Spinal ectopic recurrence of craniopharyngioma in a pediatric patient.

Craniopharyngiomas are rare, benign lesions that can be treated with surgery, radiation therapy, or a combination of these modalities. They have a propensity for local recurrence, but there have also been rare cases reported of ectopic recurrence. Here, we present the case of a 15-year-old girl with a recurrence of craniopharyngioma in the spine, which is the second-ever reported case of recurrence outside of the brain in a pediatric patient, and review the 19 reported cases of ectopic recurrence in pediatric patients due to cerebrospinal fluid dissemination.

A Sequential Targeting Strategy Interrupts AKT-Driven Subclone-Mediated Progression in Glioblastoma.

PURPOSE: Therapy resistance and fatal disease progression in glioblastoma are thought to result from the dynamics of intra-tumor heterogeneity. This study aimed at identifying and molecularly targeting tumor cells that can survive, adapt, and subclonally expand under primary therapy. EXPERIMENTAL DESIGN: To identify candidate markers and to experimentally access dynamics of subclonal progression in glioblastoma, we established a discovery cohort of paired vital cell samples obtained before and after primary therapy. We further used two independent validation cohorts of paired clinical tissues to test our findings. Follow-up preclinical treatment strategies were evaluated in patient-derived xenografts. RESULTS: We describe, in clinical samples, an archetype of rare ALDH1A1+ tumor cells that enrich and acquire AKT-mediated drug resistance in response to standard-of-care temozolomide (TMZ). Importantly, we observe that drug resistance of ALDH1A1+ cells is not intrinsic, but rather an adaptive mechanism emerging exclusively after TMZ treatment. In patient cells and xenograft models of disease, we recapitulate the enrichment of ALDH1A1+ cells under the influence of TMZ. We demonstrate that their subclonal progression is AKT-driven and can be interfered with by well-timed sequential rather than simultaneous antitumor combination strategy. CONCLUSIONS: Drug-resistant ALDH1A1+/pAKT+ subclones accumulate in patient tissues upon adaptation to TMZ therapy. These subclones may therefore represent a dynamic target in glioblastoma. Our study proposes the combination of TMZ and AKT inhibitors in a sequential treatment schedule as a rationale for future clinical investigation.

ATRT-SHH comprises three molecular subgroups with characteristic clinical and histopathological features and prognostic significance.

Atypical teratoid/rhabdoid tumor (ATRT) is an aggressive central nervous system tumor characterized by loss of SMARCB1/INI1 protein expression and comprises three distinct molecular groups, ATRT-TYR, ATRT-MYC and ATRT-SHH. ATRT-SHH represents the largest molecular group and is heterogeneous with regard to age, tumor location and epigenetic profile. We, therefore, aimed to investigate if heterogeneity within ATRT-SHH might also have biological and clinical importance. Consensus clustering of DNA methylation profiles and confirmatory t-SNE analysis of 65 ATRT-SHH yielded three robust molecular subgroups, i.e., SHH-1A, SHH-1B and SHH-2. These subgroups differed by median age of onset (SHH-1A: 18 months, SHH-1B: 107 months, SHH-2: 13 months) and tumor location (SHH-1A: 88% supratentorial; SHH-1B: 85% supratentorial; SHH-2: 93% infratentorial, often extending to the pineal region). Subgroups showed comparable SMARCB1 mutational profiles, but pathogenic/likely pathogenic SMARCB1 germline variants were over-represented in SHH-2 (63%) as compared to SHH-1A (20%) and SHH-1B (0%). Protein expression of proneural marker ASCL1 (enriched in SHH-1B) and glial markers OLIG2 and GFAP (absent in SHH-2) as well as global mRNA expression patterns differed, but all subgroups were characterized by overexpression of SHH as well as Notch pathway members. In a Drosophila model, knockdown of Snr1 (the fly homologue of SMARCB1) in hedgehog activated cells not only altered hedgehog signaling, but also caused aberrant Notch signaling and formation of tumor-like structures. Finally, on survival analysis, molecular subgroup and age of onset (but not ASCL1 staining status) were independently associated with overall survival, older patients (> 3 years) harboring SHH-1B experiencing relatively favorable outcome. In conclusion, ATRT-SHH comprises three subgroups characterized by SHH and Notch pathway activation, but divergent molecular and clinical features. Our data suggest that molecular subgrouping of ATRT-SHH has prognostic relevance and might aid to stratify patients within future clinical trials.

Aggressive Childhood-onset Papillary Craniopharyngioma Managed With Vemurafenib, a BRAF Inhibitor.

The papillary subtype of craniopharyngioma (CP) rarely occurs in children and commonly presents as a suprasellar lesion. Patients with papillary CPs frequently harbor the BRAF-V600E mutation, and treatment with a BRAF inhibitor results in tumor shrinkage in several patients. Herein, we report a patient with childhood-onset papillary CP treated with vemurafenib for 40 months after multiple surgeries. At age 10, he presented with growth failure secondary to an intrasellar cystic lesion. He had 3 transsphenoidal surgeries before age 12 and a 4th surgery 25 years later for massive tumor recurrence. Pathology showed a papillary CP with positive BRAF-V600E mutation. Rapid tumor regrowth 4 months after surgery led to treatment with vemurafenib that resulted in tumor reduction within 6 weeks. Gradual tumor regrowth occurred after a dose reduction of vemurafenib because of elevated liver enzymes. He had further surgeries and within 7 weeks after stopping vemurafenib, there was massive tumor recurrence. He resumed treatment with vemurafenib before radiation therapy and similar tumor shrinkage occurred within 16 days. In this patient with childhood-onset papillary CP that was refractory to multiple surgeries, the use of vemurafenib resulted in significant tumor shrinkage that allowed for the completion of radiation therapy and tumor control.

Effects of CAPTEM (Capecitabine and Temozolomide) on a Corticotroph Carcinoma and an Aggressive Corticotroph Tumor.

Corticotroph carcinomas and aggressive corticotroph tumors can be resistant to conventional therapy, including surgery, radiotherapy, and medical treatment. Recent evidence suggests that temozolomide (an oral alkylating agent) administered with capecitabine (pro-drug of 5-fluorouracil) may improve progression-free survival in patients with high-risk corticotroph tumors and carcinomas. This led to the use of capecitabine and temozolomide (CAPTEM) in two patients, one with a corticotroph carcinoma and the other with an aggressive corticotroph tumor, as well the in vitro analysis of capecitabine and 5-fluorouracil on cell growth and hormone production. Both patients had previous surgical and radiation therapy. The first patient developed leptomeningeal spread 2 years after his radiation treatment. He had 12 cycles of CAPTEM, which resulted in tumor control associated with clinical and radiological improvement. Twenty-seven months later, CAPTEM was restarted for disease recurrence with ongoing tumor response. The second patient had a rapid tumor regrowth 2 years after his third surgical resection. He was treated with 12 cycles of CAPTEM, which led to tumor shrinkage with no tumor regrowth 22 months after cessation of therapy. Experiments using mouse ACTH-producing pituitary tumor AtT20 cells demonstrated that treatment with 5-fluorouracil in combination with temozolomide had an additive effect in reducing cell viability and ACTH production in the culture medium. Our patients and experimental data in AtT20 cells support CAPTEM as a potential treatment option for aggressive corticotroph tumors and carcinomas. However, a prospective clinical trial is required to determine whether CAPTEM is superior to temozolomide in the treatment of these tumors.

Reflection-mode virtual histology using photoacoustic remote sensing microscopy.

Histological visualizations are critical to clinical disease management and are fundamental to biological understanding. However, current approaches that rely on bright-field microscopy require extensive tissue preparation prior to imaging. These processes are both labor intensive and contribute to creating significant delays in clinical feedback for treatment decisions that can extend to 2-3 weeks for standard paraffin-embedded tissue preparation and interpretation, especially if ancillary testing is needed. Here, we present the first comprehensive study on the broad application of a novel label-free reflection-mode imaging modality known as photoacoustic remote sensing (PARS) for visualizing salient subcellular structures from various common histopathological tissue preparations and for use in unprocessed freshly resected tissues. The PARS modality permits non-contact visualizations of intrinsic endogenous optical absorption contrast to be extracted from thick and opaque biological targets with optical resolution. The technique was examined both as a rapid assessment tool that is capable of managing large samples (> 1 cm2) in under 10 min, and as a high contrast imaging modality capable of extracting specific biological contrast to simulate conventional histological stains such as hematoxylin and eosin (H&E). The capabilities of the proposed method are demonstrated in a variety of human tissue preparations including formalin-fixed paraffin-embedded tissue blocks and unstained slides sectioned from these blocks, including normal and neoplastic human brain, and breast epithelium involved with breast cancer. Similarly, PARS images of human skin prepared by frozen section clearly demonstrated basal cell carcinoma and normal human skin tissue. Finally, we imaged unprocessed murine kidney and achieved histologically relevant subcellular morphology in fresh tissue. This represents a vital step towards an effective real-time clinical microscope that overcomes the limitations of standard histopathologic tissue preparations and enables real-time pathology assessment.

Improving maximal safe brain tumor resection with photoacoustic remote sensing microscopy.

Malignant brain tumors are among the deadliest neoplasms with the lowest survival rates of any cancer type. In considering surgical tumor resection, suboptimal extent of resection is linked to poor clinical outcomes and lower overall survival rates. Currently available tools for intraoperative histopathological assessment require an average of 20 min processing and are of limited diagnostic quality for guiding surgeries. Consequently, there is an unaddressed need for a rapid imaging technique to guide maximal resection of brain tumors. Working towards this goal, presented here is an all optical non-contact label-free reflection mode photoacoustic remote sensing (PARS) microscope. By using a tunable excitation laser, PARS takes advantage of the endogenous optical absorption peaks of DNA and cytoplasm to achieve virtual contrast analogous to standard hematoxylin and eosin (H&E) staining. In conjunction, a fast 266 nm excitation is used to generate large grossing scans and rapidly assess small fields in real-time with hematoxylin-like contrast. Images obtained using this technique show comparable quality and contrast to the current standard for histopathological assessment of brain tissues. Using the proposed method, rapid, high-throughput, histological-like imaging was achieved in unstained brain tissues, indicating PARS' utility for intraoperative guidance to improve extent of surgical resection.

Mycobacterium chimaera Encephalitis Following Cardiac Surgery: A New Syndrome.

We report the cases of 3 patients with fatal, disseminated Mycobacterium chimaera infections following cardiac surgeries. Progressive neurocognitive decline and death were explained by active granulomatous encephalitis, with widespread involvement of other organs. This syndrome is clinically elusive and, thus, may have caused deaths in prior reported series.

Alterations in ALK/ROS1/NTRK/MET drive a group of infantile hemispheric gliomas.

Infant gliomas have paradoxical clinical behavior compared to those in children and adults: low-grade tumors have a higher mortality rate, while high-grade tumors have a better outcome. However, we have little understanding of their biology and therefore cannot explain this behavior nor what constitutes optimal clinical management. Here we report a comprehensive genetic analysis of an international cohort of clinically annotated infant gliomas, revealing 3 clinical subgroups. Group 1 tumors arise in the cerebral hemispheres and harbor alterations in the receptor tyrosine kinases ALK, ROS1, NTRK and MET. These are typically single-events and confer an intermediate outcome. Groups 2 and 3 gliomas harbor RAS/MAPK pathway mutations and arise in the hemispheres and midline, respectively. Group 2 tumors have excellent long-term survival, while group 3 tumors progress rapidly and do not respond well to chemoradiation. We conclude that infant gliomas comprise 3 subgroups, justifying the need for specialized therapeutic strategies.

Therapeutic Impact of Cytoreductive Surgery and Irradiation of Posterior Fossa Ependymoma in the Molecular Era: A Retrospective Multicohort Analysis.

PURPOSE: Posterior fossa ependymoma comprises two distinct molecular variants termed EPN_PFA and EPN_PFB that have a distinct biology and natural history. The therapeutic value of cytoreductive surgery and radiation therapy for posterior fossa ependymoma after accounting for molecular subgroup is not known. METHODS: Four independent nonoverlapping retrospective cohorts of posterior fossa ependymomas (n = 820) were profiled using genome-wide methylation arrays. Risk stratification models were designed based on known clinical and newly described molecular biomarkers identified by multivariable Cox proportional hazards analyses. RESULTS: Molecular subgroup is a powerful independent predictor of outcome even when accounting for age or treatment regimen. Incompletely resected EPN_PFA ependymomas have a dismal prognosis, with a 5-year progression-free survival ranging from 26.1% to 56.8% across all four cohorts. Although first-line (adjuvant) radiation is clearly beneficial for completely resected EPN_PFA, a substantial proportion of patients with EPN_PFB can be cured with surgery alone, and patients with relapsed EPN_PFB can often be treated successfully with delayed external-beam irradiation. CONCLUSION: The most impactful biomarker for posterior fossa ependymoma is molecular subgroup affiliation, independent of other demographic or treatment variables. However, both EPN_PFA and EPN_PFB still benefit from increased extent of resection, with the survival rates being particularly poor for subtotally resected EPN_PFA, even with adjuvant radiation therapy. Patients with EPN_PFB who undergo gross total resection are at lower risk for relapse and should be considered for inclusion in a randomized clinical trial of observation alone with radiation reserved for those who experience recurrence.

Predictive chromosomal clusters of synchronous and metachronous brain metastases in clear cell renal cell carcinoma.

Synchronous (early) and metachronous (late) brain metastasis (BM) events of sporadic clear cell renal cell carcinoma (ccRCC) (n = 148) were retrospectively analyzed using comparative genomic hybridization (CGH). Using oncogenetic tree models and cluster analyses, chromosomal imbalances related to recurrence-free survival until BM (RFS-BM) were analyzed. Losses at 9p and 9q appeared to be hallmarks of metachronous BM events, whereas an absence of detectable chromosomal changes at 3p was often associated with synchronous BM events. Correspondingly, k-means clustering showed that cluster 1 cases generally exhibited low copy number chromosomal changes that did not involve 3p. Cluster 2 cases had a high occurrence of -9p/-9q (94-98%) deletions, whereas cluster 3 cases had a higher frequency of copy number changes, including loss at chromosome 14 (80%). The higher number of synchronous cases in cluster 1 was also associated with a significantly shorter RFS-BM compared with clusters 2 and 3 (P = 0.02). Conversely, a significantly longer RFS-BM was observed for cluster 2 versus clusters 1 and 3 (P = 0.02). Taken together, these data suggest that metachronous BM events of ccRCC are characterized by loss of chromosome 9, whereas synchronous BM events may form independently of detectable genetic changes at chromosomes 9 and 3p.

Tenascin-C is expressed by human glioma in vivo and shows a strong association with tumor blood vessels.

The extracellular matrix (ECM) protein tenascin-C (TN-C) is upregulated within glioma tissues and cultured glioma cell lines. TN-C possesses a multi-modular structure and a variety of functional properties have been reported for its domains. We describe five novel monoclonal antibodies identifying different domains of TN-C. The epitopes for these antibodies were investigated by using recombinantly expressed fibronectin type III domains of TN-C. The biological effects of TN-C fragments on glioma cell proliferation and adhesion were analyzed. The expression pattern of TN-C in human glioma tissue sections and in glioma cell lines was studied with the novel library of monoclonal antibodies. The immunocytochemical analyses of the established human glioma cell lines U-251-MG, U-373-MG and U-87-MG revealed distinct staining patterns for each antibody. Robust expression of TN-C was found within the tumor mass of surgery specimens from glioblastoma. In many cases, the expression of this ECM molecule was clearly associated with blood vessels, particularly with microvessels. Three of the new antibodies highlighted individual TN-C-expressing single cells in glioma tissues. The effect of TN-C domains on glioma cells was examined by a BrdU-proliferation assay and an adhesion assay. Short fragments of constitutively expressed TN-C-domains did not exert significant effects on the proliferation of glioma cells, whereas the intact molecule increased cell division rates. In contrast, the long fragment TNfnALL containing all of the FNIII domains of TN-C decreased proliferation. Additionally, we found strong differences between the adhesion-influencing properties of the recombinant fragments on glioma cells.

Generation of an antibody against the protein phosphatase 1 inhibitor KEPI and characterization of the epitope.

A monoclonal antibody against the potential tumor suppressor kinase-enhanced protein phosphatase 1 (PP1) inhibitor KEPI (PPP1R14C) was generated and characterized. Human KEPI was expressed in Escherichia coli and used to immunize Balb/c mice. Using hybridoma technology, one clone, G18AF8, was isolated producing antibodies which bound specifically to the KEPI protein in ELISA, immunoblotting and flow cytometry. The antibody was also successfully applied to stain KEPI protein in paraffin sections of human brain. The epitope was mapped using peptide array technology and confirmed as GARVFFQSPR. This corresponds to the N-terminal region of KEPI. Amino acid substitution analysis revealed that two residues, F and Q, are essential for binding. Affinity of binding was determined by competitive ELISA as 1 microM. In Western blot assays testing G18AF8 antibody on brain samples of several species, reactivity with hamster, rat and chicken samples was found, suggesting a broad homology of this KEPI epitope in vertebrates. This antibody could be used in expression studies at the protein level e.g. in tumor tissues.

Intratentorial osteochondrolipoma in a 9-year-old boy.

Intracranial osteolipomas and chondromas are rare benign tumors. Forty-five chondromas, mostly supratentorial, have been reported in the literature since 1981, with origins most commonly in the sellar regions. Twenty-one osteolipomas have been described to date, usually located near the tuber cinereum or the corpus callosum. The authors present a case of an osteochondrolipoma arising from the tentorium diagnosed in a pediatric patient at the age of 9 years. The case and treatment are discussed, and a review of the literature is provided.

Decreased expression of the active subunit of the cystine/glutamate antiporter xCT is associated with loss of heterozygosity of 1p in oligodendroglial tumours WHO grade II.

AIMS: Oligodendroglial tumours with loss of heterozygosity on 1p (LOH1p) respond better to treatment than oligodendrogliomas without LOH. Previous reports have assigned a crucial role of glutamate metabolism to glioma growth and invasion. The aim was to study the protein expression of different glutamate transporters in relation to LOH1p in low-grade oligodendroglial tumours. METHODS AND RESULTS: Seventeen oligodendrogliomas World Health Organization (WHO) grade II, 16 oligoastrocytomas WHO grade II and seven astrocytomas WHO grade II were examined. Eleven oligodendrogliomas and five oligoastrocytomas exhibited LOH1p. Immunoreactivity scores (IRS) for glutamate transporters excitatory amino acid transporter (EAAT)-1, -2 and -3 as well as the active cystine/glutamate antiporter subunit xCT were semiquantitatively rated by percentage of positive cells and intensity of immunoreactivity. Reactivity for xCT was lower in tumours with LOH1p than in those without (P = 0.03, Mann-Whitney U-test). No association was found between LOH status and IRS for EAAT-1, -2 or -3. High xCT immunoreactivity was associated with high expression of EAAT-1, -2 or -3. CONCLUSIONS: Expression of xCT is significantly reduced in low-grade oligodendroglial tumours harbouring LOH1p. Further studies should investigate a potential beneficial effect by inhibiting xCT in low-grade gliomas.

Post-mortem studies in glioblastoma patients treated with thermotherapy using magnetic nanoparticles.

Patients with glioblastoma multiforme (GBM), the most common primary brain tumor in adults, have still a poor prognosis though new strategies of radio- and chemotherapy have been developed. Recently, our group demonstrated the feasibility, tolerability and anti-tumoral effects of a newly developed therapeutic approach, termed thermotherapy using magnetic nanoparticles or magnetic fluid hyperthermia (MFH), in a murine model of malignant glioma. Currently, the efficacy of MFH is being evaluated in a phase II study. Here, we report on post-mortem neuropathological findings of patients with GBM receiving MFH. In brain autopsies the installed magnetic nanoparticles were dispersed or distributed as aggregates within geographic tumor necroses, restricted in distribution to the sites of instillation. Therefore, our results underscore the need for multiple trajectories of instillation. The typical GBM necrosis with pseudopalisading was free of particles. Dispersed particles and particle aggregates were phagocytosed mainly by macrophages whereas glioblastoma cells showed an uptake to a minor extent. MFH therapy further promotes uptake of nanoparticles in macrophages, likely as a consequence of tumor inherent and therapy induced formation of necrosis with subsequent infiltration and activation of phagocytes. We did not observe bystander effects of MFH such as sarcomatous tumour formation, formation of a sterile abscess or foreign body giant cell reaction. Furthermore, all patients did not present any clinical symptoms related to possible adverse effects of MFH.

Expression of glucose transporter 1 is associated with loss of heterozygosity of chromosome 1p in oligodendroglial tumors WHO grade II.

Objective Oligodendroglial tumors with a loss of heterozygosity of 1p (LOH1p) appear to have a better prognosis than oligodendrogliomas without LOH. Previously, we reported glucose uptake in low-grade oligodendroglial tumors to be related to LOH 1p status. Here, we performed an immunohistochemical study of the common glucose transporters (GLUT) in relation to LOH1p. Material and methods We examined 17 oligodendrogliomas (O II, 11 with LOH1p), 16 oligoastrocytomas (OA II, 5 with LOH1p) and 7 astrocytomas (A II, none with LOH1p). Confocal microscopy was performed for p53, GLUT-1, -3 and -12. Immunoreaction was rated semiquantitatively by percentage of positive cells and staining intensity on immunohistological stainings. Results Confocal microscopy depicted immunoreaction for GLUT-1, -3 and -12 in the cytoplasm of the tumor cells. Oligodendrogliomas revealed a lower immunoreactivity for GLUT-1 than oligoastrocytomas and astrocytomas (P = 0.0263). No differences in immunoreactivity were found for GLUT-3 and GLUT-12. GLUT-1 expression in tumors with LOH 1p was significantly lower than in tumors with wild type 1p status (P = 0.0017). GLUT-3 and GLUT-12 immunoreactivity was not correlated with LOH 1p. Conclusion Expression of GLUT-1 is significantly reduced in low-grade oligodendroglial tumors harboring LOH 1p. Further studies should address the functional role of GLUT-1 in regard to chemosensitivity of oligodendrogliomas.

Atypical cervical spondylotic myelopathy mimicking intramedullary tumor.

STUDY DESIGN: Case report and a review of the literature. OBJECTIVE: We report the case of a young man with a short course of progressive cervical myelopathy (CM). Cervical magnetic resonance imaging (MRI) revealed a stenosis of the cervical spinal canal at C4-C6 and an atypically enlarged intramedullary high intensity extending from C1-T1 (T2-weighted) with contrast enhancement at C4-C5 (T1-weighted). Neurologic and radiologic diagnosis therefore favored a tumor of the spinal cord. SUMMARY OF BACKGROUND DATA: CM is a clinical diagnosis of mostly degenerative origin in older patients that features circumscribed high-intensity signals near the point of compression in T2-weighted MRI. Contrast enhancement in those high-intense areas is rarely described in the literature, and the differentiation from neoplastic and infective lesions might be very difficult in these cases. METHODS: Retrospective case study with follow-up examination and MRI-control 3 months after surgery. RESULTS: The patient was decompressed and stabilized from dorsally, and a biopsy was taken. The exact diagnosis of a myelopathy and an exclusion of a neoplastic origin succeeded through histopathological examination. Three months after first surgery, the patient had improved significantly and underwent an additional anterior stabilization, while the MRI remained almost unchanged. CONCLUSION: In case of a fast progressive CM with atypical radiographic appearance initial decompression with inspection of the spinal cord and a short-term clinical follow-up with an MRI control might be the procedure of choice, if a clear diagnosis for a causative treatment cannot be made. In still suspicious cases, a biopsy could be considered to exclude a neoplastic or inflammatory process.