Manila Antonelli

Embryonal tumor with abundant neuropil and true rosettes (ETANTR), ependymoblastoma, and medulloepithelioma share molecular similarity and comprise a single clinicopathological entity

Three histological variants are known within the family of embryonal rosette-forming neuroepithelial brain tumors. These include embryonal tumor with abundant neuropil and true rosettes (ETANTR), ependymoblastoma (EBL), and medulloepithelioma (MEPL). In this study, we performed a comprehensive clinical, pathological, and molecular analysis of 97 cases of these rare brain neoplasms, including genome-wide DNA methylation and copy number profiling of 41 tumors. We identified uniform molecular signatures in all tumors irrespective of histological patterns, indicating that ETANTR, EBL, and MEPL comprise a single biological entity. As such, future WHO classification schemes should consider lumping these variants into a single diagnostic category, such as embryonal tumor with multilayered rosettes (ETMR). We recommend combined LIN28A immunohistochemistry and FISH analysis of the 19q13.42 locus for molecular diagnosis of this tumor category. Recognition of this distinct pediatric brain tumor entity based on the fact that the three histological variants are molecularly and clinically uniform will help to distinguish ETMR from other embryonal CNS tumors and to better understand the biology of these highly aggressive and therapy-resistant pediatric CNS malignancies, possibly leading to alternate treatment strategies.

KIAA1549-BRAF Fusions and IDH Mutations Can Coexist in Diffuse Gliomas of Adults

KIAA1549‐BRAF fusion gene and isocitrate dehydrogenase (IDH) mutations are considered two mutually exclusive genetic events in pilocytic astrocytomas and diffuse gliomas, respectively. We investigated the presence of the KIAA1549‐BRAF fusion gene in conjunction with IDH mutations and 1p/19q loss in 185 adult diffuse gliomas. Moreover BRAFv600E mutation was also screened. The KIAA1549‐BRAF fusion gene was evaluated by reverse‐transcription polymerase chain reaction (RT‐PCR) and sequencing. We found IDH mutations in 125 out 175 cases (71.4%). There were KIAA1549‐BRAF fusion gene in 17 out of 180 (9.4%) cases and BRAFv600E in 2 out of 133 (1.5%) cases. In 11 of these 17 cases, both IDH mutations and the KIAA1549‐BRAF fusion were present, as independent molecular events. Moreover, 6 of 17 cases showed co‐presence of 1p/19q loss, IDH mutations and KIAA1549‐BRAF fusion. Among the 17 cases with KIAA1549‐BRAF fusion gene 15 (88.2%) were oligodendroglial neoplasms. Similarly, the two cases with BRAFv600E mutation were both oligodendroglioma and one had IDH mutations and 1p/19q co‐deletion. Our results suggest that in a small fraction of diffuse gliomas, KIAA1549‐BRAF fusion gene and BRAFv600E mutation may be responsible for deregulation of the Ras‐RAF‐ERK signaling pathway. Such alterations are more frequent in oligodendroglial neoplasm and may be co‐present with IDH mutations and 1p/19q loss.

BRAF V600E expression and distribution in desmoplastic infantile astrocytoma/ganglioglioma

Desmoplastic infantile astrocytoma/ganglioglioma (DIA/DIG) is a rare primary neuroepithelial brain tumour typically affecting paediatric patients younger than 24 months. Knowledge about genetic alterations in DIA/DIG is limited. However, a previous study on BRAF V600E mutation in paediatric glioma revealed a BRAF mutation in one of two tested DIAs/DIGs. The limited number of cases in that study did not allow any conclusion about mutation frequency of BRAF in this tumour entity.

MRI Findings in Lymphomatosis Cerebri: Description of a Case and Revision of the Literature

Lymphomatosis cerebri (LC) is a rare form of primary central nervous system lymphoma; we report a case of LC mainly involving the brainstem and cerebellum. This diagnosis should be considered in patients presenting with diffuse white matter disease, and a subacute clinical history of cognitive deficits, ataxic gait, and personality changes. We present our findings along with a review of the neuroradiological literature.

Poorly differentiated chordoma with SMARCB1/INI1 loss: a distinct molecular entity with dismal prognosis

Martin Hasselblatt1 · Christian Thomas1 · Volker Hovestadt2,3 · Daniel Schrimpf3,4,5 · Pascal Johann3,6,7 · Susanne Bens8 · Florian Oyen9 · Susanne Peetz‐Dienhart1 · Yvonne Crede1 · Annika Wefers3,4,5 · Hannes Vogel10 · Markus J. Riemenschneider11 · Manila Antonelli12,13 · Felice Giangaspero12,13 · Marie Christine Bernardo14 · Caterina Giannini15 · Nasir Ud Din16 · Arie Perry17 · Kathy Keyvani18 · Frank van Landeghem19 · David Sumerauer20 · Peter Hauser21 · David Capper3,4,5 · Andrey Korshunov3,4,5 · David T. W. Jones3,6 · Stefan M. Pfister3,6,7 · Reinhard Schneppenheim9 · Reiner Siebert8 · Michael C. Frühwald22 · Marcel Kool3,6

Expression of brachyury in hemangioblastoma: potential use in differential diagnosis.

Hemangioblastoma (HBL) accounts for up to 2.5% of all intracranial tumors. It may occur as a sporadic entity or as a part of Von Hippel-Lindau syndrome. Patients with Von Hippel-Lindau syndrome are also at an increased risk of developing clear cell renal cell carcinoma (CCRCC). The distinction of HBL from CCRCC metastatic to the central nervous system (CNS) or from other histologic mimics can be challenging at times when based solely on hematoxylin and eosin-stained sections. In the present study we evaluated the potential use of the immunohistochemical evaluation of brachyury protein in the differential diagnosis of these lesions. Archival tissues from 22 HBLs, 16 primary CCRCCs, 8 CCRCCs metastatic to the CNS, and 4 angiomatous and 4 clear cell meningiomas were retrieved from our surgical pathology files and submitted to the immunohistochemical procedures against brachyury. Cases showing nuclear and/or cytoplasmic staining were considered to be positive for brachyury. Positive cytoplasmic staining was evidenced in the stromal cells of 20 of the 22 HBLs. In most cases, >50% of the neoplastic cells were labeled, with strong or moderate intensity of staining. No nuclear or cytoplasmic staining for brachyury was observed in any of the primary renal or metastatic CCRCCs, nor in either of the meningioma types. Thus, brachyury cytoplasmic staining was demonstrated to be highly specific for HBL (specificity, 100%) and represented a sensible (sensitivity, 91%) method, with high positive (100%) and negative (89%) predictive values and high diagnostic accuracy (95%) in the differential diagnosis between HBL and CCRCC metastatic to the CNS or meningioma. On the basis of our findings we propose the use of brachyury as an additional helpful immunohistochemical marker to resolve the differential diagnosis of HBL toward histologic mimics.

Predictors of outcome in an AIEOP series of childhood ependymomas: a multifactorial analysis

Several molecular biomarkers have been suggested as predictors of outcome for pediatric ependymomas but deserve further validation in independent case series. We analyzed intracranial ependymomas belonging to a series of 60 patients prospectively treated according to the protocol sponsored by the Italian Association of Pediatric Hematology-Oncology. We used a tissue microarray to analyze nucleolin (NCL), cyclin-dependent kinase inhibitor 2A (CDKN2A), tumor protein 53 (TP53), and epidermal growth factor receptor (EGFR) by immunohistochemistry and by 1q gain by fluorescent in situ hybridization. The mRNA expression levels of EGFR, human telomerase reverse-transcriptase (HTERT), and Prominin 1 (PROM 1)/CD133 were evaluated by quantitative real-time PCR from cases with fresh-frozen tumor material available. Univariate and multivariate analyses of updated clinical data confirmed the prognostic significance of surgery (P < .01) and tumor grading (P < .05) for both relapse-free survival (RFS) and overall survival (OS). Among biomolecular markers, HTERT mRNA expression emerged with the strongest association with OS at multivariate analysis (hazard ratio [HR] = 9.9; P = .011); the 5-year OS was 84% versus 48% in the subgroups with HTERT median value <6 versus ≥ 6, respectively (P = .005). Five-year RFS was 46% versus 20% in the subgroups with low versus high NCL protein expression, respectively (P = .004), while multivariate Cox analyses gave suggestively high HRs for high versus low NCL (HR = 1.9; P = .090). The other genes tested were not significant at multivariate analyses, and genetic alterations of CDKN2A, TP53, EGFR, and HTERT loci were rare. The PROM1/CD133 cancer stem cell marker was strongly expressed at both RNA and protein levels in a substantial fraction of cases and was suggestively associated with a more indolent form of the disease. We conclude that NCL and HTERT represent the strongest prognostic biomarkers of RFS and OS, respectively, in our ependymoma case series.

Histological variants of medulloblastoma are the most powerful clinical prognostic indicators

Medulloblastoma histological classification has gained in importance and newer treatment protocols will include histology stratification. We centrally reviewed medulloblastoma cases from past 10 years reassessing their histology to ascertain its prognostic significance.

Final results of the second prospective AIEOP protocol for pediatric intracranial ependymoma

BACKGROUND This prospective study stratified patients by surgical resection (complete = NED vs incomplete = ED) and centrally reviewed histology (World Health Organization [WHO] grade II vs III). METHODS WHO grade II/NED patients received focal radiotherapy (RT) up to 59.4 Gy with 1.8 Gy/day. Grade III/NED received 4 courses of VEC (vincristine, etoposide, cyclophosphamide) after RT. ED patients received 1-4 VEC courses, second-look surgery, and 59.4 Gy followed by an 8-Gy boost in 2 fractions on still measurable residue. NED children aged 1-3 years with grade II tumors could receive 6 VEC courses alone. RESULTS From January 2002 to December 2014, one hundred sixty consecutive children entered the protocol (median age, 4.9 y; males, 100). Follow-up was a median of 67 months. An infratentorial origin was identified in 110 cases. After surgery, 110 patients were NED, and 84 had grade III disease. Multiple resections were performed in 46/160 children (28.8%). A boost was given to 24/40 ED patients achieving progression-free survival (PFS) and overall survival (OS) rates of 58.1% and 68.7%, respectively, in this poor prognosis subgroup. For the whole series, 5-year PFS and OS rates were 65.4% and 81.1%, with no toxic deaths. On multivariable analysis, NED status and grade II were favorable for OS, and for PFS grade II remained favorable. CONCLUSIONS In a multicenter collaboration, this trial accrued the highest number of patients published so far, and results are comparable to the best single-institution series. The RT boost, when feasible, seemed effective in improving prognosis. Even after multiple procedures, complete resection confirmed its prognostic strength, along with tumor grade. Biological parameters emerging in this series will be the object of future correlatives and reports.

Second-look surgery for ependymoma: the Italian experience

OBJECT Complete ependymoma resection ensures a better prognosis for children with this tumor, but the complete excision of infratentorial ependymomas involves serious risks. Second-look surgery for tumor remnants may be less harmful and enable complete removal. There is a potential, although still unclear, role for neoadjuvant chemotherapy in preparation for further surgery. METHODS Since 1994, the authors have adopted two successive protocols for intracranial ependymoma, both including a phase of adjuvant chemotherapy for children with surgical tumor remnants with a plan for potential second-look surgery before radiotherapy. RESULTS In the first protocol, 9 of 63 children underwent further surgery, and 6 became tumor free with no additional sequelae. Their prognosis for progression-free survival and freedom from local relapse was comparable to that of children who were operated on only once. In the second protocol, efforts were made to achieve complete resection and 29 of 110 patients underwent reoperations: 9 after the first surgery, 17 after chemotherapy, and 3 soon after radiotherapy. Fourteen of the 29 patients became tumor free, 1 of them with worsening neurological symptoms. The outcome of the 66 patients who became tumor free after 1 operation was compared with that of the 14 who became tumor free after reoperation. The 3-year progression-free survival of the 66 patients compared with the 14 other patients was 71.4% ± 6.9% and 90% ± 9.5%, respectively; the 3-year freedom from local relapse was 84.7% ± 5.9% and 90% ± 9.5%, respectively; and the 3-year overall survival was 85.9% ± 5.4% and 87.5% ± 11.7%, respectively. CONCLUSIONS Second-look surgery proved feasible with no major morbidity, and results improved with time. Local tumor control was comparable in patients undergoing 1 or more resections.