From the archives of MD Anderson Cancer Center: Plasmablastic lymphoma presenting as a kidney mass in an immunocompetent patient: Case report and literature review.

BACKGROUND: Plasmablastic lymphoma (PBL) is a rare, aggressive large B-cell lymphoma with plasmablastic or immunoblastic morphology and a terminally differentiated B-cell immunophenotype. PBL often presents at extranodal sites, commonly the oral cavity of immunocompromised patients with human immunodeficiency virus (HIV) and/or Epstein-Barr virus (EBV) infection. Cases of PBL arising outside the oral cavity in previously healthy immunocompetent patients are rare. CASE REPORT: We report a 65-year-old HIV- and EBV-negative man who presented with abdominal pain, fatigue, and vomiting. Imaging studies showed a 30 × 18 cm bulky lobulated mass located within the left kidney with surrounding para-aortic lymphadenopathy. Serum and urine protein electrophoresis revealed a monoclonal gammopathy of IgA lambda type. Biopsy of the mass showed PBL. Bone marrow lumbar puncture evaluations also showed evidence of PBL. The patient was treated with chemotherapy and radiation with initial improvement; however, he died 14 months after initial diagnosis. CONCLUSIONS: Based on our literature review, this case of PBL is one of the few reported to present as a kidney mass in immunocompetent, HIV- and EBV-negative patient. Distinguishing PBL from plasma cell myeloma (PCM) can be challenging. Knowledge of clinical features including presence of CRAB (hypercalcemia, renal failure, anemia, bone lesions) or bone marrow infiltration by mature clonal plasma cells is helpful to establish a diagnosis of PCM. Genetic features of PCM (typical translocations or mutations) also can be helpful in distinguishing plasmablastic transformation of PCM and from PBL. The case we report also highlights the need for more studies to identify specific immunohistochemical and molecular markers to improve PBL diagnosis in immunocompetent patients.

Primary Hepatic Neuroendocrine Carcinoma: Case Reports and Review of the Literature.

Primary neuroendocrine tumors of the liver are exceedingly rare, and unlike metastatic neuroendocrine tumors, rarely cause carcinoid syndrome. There are fewer than 150 cases reported in the current literature. We report two cases of primary hepatic neuroendocrine carcinomas of the liver. Both patients remain healthy without any recurrence to date. A review of the current literature regarding diagnosis, pathology, and management of this disease is included.

Application of the newly published International System for Reporting Serous Fluid Cytopathology in atypical and suspicious diagnosis: a four-year retrospective analysis.

INTRODUCTION: Serous fluids offer crucial diagnostic insights, but inconsistent analysis hampers reporting quality, especially in indeterminate (ID) categories like atypia of undetermined significance (AUS) and suspicious for malignancy (SFM). The 2020 International System for reporting Serous Fluid Cytopathology (TIS) aims to standardize communication and reduce reporting disparities. This study evaluates TIS's role in AUS and SFM categories within our institution. MATERIALS AND METHODS: A 4-year retrospective search of cytopathology reports from December 2015 to December 2019 for AUS and SFM diagnoses in pleural, ascitic, pericardial fluids, and peritoneal washings was performed and results reclassified using TIS definitions. The risk of malignancy (ROM) was calculated for existing and reclassified diagnoses. RESULTS: Over 4 years, we received 2998 serous fluid specimens. AUS constituted 2.3% (70 cases), while SFM constituted 0.5% (16 cases). Excluding repeats, 80 cases were TIS-reviewed. Sixteen cases of ID diagnoses were reclassified. Two cases of AUS were changed to negative for malignancy (NFM) and 12 to SFM. Two SFM cases were upgraded to malignancy. ROM shifted from 63% to 60% for AUS and 100% to 85% for SF (TIS's ROM range: AUS: 66% ± 10%; SFM: 82% ± 4.8%). CONCLUSIONS: This institution's ID diagnosis rate is low. AUS ROM is challenging but aligns with TIS, primarily favoring benign. All SFM diagnoses are highly suspicious but quantitatively inadequate for definitive malignancy, explaining the elevated ROM. AUS rate should gauge quality, not serve as a catch-all category. Algorithmic cytology with cell blocks and ancillary studies aids reclassification. TIS is user-friendly and is a consistent methodology for standardized reporting. Further studies are needed to evaluate ROM and define reproducible diagnostic criteria for each category for better system utilization.

Non-IgG4-Related Fibrosing Mediastinitis Diagnosed on Core Needle Biopsy and Treated with Steroids: A Case Study and Review of the Differential Diagnoses.

OBJECTIVES: This study aimed to investigate the histological characteristics and treatment efficacy of non-immunoglobulin G4-related fibrosing mediastinitis and discuss differential diagnoses for this rare entity. METHODS: We present a case study of non-immunoglobulin G4-related fibrosing mediastinitis diagnosed on core biopsy and treated with steroids. A total of four 18-gauge core needle biopsy specimens were obtained for surgical pathology. Analysis of the patient's medical history, radiological characteristics of fibrosing mediastinitis, histological features, immunohistochemistry results, the differential diagnosis and treatment efficacy of different types of fibrosing mediastinitis was performed. RESULTS: This report describes a unique presentation of fibrosing mediastinitis (syncope and weight loss) that was concerning for malignancy. Histological, laboratory and radiographical studies confirmed the diagnosis of non-immunoglobulin G4-related fibrosing mediastinitis. The patient received corticosteroid treatment which showed marked improvement after 1 month of treatment. CONCLUSIONS: Fibrosing mediastinitis is an extremely uncommon entity with unknown pathogenesis, and it is more important to rule out malignancy and infection than to delineate between fibrosing mediastinitis and IgG4-related disease. In doing this, we may reasonably initiate a trial of corticosteroids which may prove beneficial, as in this patient. More studies on the pathogenesis of fibrosing mediastinitis are necessary to guide better directed treatments.

Mesenchymal stem cell-derived exosomes for treatment of sepsis.

Introduction: The pathogenesis of sepsis is an imbalance between pro-inflammatory and anti-inflammatory responses. At the onset of sepsis, the lungs are severely affected, and the injury progresses to acute respiratory distress syndrome (ARDS), with a mortality rate of up to 40%. Currently, there is no effective treatment for sepsis. Cellular therapies using mesenchymal stem cells (MSCs) have been initiated in clinical trials for both ARDS and sepsis based on a wealth of pre-clinical data. However, there remains concern that MSCs may pose a tumor risk when administered to patients. Recent pre-clinical studies have demonstrated the beneficial effects of MSC-derived extracellular vesicles (EVs) for the treatment of acute lung injury (ALI) and sepsis. Methods: After recovery of initial surgical preparation, pneumonia/sepsis was induced in 14 adult female sheep by the instillation of Pseudomonas aeruginosa (~1.0×1011 CFU) into the lungs by bronchoscope under anesthesia and analgesia. After the injury, sheep were mechanically ventilated and continuously monitored for 24 h in a conscious state in an ICU setting. After the injury, sheep were randomly allocated into two groups: Control, septic sheep treated with vehicle, n=7; and Treatment, septic sheep treated with MSC-EVs, n=7. MSC-EVs infusions (4ml) were given intravenously one hour after the injury. Results: The infusion of MSCs-EVs was well tolerated without adverse events. PaO2/FiO2 ratio in the treatment group tended to be higher than the control from 6 to 21 h after the lung injury, with no significant differences between the groups. No significant differences were found between the two groups in other pulmonary functions. Although vasopressor requirement in the treatment group tended to be lower than in the control, the net fluid balance was similarly increased in both groups as the severity of sepsis progressed. The variables reflecting microvascular hyperpermeability were comparable in both groups. Conclusion: We have previously demonstrated the beneficial effects of bone marrow-derived MSCs (10×106 cells/kg) in the same model of sepsis. However, despite some improvement in pulmonary gas exchange, the present study demonstrated that EVs isolated from the same amount of bone marrow-derived MSCs failed to attenuate the severity of multiorgan dysfunctions.

Metastatic Signet Ring Cell Adenocarcinoma Manifesting as Chronic Leg Pain.

Signet ring cell carcinoma, a type of gastrointestinal system-related cancer, rarely metastasizes to the skeletal muscle. We present signet ring-cell carcinoma in a 28-year-old man who presented with left lower extremity pain and swelling. Imaging showed thickening of the distal esophagus, intestines, and bladder wall. Endoscopy revealed friable gastric mucosa and stenosis in the ascending colon, but biopsies were unrevealing. Leg muscle biopsy showed metastatic adenocarcinoma with focal signet ring features. Carcinoembryonic antigen and cancer antigen 19-9 were elevated. A gastrointestinal primary tumor was suspected. Our case urges clinicians to consider this rare cancer in patients presenting with skeletal muscle mass.

BCOR Expression in Mullerian Adenosarcoma: A Potential Diagnostic Pitfall.

Adenosarcoma can mimic high-grade endometrial stromal sarcoma with ZC3H7B-BCOR fusion that may show entrapped glands and often exhibits diffuse BCOR expression. We encountered diffuse BCOR expression in rare adenosarcomas and sought to define its frequency among a larger cohort of these tumors. BCOR immunohistochemistry was performed on archival formalin-fixed paraffin-embedded tumor tissue in 13 of 14 adenosarcomas with and without stromal overgrowth arising in the uterus or ovary. The staining intensity and percentage of positive tumor nuclei in the mesenchymal component were evaluated. Eleven cases with sufficient tumoral tissue were subjected to fluorescence in situ hybridization for the detection of BCOR, BCORL1, NUTM1, ZC3H7B, and JAZF1 rearrangement. Three cases were subjected to targeted RNA sequencing. BCOR was expressed in 9 of 13 (70%) tumors, including 6 with and 3 without stromal overgrowth. Moderate to strong staining in >70% of cells was seen throughout in 1 low-grade and 6 high-grade tumors, 5 of which had stromal overgrowth. No staining was seen in 3 low-grade and 1 high-grade tumors with stromal overgrowth. One tumor demonstrating extensive sex cord-like differentiation and diffuse BCOR expression harbored JAZF1 and BCORL1 rearrangements. No BCOR or BCORL1 rearrangement was identified in the remaining tumors. BCOR expression is seen in most adenosarcomas with and without stromal overgrowth. BCORL1 rearrangement is seen in rare tumors with diffuse BCOR expression. Assessment of BCOR or BCORL1 rearrangement status is required in adenosarcomas demonstrating BCOR expression.

"Russell Body Gastroenterocolitis" in a Posttransplant Patient: A Case Report and Review of Literature.

Russell bodies represent a cellular response to overstimulation of plasma cells, leading to the accumulation of abundant, nondegradable, condensed immunoglobulin in dilated rough endoplasmic reticulum cisternae. Russell body gastritis was first described 1998 by Tazawa and Tsutsumi. Since then only 39 cases involving the gastrointestinal tract have been reported in English literature, which include Russell body gastritis, duodenitis, and esophagitis. We report a case of a 44-year-old female with a history of diabetes mellitus, status post kidney and pancreas transplant who presented with multiple episodes of watery diarrhea associated with abdominal pain, nausea, and vomiting. Upper gastroendoscopic examination showed diffuse mild erythema in the gastric body and a clean-based duodenal ulcer. Lower gastroendoscopic examination was normal. Examination of multiple biopsies from duodenal, gastric, terminal ileum, and colonic mucosae revealed numerous plasma cells with abundant eosinophilic granular cytoplasm (Russell bodies) and eccentric nuclei, highlighted by PAS stain and CD 138 plasma cell marker. Helicobacter pylori stains were performed on gastric biopsies and were negative for organisms. To date, there are no cases described in English literature with multifocal Russell body infiltrates in gastrointestinal tract in a single patient including ileum and/or colon. This makes our case the first to be reported with these unique findings; thus, the spectrum of Russell body-associated chronic inflammation of the gastrointestinal tract would be more suitably referred to as "Russell body gastroenterocolitis."