[Inflammatory Polyp due to Peanut Aspiration, Needed to Differentiate from Malignant Tumor: Report of a Case].

The patient was in his 70s. He was addmitted to our hospital because of obstructive pneumonia for 3 months. Chest computed tomography( CT) showed a nodule at the base of the right B8, obstructing the basal branch, with consolidation of the peripheral lung. Bronchoscopy revealed the right basal trunk obstruction by a tumorous lesion. FDG-PET showed heterogeneous FDG uptake at the right hilum and the lower lobe suggesting malignancy, and a thoracoscopic right lower lobectomy was performed. Pathology showed a granulation-like nodule and a brown oval foreign body incarcerated in the peripheral bronchus, which was later revealed to be a peanut, and no obvious malignant findings were observed.

The risk of weekend biopsy: Impact of specimen source and fixation status on HER2 assessment in the treatment of advanced gastric cancer (The HER_WEEKEND study).

Accurate evaluation of human epidermal growth factor receptor type 2 (HER2) expression is crucial for determining chemotherapy regimens in gastric cancer. However, formalin fixation status has been identified as an important factor affecting HER2 assessment reliability. This retrospective cohort study aimed to investigate the correlation between sample collection day (weekday vs. weekend) and source (biopsy vs. surgical specimens) in assessing HER2 expression in patients with unresectable advanced/recurrent gastric cancer. Data were collected from gastric cancer patients who received chemotherapy at a single public hospital in Japan from 2008 to 2021. The analysis included 177 patients (109 men, 68 women) with a median age of 68.0 (21-88) years, and the primary outcome was the HER2 positivity rate. The overall HER2 positivity rate was 18.1%, with higher rates on weekdays (20.0%) compared to weekends (12.8%). Biopsies had higher positivity rates on weekdays (23.9%) but lower rates on weekends (11.1%) than surgical specimens. Significant differences were observed in formalin fixation times between weekdays and weekends for both biopsies and surgical samples. The study findings suggest that longer formalin fixation times on weekends may lead to underestimating HER2 expression, particularly in biopsies. Therefore, it is crucial to be cautious of excessive formalin fixation when collecting samples, especially during weekend biopsies.

BK Polyomavirus-Associated Urothelial Carcinoma of the Bladder with a Background of BK Polyomavirus Nephropathy in a Kidney Transplant Recipient.

Renal transplant recipients are at increased risk for the development of a malignant neoplasm. Polyomavirus-associated urothelial carcinoma is a rare tumor that occurs in renal transplant recipients, with approximately 41 cases reported since 2002. It accounts for 27-31% of all post-transplant urothelial carcinomas and develops at an average of 8.5 years after transplantation. Histologically, it shows high-grade urothelial carcinoma (95.1%) with a high frequency of glandular differentiation and micropapillary structures (58.5%) and positive immunohistochemistry for polyomavirus large T antigen, p53 (92.9%), and p16 (100%). We encountered a case of BK polyomavirus (BKPyV)-associated urothelial carcinoma of the bladder diagnosed 54 months after kidney transplantation. Histologically, it was a high-grade urothelial carcinoma with micropapillary features, and immunohistochemically, it was diffusely positive for polyomavirus large T antigen, p16, and p53. BKPyV DNA and mRNA for BKPyV large T antigen have been identified in tissues using real-time polymerase chain reaction. The same sequence of the BKPyV VP1 genome hypervariable region was detected in both transplanted kidney tissue with polyomavirus nephropathy and urothelial carcinoma tissue, suggesting that polyomavirus-associated urothelial carcinoma developed in a background of persistent polyomavirus nephropathy. This case showed typical histological features and was detected and treated at an earlier stage than has been reported. It is important to keep in mind that polyomavirus-associated urothelial carcinoma can develop early after transplantation and might be associated with polyomavirus nephropathy. Because of its rapidly progressive nature, careful follow-up with urine cytology and cystoscopy is necessary. We report this case with a literature review.

CD47 blockade ameliorates autoimmune vasculitis via efferocytosis of neutrophil extracellular traps.

Neutrophil extracellular trap (NET) formation contributes to immune defense and is a distinct form of cell death. Excessive NET formation is found in patients with anti-neutrophil cytoplasmic antibody-associated (ANCA-associated) vasculitis (AAV), contributing to disease progression. The clearance of dead cells by macrophages, a process known as efferocytosis, is regulated by the CD47-mediated "don't eat me" signal. Hence, we hypothesized that pathogenic NETs in AAV escape from efferocytosis via the CD47 signaling pathway, resulting in the development of necrotizing vasculitis. Immunostaining for CD47 in human renal tissues revealed high CD47 expression in crescentic glomerular lesions of patients with AAV. In ex vivo studies, ANCA-induced netting neutrophils increased the expression of CD47 with the reduction of efferocytosis. After efferocytosis, macrophages displayed proinflammatory phenotypes. The blockade of CD47 in spontaneous crescentic glomerulonephritis-forming/Kinjoh (SCG/Kj) mice ameliorated renal disease and reduced myeloperoxidase-ANCA (MPO-ANCA) titers with a reduction in NET formation. Thus, CD47 blockade would protect against developing glomerulonephritis in AAV via restored efferocytosis of ANCA-induced NETs.

Exacerbation of Intimal Fibrosis and Endarteritis in a Kidney Transplant Recipient with Chronic Active Antibody-Mediated Rejection and COVID-19: A Case Report.

Kidney transplant recipients are immunocompromised hosts at risk for comorbidity and mortality due to infection. Currently, there are no established guidelines for the management of immunosuppressed transplant recipients with coronavirus disease 2019 (COVID-19). The impact of COVID-19 and its therapeutic management on chronic active antibody-mediated rejection (CAAMR) are still unclear. Here, we report a case of CAAMR exacerbation with endarteritis and intimal fibrosis after COVID-19. A 41-year-old female kidney transplant recipient with CAAMR was admitted to a local hospital with moderately severe COVID-19. Her doses of tacrolimus and mycophenolate mofetil were reduced, and she was administered methylprednisolone pulse and antiviral drugs. This resulted in a good clinical course and she was discharged in 15 days. During and after hospitalization, the immunosuppressants were gradually returned to the baseline levels. However, about 1.5 months after discharge, the serum creatinine level became elevated. An indication kidney biopsy showed CAAMR with intimal fibrosis and endarteritis in all interlobular arteries. An increase of immunosuppressant led to a decrease of the serum creatinine level. Factors contributing to CAAMR with intimal fibrosis and endarteritis may include (1) insufficient immunosuppression due to changes in the levels of immunosuppressive; (2) overlap with endothelial cell injury caused by COVID-19, and (3) an immune-activated state associated with COVID-19. COVID-19 is a life-threatening disease that can result in unexpected changes in immunological status. Possible allograft rejection should be carefully managed in such patients.

A Case of Kidney Transplantation from a Deceased Donor with Acute Kidney Injury due to Rhabdomyolysis.

Acute kidney injury (AKI) due to rhabdomyolysis occurs because of renal ischemia or acute tubular necrosis due to the deposition of myoglobin casts in the renal tubules. Donors with AKI due to rhabdomyolysis are not contraindication for transplantation. However, the dark red kidney raises concerns about renal hypofunction or primary nonfunction after transplantation. We report the case of a 34-year-old man with a 15-year history of hemodialysis for chronic renal failure due to congenital anomalies of the kidney and urinary tract. The patient received a renal allograft from a young woman who suffered cardiac death. The serum creatinine (sCre) level of the donor at the time of transport was 0.6 mg/dL, and renal ultrasonography revealed no abnormalities in renal morphology or blood flow. Her serum creatinine kinase level increased to 57,000 IU/L 58 h after femoral artery cannulation and sCre level worsened to 1.4 mg/dL, suggesting AKI due to rhabdomyolysis. However, since the urine output of the donor was maintained, the sCre elevation was thought to be nonproblematic. The allograft had a dark red appearance at the time of procurement. The perfusion of the isolated kidney was good, but the dark red color did not improve. A 0-h biopsy showed flattening of the renal tubular epithelium and absence of the brush border and myoglobin casts in 30% of the renal tubules. Rhabdomyolysis-related tubular damage was diagnosed. Hemodialysis was discontinued on postoperative day 14. Twenty-four days after the operation, the transplanted kidney function progressed favorably (sCre 1.18 mg/dL), and the patient was discharged. Protocol biopsy 1 month after transplantation showed disappearance of myoglobin casts and improvement in renal tubular epithelial damage. The patient's sCre level was approximately 1.0 mg/dL 24 months after transplantation, and he is doing well without complications.

Expression of the immunoproteasome subunit ß5i in non-small cell lung carcinomas.

AIM: The immunoproteasome is a specific proteasome isoform whose proteolytic activity enhances the generation of antigenic peptides to be presented by major histocompatibility complex class I molecules to CD8+ T cells. Physiologically, it is expressed abundantly in immune cells and is induced in somatic cells by cytokines, especially interferon-γ. Recently, variable expression of immunoproteasomes has been demonstrated in different types of cancers. However, the clinical significance of immunoproteasome expression in malignant tumours is poorly understood. In this study, we performed clinicopathological evaluation of immunoproteasome subunit ß5i in non-small cell lung carcinomas (NSCLCs). METHODS: Tumour tissues were collected from 155 patients with NSCLCs, and immunohistochemical analysis for ß5i was performed in relation to the prognosis of patients. RESULTS: High expression of ß5i was found in about 20% of all NSCLCs and was found significantly more frequently (40%) in the adenocarcinoma subset. High expression of ß5i was associated with a better 5-year relative survival rate in patients with pStage I to II adenocarcinoma and was also a significant and independent favourable prognostic factor in adenocarcinoma patients. In addition, when we performed in vitro analysis using NSCLC cell lines, combined treatment with the immunoproteasome-specific inhibitor ONX0914 and the proteasome inhibitor MG132 enhanced cell death in ß5i-expressing NSCLC cell lines. CONCLUSION: The expression of immunoproteasome can be explored as both a prognostic factor and a potential therapeutic target in NSCLCs. Since immunoproteasomes have crucial role in the antigen presentation, further studies may help to provide essential knowledge for therapeutic strategies in anticancer immunotherapy.

Preceding T-Cell-Mediated Rejection Is Associated with the Development of Chronic Active Antibody-Mediated Rejection by de Novo Donor-Specific Antibody.

AIM: Chronic active antibody-mediated rejection (CAABMR) is an important cause of late-stage renal allograft loss. Early inflammatory events such as acute rejection and infection after transplantation are considered to be the risk factors of de novo donor-specific antibody (dnDSA) production. In this study, we investigated the relationship between pre-disposing T-cell-mediated rejection and dnDSA-positive CAABMR. METHODS: We recruited 365 patients who underwent ABO-compatible renal transplantation at our hospital. Among them, 16 patients diagnosed as having dnDSA-positive CAABMR were designated as a CAABMR group, and 38 randomly selected patients were designated as a control group. All biopsies from 1 month after transplantation were included in the study. The presence or absence of borderline changes (BLCs), acute T-cell-mediated rejection (ATMR), microvascular inflammation (MVI), and C4d positive on peritubular capillaries (C4d-P) was examined. RESULTS: In the CAABMR group, BLC/ATMR was found in 12 cases (75%), and the mean duration until appearance of BLC/ATMR was 282.7 ± 328.7 days. C4d-P was found in 11 cases (68.8%), and the mean duration until its appearance was 1,432 ± 1,307 days. MVI was found in all cases, and the mean duration until its appearance was 1,333 ± 1,126 days. The mean duration until diagnosis of CAABMR was 2,268 ± 1,191 days. In the control group, BLC/ATMR was found in 13 cases (34.2%), and the mean duration until the appearance of BLC/ATMR was 173.1 ± 170.4 days. C4d-P was found in 2 cases (5.3%), and the durations until its appearance were 748 and 1,881 days. No cases of MVI were found in the control group. The frequency of BLC/ATMR was significantly higher in the CAABMR group (p < 0.01). CONCLUSION: Preceding BLC/ATMR is associated with the development of CAABMR with dnDSA.

Novel Detection of CALR-Mutated Cells in Myeloproliferative Neoplasm-Related Glomerulopathy With Interstitial Extramedullary Hematopoiesis: A Case Report.

Myeloproliferative neoplasms (MPNs) are associated with somatic mutations of genes including JAK2, CALR, or MPL in hematopoietic stem cells. Various glomerular lesions are known to be involved in MPN-related glomerulopathy, including mesangial hypercellularity, segmental sclerosis, features of chronic thrombotic microangiopathy, and intracapillary hematopoietic cell infiltration. Renal extramedullary hematopoiesis (EMH) is uncommon, but it is reported to occur in the setting of MPN; however, to our knowledge, there have been no reports of renal EMH with pathologically verified mutations. We report the case of a 65-year-old woman with MPN who had a CALR mutation and developed nephrotic syndrome. Kidney biopsy showed the typical findings of MPN-related glomerulopathy. CALR mutation-specific immunostaining of the kidney revealed immunopositive cells in the EMH lesion of the interstitium, indicating that renal EMH was caused by CALR-mutated cells. Based on these findings, we diagnosed nephrotic syndrome caused by MPN-related glomerulopathy. After initiation of steroid therapy, the patient's proteinuria gradually decreased and she achieved an incomplete remission. Additionally, the patient was prescribed the JAK inhibitor ruxolitinib and maintained incomplete remission. There is no established treatment for MPN-related glomerulopathy; therefore, further studies are needed to elucidate its pathophysiology.

Formation and Disordered Degradation of Neutrophil Extracellular Traps in Necrotizing Lesions of Anti-Neutrophil Cytoplasmic Antibody-Associated Vasculitis.

Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is characterized by the production of ANCAs and systemic necrotizing vasculitis in small vessels. Disordered regulation of neutrophil extracellular traps (NETs) is critically involved in the pathogenesis of AAV. NETs are web-like DNA decorated with antimicrobial proteins; they are extruded from activated neutrophils. The principal degradation factor of NETs in vivo is DNase I; however, NETs resistant to DNase I can persist in tissues and can lead to the production of ANCAs. Deposition of NETs has been demonstrated in glomerular crescents and necrotizing vasculitis in AAV. Here, the amount of NETs in formalin-fixed, paraffin-embedded tissue sections was examined, and the results for AAV were compared with the results for diseases that should be distinguished from AAV. NETs were more abundant in necrotizing vasculitis of AAV than in non-ANCA-associated vasculitis, or in granulomatous angiitis. Pulmonary granulomas in AAV and non-ANCA-associated diseases were further studied. The amount of NETs was significantly greater in necrotizing granulomas of AAV than in granulomas of sarcoidosis without necrosis. Although NETs were formed in necrotizing granulomas of tuberculosis equivalently to those formed in AAV, they were more susceptible to degradation by DNase I than were NETs in AAV. The formation and disordered degradation of NETs in necrotizing lesions are characteristics of AAV and are possibly related to its pathogenesis.

Expression of cathepsins V and S in thymic epithelial tumors.

Cathepsins are a group of proteolytic enzymes of the endosomal/lysosomal pathway involved in the thymic development of T cells restricted by major histocompatibility complex class II molecules. In the normal thymus, cathepsin V (CTV) and cathepsin S (CTS) are expressed in cortical and medullary epithelial cells, respectively. To investigate whether cathepsins could serve as a diagnostic marker, we performed immunohistochemical analysis for CTV and CTS in 77 cases of thymic epithelial tumors. Almost all cases (59/60) of thymoma expressed CTV, whereas 28 of 60 cases of thymoma expressed CTS. Notably, CTS was expressed in most cases of type A and type AB thymomas, but not in type B thymoma. The expression of cathepsins in type AB thymoma showed a clear correlation with histologic features; CTV was found predominantly in the type B component, and CTS was frequently expressed in the type A component. In thymic carcinoma, CTV was expressed in less than half cases (7/17), and the ratio of CTS-positive cases was equivalent to that of thymoma (8/17). Cases of CTV-negative thymic carcinoma tended to have a higher incidence of recurrence than did CTV-positive cases. Although further studies with a larger number of cases are required to confirm the utility of cathepsin immunostaining, CTV and CTS appear to serve as auxiliary diagnostic and/or prognostic markers in thymic epithelial tumors.

An unusual case of uterine cotyledonoid dissecting leiomyoma with adenomyosis.

BACKGROUND: Cotyledonoid dissecting leiomyoma is a rare variant of uterine smooth muscle tumor with an unusual growth pattern that shows intramural dissection within uterine myometrium and often a placenta-like appearance in its extrauterine components. CASE PRESENTATION: We present a unique case of cotyledonoid dissecting leiomyoma with adenomyosis. A 40-year-old Japanese female presented with prolonged menorrhagia and severe anemia. She had a pelvic mass followed-up for 6 years with a diagnosis of leiomyoma. However, increase in tumor size and cystic changes with hemorrhage were found by magnetic resonance imaging, and total abdominal hysterectomy with bilateral salpingectomy was performed. Macroscopically, the placenta-like exophytic mass protruding from the posterior uterine wall was composed of multiple nodules containing numerous hemorrhagic cysts. The mass showed continuity as a white multinodular dissecting mass infiltrating the posterolateral myometrium. Microscopically, both extra-and intrauterine portions of the mass were composed of nodules that contained swirled neoplastic smooth muscle cells with marked hyalinized degeneration, as observed in cotyledonoid dissecting leiomyomas of conventional type. In addition, numerous non-neoplastic glands of endometrial type surrounded by abundant endometrium-like stromal cells and non-neoplastic smooth muscle cells were found in the tumor, suggesting that it involved a part of concomitant adenomyosis originating from the nontumoral myometrium. CONCLUSIONS: Thus far, over 30 cases of cotyledonoid dissecting leiomyoma have been reported, none of which have described the presence of adenomyosis within the tumor. The present case suggested that cotyledonoid dissecting leiomyoma might have a unique clinical presentation involving concomitant uterine adenomyosis. It is critical for pathologists, gynecologists, and radiologists to be cognizant of cotyledonoid dissecting leiomyoma variants for timely and appropriate diagnosis and treatment.

Thrombocytopenia and Anemia with Anti-c-Mpl antibodies Effectively Treated with Cyclosporine in a Patient with Rheumatoid Arthritis and Chronic Renal Failure.

A 61-year-old woman with rheumatoid arthritis who was undergoing hemodialysis for end-stage renal failure was transferred to our hospital due to severe thrombocytopenia and anemia. A bone marrow biopsy showed the complete absence of megakaryocytes and erythroblasts. Cyclosporine treatment resulted in the improvement of her megakaryocyte and erythroblast levels, and a decrease in her serum level of anti-c-Mpl (thrombopoietin receptor) antibodies. After this initial improvement, her anemia progressively worsened, despite the continuous administration of immunosuppressive therapy with cyclosporine. Her platelet and leukocyte counts remained stable. This is the first report of a probable case of anti-c-Mpl antibody-associated pure red cell aplasia and acquired amegakaryocytic thrombocytopenic purpura.

[Successful treatment with dose-adjusted EPOCH-R for triple-hit lymphoma having BCL2, BCL6 and MYC translocations].

Double- and triple-hit lymphomas (DHL/THL), high-grade B-cell lymphomas with an extremely poor prognosis, are defined by a chromosomal breakpoint affecting the MYC/8q24 locus in combination with another recurrent breakpoint. The successful use of dose-adjusted (DA) EPOCH-R in patients with MYC-positive lymphoma and Burkitt lymphoma (BL) was recently reported. A 74-year-old man with acute renal dysfunction and hyperkalemia was transferred to our emergency center by ambulance. PET-CT revealed a left renal hilar mass enveloping the abdominal para-aortic domain and bladder and hydronephrosis. High (18)F-FDG uptake revealed lymph node, peritoneum, and multiple bone metastases. Analysis of the bone marrow aspirate revealed abnormal lymphoid cells with deeply basophilic cytoplasm and numerous vacuoles resembling Burkitt cells. Chromosomal analysis revealed a complex chromosomal karyotype, including t(14;18)(q32;q21), and FISH analysis confirmed split BCL2, BCL6, and MYC signals. Bone marrow biopsy revealed diffusely infiltrating large abnormal lymphoid cells with a CD10⁺, CD20⁺, BCL2⁺, BCL6⁺, c-MYC⁺ and MUM1(-) immunophenotype. B-cell lymphoma, unclassifiable with features intermediate between diffuse large B-cell lymphoma and BL, was diagnosed. The patient achieved a partial response after eight courses of DA-EPOCH-R chemotherapy. Our experience suggests that DA-EPOCH-R may be an effective treatment for DHL/THL.

Fatal cardiac small-vessel involvement in ANCA-associated vasculitis: an autopsy case report.

An 80-year-old Japanese man, who had fever and generalized fatigue not improved by antibiotics, was admitted to our hospital. Laboratory data indicative of renal dysfunction and antineutrophil cytoplasmic antibody (ANCA) in the serum led to the consideration of ANCA-associated vasculitis as a differential diagnosis. However, before the diagnostic confirmation, he was found dead on the bed. Autopsy revealed necrotizing crescentic glomerulonephritis in the kidneys. In addition, necrotizing granulomatous vasculitis with infiltration of multinucleated giant cells and neutrophils but not eosinophils was present in multiple organs. The direct cause of death was presumed as cardiac arrest by lethal arrhythmia because vasculitic lesions were distributed widely in the cardiac walls, acute congestion was observed in the systemic organs, and other causes of death were ruled out. This report presents the unusual manifestation of cardiac small-vessel involvement in ANCA-associated vasculitis related to sudden death.

[A case of complete response to multiple liver metastasis of gastric cancer after discontinuation of S-1 administration].

An 80-year-old man was diagnosed with advanced gastric cancer and underwent distal gastrectomy. Although the pathological Stage of the cancer was III A, he refused adjuvant chemotherapy. One year later, CT revealed multiple liver metastases. Therefore, he was started with S-1 administration and a complete response was obtained at 10 months after starting S-1 administration. He has maintained a complete response for 22 months after S-1 discontinuation.