The first pineoblastoma case report of a patient with Sotos syndrome harboring NSD1 germline mutation.

Germline mutations of NSD1 are associated with Sotos syndrome, characterized by distinctive facial features, overgrowth, and developmental delay. Approximately 3% of individuals with Sotos syndrome develop tumors. In this study, we describe an infant in pineoblastoma with facial anomalies, learning disability and mild autism at 1 years diagnosed as Sotos syndrome owing to carrying a novel mutation de novo germline NSD1 likely pathogenic variant. This patient expands both the mutation and phenotype spectrum of the Sotos Syndrome and provides new clinical insights into the potential mechanism of underlying pinealoblastoma pathology.

An atypical location of pineoblastoma RB1 subgroup without pineal or retinal tumor.

PURPOSE: To describe the clinical and imaging features of a sellar-suprasellar pineoblastoma RB1 subgroup without pineal or retinal involvement. CASE REPORT: An 11-month-old girl presented to the emergency department with fever, rhinorrhea, vomiting, altered level of consciousness, and one seizure. Head CT and brain MRI demonstrated a large lobulated mass with calcifications and heterogeneous enhancement in the suprasellar region causing mass effect to the ventricular system and hydrocephalus. Histology revealed a CNS embryonal tumor not otherwise specified (NOS) with small round nuclei with mitotic activity and necrosis. DNA methylation analysis classified the tumor in the pineoblastoma RB1 subgroup. CONCLUSION: Pineoblastoma RB1 subgroup should be considered in the differential diagnosis of large sellar-suprasellar masses with calcifications and heterogeneous enhancement in children younger than 18 months even in cases of absent pineal or retinal involvement. Molecular analysis with DNA methylation profiling is critical for diagnosis and management.

BCOR expression in paediatric pineoblastoma.

BCOR is expressed in a new brain tumour entity, i.e. 'CNS tumour with BCOR internal tandem duplication' (HGNET BCOR) but not in several other high grade paediatric brain tumours investigated. Immunohistochemical detection of BCOR expression may therefore serve as a potential diagnostic marker. Nevertheless, in rare paediatric glioma cases recurrent EP300-BCOR fusions were detected, which resulted in strong BCOR immunopositivity. We have therefore examined other, not analysed so far, types of central nervous system (CNS) tumours, pineoblastoma and germinoma, to assess a potential involvement of BCOR in these tumours. Levels of BCOR RNA expression were investigated by NanoString nCounter system analysis in a series of altogether 66 high grade paediatric tumours, including four pineoblastoma cases. Immunohistological detection of BCOR was performed in eight pineoblastoma, five germinoma and four atypical teratoid rhabdoid tumours (ATRTs), all located in the pineal region. We detected BCOR expression in all pineoblastomas, at the RNA and protein levels, but not in germinomas and ATRTs. Further analysis of pineoblastoma samples did not reveal the presence of either BCOR internal tandem duplication or BCOR fusion involvement. Positive immunohistological BCOR nuclear reaction in pineoblastoma may therefore differentiate this type of tumour from other high grade tumours located in the pineal region.

Benign and Malignant Tumors of the Pineal Region.

Pineal region tumors fall into five broad categories: benign pineal region tumors, glial tumors, papillary tumors, pineal parenchymal tumors, and germ cell tumors. Genetic and transcriptional studies have identified key chromosomal alterations in germinomas (RUNDC3A, ASAH1, LPL) and in pineocytomas/pineoblastomas (DROSHA/DICER1, RB1). Pineal region tumors generally present with symptoms of hydrocephalus including nausea, vomiting, papilledema, and the classical Parinaud's triad of upgaze paralysis, convergence-retraction nystagmus, and light-near pupillary dissociation. Workup requires neuroimaging and tissue diagnosis via biopsy. In germinoma cases, diagnosis may be made based on serum or CSF studies for alpha-fetoprotein or beta-HCG making the preferred treatment radiosurgery, thereby preventing the need for unnecessary surgeries. Treatment generally involves three steps: CSF diversion in cases of hydrocephalus, biopsy through endoscopic or stereotactic methods, and open surgical resection. Multiple surgical approaches are possible for approach to the pineal region. The original approach to the pineal region was the interhemispheric transcallosal first described by Dandy. The most common approach is the supracerebellar infratentorial approach as it utilizes a natural anatomic corridor for access to the pineal region. The paramedian or lateral supracerebellar infratentorial approach is another improvement that uses a similar anatomic corridor but allows for preservation of midline bridging veins; this minimizes the chance for brainstem or cerebellar venous infarction. Determination of the optimal approach relies on tumor characteristics, namely location of deep venous structures to the tumor along with the lateral eccentricity of the tumor. The immediate post-operative period is important as hemorrhage or swelling can cause obstructive hydrocephalus and lead to rapid deterioration. Adjuvant therapy, whether chemotherapy or radiation, is based on tumor pathology. Improvements within pineal surgery will require improved technology for access to the pineal region along with targeted therapies that can effectively treat and prevent recurrence of malignant pineal region tumors.

Current Open Trials and Molecular Update for Pediatric Embryonal Tumors.

BACKGROUND: Embryonal tumors are highly malignant cancers of the central nervous system, with a relatively high incidence in infants and young children. Even with intensive multimodal treatment, the prognosis of many types is guarded, and treatment-related toxicity is significant. Recent advances in molecular diagnostics allowed the discovery of novel entities and inter-tumor subgroups, with opportunities for improved risk-stratification and treatment approaches. SUMMARY: Medulloblastomas separate into four distinct subgroups with distinct clinicopathologic characteristics, and data from recent clinical trials for newly diagnosed medulloblastoma support subgroup-specific treatment approaches. Atypical teratoid rhabdoid tumor (ATRT), embryonal tumor with multilayered rosettes (ETMR), and pineoblastoma, as well as other rare embryonal tumors, can be distinguished from histologically similar tumors by virtue of characteristic molecular findings, with DNA methylation analysis providing a strong adjunct in indeterminate cases. Methylation analysis can also allow further subgrouping of ATRT and pineoblastoma. Despite the dire need to improve outcomes for patients with these tumors, their rarity and lack of actionable targets lead to a paucity of clinical trials and novel therapeutics. KEY MESSAGES: (1) Embryonal tumors can be accurately diagnosed with pediatric-specific sequencing techniques. (2) Medulloblastoma risk stratification and treatment decisions should take into account molecular subgroups. (3) There is a dire need for a novel collaborative clinical trial design to improve outcomes is rare pediatric embryonal tumors.

Clinicopathologic analysis of pineal parenchymal tumors of intermediate differentiation: a multi-institutional cohort study by the Kyushu Neuro-Oncology Study Group.

PURPOSE: Pineal parenchymal tumors of intermediate differentiation (PPTIDs), which were recognized in the 2007 World Health Organization (WHO) classification, are rare, accounting for less than 1% of all central nervous system tumors. This rarity and novelty complicate the diagnosis and treatments of PPTID. We therefore aimed to evaluate the clinicopathological significance of this tumor. METHODS: At 11 institutions participating in the Kyushu Neuro-Oncology Study Group, data for patients diagnosed with PPTID were collected. Central pathology review and KBTBD4 mutation analysis were applied to attain the diagnostically accurate cohort. RESULTS: PPTID was officially diagnosed in 28 patients: 11 (39%) with WHO grade 2 and 17 (61%) with WHO grade 3 tumors. Median age was 49 years, and the male:female ratio was 1:2.1. Surgery was attempted in all 28 patients, and gross total resection (GTR) was achieved in 46% (13/28). Adjuvant radiotherapy and chemotherapy were administered to, respectively, 82% (23/28) and 46% (13/28). The 5-year progression-free survival (PFS) and overall survival rates were 64.9% and 70.4% respectively. Female sex (p = 0.018) and GTR (p < 0.01) were found to be independent prognostic factors for PFS and female sex (p = 0.019) was that for OS. Initial and second recurrences were most often leptomeningeal (67% and 100% respectively). 80% (20/25) of patients harbored a KBTBD4 mutation. CONCLUSIONS: Female sex and GTR were independent prognostic factors in our patients with PPTID. Leptomeningeal recurrence was observed to be particularly characteristic of this tumor. The rate of KBTBD4 mutation observed in our cohort was acceptable and this could prove the accuracy of our PPTID cohort.

A temporal in vivo catalog of chromatin accessibility and expression profiles in pineoblastoma reveals a prevalent role for repressor elements.

Pediatric pineoblastomas (PBs) are rare and aggressive tumors of grade IV histology. Although some oncogenic drivers are characterized, including germline mutations in RB1 and DICER1, the role of epigenetic deregulation and cis-regulatory regions in PB pathogenesis and progression is largely unknown. Here, we generated genome-wide gene expression, chromatin accessibility, and H3K27ac profiles covering key time points of PB initiation and progression from pineal tissues of a mouse model of CCND1-driven PB. We identified PB-specific enhancers and super-enhancers, and found that in some cases, the accessible genome dynamics precede transcriptomic changes, a characteristic that is underexplored in tumor progression. During progression of PB, newly acquired open chromatin regions lacking H3K27ac signal become enriched for repressive state elements and harbor motifs of repressor transcription factors like HINFP, GLI2, and YY1. Copy number variant analysis identified deletion events specific to the tumorigenic stage, affecting, among others, the histone gene cluster and Gas1, the growth arrest specific gene. Gene set enrichment analysis and gene expression signatures positioned the model used here close to human PB samples, showing the potential of our findings for exploring new avenues in PB management and therapy. Overall, this study reports the first temporal and in vivo cis-regulatory, expression, and accessibility maps in PB.

All pineal tumors expressing germ cell tumor markers are not necessarily germ cell tumors: histopathological and molecular study of a midline primary intracranial sarcoma DICER1-mutant.

Primary intracranial sarcoma DICER1-mutant is a rare and newly recognized tumor type introduced in the 2021 WHO Classification of Central Nervous System Tumors. It is defined as a spindle cell sarcoma dysplaying eosinophilic intracytoplasmic globules, myogenic differentiation, and DICER1 gene mutation, either somatic or germline. Most reported cases were hemispheric except one, recently described in the pineal region. Here, we report the case of a 12 year-old boy with a pineally located tumor. Despite midline location, poorly differenciated morphology and germ cell marker expression, the association of DICER1 and NF1 hotspot mutations and a specific DNA methylation signature finally lead to the diagnosis of primary intracranial sarcoma DICER1-mutant instead of germ cell tumor. Furthermore, our molecular exploratory results involved a pathway, which was not previously evidenced in those DICER1 mutated cerebral sarcoma that is the canonical Wnt signaling driving likely a part of oncogenesis in this newly described pineal entity.

Pineal Parenchymal Tumor of Intermediate Differentiation and DICER1 Syndrome: A Case Report.

DICER1 syndrome is a rare inherited tumor predisposition syndrome associated with an increased risk for several malignant and benign tumors. We present a patient with pineal parenchymal tumor of intermediate differentiation who was found to have a germline pathogenic variant in DICER1 gene. Pineoblastoma is a known DICER1-related tumor; however, the association between pineal parenchymal tumor of intermediate differentiation and DICER1 mutation is rare with only 1 recent large molecular study that has reported this association. This report adds to the evolving tumor spectrum of DICER1 and highlights the importance of molecular evaluation of pediatric brain tumors, for both therapeutic decisions and long-term surveillance.

Adult Primary Pineal Alveolar Rhabdomyosarcoma with FOXO1 Gene Rearrangement and OLIG2 Expression: A Rare Case Report and Literature Review.

Alveolar rhabdomyosarcoma is a common malignant soft tissue tumor in child and adolescents. Intracranial alveolar rhabdomyosarcoma in adults is rare, especially in the pineal region. We present a case of primary alveolar rhabdomyosarcoma of the pineal gland in a 36-year-old Chinese male with a chief complaint of dizziness, headache and a loss of balance when walking. Imaging identified a space-occupying mass in the pineal region with obstructive hydrocephalus. An endoscopic-assisted pineal mass resection was performed. Pathology revealed a solid, sheet-like growth of medium-sized, round or oval cells with map-like necrosis and some rhabdomyoblasts. The tumor cells were diffusely positive for desmin, myogenin, MyoD1, ALK, and OLIG2. Fluorescence in situ hybridization (FISH) detected FOXO1 gene rearrangement. This rare case is presented to expand the knowledge of pineal gland tumors and alert us to pay attention to the differential diagnosis of OLIG2-positive round-cell tumors of the central nervous system.

Two cases of pineal anlage tumor with molecular analysis.

Pineal anlage tumor is a rare pediatric tumor with clinical and histological features overlapping with pineoblastoma. Two patients with pineal anlage tumor, a 13-month-old female and an 11-month-old male, underwent subtotal resection, high-dose chemotherapy with autologous stem cell rescue, and radiation. Neither had tumor progression 50 months after diagnosis. The tumors underwent next-generation sequencing on a panel of 340 genes. Chromosomal copy gains and losses were present and differed between the tumors. No mutations or amplifications, including none specific to pineoblastoma, were identified.

Clinical and molecular heterogeneity of pineal parenchymal tumors: a consensus study.

Recent genomic studies have shed light on the biology and inter-tumoral heterogeneity underlying pineal parenchymal tumors, in particular pineoblastomas (PBs) and pineal parenchymal tumors of intermediate differentiation (PPTIDs). Previous reports, however, had modest sample sizes and lacked the power to integrate molecular and clinical findings. The different proposed molecular group structures also highlighted a need to reach consensus on a robust and relevant classification system. We performed a meta-analysis on 221 patients with molecularly characterized PBs and PPTIDs. DNA methylation profiles were analyzed through complementary bioinformatic approaches and molecular subgrouping was harmonized. Demographic, clinical, and genomic features of patients and samples from these pineal tumor groups were annotated. Four clinically and biologically relevant consensus PB groups were defined: PB-miRNA1 (n = 96), PB-miRNA2 (n = 23), PB-MYC/FOXR2 (n = 34), and PB-RB1 (n = 25). A final molecularly distinct group, designated PPTID (n = 43), comprised histological PPTID and PBs. Genomic and transcriptomic profiling allowed the characterization of oncogenic drivers for individual tumor groups, specifically, alterations in the microRNA processing pathway in PB-miRNA1/2, MYC amplification and FOXR2 overexpression in PB-MYC/FOXR2, RB1 alteration in PB-RB1, and KBTBD4 insertion in PPTID. Age at diagnosis, sex predilection, and metastatic status varied significantly among tumor groups. While patients with PB-miRNA2 and PPTID had superior outcome, survival was intermediate for patients with PB-miRNA1, and dismal for those with PB-MYC/FOXR2 or PB-RB1. Reduced-dose CSI was adequate for patients with average-risk, PB-miRNA1/2 disease. We systematically interrogated the clinical and molecular heterogeneity within pineal parenchymal tumors and proposed a consensus nomenclature for disease groups, laying the groundwork for future studies as well as routine use in tumor diagnostic classification and clinical trial stratification.

Desmoplastic myxoid tumor, SMARCB1-mutant: a new variant of SMARCB1-deficient tumor of the central nervous system preferentially arising in the pineal region.

Desmoplastic myxoid tumor (DMT), SMARCB1-mutant is a recently proposed brain tumor that occurs in the pineal region of adults. This tumor is characterized by desmoplastic stroma and various degrees of myxoid matrix. Tumor cells with low-grade morphology show polyphenotypic immunoreactivity, and rhabdoid cells are rare. We herein present a case with some uncommon features such as no myxoid stroma and slightly elevated proliferating activity. To date, knowledge on the variety of SMARCB1/INI1-deficient tumors of the central nervous system is gradually increasing, encompassing highly aggressive to slow-growing varieties. DMT, SMARCB1-mutant seems to be relatively benign, but careful attention is necessary because SMARCB1/INI1 deficiency is generally a genetic signature of concern.

Could Aberrant Migration Explain Metachronous Germ Cell Tumors?

BACKGROUND: Extragonadal germ cell tumors (GCTs) are thought to arise as a result of local transformation of primordial gonadal cells (PGCs) that become misplaced during embryogenesis. With the exception of bilateral testis tumors, metachronous GCT (i.e., occurring at a site classically described for primary GCTs) are rare events. PATIENTS AND METHODS: The clinical, radiological, and molecular data (if available) of patients with metachronous GCT were analyzed. RESULTS: Three Caucasian males were identified: case 1 presented with a pineal germinoma 19 years after a mediastinal seminoma that had been treated with chemotherapy, case 2 presented with a pineal non-seminomatous GCT (NSGCT) that occurred three years after a mediastinal seminoma treated with chemotherapy, and case 3 presented with a mediastinal seminoma concomitant with a suprasellar germinoma that occurred two years after a stage I testicular NSGCT treated exclusively with surgery. None of these patients had a positive family history or disorder of sex development. Molecular data were available for cases 2 and 3. In case 2, a CHEK2 gene biallelic inactivation in the second tumor suggested chemoresistance to cisplatin. This was further confirmed by tumor progression during second-line treatment. In case 3, the molecular analysis revealed different profiles in the three tumors, thus suggesting distinct tumor cell origins. CONCLUSION: These rare cases should alert clinicians of the possibility of multiple GCTs that should not be considered to be relapses. The underlying physiopathology is unknown, but multiple PGC mismigrations is a likely cause. Initial treatment with cisplatin may select chemo-resistant clones, thereby making the subsequent treatment more of a challenge.

H3K27M-mutant diffuse midline glioma presenting as synchronous lesions involving pineal and suprasellar region: A case report and literature review.

INTRODUCTION: The differential diagnoses for multifocal lesions with pineal and suprasellar involvement in a young adult include germ cell tumour and intracranial metastasis. Other differentials include atypical teratoid/rhabdoid tumour and pineoblastoma. We present the first known case of multicentric H3K27M mutant diffuse midline glioma, which is typically defined by its diffuse nature, midline location, and H3K27M mutation. CASE REPORT: A young Chinese female presented subacutely with giddiness, right abducens nerve palsy and unsteady gait. Magnetic resonance imaging (MRI) of the brain with contrast revealed a moderately sized pineal region tumour, extending into the third ventricle, associated with hydrocephalus. There were two other synchronous lesions noted in the suprasellar and left occipital region. Serum and cerebrospinal fluid tumour markers, along with a computed tomography scan of her thorax and abdomen and were unremarkable. She underwent an endoscopic third ventriculostomy and biopsy of pineal and suprasellar lesions. Histology demonstrated a poor prognosis variant multifocal glioblastoma multiforme that was IDH wildtype, H3K27M positive, and MGMT unmethylated. MRI of the whole spine did not reveal any drop metastasis. The patient subsequently underwent adjuvant chemotherapy and radiotherapy after she was deemed to be unsuitable for surgical resection. CONCLUSION: Although rare, multicentric H3K27M mutant diffuse midline glioma should be included in the list of differential diagnoses for multifocal enhancing lesions with involvement of the pineal and suprasellar regions, especially if the lesions demonstrate imaging features atypical for more common diagnosis such as germ cell tumours.

Pineal teratoma with nephroblastic component in a newborn male: Case report and review of the literature.

Neonatal germ cell tumors are rare and comprise both benign and malignant neoplasms. Teratoma with nephroblastoma is a malignant subset defined pathologically by the presence of nephroblastoma and teratoma elements. Although teratoma with nephroblastoma is most often found in the kidney, 24 of 59 reported cases are associated with extrarenal locations, such as the mediastinum or retroperitoneum. To our knowledge, this is the first patient in the literature with intracranial/pineal teratoma with nephroblastoma, which was managed with staged transcranial approaches resulting in gross total resection and no adjuvant therapy (surveillance observation imaging). We further augmented the patient's management by comprehensive genomic profiling of the tumor to better understand the molecular biology and explore options for targeted therapy.