitial fluid, and its surrogate efferent lymph, can be used to provide unique information about responses in AML-infiltered organs and substances released to the general circulation during leukemia development.

T-prolymphocytic leukemia (T-PLL) is a rare malignancy of mature T-cells with distinct clinical, cytomorphological, and molecular genetic features. The disease typically presents at an advanced stage, with marked leukocytosis, B symptoms, hepatosplenomegaly, and bone marrow failure. It usually follows an aggressive course from presentation, and the prognosis is often considered dismal; the median overall survival is less than one year with conventional chemotherapy. This case report describes a patient with T-PLL who, after an unusually protracted inactive phase, ultimately progressed to a highly invasive, organ-involving disease. After initial treatments failed, a novel treatment approach resulted in a significant response.

BACKGROUND:While standard blood tests are often sufficient for an anaemia workup, sometimes more invasive diagnostic testing is required to exclude rare conditions. CASE PRESENTATION:A man in his forties contacted his general practitioner because of increasing functional dyspnoea. He had completed a course of dicloxacillin a few months previously for a skin abscess on his abdomen. Bloodwork revealed severe anaemia (haemoglobin 5.4 g/dL), which required transfusion. Subsequent testing excluded iron and vitamin deficiency anaemia, haemolysis and malignancy. Initial bone marrow biopsy was of suboptimal quality. However, repeat tissue sample supported a diagnosis of pure red cell aplasia. The patient improved with ciclosporin treatment, which was gradually tapered. INTERPRETATION:Pure red cell aplasia should be considered in patients with new onset isolated anaemia with severe reticulocytopenia. Diagnosis depends on obtaining representative tissue from bone marrow biopsy. It is difficult to conclude for this patient whether the aetiology of his pure red cell aplasia was idiopathic or secondary to recent dicloxacillin use.

Basal cell carcinoma (BCC) is the most common cancer in Caucasians. It is slow growing and rarely metastasizes. If left untreated over time, invasive growth can occur. We present a patient case with a primary BCC located in the right sub-mammary area, with extensive metastases to the skeleton and bone marrow. Histopathological examination of the tumour showed BCC with a diverse growth pattern. There were no signs of local metastases. Surgery was successfully performed. Three months post-surgery the patient developed normocytic anaemia and elevated inflammation markers. [18F]FDG PET/CT showed extensive FDG uptake in the entire skeleton and bone marrow. Biopsy confirmed the infiltration of BCC with similar histopathological features as the primary tumour. Prognosis of metastasized BCC is poor and, therefore, long-term follow-up of patients with risk factors is of importance.

Oropharynx squamous cell carcinoma (OPSCC) is of special interest because human papilloma virus (HPV) and/or smoking cause this disease. Influxes of inflammatory cells into such tumors are known to vary with prognoses. Aims: To study whether the density of tumor-infiltrating T lymphocytes and tumor-infiltrating macrophages predicted general 20-year overall survival (OS), as well as OS with only disease-specific survival (DSS) patients included. Methods: Biopsies from patients treated for OPSCC (n = 180) were stained by immunohistochemistry and the tumor cell macrophage (CD68), pan T lymphocytes (CD3), and regulatory T lymphocytes (Foxp3) densities were determined. The HE-determined percentage of matured tumor cells and the rate of invasion were calculated, and stromal desmoplasia were performed. Tumor HPV presence was studied by PCR. Twenty-year OS and five-year DSS patients were determined. Results: Tumor HPV status strongly predicted survival. High tumor infiltration of CD3, Foxp3 and CD68-positive cells predicted better twenty-year OS, with and without HPV stratification. Foxp3 and CD68 levels predicted OS, and 20-year among DSS patients, primarily among HPV(+) patients. Tumor HE-derived variables did not predict such survival. Conclusions: Tumor HPV status, level of Foxp3 tumor-infiltrating lymphocytes and CD68 tumor-infiltrating macrophages predicted up to 20-year OS of both all patients and disease-specific survived patients.

Background Hemophagocytic lymphohistiocytosis (HLH) is an immune mediated life-threatening condition. It is driven by an overactivation of the immune system and causes inflammatory tissue damage potentially leading to organ failure and death. Primary HLH is caused by genetic mutations, while secondary HLH is triggered by external factors. Viral infections are a well-known cause of secondary HLH. Cytomegalovirus (CMV) is a virus in the herpes family known to cause HLH in rare cases. Methods We report a recent case of CMV-induced HLH, followed by a systematic review of described cases of this rare disease entity, through a structured search in the medical database PubMed. All articles were assessed on a predetermined set of inclusion criteria. Results A total of 74 patients (age > 18 years) with CMV-related HLH were identified, 29 men, 42 women, and three patients with unspecified gender. Median age was 37.5 years (range 18–80). Sixty-six patients (88%) had one or more comorbid conditions and 22 patients (30%) had inflammatory bowel disease (IBD), the most frequent comorbidity. Forty patients (54%) received some form of immunomodulating treatment prior to HLH development. The general treatment approach was in general dual, consisting of antiviral treatment and specific immunomodulating HLH treatment approaches. Treatment outcome was at 77% survival, while 23% had fatal outcome. Conclusion The findings highlight the importance of early diagnostic work up and treatment intervention. Ability to recognize the characteristic clinical traits and perform specific HLH diagnostic workup are key factors to ensure targeted diagnostic work and treatment intervention for this patient group.

Head and neck cancer (HNC) is the sixth most common cancer worldwide. Oropharyngeal (OP) cancers are of special interest because of possible underlying HPV infection which is tied to prognosis. Influxes of inflammatory cells into tumors may vary with prognoses. We wanted to study whether the number of tumor-infiltrating lymphocytes (TIL) and tumor-associated macrophages (TAM) in tumors correlated to HPV status and predicted 5-year disease-specific survival (DSS). Formalin-fixed paraffin-embedded (FFPE) biopsies cut sections from 170 patients treated for OP cancer were stained by immunohistochemistry and evaluated for the number of CD68 (+) TAMs, CD3 (+), and Foxp3 (+) (T regulatory) TILs. From FFPE slides HPV by PCR and p16 by immunohistochemistry were established. From FFPE Hematoxylin-Eosin slides, levels of tumor nuclear polymorphism, tumor invasion, desmoplasia, and inflammation were determined as previously published. Levels of TIL CD3 (+) and TIL Foxp3 (+) were increased among the HPV (+) compared to the HPV (−) patients. High levels of TIL Foxp3 (+) and CD68 (+) macrophages predicted better 5-year DSS. TIL Foxp3 (+) levels predicted independent of age, gender, TNM stage, and HPV infection as well as level of stromal desmoplasia, tumor invasion, and nuclear polymorphism, but more pronounced among tumor HPV (+) than HPV (−) patients.

Introduction. Necrotizing soft tissue infections are rapidly progressing infections associated with severe inflammation and cytokine release. Early recognition and surgical intervention are key factors to secure survival. The current case presents a patient with multifocal necrotizing soft tissue infection as the initial presentation of severe aplastic anaemia. Case Presentation. A man in his fifties was admitted with septic shock with multiorgan failure and severe pancytopenia, after two days of malaise with high fever and right flank pain. The diagnosis streptococcal necrotizing myositis was significantly delayed due to atypical clinical findings. After initial surgical exploration, the decision was made to defer from surgical debridement due to extensive involvement of several muscle groups, grave pancytopenia, and suspected dismal prognosis. Surprisingly, the patient stabilized after antibiotics and intensive care treatment. Based on severe pancytopenia and hypocellular bone marrow, with no evidence of other bone marrow disorders, the patient was diagnosed with aplastic anaemia. Treatment for aplastic anaemia with antithymocyte globulin, cyclosporine, and eltrombopaq was started, and 2 months later, a partial haematological recovery was observed. The patient could be discharged from hospital without antibiotic treatment. Conclusions. This case illustrates the crucial role of a multidisciplinary approach on admission and further during the clinical course. Clinical improvement despite severe neutropenia and stabilization during immunosuppressive therapy suggest that immunological factors modulate clinical course in necrotizing soft tissue infections.

The entity myelodysplastic syndrome/myeloproliferative neoplasm overlap syndrome is characterized by the coexistence of both myeloproliferative and myelodysplastic features in the bone marrow. Risk assessment and treatment recommendations have not been standardized, and clinicians rely on updated patient studies and reviews to make decisions for treatment approaches. Histopathological features have traditionally been important, although in the last decade, several studies have reported mutational profiles of this rare disease. Here, we present a case, wherein the patient presented with leukocytosis and the diagnostic work-up revealed features of myelodysplastic syndrome/myeloproliferative neoplasm overlap syndrome. Mutational profiling revealed mutations in four genes associated with myeloid malignancies, namely, EZH2, CUX1, TET2 , and BCOR . After initial therapy with hydroxyurea and interferon-α, the patient underwent allogeneic hematopoietic stem cell transplantation, with reduced intensity conditioning and a matched sibling donor. He had no signs of relapsed disease 2 years after the transplant. Based on the patient outcome, we summarize the diagnostic and therapeutic approaches for patients diagnosed with myelodysplastic syndrome/myeloproliferative neoplasm overlap syndrome, and review the current literature, emphasizing the role of genetic mutations and allogeneic hematopoietic stem cell transplantation. Larger and more detailed clinical studies are strongly needed to optimize and standardize diagnostic and therapeutic approaches for this disease.

Mantle cell lymphoma (MCL) shows a clinical aggressiveness that varies from patient to patient. Despite major advances in outcomes with current immunochemotherapy, the future development of therapies requires risk stratification to tailor therapy intensity. Within the group of reference pathologists for the ongoing trials of the European MCL Network, we performed a round robin test on a tissue microarray to evaluate the reproducibility in assessing the biomarkers of outcome in MCL. Cytological subtype, Ki67-index and expression of p53 and SOX11 were evaluated on 20 diagnostic tumour samples by eight participating labs independently. We demonstrate that the assessment of the proliferation index by counting the Ki67 positive cells as well as assessment of SOX11 and p53 expression status is reproducible between labs. For the most established prognostic biomarker, Ki67, the intra-class correlation coefficient was very good when assessed as a continuous parameter (0.87). The agreement was lower when the values were analysed in a dichotomized way applying the commonly used cutoff of 30% (kappa = 0.65, complete concordance of all labs in 13/20 (65%)). Cases with discrepant results between labs in the dichotomized analysis showed mean values close to the cutoff of 30%. Centralised scoring and digital image analysis revealed results in line with the scores from individual labs. All cases in our cohort were additionally assessed for gene expression signatures and of TP53 gene alterations. Given the good reproducibility when guidelines of assessment are applied, the biomarker studied in this inter-laboratory test presents potential candidates to be enhanced for risk-stratification in the future clinical trials.

BACKGROUND:Febrile illness is a common clinical problem and frequently caused by bacterial and viral infections. When blood cultures are negative and symptoms persist despite empirical antibiotic treatment, clinicians must consider other differential diagnoses including malignancy, rheumatologic disease and parasitic infections.CASE PRESENTATION:A Norwegian male in his eighties experienced febrile illness during a stay in Southern Spain. Upon return to Norway, he was hospitalized with fever, weight-loss, enlarged spleen, pancytopenia and hypergammaglobulinemia. After failing to respond to broad-spectrum antibiotics and antifungals, he was diagnosed with visceral leishmaniasis and Leishmania infantum was confirmed by PCR and sequencing of spleen biopsy and blood.INTERPRETATION:With increasing migration and tourism, doctors in non-endemic countries should be familiar with visceral leishmaniasis.