KR158 Spheres Harboring Slow-Cycling Cells Recapitulate High-Grade Glioma Features in an Immunocompetent System.

Glioblastoma (GBM) poses a significant challenge in clinical oncology due to its aggressive nature, heterogeneity, and resistance to therapies. Cancer stem cells (CSCs) play a critical role in GBM, particularly in treatment resistance and tumor relapse, emphasizing the need to comprehend the mechanisms regulating these cells. Also, their multifaceted contributions to the tumor microenvironment (TME) underline their significance, driven by their unique properties. This study aimed to characterize glioblastoma stem cells (GSCs), specifically slow-cycling cells (SCCs), in an immunocompetent murine GBM model to explore their similarities with their human counterparts. Using the KR158 mouse model, we confirmed that SCCs isolated from this model exhibited key traits and functional properties akin to human SCCs. KR158 murine SCCs, expanded in the gliomasphere assay, demonstrated sphere forming ability, self-renewing capacity, positive tumorigenicity, enhanced stemness and resistance to chemotherapy. Together, our findings validate the KR158 murine model as a framework to investigate GSCs and SCCs in GBM pathology, and explore specifically the SCC-immune system communications, understand their role in disease progression, and evaluate the effect of therapeutic strategies targeting these specific connections.

Cecal Metastasis of Clear Cell Renal Cell Carcinoma After Previous Nephrectomy.

Metastasis of renal cell carcinoma (RCC) to the gastrointestinal (GI) tract is exceedingly rare. We present a case of a man in his 40s with a history of RCC that had metastasized to his abdominal wall and brain who then presented with abdominal pain and melena. On presentation, imaging showed new bone metastases and a colonic mass in the ascending colon. The biopsy of the mass from colonoscopy demonstrated RCC primary. Although rare, this case report highlights the importance of a thorough evaluation of patients with a history of RCC and considers GI tract involvement in those presenting with GI bleeding.

RNA aggregates harness the danger response for potent cancer immunotherapy.

Cancer immunotherapy remains limited by poor antigenicity and a regulatory tumor microenvironment (TME). Here, we create "onion-like" multi-lamellar RNA lipid particle aggregates (LPAs) to substantially enhance the payload packaging and immunogenicity of tumor mRNA antigens. Unlike current mRNA vaccine designs that rely on payload packaging into nanoparticle cores for Toll-like receptor engagement in immune cells, systemically administered RNA-LPAs activate RIG-I in stromal cells, eliciting massive cytokine/chemokine response and dendritic cell/lymphocyte trafficking that provokes cancer immunogenicity and mediates rejection of both early- and late-stage murine tumor models. In client-owned canines with terminal gliomas, RNA-LPAs improved survivorship and reprogrammed the TME, which became "hot" within days of a single infusion. In a first-in-human trial, RNA-LPAs elicited rapid cytokine/chemokine release, immune activation/trafficking, tissue-confirmed pseudoprogression, and glioma-specific immune responses in glioblastoma patients. These data support RNA-LPAs as a new technology that simultaneously reprograms the TME while eliciting rapid and enduring cancer immunotherapy.

KR158 spheres harboring slow-cycling cells recapitulate GBM features in an immunocompetent system.

Glioblastoma (GBM) poses a significant challenge in clinical oncology due to its aggressive nature, heterogeneity, and resistance to therapies. Cancer stem cells (CSCs) play a critical role in GBM, particularly in treatment-resistance and tumor relapse, emphasizing the need to comprehend the mechanisms regulating these cells. Also, their multifaceted contributions to the tumor-microenvironment (TME) underline their significance, driven by their unique properties. This study aimed to characterize glioblastoma stem cells (GSCs), specifically slow-cycling cells (SCCs), in an immunocompetent murine GBM model to explore their similarities with their human counterparts. Using the KR158 mouse model, we confirmed that SCCs isolated from this model exhibited key traits and functional properties akin to human SCCs. KR158 murine SCCs, expanded in the gliomasphere assay, demonstrated sphere forming ability, self-renewing capacity, positive tumorigenicity, enhanced stemness and resistance to chemotherapy. Together, our findings validate the KR158 murine model as a framework to investigate GSCs and SCCs in GBM-pathology, and explore specifically the SCC-immune system communications, understand their role in disease progression, and evaluate the effect of therapeutic strategies targeting these specific connections.

A Case of Statin-Associated Autoimmune Myopathy: Management and Treatment.

Elevated lipid panels are associated with an increased risk of cardiovascular disease. Management of heart disease with lipid lowering agents play a vital role in medicine. Statins are one group of medications that are widely utilized in the medical field to decrease the risk of atherosclerotic disease. Statins work by inhibiting the hepatic enzyme 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR). Although statins are one of the most effective drugs for secondary and primary prevention of heart disease, they are not without risks and side effects such as hepatotoxicity and myopathy. We present a case of a male patient who developed progressively worsening muscle weakness and elevated muscle enzyme markers upon initiation of a statin. His symptoms persisted despite a trial of an alternative statin and subsequent discontinuation of all statin medications. A multitude of possible etiologies were considered and ranged from infectious, autoimmune, cancerous, to congenital in nature. Environmental factors, such as exposure to medications or toxins, were also considered as one of the possible precipitating factors. The association between his statin consumption and muscle weakness were not easily apparent at first. He required further workup including physical examination, electromyography, panel of myositis antibodies, and muscle biopsy. After clinical suspicion and elevated antibodies to HMGCR beyond the normal limit, he was discovered to have statin-associated autoimmune myopathy. The patient improved with the treatment of immunosuppressive agent's prednisone and methotrexate.

Educational Case: Opportunistic Infections of the Central Nervous System.

The following fictional case is intended as a learning tool within the Pathology Competencies for Medical Education (PCME), a set of national standards for teaching pathology. These are divided into three basic competencies: Disease Mechanisms and Processes, Organ System Pathology, and Diagnostic Medicine and Therapeutic Pathology. For additional information, and a full list of learning objectives for all three competencies, see http://journals.sagepub.com/doi/10.1177/2374289517715040.1.

CXCR1- or CXCR2-modified CAR T cells co-opt IL-8 for maximal antitumor efficacy in solid tumors.

Chimeric antigen receptor (CAR) T-cell therapy targeting solid tumors has stagnated as a result of tumor heterogeneity, immunosuppressive microenvironments, and inadequate intratumoral T cell trafficking and persistence. Early (≤3 days) intratumoral presentation of CAR T cells post-treatment is a superior predictor of survival than peripheral persistence. Therefore, we have co-opted IL-8 release from tumors to enhance intratumoral T-cell trafficking through a CAR design for maximal antitumor activity in solid tumors. Here, we demonstrate that IL-8 receptor, CXCR1 or CXCR2, modified CARs markedly enhance migration and persistence of T cells in the tumor, which induce complete tumor regression and long-lasting immunologic memory in pre-clinical models of aggressive tumors such as glioblastoma, ovarian and pancreatic cancer.

Primary Extracranial Meningioma of Mastoid in a Patient With History of Skin Squamous Cell Carcinoma, Lung Adenocarcinoma and Prostatic Carcinoma.

BACKGROUND: Meningiomas are the most common benign intracranial tumors and frequently develop in the parasagittal region, but can also present extracranially. Rarely, meningiomas may involve the middle ear and mastoid, resulting from contiguous spread of adjacent intracranial tumor, or extremely rarely, as an isolated primary tumor, which is frequently misdiagnosed and unrecognized, resulting in inappropriate clinical management. CASE REPORT: Herein we report such a case of an 80-year-old man with history of multiple cancer who presented with ear pain, vertigo and hearing loss. Audiometry demonstrated bilateral sensorineural hearing loss. Contrast-enhanced temporal bone computed tomography revealed a soft-tissue mass in the right epitympanum without bone erosion or any intracranial involvement. Radiological and operative findings were suspicious for cholesteatoma. Histological examination showed an epithelial neoplasm arranged in nests and whorls with intranuclear inclusions. No psammoma bodies, mitotic figures, or tumor necrosis were identified. The tumor cells were positive for epithelial membrane antigen, vimentin, progesterone receptor and CD56; and negative for synaptophysin, chromogranin, pancytokeratin (AE1/AE3), cytokeratin 7, prostate-specific antigen, inhibin, S100, P63, and P40. Ki67 highlighted about 2% of the tumor cells. Based on the morphological features and immunohistochemical profile, the tumor was diagnosed as primary extracranial meningioma of the mastoid, meningothelial subtype, World Health Organization grade 1. CONCLUSION: To the best of our knowledge, primary mastoid meningioma clinically mimicking a cholesteatoma presenting in a patient with a history of multiple primary carcinomas has not been previously reported. The pathogenesis, diagnosis and treatment of this entity are discussed.

Gastric Plexiform Fibromyxoma: A Great Mimic of Gastrointestinal Stromal Tumor (GIST) and Diagnostic Pitfalls.

Through a multicenter study, we collected seven cases of gastric plexiform fibromyxoma including four females and three males, 21 to 79 y old (46.1 ± 10.1). All cases showed a unilocular lesion measuring 0.3 to 17 cm (5.3 ± 2.4), arising from antrum (5/7) or body (2/7). Six of the seven cases had intraoperative frozen sections and/or endoscopic ultrasound fine needle aspiration (EUS-FNA), and all of them were preoperatively or intraoperatively diagnosed as gastrointestinal stromal tumor (GIST). EUS-FNA material showed markedly elongated spindle cells with streaming oval to elongated nuclei with rounded ends. Histologically, the tumors exhibited a plexiform growth pattern and were composed of a rich myxoid stroma and cytologically bland uniform spindle cells without mitotic figures, with the exception of one case which displayed nuclear pleomorphism and increased mitosis. Immunostains showed the tumor cells to be focally positive for SMA (6/6), focally and weakly positive for desmin (3/6) and caldesmon (2/3), negative for CD117 (0/7), CD34 (0/7), DOG1 (0/4), and S100 (0/5). No mutations were identified on Next-Generation Sequencing test, and no loss of SDHB immunoreactivity was identified in the tumor with nuclear pleomorphism. One case was treated with Gleevec because of the initial diagnosis of GIST. All patients had a follow-up for up to 11 y, with no tumor recurrence or metastasis reported. Our results suggest that gastric plexiform fibromyxoma is rare and may be underrecognized and misinterpreted as GIST during intraoperative frozen section or preoperative EUS-FNA diagnosis without immunostains leading to inappropriate treatment.

Duodenal gangliocytic paraganglioma: A case report and literature review.

INTRODUCTION: Gangliocytic paraganglioma is a rare tumor that is most commonly located in the duodenum. At presentation, it may be confused with a gastrointestinal stromal tumor (GIST), but distinguishing between these tumors is critical because the natural history and treatment of these two tumors differs markedly. Duodenal gangliocytic paraganglioma typically exhibits benign behavior with occasional regional lymph node metastasis and no reports of tumor associated deaths. Recurrence after resection is rare. PRESENTATION OF CASE: A 50 year-old male presented with melena and hemoglobin concentration of 4.6g/dl. Esophagogastroduodenoscopy demonstrated a submucosal mass in the third portion of the duodenum with no active bleeding. CT scan identified no regional lymphadenopathy or distant metastasis. The tumor was resected through a longitudinal duodenotomy with negative margins. DISCUSSION: Endoscopic resection of duodenal gangliocytic paraganglioma appears to be safe and effective when tumor may be removed in its entirety by this method. If the tumor is not suspended by a stalk or there is suspicion for regional lymph node disease then surgical management is preferred. Radiation oncologists at high volume centers have endorsed utilization of adjuvant radiotherapy to the postsurgical bed in cases involving lymph node metastasis. Utilization of chemotherapy for management of this disease has not been reported. CONCLUSION: Localized duodenal gangliocytic paragangliomas are best managed by resection with negative margins. In cases in which the tumor is resected with negative margins, it appears to be safe to embark on a course of surveillance and forego adjuvant therapy.