Enhancing mitosis quantification and detection in meningiomas with computational digital pathology.

Mitosis is a critical criterion for meningioma grading. However, pathologists' assessment of mitoses is subject to significant inter-observer variation due to challenges in locating mitosis hotspots and accurately detecting mitotic figures. To address this issue, we leverage digital pathology and propose a computational strategy to enhance pathologists' mitosis assessment. The strategy has two components: (1) A depth-first search algorithm that quantifies the mathematically maximum mitotic count in 10 consecutive high-power fields, which can enhance the preciseness, especially in cases with borderline mitotic count. (2) Implementing a collaborative sphere to group a set of pathologists to detect mitoses under each high-power field, which can mitigate subjective random errors in mitosis detection originating from individual detection errors. By depth-first search algorithm (1) , we analyzed 19 meningioma slides and discovered that the proposed algorithm upgraded two borderline cases verified at consensus conferences. This improvement is attributed to the algorithm's ability to quantify the mitotic count more comprehensively compared to other conventional methods of counting mitoses. In implementing a collaborative sphere (2) , we evaluated the correctness of mitosis detection from grouped pathologists and/or pathology residents, where each member of the group annotated a set of 48 high-power field images for mitotic figures independently. We report that groups with sizes of three can achieve an average precision of 0.897 and sensitivity of 0.699 in mitosis detection, which is higher than an average pathologist in this study (precision: 0.750, sensitivity: 0.667). The proposed computational strategy can be integrated with artificial intelligence workflow, which envisions the future of achieving a rapid and robust mitosis assessment by interactive assisting algorithms that can ultimately benefit patient management.

Extra-Axial Cavernous Angioma: A Case Report and Review of the Literature.

Cavernous angiomas (CAs) are benign vascular malformations predominantly seen in the brain parenchyma and therefore referred to as intra-axial. Extra-axial dural-based cavernous angiomas, on the other hand, are rare vascular lesions found outside of the brain parenchyma. They occur in the middle fossa and may be easily misdiagnosed as meningiomas due to their extra-axial location. In addition, CAs that are located outside the middle fossa, such as in the convexity, have a better prognosis since they are more surgically accessible. Surgical resection is the main treatment of choice in CAs. However, other options, such as embolization and radiotherapy, may also be considered therapeutic choices or additive treatment options. The pathogenesis of CA and the involvement of other factors (genetics or environmental factors) are still unknown and require further investigation. We are presenting a young man who presented for evaluation of seizure-like events without any family history of neurologic conditions. The physical examination was unremarkable except for a slightly antalgic gait. Imaging studies showed an extra-axial left tentorial mass suggestive of a meningioma, hemangiopericytoma, or other extra-axial lesions. The lesion was resected where its vascular nature was mentioned initially, and the histology proved the diagnosis of cavernous angioma. Here we give an overview of the known pathogenesis, causes, clinical features, and diagnostic and therapeutic options in CA. Better knowledge about CA, its causes, clinical features, and treatment options would help clinicians in early diagnosis and patient management.

EGFR as a potent CAR T target in triple negative breast cancer brain metastases.

PURPOSE: There is currently no curative treatment for patients diagnosed with triple-negative breast cancer brain metastases (TNBC-BM). CAR T cells hold potential for curative treatment given they retain the cytolytic activity of a T cell combined with the specificity of an antibody. In this proposal we evaluated the potential of EGFR re-directed CAR T cells as a therapeutic treatment against TNBC cells in vitro and in vivo. METHODS: We leveraged a TNBC-BM tissue microarray and a large panel of TNBC cell lines and identified elevated epidermal growth factor receptor (EGFR) expression. Next, we designed a second-generation anti-EGFR CAR T construct incorporating a clinically relevant mAb806 tumor specific single-chain variable fragment (scFv) and intracellular 4-1BB costimulatory domain and CD3ζ using a lentivirus system and evaluated in vitro and in vivo anti-tumor activity. RESULTS: We demonstrate EGFR is enriched in TNBC-BM patient tissue after neurosurgical resection, with six of 13 brain metastases demonstrating both membranous and cytoplasmic EGFR. Eleven of 13 TNBC cell lines have EGFR surface expression ≥ 85% by flow cytometry. EGFR806 CAR T treated mice effectively eradicated TNBC-BM and enhanced mouse survival (log rank p < 0.004). CONCLUSION: Our results demonstrates anti-tumor activity of EGFR806 CAR T cells against TNBC cells in vitro and in vivo. Given EGFR806 CAR T cells are currently undergoing clinical trials in primary brain tumor patients without obvious toxicity, our results are immediately actionable against the TNBC-BM patient population.

Stem cell phenotype predicts therapeutic response in glioblastomas with MGMT promoter methylation.

A growing body of evidence supports the presence of a population of cells in glioblastoma (GBM) with a stem cell-like phenotype which shares certain biological markers with adult neural stem cells, including expression of SOX2, CD133 (PROM1), and NES (nestin). This study was designed to determine the relationship between the expression of these stem cell markers and the clinical outcome in GBM patients. We quantified the intensity of expression of the proteins CD133 and SOX2 by immunohistochemistry (IHC) in a cohort of 86 patients with IDH-wildtype GBM, and evaluated patient outcomes using Kaplan-Meier and Cox proportional hazards analysis. In our patients, MGMT promoter methylation status and age were predictors of overall survival and progression free survival. The levels of SOX2 and CD133 were not associated with outcome in univariate analysis; however, stratification of tumors based on low or high levels of CD133 or SOX2 expression revealed that MGMT methylation was a predictor of progression-free survival and overall survival only for tumors with high levels of expression of CD133 or SOX2. Tumors with low levels of expression of CD133 or SOX2 did not show any relationship between MGMT methylation and survival. This relationship between MGMT and stem cell markers was confirmed in a second patient cohort, the TCGA dataset. Our results show that stratification of GBM by the level of expression of CD133 and SOX2 improved the prognostic power of MGMT promoter methylation status, identifying a low-expressing group in which the clinical outcome is not associated with MGMT promoter methylation status, and a high-expressing group in which the outcome was strongly associated with MGMT promoter methylation status. These findings support the concept that the presence of a high stem cell phenotype in GBM, as marked by expression of SOX2 or CD133, may be associated with the clinical response to treatment.

Intracranial tuberculoma: a rare complication of extrapulmonary tuberculosis. Illustrative case.

BACKGROUND: Intracranial tuberculomas are rare entities commonly seen only in low- to middle-income countries where tuberculosis remains endemic. Furthermore, following adequate treatment, the development of intracranial spread is uncommon in the absence of immunosuppression. OBSERVATIONS: A 22-year-old man with no history of immunosuppression presented with new-onset seizures in the setting of miliary tuberculosis status post 9 months of antitubercular therapy. Following a 2-month period of remission, he presented with new-onset tonic-clonic seizures. Magnetic resonance imaging demonstrated interval development of a mass concerning for an intracranial tuberculoma. After resection, pathological analysis of the mass revealed caseating granulomas within the multinodular lesion, consistent with intracranial tuberculoma. The patient was discharged after the reinitiation of antitubercular medications along with a steroid taper. LESSONS: To the best of the authors' knowledge, this case represents the first instance of intracranial tuberculoma occurring after the initial resolution of a systemic tuberculosis infection. The importance of retaining a high level of suspicion when evaluating these patients for seizure etiology is crucial because symptoms are rapidly responsive to resection of intracranial tuberculoma masses. Furthermore, it is imperative for surgeons to recognize the isolation steps necessary when managing these patients within the operating theater and inpatient settings.

FOXO3 regulates a common genomic program in aging and glioblastoma stem cells.

Background: Glioblastoma (GBM) is an aggressive, age-associated malignant glioma that contains populations of cancer stem cells. These glioma stem cells (GSCs) evade therapeutic interventions and repopulate tumors due to their existence in a slowly cycling quiescent state. Although aging is well known to increase cancer initiation, the extent to which the mechanisms supporting GSC tumorigenicity are related to physiological aging remains unknown. Aims: Here, we investigate the transcriptional mechanisms by which Forkhead Box O3 (FOXO3), a transcriptional regulator that promotes healthy aging, affects GSC function and the extent to which FOXO3 transcriptional networks are dysregulated in aging and GBM. Methods and results: We performed transcriptome analysis of clinical GBM tumors and observed that high FOXO3 activity is associated with gene expression signatures of stem cell quiescence, reduced oxidative metabolism, and improved patient outcomes. Consistent with these findings, we show that elevated FOXO3 activity significantly reduces the proliferation of GBM-derived GSCs. Using RNA-seq, we find that functional ablation of FOXO3 in GSCs rewires the transcriptional circuitry associated with metabolism, epigenetic stability, quiescence, and differentiation. Since FOXO3 has been implicated in healthy aging, we then investigated the extent to which it regulates common transcriptional programs in aging neural stem cells (NSCs) and GSCs. We uncover a shared transcriptional program and, most strikingly, find that FOXO3-regulated pathways are associated with altered mitochondrial functions in both aging and GBM. Conclusions: This work identifies a FOXO-associated transcriptional program that correlates between GSCs and aging NSCs and is enriched for metabolic and stemness pathways connected with GBM and aging.

INSL3 Expression in Leydig Cell Hyperplasia and Leydig Cell Tumors.

Insulin-like 3 (INSL3) is a hormone produced by Leydig cells (LCs) and leads to physiological testicular descent during embryonic development. We investigated the expression of INSL3 by immunohistochemistry in normal LCs, in Leydig cell tumor (LCT) (n=17 including 15 testes and 2 ovaries) and in Leydig cell hyperplasia (LCH) (n=10). Normally distributed LCs showed strong immunostaining in the cytoplasm in all cases. All 10 cases (100%) of LCH were strongly and diffusely positive in the intertubular areas. Six cases of LCH had nodules raging in size from 0.2 to 0.9 cm with variable INSL3 staining. Fifteen of 17 (88.2%) LCTs showed marked decrease INSL3 staining, 10/17 (58.8%) were completely negative, and 5/17 (29.4%) were only focally positive. Two cases with multifocal LCTs showed strong and diffuse cytoplasmic staining of LCs around seminiferous tubules while the LCTs were negative. Two cases diagnosed as LCT were strongly positive for INSL3. Other sex cord stromal tumors tested were consistently negative including Sertoli-cell tumor (n=4), granulosa cell tumor (n=2), and fibrothecoma (n=1). In conclusion, our results contrast with those of previously published studies, and show that the great majority of LCTs are negative or have decreased expression of INSL3 while its expression is retained in LCH. INSL3 negative nodules within LCH may represent early LCTs. INSL3 immunostaining could be helpful to highlight LCs in cases where it is difficult to identify them (ie, small testicular biopsies performed for infertility workup) and in the differential diagnosis between florid LCH and LCT.

Primary Spinal Epidural CIC-DUX4 Undifferentiated Sarcoma in a Child.

Primitive round- or spindle-cell EWSR1-negative undifferentiated sarcomas harboring CIC-DUX4 gene fusion are the most common form of Ewing-like sarcomas. These tumors primarily occur in peripheral soft tissues, but examples have been described within viscera and the brain. As far as we are aware, CIC-DUX4 positive primary epidural spinal sarcoma has not been reported. Herein, we describe a T5-T6 epidural tumor in a 15-year-old girl in which many neoplastic cells had moderate and focally abundant cytoplasm, including plasmacytoid or rhabdoid cells, rather than the more common Ewing-like morphology described in the majority of such tumors. The diagnosis was confirmed by fluorescent in situ hybridization after the tumor was found to be WT-1 positive, and comprehensive genomic profiling demonstrated breakpoints in exon 20 and exon 1 of the CIC and DUX4 genes, respectively. After treatment with local radiation and systemic chemotherapy, resected recurrent tumor demonstrated more pleomorphic neoplastic cells as well as intracytoplasmic eosinophilic globules and nuclear pseudoinclusions which may reflect therapy-related changes. Unfortunately, there was further progression of tumor including the development of intracranial lesions, and the patient succumbed to her tumor 22 months after the original resection.

Upgrading and upstaging at radical prostatectomy in the post-prostate-specific antigen screening era: an effect of delayed diagnosis or a shift in patient selection?

Prostate cancer management changed in recent times given the recommendation against prostate-specific antigen screening, adherence to active surveillance, and "cytoreductive" surgery. We hypothesized that radical prostatectomy (RP) findings changed as well. All consecutive RPs (n=1348) and first time prostate needle biopsies (n=1719) in a period of 9 years were reviewed. The cohort was separated into 3 groups: (1) from May 2006 to April 2009, (2) from May 2009 to April 2012, and (3) from May 2012 to April 2015. The number of RPs decreased 15% from 551 in group 1 to 476 in group 2 and decreased a further 35% to 311 in group 3. Pure Gleason 6 (grade group 1) decreased from 46% in group 1 to 24% in group 2 (P<.001) to 12% in group 3 (P<.001). Gleason score 4+3=7 (grade group 3) increased from 9.8% in group 1 to 13.4% in group 2 (P=.07) to 20.6% in group 3 (P=.01). Gleason score 8, 9, or 10 (grade groups 4 and 5) increased from 0.9% in group 1 to 8.4% in group 2 (P<.001) to 13.2% in group 3 (P=.04). Pathologic stage pT3 or above increased from 15.5% in group 1 to 29.2% in group 2 (P<.01) to 38.3% in group 3 (P=.01). In needle biopsies, there was no difference in number of cancer diagnoses, number of positive cores, or distribution of grades among 3 groups. More patients with low-risk disease are opting for active surveillance, and patients with high-risk disease are offered cytoreductive surgery. Lack of similar changes in needle biopsies suggests that a decrease in screening is not playing a role in the changes seen at RPs.