Multidisciplinary management of difficult/aggressive growth-hormone pituitary neuro-endocrine tumors

Growth Hormone-secreting adenomas exhibits variable biological behavior and heterogeneous natural history, ranging from small adenomas and mild disease, to invasive and aggressive neoplasms with more severe clinical picture. Patients not cured or controlled after neurosurgical and first-generation somatostatin receptor ligands (SRL) therapy could require multiple surgical, medical and/or radiation treatments to achieve disease control. To date, no clinical, laboratory, histopathological, or neuroradiological markers are able to define the aggressiveness or predict the disease prognosis in patients with acromegaly. Therefore, the management of these patients requires careful evaluation of laboratory assessments, diagnostic criteria, neuroradiology examinations, and neurosurgical approaches to choose an effective and patient-tailored medical therapy. A multidisciplinary approach is particularly useful in difficult/aggressive acromegaly to schedule multimodal treatment, which includes radiation therapy, chemotherapy with temozolomide and other, recent emerging treatments. Herein, we describe the role of the different members of the multidisciplinary team according to our personal experience; a flow-chart for the therapeutic approach of difficult/aggressive acromegaly patients is proposed.

Spinal Epidural Atypical Meningioma: Case Report and Review of the Literature

Spinal atypical meningiomas are rare, and those whose main extension is in the epidural space are anecdotal. Here, we report a case of a young woman presenting with sensory disturbances and a radiological diagnosis of a dorsal epidural sleeve-like mass. The surgical resection of the lesion allowed the decompression of the spinal cord and led to the histopathological diagnosis of atypical meningioma. At the 3-month follow-up, her neurological recovery was complete. Because of the gross total removal of the lesion, adjuvant radiotherapy was not performed: At the 2-year follow-up, no recurrence of disease was detected. A comprehensive literature review was performed, and just two more case reports on epidural atypical meningiomas were found in the English literature. Through this case report and literature review, we described a rare manifestation of spinal meningioma that entered into a differential diagnosis for extradural spinal lesions, such as secondary malignancies.

Expanding the spectrum of "mesenchymal" tumors of the central nervous system

In this review, we summarize the clinical, histopathological, and molecular features of central nervous system (CNS) tumors with BCOR internal tandem duplication, intracranial mesenchymal tumor with FET/CREB fusion, CNS CIC-rearranged sarcomas and primary intracranial sarcoma DICER1-mutant, now included in the 2021 WHO classification of CNS tumors. Possible relationships between tumors occurring in the CNS and their systemic counterparts are discussed.

BIOM-36. A STUDY OF CLINICAL AND MOLECULAR PROGNOSTIC FACTORS FOR RESPONSE TO REGORAFENIB IN RECURRENT GLIOBLASTOMA

Introduction

Following the results from the REGOMA study, regorafenib has become the first chemotherapeutic option for recurrent glioblastoma, IDH-wildtype, in many countries. However, predictive factors for response to regorafenib are scarcely recognized. The objective of this study was to identify molecular predictive factors for response to regorafenib using a clinically available platform.

METHODS

We analyzed a prospective cohort of 30 patients harboring recurrent glioblastoma, IDH-wildtype, and treated with regorafenib. Next-generation sequencing (NGS) analysis was performed on DNA extracted from paraffin-embedded tissues using a rapid, cheap, and clinically validated platform. MGMT methylation was assessed using methylation-specific PCR, and EGFRvIII expression was assessed using RT-PCR.

RESULTS

In our series, six-month progression-free survival (PFS) was 30% and median overall survival (OS) was 7.5 months: these data are consistent with current literature. Among clinical variables, gross-total resection was endowed with a positive prognostic value for PFS (p=0.0296, log-rank test). NGS analysis revealed a mutation in the EGFR pathway (EGFR and/or PIK3CA) in 18% of cases; a mutation in the mitogen-activated protein-kinase (MAPK) pathway (RAS and/or RET) in 18% of cases; no mutations in the remaining cases. Patients carrying MAPK pathway mutation had a poor response to regorafenib treatment, with a significantly shorter PFS and a nonsignificantly shorter OS compared to EGFR-mutated patients (for PFS, 2.5 vs 4.5 months, p=0.0061; for OS, 7 vs 9 months, p=0.1076). By combining NGS analysis with RT-PCR for EGFRvIII, we identified 14 patients with EGFR pathway activation, who had a significantly longer PFS and OS after regorafenib treatment. Multivariate analysis confirmed that MAPK pathway mutations predicted a scarce response to regorafenib treatment.

Conclusions

Through an easy-to-use and cheap platform, we identified a mesenchymal, MAPK-altered signature in IDH-wildtype glioblastoma, predictive of scarce response to regorafenib at recurrence. We thus provide a molecular selection criterion to implement in the clinical practice.

BIOM-57. DISSECTING STEMNESS IN AGGRESSIVE MENINGIOMAS: PROGNOSTIC ROLE OF SOX2 EXPRESSION

Aggressive meningiomas are prone to recur despite GTR and eventually progress: they represent a challenge and are difficult to recognize at first diagnosis. SOX2 (Sex-determining region Y-box2) is a transcription regulator whose role is crucial for cell’s fate and maintenance of progenitor’s identity during embryogenesis, and homeostasis and regeneration in adult tissue through stem cell activity preservation. We reviewed meningioma cases surgically treated at Gemelli Hospital, Rome between 2014 and 2019. We included all patients with diagnosis of grade 3 meningiomas, both progressive and de novo, grade 2 with at least one surgical recurrence after GTR and benign grade 1 and grade 2 without recurrence at 10 and 5 years long follow-up respectively. SOX2 expression was evaluated through IHC and RT-PCR. Its role in predicting progression, recurrence, OS and PFS was investigated. 87 patients were included: 16 de novo grade 3 meningioma, 7 progressive grade 1, 13 progressive grade 2, 12 recurrent grade 2, 20 benign grade 1, 19 benign grade 2. The IHC method for SOX2 was validated by correlation between IHC score and mRNA levels (Spearman R=0.0398, p=0.001, AUC 0.87). Although SOX2 expression is related to WHO grade in the series, its status doesn’t change with progression. SOX2 expression at first surgery is related to risk of progression (p< 0,0001) and represents a grade independent prognostic factor for PFS and OS (PFS 38,41 months in positive cases vs not reached in negative cases; p< 0,0001; OS 173,9 months in positive cases vs not reached in negative cases; p=0,0001) and both in grade 1 and grade 2. Histomorphological criteria, cornerstone of the current WHO classification, are inadequate to predict aggressiveness. SOX2 expression since first diagnosis is able to point out meningiomas prone to recur and progress. SOX2 status could integrate current classification as molecular biomarker of stemness and aggressiveness.

Clinical and NGS predictors of response to regorafenib in recurrent glioblastoma

Predictive factors for response to regorafenib in recurrent glioblastoma, IDH-wildtype, are scarcely recognized. The objective of this study was to identify molecular predictive factors for response to regorafenib using a clinically available platform. We analyzed a prospective cohort of 30 patients harboring recurrent glioblastoma, IDH-wildtype, and treated with regorafenib. Next-generation sequencing (NGS) analysis was performed on DNA extracted from paraffin-embedded tissues using a clinically available platform. Moreover, MGMT methylation and EGFRvIII expression analyses were performed. Six-month progression-free survival (PFS) was 30% and median overall survival (OS) was 7.5 months, in line with literature data. NGS analysis revealed a mutation in the EGFR pathway in 18% of cases and a mutation in the mitogen-activated protein-kinase (MAPK) pathway in 18% of cases. In the remaining cases, no mutations were detected. Patients carrying MAPK pathway mutation had a poor response to regorafenib treatment, with a significantly shorter PFS and a nonsignificantly shorter OS compared to EGFR-mutated patients (for PFS, 2.5 vs 4.5 months, p = 0.0061; for OS, 7 vs 9 months, p = 0.1076). Multivariate analysis confirmed that MAPK pathway mutations independently predicted a shorter PFS after regorafenib treatment (p = 0.0188). The negative prognostic role of MAPK pathway alteration was reinforced when we combined EGFR-mutated with EGFRvIII-positive cases. Recurrent glioblastoma tumors with an alteration in MAPK pathway could belong to the mesenchymal subtype and respond poorly to regorafenib treatment, while EGFR-altered cases have a better response to regorafenib. We thus provide a molecular selection criterion easy to implement in the clinical practice.

MiR-1248: a new prognostic biomarker able to identify supratentorial hemispheric pediatric low-grade gliomas patients associated with progression

Background

Pediatric low-grade gliomas (pLGGs), particularly incompletely resected supratentorial tumours, can undergo progression after surgery. However to date, there are no predictive biomarkers for progression. Here, we aimed to identify pLGG-specific microRNA signatures and evaluate their value as a prognostic tool.

Methods

We identified and validated supratentorial incompletey resected pLGG-specific microRNAs in independent cohorts from four European Pediatric Neuro-Oncology Centres.

Results

These microRNAs demonstrated high accuracy in differentiating patients with or without progression. Specifically, incompletely resected supratentorial pLGGs with disease progression showed significantly higher miR-1248 combined with lower miR-376a-3p and miR-888-5p levels than tumours without progression. A significant (p < 0.001) prognostic performance for miR-1248 was reported with an area under the curve (AUC) of 1.00. We also highlighted a critical oncogenic role for miR-1248 in gliomas tumours. Indeed, high miR-1248 levels maintain low its validated target genes (CDKN1A (p21)/FRK/SPOP/VHL/MTAP) and consequently sustain the activation of oncogenic pathways.

Conclusions

Altogether, we provide a novel molecular biomarker able to successfully identify pLGG patients associated with disease progression that could support the clinicians in the decision-making strategy, advancing personalized medicine.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40364-022-00389-x.

HGG-59. Pediatric high-grade gliomas and the WHO classification on CNS Tumors - Different perspectives of pediatric neuro-oncologists and neuropathologists in the light of recent updates

BACKGROUND: The WHO Classification of Tumors of the Central Nervous System has undergone major restructuring following rapid advances in brain tumor genomics and epigenomics. The most significant changes resulted from the introduction of molecularly defined diagnostic criteria in 2016 (revised 4th edition). In 2021 (5th edition), further essential molecular criteria were incorporated. In the present study, we sought to investigate potential differences between specialists in perception of these newly defined molecular subtypes of pediatric high-grade gliomas (pedHGG). METHODS: We designed a 22-question survey studying the impact of the revised 4th edition of the WHO classification on pedHGG. Data were collected and statistically analyzed to capture the spectrum of viewpoints and possible differences among neuro-oncologists and neuropathologists. RESULTS: 465 participants from 53 countries responded, of which 187 pediatric neuro-oncologists (40%), 160 neuropathologists (34%) and 118 experts in other related fields (neurosurgeons, radiotherapists, neuroradiologists and others; 26%). Neuro-oncologists reported having issues with the introduction of new molecular entities, such as the abolishment and renaming of established tumor entities. Neuropathologists did not define these problems to the same extent. However, both groups felt that in the 2016 version, less relevant or insufficient diagnostic definitions were available for pedHGG. Within the 2021 WHO classification, a substantial improvement was perceived regarding the definition of pedHGG entities. However, some issues of high clinical relevance, like the definition of clinical phenotypes such as diffuse intrinsic pontine glioma (DIPG) and gliomatosis cerebri, are yet to be addressed. CONCLUSIONS: Within the WHO classification of pediatric brain tumors, such as high-grade gliomas, rapid changes in nomenclature have been introduced because of substantial improvement in molecular characterization. This study highlights that ongoing cross-talk between advancing classification of pedHGG subtypes and its biological relevance and clinical impact is essential.

POS0316 SEMIQUANTITATIVE ASSESSMENT OF SYNOVITIS ON US-GUIDED SYNOVIAL MEMBRANE BIOPSIES IS CONTINGENT ON DISEASE PHASE AND PREDICTIVE OF TREATMENT RESPONSE IN NAIVE TO TREATMENT PSORIATIC ARTHRITIS

Background

Ultrasound (US)-guided minimally invasive Synovial Tissue (ST) biopsy serves as a safe and well tolerated procedure for basic and translational research on chronic inflammatory joint disease.

Objectives

(i) to assess the diagnostic value of the Krenn score (KSS) on ST samples obtained from US-guided biopsies in a large bio-samples dataset of patients with Psoriatic Arthritis (PsA) across different disease phases; (ii) to develop a multiparametric nomogram integrating clinical and histological characteristics enabling treatment response prediction in naïve to treatment PsA.

Methods

410 patients fulfilling the CASPAR criteria for PsA who underwent US-guided ST biopsy were enrolled. At baseline, patients were categorized based on their disease phase and treatment: n=207 naïve to DMARDs; n=101 resistant to c-DMARDs; n=48 resistant to b-DMARDs and n=54 in sustained clinical and ultrasound remission or in low disease activity (LDA) state (DAPSA ≤ 4 or among 4-14, respectively). Clinical, demographic, and immunological characteristics were recorded for each patient. All ST specimens were stained with H&E and classified by a pathologist, blinded to clinical characteristics, using the Krenn score to assess ST inflammation degree (1) implemented with the determination of lymphocytes, plasma cells, granulocytes and tissue oedema presence. Each naive to treatment PsA was treated according to the EULAR recommendations (2) and DAPSA remission rate at 6 months was recorded.

Results

Considering the whole enrolled cohort, the distribution of KSS was significantly different among patients across the different PsA phases (ANOVA p<0.001). In particular, among the different phases, KSS was significantly higher in b-DMARDs resistant (p<0.0001) and c-DMARDs resistant (p<0.0001) compared to remission/LDA disease patients as well as naive to treatment PsA (p<0.0001). Interestingly, regardless to the disease phase, KSS of the biopsied joint directly correlated to disease activity in terms of DAPSA (r=0.476, p<0.001) and DAS28 scores (r=0.476, p<0.001). Considering the naïve to treatment PsA cohort, patients achieving DAPSA defined-LDA/remission had, before treatment, significantly lower KSS (p<0.001), lower rate of ST plasmacells presence (p<0.001) and shorter symptoms duration (p=0.01) as compared to naïve to treatment PsA not achieving this clinical outcome. Moreover, considering distinct clinical phenotype domains, naive to treatment PsA patients with concomitant dactylitis and skin disease were less likely to achieve DAPSA LDA/remission (p<0.001), regardless of treatment scheme. On logistic regression, at baseline, having a KSS <5 [OR: 5.30 (95%CI:2.21-12.74) p<0.001], absence of plasma cells ST infiltrate [OR: 3.87 (2.11-7.10 95%CI) p<0.001], concomitant dactylitis [OR: 2.55 (95%CI:1.24-5.25) p=0.01] and skin involvement [OR: 2.06 (95%CI:1.17-3.62) p=0.01] were independent factors associated with DAPSA score-LDA/remission achievement at 6 months. Finally, a multiparametric nomogram integrating baseline clinical and histological characteristics of naïve PsA enabling to predict up to 75% of probability to achieve DAPSA remission at 6 months was developed.

Conclusion

KSS is a reliable tool for synovitis assessment in PsA, being contingent on disease phases, related to disease burden and included within a treatment response predictive multiparametric nomogram in naïve PsA.

References

[1]Krenn V, et al. Histopathology 2006

[2]Gossec L, et al. Annals of the Rheumatic Diseases 2020

Disclosure of Interests

None declared

POS0105 IMMUNOLOGICAL AND TISSUE DERIVED BIOMARKERS OF EARLY RESPONSE IN MODERATE-TO-SEVERE RHEUMATOID ARTHRITIS TREATED WITH JAK-INHIBITORS

Background

Among Janus kinase inhibitors (JAKi) approved for Rheumatoid Arthritis (RA) treatment, tofacitinib and baricitinib are considered as pan-JAKi (pJAKi) while upadacitinib and filgotinib as selective anti-JAK1 (sJAKi) drugs. To date, despite ≈30% of RA patients exposed to JAKi achieve DAS28-CRP remission at 12 weeks, there is still lack of predictive biomarkers of response in RA treated with distinct JAKi.

Objectives

To determine whether pre-treatment immunological and synovial tissue features can predict clinical improvement in moderate-to-severe RA treated with JAKi.

Methods

Among 174 RA patients treated with JAKi, 84 underwent peripheral blood (PB) drawing and US-guided synovial tissue (ST) biopsy. Demographic, clinical and immunological features were collected for each patient at baseline and after 12 weeks. The distribution of PB-derived B lymphocytes subsets was assessed by flow cytometry, using CD27/IgD classification. Synovitis degree assessment was determined using Krenn score (KSS) by trained pathologist, blinded to clinical characteristics.

Results

Among enrolled RA patients, 82.7% was treated with pJAKi and 17.3% with sJAKi. Moreover, 35.6% of RA patients was b/ts-DMARDs naïve, 18.4% b/ts-DMARDs non-responder and 46.0% was difficult-to-treat (D2T) RA. In the whole cohort, 49.2% and 50.8% of RA patients achieved DAS28-CRP and CDAI low disease activity (LDA), respectively, after 12 weeks of JAKi treatment. Moreover, 37.7% and 5.9% of RA patients achieved DAS28-CRP and CDAI remission (REM), respectively, after 12 weeks of JAKi treatment regardless to JAKi category. Considering the immunological profile, RA patients achieving CDAI LDA were more likely rheumatoid factor (60.0%) and ACPA positive (60.5%) compared to RA patients not achieving this outcome (RF: 40.0%, p= 0.03 and ACPA: 39.5%, p= 0.02). Considering PB-derived B cell phenotype, b/ts-DMARDs naïve RA achieving DAS28-CRP LDA at 12 week had pre-treatment lower unswitched memory B (IgDposCD27pos) cell rate (6.91±7.70%) compared to b/ts-DMARDs naïve RA not achieving the same outcome (13.21±5.68%, p= 0.009). ROC analysis identified a cut-off value of 6.89% for IgDposCD27pos cells discriminating b/ts-DMARDs naïve RA achieving DAS28-CRP LDA at 12 week [AUC: 0.174±0.086; p= 0.008; OR(95%CIs): 18.20 (1.761-188.069)]. Furthermore, b/ts-DMARDs naïve RA achieving DAS28-CRP REM at 12-week follow up visit, had PB enrichment of naïve B cells (IgDposCD27neg: 68.08±17.38%) and lower percentage of unswitched memory B lymphocytes (5.10±4.29%) compared to RA not achieving the same outcome (IgDposCD27neg: 54.68±16.16%, p= 0.05; IgDposCD27pos: 13.96±8.34%, p= 0.001) [IgDposCD27neg cut-off: 62.6%, AUC:0.727±0.101, p=0.05; OR(95%CIs): 7.33(1.272-42.294); IgDposCD27pos cut-off: 6.89%, AUC: 0.139±0.073, p= 0.002; OR(95%CIs): 12.37 (1.828-83.767)]. Interestingly, considering the D2T RA subgroup, patients achieving DAS28-CRP LDA at 12 week follow up had lower rates of PB-derived IgDnegCD27neg B cells (3.83±0.96%) compared to RA not achieving the same outcome (7.25±2.83%, p= 0.04; cut-off: 5.46%, AUC: 0.083±0.095, p=0.041). Considering the pre-treatment synovitis degree, b/ts-DMARDs naïve RA achieving CDAI LDA status had significantly higher KSS at baseline (3.8±2.2) compared to RA not achieving the same outcome [1.7±1.4, p= 0.02; KSS cut-off: 3.00, AUC: 0.795±0.097; p=0.018; OR(95%CIs): 14.0 (1.39-141.49)]. Finally, no significant associations were observed between PB-derived B cell subpopulations rate and synovitis degree both in the whole RA cohort as well as stratifying patients for disease phase.

Conclusion

Pre-treatment immunological profile, peripheral blood-derived B cell phenotype and synovitis degree are associated with the early achievement of at least DAS28-CRP/CDAI LDA in RA patients receiving JAKi despite their selectivity.

References

[1]Gremese E et. J Leukoc Biol. 2019

[2]Alivernini S et al. Pharmacol Res. 2019

[3]Alivernini S et al. Arthritis Rheumatol. 2021

Disclosure of Interests

None declared

OP0084 DIGITAL SPATIAL PROFILING REVEALS DISTINCT SYNOVIAL TISSUE MACROPHAGE TRANSCRIPTOMIC SIGNATURE OF SUSTAINED REMISSION IN RHEUMATOID ARTHRITIS PATIENTS AT RISK OF DISEASE FLARE AFTER TREATMENT CESSATION

Background

Sustained remission is the treatment goal for Rheumatoid Arthritis (RA) and once achieved patients are eligible to treatment tapering or discontinuation. However, this exposes patients to the occurrence of unpredictable disease flare, and to date there are no definitive predictive biomarkers of flare for RA in remission that could be used in clinical practice.

Objectives

To assess the impact of clinical classification of remission on synovial tissue (ST) features of RA in sustained remission and to identify predictive biomarkers of disease flare.

Methods

200 RA in sustained clinical (102 RA with DAS<1.6 and 98 RA fulfilling Boolean remission criteria for at least 9 months, respectively) and ultrasound (US) remission (PD negative) under Methotrexate with or without biological-Disease Modifying Anti-Rheumatic Drugs (bDMARDs) were enrolled and underwent to US guided ST biopsy. 373 naive RA were included as comparison. For each patient, synovitis degree was determined using a H&E-based semiquantitative score1. Some ST samples of remission RA were used for synovial tissue macrophage (STMs)(CD206/MerTK) FACS phenotyping and digital spatial profiling (GeoMx DSP, Nanostring) to quantitate transcript abundance of CD68pos cells in 138 spatially distinct ST regions of interest (ROI). After study entry, RA were randomly assigned to tapering/discontinuation (TAP/DISC) (tapering c- or b-DMARD treatment for 6 months and discontinuing c- or bDMARD afterwards) or maintaining the same therapeutic scheme (CONT). Each RA was followed every 3 months to assess flare rate after treatment modifications for 24 months.

Results

Regardless of either DAS- or Boolean-defined, remission patients had significantly lower KSS than naive RA (p<0.0001 for both). However, ST of RA in Boolean remission had lower KSS (p<0.0001) and was enriched in CD206posMerTKpos STMs (p=0.0012) as compared to DAS-defined remission RA. 73(36.5%) RA experienced a disease flare regardless of the treatment change during 24 months follow-up. Stratifying RA in remission based on remission definition and treatment group, DAS-defined remission RA who had a disease flare within at least 6 months follow-up had, at study entry, significantly higher KSS (p<0.0001) than RA who maintained a sustained remission, regardless of the treatment change (CONT:p=0.0027 and TAP/DISC:p=0.0011). Logistic regression analysis revealed that baseline KSS≥3 [AUC:0.748(95%CI:0.649-0.846)p<0.0001] was an independent predictive factor of disease flare [OR:6.9(95%CI:2.82-16.81)] within 24 months follow-up in DAS-defined remission RA. Conversely, RA in Boolean remission did not differ for KSS at study entry in both the CONT (p>0.05) and the TAP/DISC (p>0.05) group in relation to disease flare. However, considering STMs phenotype, RA in Boolean remission in the TAP/DISC group who had low levels of CD206posMerTKpos (<38.1%), experienced more likely a disease flare compared to RA in the CONT subgroup with CD206posMerTKpos≥38.1% (p=0.0014). Logistic regression analysis confirmed that, before treatment change, STMs phenotype (CD206posMerTKpos <38.1%) in RA in remission is an independent predictor of disease flare [OR:6.25(95%CI:1.33-29.43)] within 24 months. Finally, DSP analysis using CD68 morphology marker, revealed that lining and sublining layer CD68pos spatial transcriptomics distinguished, at baseline, remission RA who flared after treatment modification from those who did not.

Conclusion

Disease flare is a common event in RA in sustained remission after treatment modification. KSS and STMs phenotype identified by flow cytometry or by tissue spatial transcriptomic can identify RA in remission at higher risk of flare after treatment modification. Thus, spatial transcriptomic with defined panel of markers on histological biopsy tissues could be a way forward in predicting disease flare.

References

[1]Alivernini S, et al. Arthritis & Rheumatology 2021

Disclosure of Interests

Simone Perniola: None declared, Barbara Tolusso: None declared, Aziza Elmesmari: None declared, Marco Gessi: None declared, Clara Di Mario: None declared, Maria Rita Gigante: None declared, Luca Petricca: None declared, Dario Bruno: None declared, Domenico Somma: None declared, Annamaria Paglionico: None declared, Valentina Varriano: None declared, Laura Bui: None declared, Maria Antonietta D’Agostino: None declared, Mariola Kurowska-Stolarska Grant/research support from: Pfizer, GSK, Novartis, Eli Lilly, Elisa Gremese Speakers bureau: Abbvie, BMS, Novartis, GSK, Galapagos, Eli Lilly, Pfizer., Grant/research support from: Abbvie, BMS., Stefano Alivernini Speakers bureau: Abbvie, BMS, Novartis, Galapagos, Eli Lilly, Pfizer., Grant/research support from: Pfizer, Novartis, GSK.

A Cystic Clival Chordoma with CT and MRI Unconventional Appearances

We present the first case of clival cystic chordoma with extradural location, transdural transgression, and moderate bone involvement in a 10-year-old girl. Chordoma showed unconventional appearances on computed tomography (CT) and magnetic resonance imaging (MRI), due to cystic components, extradural space location with extensive intradural extension, moderate superficial bone involvement. Surgery confirmed the extradural location and histopathological examination revealed cystic chordoma. MRI and CT findings were not characteristic for a single lesion; differential diagnoses included cystic lesions such as epidermoid and dermoid cyst, ecchordosis physaliphora, and benign notochordal cell tumors.

Characterization of high-grade pineal region lesions: the usefulness of apparent diffusion coefficient volumetric values

BACKGROUND

High-grade pineal region tumors are rare and heterogeneous types of primary central nervous system neoplasms; radiological differential diagnosis is challenging but it is important because it has a therapeutic relevance.

PURPOSE

To discriminate among high-grade pineal region tumors by combining apparent diffusion coefficient (ADC) volumetric values and qualitative features in order to predict their histology.

MATERIAL AND METHODS

Twenty-two patients with high-grade pineal region tumors were assessed by qualitative and quantitative analysis. Margins, T2-weighted signal intensity, contrast enhancement, hemorrhage, calcifications, different volumetric ADC fractions (ADC_mean, ADC_max, ADC_min) were evaluated and were compared to the histopathologic findings (cell count and proliferation index).

RESULTS

Our qualitative imaging data showed that only margins were different among different tumors and each tumor type showed peculiar age onset. ADC_mean was found the best quantitative value to discriminate high-grade tumors of the pineal region. ADC_mean correlated with proliferation index but not with cell count. ADC_mean values were lower in tumors with higher proliferation rate and a significant difference in ADC_mean values were found between germinomas and pineoblastomas, between germinomas and papillary tumors and between papillary tumors and pineoblastomas. Moreover, the cut-off value of 0.865 × 10^-3 mm²/s for ADC_mean (ADC mean threshold value) could differentiate germinoma from pineoblastomas with the best combination of sensitivity and specificity.

CONCLUSION

The ADC_mean value measured on the whole tumor, reflecting tumor proliferative activity, may be a practical and non-invasive marker for predicting tumor histology in high-grade pineal region lesions and might be useful in preoperative assessment.

Neuro-Oncology Multidisciplinary Tumor Board: The Point of View of the Neuroradiologist

Background: The multi-disciplinary tumor board (MTB) is essential to quality cancer care and currently recommended to offer the best personalized clinical approach, but little has been published regarding MTBs in neuro-oncology (nMTBs). The aim of the present paper is to describe our nMTB, to evaluate its impact on clinical management decisions, and to assess the role of neuroradiologists. Methods: The retrospective evaluation of the cases discussed at our nMTB from March 2017 to March 2020. From the electronic records, we extracted epidemiological, clinical and other specific data of nMTB. From the radiological records, we calculated data relating to the number, time for revision, and other specifications of MRI re-evaluation. Statistical analysis was performed. Results: a total of 447 discussions were analyzed, representing 342 patients. The requests for case evaluations came from radiation oncologists (58.8%) and neurosurgeons (40.5%), and were mainly addressed to the neuroradiologist (73.8%). The most frequent questions were about the treatment’s changes (64.4%). The change in patient treatment was reported in 40.5% of cases, 76.8% of these were based on the neuroradiologic assessment. A total of 1514 MRI examinations were re-evaluated, employing approximately 67 h overall. The median of the MRI exams reviewed per patient was 3 (min–max 1–12). Conclusions: Our study supported that the multidisciplinary approach to patient care can be particularly effective in managing brain tumors. A review by an expert neuroradiologist impacts patient management in the context of nMTBs, but has costs in terms of the time and effort spent preparing for it.

ALK-positive histiocytosis: a new clinicopathologic spectrum highlighting neurologic involvement and responses to ALK inhibition

ALK-positive histiocytosis is a rare subtype of histiocytic neoplasm first described in 2008 in 3 infants with multisystemic disease involving the liver and hematopoietic system. This entity has subsequently been documented in case reports and series to occupy a wider clinicopathologic spectrum with recurrent KIF5B-ALK fusions. The full clinicopathologic and molecular spectra of ALK-positive histiocytosis remain, however, poorly characterized. Here, we describe the largest study of ALK-positive histiocytosis to date, with detailed clinicopathologic data of 39 cases, including 37 cases with confirmed ALK rearrangements. The clinical spectrum comprised distinct clinical phenotypic groups: infants with multisystemic disease with liver and hematopoietic involvement, as originally described (Group 1A: 6/39), other patients with multisystemic disease (Group 1B: 10/39), and patients with single-system disease (Group 2: 23/39). Nineteen patients of the entire cohort (49%) had neurologic involvement (7 and 12 from Groups 1B and 2, respectively). Histology included classic xanthogranuloma features in almost one-third of cases, whereas the majority displayed a more densely cellular, monomorphic appearance without lipidized histiocytes but sometimes more spindled or epithelioid morphology. Neoplastic histiocytes were positive for macrophage markers and often conferred strong expression of phosphorylated extracellular signal-regulated kinase, confirming MAPK pathway activation. KIF5B-ALK fusions were detected in 27 patients, whereas CLTC-ALK, TPM3-ALK, TFG-ALK, EML4-ALK, and DCTN1-ALK fusions were identified in single cases. Robust and durable responses were observed in 11/11 patients treated with ALK inhibition, 10 with neurologic involvement. This study presents the existing clinicopathologic and molecular landscape of ALK-positive histiocytosis and provides guidance for the clinical management of this emerging histiocytic entity.

Pediatric high-grade gliomas and the WHO CNS Tumor Classification—Perspectives of pediatric neuro-oncologists and neuropathologists in light of recent updates

Background

The WHO Classification of Tumors of the Central Nervous System has undergone major restructuring. Molecularly defined diagnostic criteria were introduced in 2016 (revised 4th edition) and expanded in 2021 (5th edition) to incorporate further essential diagnostic molecular parameters. We investigated potential differences between specialists in perception of these molecularly defined subtypes for pediatric high-grade gliomas (pedHGG).

Methods

We designed a 22-question survey studying the impact of the revised 4th edition of the WHO classification on pedHGG. Data were collected and statistically analyzed to examine the spectrum of viewpoints and possible differences between neuro-oncologists and neuropathologists.

Results

465 participants from 53 countries were included; 187 pediatric neuro-oncologists (40%), 160 neuropathologists (34%), and 118 additional experts (26%). Neuro-oncologists reported issues with the introduction of molecularly defined tumor types, as well as the abolishment or renaming of established tumor entities, while neuropathologists did not to the same extent. Both groups indicated less relevant or insufficient diagnostic definitions were available in 2016. Reported issues were classified and assessed in the 2021 WHO classification and a substantial improvement was perceived. However, issues of high clinical relevance remain to be addressed, including the definition of clinical phenotypes for diffuse intrinsic pontine glioma and gliomatosis cerebri.

Conclusions

Within the WHO classification of pediatric brain tumors, such as pedHGG, rapid changes in molecular characterization have been introduced. This study highlights the ongoing need for cross talk between pathologist and oncologist to advance the classification of pedHGG subtypes and ensure biological relevance and clinical impact.

Multinodular plexiform tumors of major peripheral nerves: A practical overview

BACKGROUND AND AIMS

Multinodular/plexiform schwannomas and neurofibromas of major nerves are rare: before surgery, differential diagnosis among these two uncommon variants is challenging. For both forms, surgical removal is recommended in case of progressive growth and worsening of neurological symptoms. Surgery has a higher risk of neurological damage than conventional schwannomas or neurofibromas. In literature, a comparison among these rare tumors is usually limited to the pathological aspect while specific surgical and clinical management indications are lacking. Cutaneous tumors of both forms arising from terminal peripheral nerves' branches might be treated by plastic surgeons while tumors of major nerves remain under neurosurgical competence. Here we report our recent neurosurgical experience on the matter, to furnish useful suggestions for the management of these tumors.

METHOD

We analyzed the clinical, radiological, and pathological data in a consecutive case series of plexiform/multinodular nerve tumors operated at our institution in the last five years.

RESULTS

In our series, neurofibroma type of plexiform tumors was more frequent than schwannoma type: two sporadic plexiform-multinodular schwannomas (patients 1, and 5) and three multinodular/plexiform Neurofibromatosis familial (Neurofibromatosis 1 / NF-1) (patients 2, 3, and 4). Surgery was complex when major nerves were involved. The early outcome appeared mostly related to the pre-surgical neurological conditions and histological grading.

INTERPRETATION

Although sharing some features, multinodular-plexiform schwannomas and neurofibromas have consistent differences from the clinical, surgical and pathological points of view.

A "polymorphous low-grade neuroepithelial tumor of the young (PLNTY)" diagnosed in an adult. Report of a case and review of the literature

Background:

Polymorphous low-grade neuroepithelial tumor of the young (PLNTY) is a rare neuropathological entity, recently introduced in neuro-oncology. These tumors, histologically similar to oligodendrogliomas, cause epilepsy, occurring in children and young adults. Only few cases of PLNTY have been described in literature and all reported cases invariably focused on the onset of these tumors in children and young adults.

Case Description:

We report the case of a 50-year-old woman suffering from epilepsy since the 1^st year of her life. Computed tomography scan and magnetic resonance imaging of the brain documented the presence of a calcified mass involving left temporal lobe. The tumor was surgically excised and the histological examination showed a hypocellular and massively calcified neoplasm with morphological and immunohistochemical features consistent with the diagnosis of “PLNTY.”

Conclusion:

A review of the literature revealed that there are 31 cases of PLNTY reported in literature, most of which are children or young adults. The present case represents the second PLNTY diagnosed in a middle-aged adult to the best of our knowledge, suggesting that PLNTY should always be included in the differential diagnosis of low-grade brain tumors, also in adult patients.

What to Trust, PSA or [68Ga]Ga-PSMA-11: Learn from Experience

Brain metastases from prostate cancer typically occur in the more advanced stages of the disease. Clinically, the early diagnosis of visceral disease is crucial, impacting on patient’s management and prognosis. Although magnetic resonance imaging (MRI) is the modality of choice for the detection of brain metastases, it is not routinely performed in the surveillance of prostate cancer patients unless neurological manifestations appear. Prostate-specific membrane antigen (PSMA) is a glycoprotein, a membrane-bound metallopeptidase, overexpressed in more than 90% of prostate cancer cells. This molecular target is a suitable tissue biomarker for prostate cancer functional imaging. We present a case of a 73-year gentleman diagnosed with prostate adenocarcinoma and surgically treated (pT3bN1Mx, Gleason Score of 9) in February 2016. Subsequently, he underwent androgen deprivation therapy because of the occurrence of a bone metastasis. Between 2016 and January 2019 PSA levels were maintained under control. Starting from September 2019, it progressively raised up to 0.85 ng/mL with a doubling time of 3.3 months. Therefore, he performed a [⁶⁸Ga]Ga-PSMA-11 PET/CT which showed a focal radiopharmaceutical uptake in the right temporal lobe corresponding to the presence of a rounded cystic lesion on brain MRI. The subsequent excisional biopsy diagnosed a prostate adenocarcinoma metastasis. PSMA expression has been reported in brain parenchyma after ischemic strokes and in some brain tumors including gliomas, meningiomas, and neurofibromas. In our case, the lack of symptoms and the relatively low PSA level raised questions about the nature of the lesion, posing the differential diagnosis between brain metastases and primary brain tumor. Finally, our case shows the capability of [⁶⁸Ga]Ga-PSMA-11 PET/CT to detect metachronous distant brain metastases in a low biochemical recurrent asymptomatic prostate cancer patient, indicating that proper acquisition – from the vertex to thigh – should be always considered, regardless of the PSA level.

Clinical-Pathological, Immunohistochemical, and Genetic Characterization of a Series of Posterior Pituitary Tumors

Posterior pituitary tumors are supposed to represent the morphological spectrum of a single entity. Herein, we report the clinical-pathological, immunohistochemical, and genetic features of 5 spindle cell oncocytomas (SCOs), 3 pituicytomas, and 1 granular cell tumor (GCT). SCOs had the highest local invasiveness and affected older subjects. The 3 histotypes differed in the content of spindle cells (predominant in pituicytoma and absent in GCT), presence of lymphocytic infiltrate (in SCO and GCT, but not in the pituicytoma) and EMA/GFAP staining (negative in GCT; EMA-positive/GFAP-negative in 4/5 SCO and GFAP-positive in 3/3 pituicytomas). Three SCOs and 1 pituicytoma analyzed with next-generation sequencing had no mutations in 409 genes. However, 1 SCO had previously unreported homozygous deletion of CDKN2A/B and another of SMARCA4, SMARCB1, and NF2. All 3 SCOs had loss of heterozygosity of chromosome 1p, while the pituicytoma had chromosome 19 homozygous loss and chromosomes 10, 13q, and 18q loss of heterozygosity. Since 1p and 13q losses were previously reported in 1 pituicytoma and 1 SCO, respectively, our data demonstrate that posterior pituitary tumors share common genetic alterations. The possibility that posterior pituitary tumors are SMARCA4/SMARCB1-deficient should be kept in mind in the differential diagnosis toward other entities.

Unusual case of long survival patient with leptomeningeal carcinomatosis from breast cancer

Leptomeningeal carcinomatosis (LC) is defined as infiltration of the leptomeninges by metastatic carcinoma and often represents the end stage of cancer disease. In breast cancer, LC is associated with a median survival of approximately 6-8 weeks without specific treatment. It could increase by only few months with personalized treatment plans. Usually, the median time of onset of leptomeningeal spread is 18 months and it is diagnosed in up to 70% of patients with active and progressive systemic disease. We present an uncommon case of LC in a patient with history of breast cancer with a 10 year-disease-free condition and an overall survival after LC diagnosis of 10 months. Central Nervous System (CNS) Magnetic Resonance Imaging (MRI) showed contrast enhancement of medullary cone and cauda. Despite the negativity of cytological analysis of Cerebral-Spinal Fluid (CSF), the patient underwent meningeal and radicular biopsy in November 2019. The neuropathological examination confirmed the diagnosis of LC. The patient was started on the aromatase inhibitor anastrozole. A whole body contrast Computed Tomography (CT) scan at three months follow-up was negative for further disease dissemination. The patient is currently under oncological and radiological follow-up after more than 10 months from diagnosis. Although nowadays diagnosis of LC is prompted by cytological examination of CSF, its negativity should not halt the diagnostic process. In the presence of a high clinical suspicion of LC, we suggest the biopsy of lesion.

Therapeutic implications of improved molecular diagnostics for rare CNS-embryonal tumor entities: results of an international, retrospective study

BACKGROUND

Only few data are available on treatment-associated behavior of distinct rare CNS-embryonal tumor entities previously treated as "CNS-primitive neuroectodermal tumors" (CNS-PNET). Respective data on specific entities, including CNS neuroblastoma, FOXR2 activated (CNS NB-FOXR2), and embryonal tumor with multi-layered rosettes (ETMR) are needed for development of differentiated treatment strategies.

METHODS

Within this retrospective, international study, tumor samples of clinically well-annotated patients with the original diagnosis of CNS-PNET were analyzed using DNA methylation arrays (n=307). Additional cases (n=66) with DNA methylation pattern of CNS NB-FOXR2 were included irrespective of initial histological diagnosis. Pooled clinical data (n=292) were descriptively analyzed.

RESULTS

DNA methylation profiling of "CNS-PNET" classified 58(19%) cases as ETMR, 57(19%) as HGG, 36(12%) as CNS NB-FOXR2, and 89(29%) cases were classified into 18 other entities. Sixty-seven (22%) cases did not show DNA methylation patterns similar to established CNS tumor reference classes. Best treatment results were achieved for CNS NB-FOXR2 patients (5-year PFS: 63%±7%, OS: 85%±5%, n=63), with 35/42 progression-free survivors after upfront craniospinal irradiation (CSI) and chemotherapy. The worst outcome was seen for ETMR and HGG patients with 5-year PFS of 18%±6% and 22%±7%, and 5-year OS of 24%±6% and 25%±7%, respectively.

CONCLUSION

The historically reported poor outcome of CNS-PNET patients becomes highly variable when tumors are molecularly classified based on DNA methylation profiling. Patients with CNS NB-FOXR2 responded well to current treatments and a standard-risk-CSI based regimen may be prospectively evaluated. The poor outcome of ETMR across applied treatment strategies substantiates the necessity for evaluation of novel treatments.