SNO-EANO-EURACAN consensus on management of pineal parenchymal tumors.

Pineal parenchymal tumors account for less than 0.3% of all CNS tumors and "Pineal parenchymal tumor of intermediate differentiation" (PPTID; World Health Organization (WHO) grades II and III) exhibit intermediary differentiation and prognosis. However "Papillary tumor of the pineal region" (PTPR; WHO grades II and III) is a distinct entity. This combination of rarity and apparent similarity often leads to perplexity regarding the treatment and prognosis among neurosurgeons. In this review, we have tried to elucidate the differences in clinical as well as treatment modalities and outcomes of these two entities. We used the PubMed Database to search for all relevant articles using the keywords "pineal parenchymal tumor of intermediate differentiation" and "Papillary tumor of the pineal region." Articles having details regarding demographic and clinical variables along with treatment and outcomes were chosen for this study. Full text of these articles was analyzed, and data tabulated. A total of 25 articles for PPTID and 45 for PTPR were found suitable for inclusion in this study. The studies were either case reports or small retrospective series with only one systemic review for each pathology. Despite the poor quality of data, some trends were apparent. Surgical resection offered a survival benefit in both pathologies. Radiotherapy was effective in increasing the survival in PPTID, while there was little to no effect in PPTR. Chemotherapy was not found to be beneficial in either. Both of these tumors have moderate growth rate and potential for malignant behavior. This continuum of characteristics makes their optimal treatment strategy difficult and confusing. The discussion on comprehensive literature review should give information for neurosurgeons to decide on optimal treatment strategies.

Papillary tumor of the pineal region (PTPR) is a neuroepithelial brain tumor, which might pose diagnostic difficulties and recurs often. Little is known about underlying molecular alterations. We therefore investigated chromosomal copy number alterations, DNA methylation patterns and mRNA expression profiles in a series of 24 PTPRs. Losses of chromosome 10 were identified in all 13 PTPRs examined. Losses of chromosomes 3 and 22q (54%) as well as gains of chromosomes 8p (62%) and 12 (46%) were also common. DNA methylation profiling using Illumina 450k arrays reliably distinguished PTPR from ependymomas and pineal parenchymal tumors of intermediate differentiation. PTPR could be divided into two subgroups based on methylation pattern, PTPR group 2 showing higher global methylation and a tendency toward shorter progression-free survival (P = 0.06). Genes overexpressed in PTPR as compared with ependymal tumors included SPDEF, known to be expressed in the rodent subcommissural organ. Notable SPDEF protein expression was encountered in 15/19 PTPRs as compared with only 2/36 ependymal tumors, 2/19 choroid plexus tumors and 0/23 samples of other central nervous system (CNS) tumor entities. In conclusion, PTPRs show typical chromosomal alterations as well as distinct DNA methylation and expression profiles, which might serve as useful diagnostic tools.

Tumors of the pineal region comprise several different entities with distinct clinical and histopathological features. Whereas some entities predominantly affect adults, pineoblastoma (PB) constitutes a highly aggressive malignancy of childhood with a poor outcome. PBs mainly arise sporadically, but may also occur in the context of cancer predisposition syndromes including DICER1 and RB1 germline mutation. With this study, we investigate clinico-pathological subgroups of pineal tumors and further characterize their biological features. We performed genome-wide DNA methylation analysis in 195 tumors of the pineal region and 20 normal pineal gland controls. Copy-number profiles were obtained from DNA methylation data; gene panel sequencing was added for 93 tumors and analysis was further complemented by miRNA sequencing for 22 tumor samples. Unsupervised clustering based on DNA methylation profiling separated known subgroups, like pineocytoma, pineal parenchymal tumor of intermediate differentiation, papillary tumor of the pineal region and PB, and further distinct subtypes within these groups, including three subtypes within the core PB subgroup. The novel molecular subgroup Pin-RB includes cases of trilateral retinoblastoma as well as sporadic pineal tumors with RB1 alterations, and displays similarities with retinoblastoma. Distinct clinical associations discriminate the second novel molecular subgroup PB-MYC from other PB cases. Alterations within the miRNA processing pathway (affecting DROSHA, DGCR8 or DICER1) are found in about two thirds of cases in the three core PB subtypes. Methylation profiling revealed biologically distinct groups of pineal tumors with specific clinical and molecular features. Our findings provide a foundation for further clinical as well as molecular and functional characterization of PB and other pineal tumors, including the role of miRNA processing defects in oncogenesis.

Pineal tumors are quite rare and are fairly aggressive tumors seen in young adults and children. These tumors arise from the pineal region or recess from various types of cells in the gland and structures located in close propinquity to the gland. Pineal gland tumors have a heterogeneous spectrum that includes pineal parenchymal tumors (PPTs) and papillary tumors of the pineal region (PTPR). The PPTs are further subclassified into pineocytomas (Grade 1), PPTs of intermediate differentiation (grade 2 or 3), and pineoblastomas (grade 4) based on the World Health Organization (WHO) grades and histopathological features. We discuss the case of an 11-year-old male child who presented with complaints of headache for 15 days, vomiting for seven days, and diplopia for four days. On magnetic resonance imaging (MRI), a soft tissue density lesion was noticed in the posterior third ventricle region. Based on the location and the MRI findings, the differential diagnosis considered were a pineal lesion, a choroid plexus papilloma, or a meningioma. He underwent a right occipital ventriculoperitoneal shunt followed by total excision of the tumor, and the resected specimen was sent for histopathological examination. After pathologic examination, the diagnosis of pineoblastoma (grade 4) with features of a PPT of intermediate differentiation (grades 2-3) was revealed, and the same was confirmed on immunohistochemistry.

Since it has become evident that histopathological grading of ependymoma according to the WHO classification of CNS tumors is not capable of accurately classifying patients into meaningful strata, a broadly accepted molecular classification scheme with prognostic significance is desperately needed. In recent years, ependymomas were classified into molecular subgroups based on transcriptomic alterations. In tumors localized within the posterior fossa, two distinct biological entities of ependymoma were delineated by several studies (designated posterior fossa A and posterior fossa B), which show striking differences in genetic characteristics and clinical outcome. A similar consensus for supratentorial and spinal ependymoma is lacking. We studied genome-wide DNA methylation (Illumina HumanMethylation450 (450k) array) in 180 primary ependymal tumors (80 with corresponding gene expression profiling data generated by Affymetrix 133plus2.0 arrays), including ependymomas (posterior fossa, supratentorial, spinal), subependymomas (SE), myxopapillary ependymoma (MPE), pineal parenchymal tumors of intermediate differentiation (PPTID), and papillary tumors of the pineal region (PTPR). We performed hierarchical clustering to identify robust molecular subgroups. Independent gene expression profiling datasets from previously published ependymoma studies (Johnson et al.; Wani et al.; Witt et al.) were used as validation cohorts. DNA methylation data showed that ependymal brain tumors can be classified into eight molecular subgroups. Notably, MPE, SE, PPTID and PTPR tumors formed robust distinct clusters, as did posterior fossa Group A and Group B ependymomas. Supratentorial ependymomas can be classified into two principle molecular subgroups, one of which displays a dismal prognosis, and comprises predominantly children and infants, and is associated with highly recurrent gene fusion. Notably, a significant number of ependymomas previously classified by histology as WHO Grade II/III look like SE by methylation, and also have extremely good survival. In summary, using genome-wide DNA methylation and transcriptome analysis we could decipher robust molecular subgroups of ependymal brain tumors including supratentorial ependymoma. Diagnoses of tumors with challenging histopathological features can now be supported by this technology. Hence, this approach offers the possibility to replace the unambiguous histological grading system that is currently in use with a robust molecular classification that readily distinguishes biologically, genetically, and clinically meaningful subgroups of ependymal brain tumors. Citation Format: Hendrik Witt, Martin Sill, Khalida Wani, Steve Mack, David Capper, Stephanie Heim, Pascal Johann, Sally Lambert, Marina Rhyzova, Volker Hovestadt, Theophilos Tzaridis, Kristian Pajtler, Sebastian Bender, Till Milde, Paul A. Northcott, Andreas E. Kulozik, Olaf Witt, Peter Lichter, V Peter Collins, Andreas von Deimling, Marcel Kool, Michael D. Taylor, Martin Hasselblatt, David TW Jones, Andrey Korshunov, Ken Aldape, Stefan Pfister. Epigenetic classification of ependymal brain tumors across age groups. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 3094. doi:10.1158/1538-7445.AM2014-3094

Pineal parenchymal tumours of intermediate differentiation are a rare type of pineal parenchymal tumours. As indicated by their name, these tumours fall between pineoblastoma (a malignant pineal parenchymal tumour) and pineocytoma (a benign pineal parenchymal tumour). In this article, we present a case of pineal parenchymal tumour of intermediate differentiation that was successfully treated by resection via the supracerebellar approach. We also discuss the differential consideration based on epidemiological, pathological and radiological findings.

INTRODUCTION: Pineoblastoma (PB) is one of the rarest and most aggressive brain tumors of childhood. PB is considered a “primitive neuroectodermal tumor” (PNET) based on histology, and commonly treated using treatment protocols developed for medulloblastoma; however the survival remains poor. A subset of PBs may occur in the setting of germline mutations involving DICER1 or RB1, but no next-generation sequencing studies have been published on PB to date, and the genetic drivers of sporadic PB remain unknown. METHODS: 21 tumor samples with a histological diagnosis of PB (including recurrent/metastatic samples) from 15 patients were included in this study. Matching germline DNA was available from 2 patients. We performed genome-wide methylation array profiling (Illumina Infinium 450k) on all samples, as well as whole-genome (for samples with matching germline DNA) or whole-exome sequence analysis. Fluorescence in situ hybridization (FISH) and digital droplet PCR (ddPCR) was performed to confirm select focal somatic gains. RESULTS: 14/18 samples from 9/13 patients analyzed by 450k profiling had a methylation signature similar to previously profiled PBs from a reference cohort. Samples from 4 patients were found to be more consistent with a diagnosis of embryonal tumor with multilayered rosettes (ETMR) - like tumor (non 19q amplified), papillary tumor of the pineal region, or pineal parenchymal tumor of intermediate differentiation, respectively. No mutations in DICER1 or RB1 were found. Homozygous deletions in DROSHA were found in tumors from 3 PB patients. In addition, we identified novel recurrent somatic gains involving chromosomal region 1q21 that were confirmed by FISH and ddPCR in 4/5 PB patients. CONCLUSION: Our studies revealed multiple candidate drivers of oncogenesis in PB. We identified novel homozygous deletions in DROSHA, a nuclease involved in microRNA processing. We also identified novel, highly recurrent somatic focal gains involving chromosomal region 1q21, which has been linked to brain growth, autism and schizophrenia, but not previously associated with cancer. Citation Format: Matija Snuderl, Kasthuri Kannan, Olga Aminova, Igor Dolgalev, Adriana Heguy, Arline Faustin, David Zagzag, Sharon L. Gardner, Jeffrey C. Allen, Jeffrey H. Wisoff, David Capper, Volker Hovestadt, Sama Ahsan, Charles Eberhart, Stefan M. Pfister, David T. w. Jones, Matthias A. Karajannis. Novel candidate oncogenic drivers in pineoblastoma. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr LB-172. doi:10.1158/1538-7445.AM2015-LB-172

Chapter 16 - Pineal parenchymal tumors

BACKGROUND Representing 0-4-3% of all intracranial tumors, pineal region tumors (PRTs) are exceedingly rare, histologically diverse lesions. Their rarity and varying responses to treatment have hampered the development of a uniform treatment protocol for these lesions. We aimed to examine our experience with GKRS in pineal parenchymal tumors (PPTs), determining the long-term neurological and radiological outcomes. METHODS All patients with PPT who underwent GKRS between 2015 and 2023 were included in the analysis. Details of clinical presentation and imaging, surgical procedures performed, histopathology, radiosurgical parameters and follow-up were recorded. Outcomes assessed were resolution of hydrocephalus, percentage regression of tumor volume and occurrence of complications. RESULTS Eight patients underwent GKRS for PPTs- Six pineal parenchymal tumors of intermediate differentiation (PPTID), one papillary tumor of pineal region (PTPR), and one radiologically diagnosed PPT. Seven patients had hydrocephalus, managed with an ETV in five cases and VP shunt in two cases. An endoscopic biopsy was performed in six cases, while microsurgical resection was performed in one. The mean dose delivered was 14.9 ± 2.1 Gy. After a mean follow-up of 40.38 ± 13.8 months, all lesions were noted to regress, with a mean 80.7% ± 10.7% reduction in volume. In all cases, hydrocephalus has resolved, and there were no persistent neurological deficits. CONCLUSIONS GKRS is safe and effective in pineal parenchymal tumors (PPTID and PTPR), with a consistent regression of tumor noted in all cases. Emergent management of hydrocephalus, with a biopsy of the lesion followed by GKRS, represent an effective treatment protocol for most pineal lesions, with sustained long-term neurological outcomes.

Papillary tumor of the pineal region (PTPR) is a recently defined tumor entity. Its clinical course is characterized by frequent local recurrence, and patients may experience the burden of symptoms due to the anatomical location of the growing mass. Guidelines for treatment protocols, and the role of radiotherapy are still being investigated. We report the case of a 27-year old woman who was referred to our department after she was diagnosed with PTPR and had undergone multiple surgical interventions. We delivered adjuvant conformal radiotherapy on the gross residual tumor to a total dose of 59.4 Gy (33 × 1.8 Gy). After a follow-up period of 41 months, we obtained a complete response to the treatment, according to the Response evaluation criteria in solid tumors criteria (RECIST). Radiation treatment was well tolerated, and the patient did not develop acute and late side effects. The neurological symptoms, which were documented at the diagnosis and after the surgical procedure, have not been recorded at last follow-up. Formal consensus for managing patients with a diagnosis of PTPR are nonexistent. Despite surgery, this tumor has a tendency to recur. Radiotherapy could have a role in the adjuvant setting and needs to be investigated in a multicenter setting with a long follow-up.Key words: radiotherapy - neurosurgery - magnetic resonance - pineal region - brain tumor.

Background: Papillary tumor of the pineal region (PTPR) represents a rare and histologically distinct subgroup of tumors originating in the pineal region. Few pediatric cases have been reported so far in the literature; therefore, clinical data are scarce.Case Description: We describe a case of PTPR in a 9-year-old girl who presented with a 5-month history of excessive appetite and weight gain. The patient underwent neuroimaging procedures and total gross surgical resection with postoperative adjuvant local radiotherapy, which from our experience was the best treatment choice as an attempt to avoid local recurrence. During 78-month follow-up, the patient from our study manifested no disease recurrence.Conclusion: PTPR should be included in the differential diagnosis of pineal region masses.

Pineal parenchymal tumors of intermediate differentiation (PPTIDs) account for a significant proportion of pineal tumors and are classified as grade II/III according to the WHO classification. The management of PPTIDs remains controversial because of limited reported cases and the absence of standardized treatment guidelines. We present a case of an eight-year-old male child who presented with vomiting and a sudden squint of the eyes. Imaging revealed a well-defined heterogeneous enhancing lesion in the pineal region with acute hydrocephalus. The patient underwent surgical resection, and the tumor was diagnosed as PPTID. Local recurrence occurred 10 months later, requiring a second surgical intervention and adjuvant radiation therapy. A follow-up showed a regression of the tumor and improvement in symptoms. A literature review of reported PPTID cases revealed variability in clinical presentation, treatment approaches, and outcomes. Headaches were the most common symptom, and surgical resection was the primary treatment modality. Adjuvant therapies such as radiation therapy and chemotherapy were utilized in some cases. Tumor recurrence was observed in several instances, underscoring the need for long-term follow-up. In conclusion, PPTIDs are rare brain tumors with challenging diagnosis and management. Surgical resection remains the mainstay of treatment; however, the optimal approach is uncertain. Standardized reporting and larger studies are necessary to establish guidelines for the management of PPTIDs and improve long-term outcomes.

Quantitative values of CT attenuation, apparent diffusion coefficient (ADC), and standardized uptake value (SUV) were investigated for differentiation between pineal parenchymal tumors (PPTs) and germinomas. Differences in age, sex, and calcification pattern were also evaluated. Twenty-three patients with PPTs and germinomas in 20years were retrospectively enrolled under the approval of the institutional review board. CT attenuation, ADC, and SUV (20, 13, and 10 patients, respectively) were statistically compared between the two tumors. Differences in sex and patterns of calcification ("exploded" or "engulfed") were also examined. Mean patient ages were compared among three groups of pineoblastoma, pineal parenchymal tumor of intermediate differentiation, (PPTID) and pineocytoma and germinoma. None of the quantitative values of CT attenuation, ADC, and SUV showed significant differences between PPTs and germinomas (p > .05). However, there was a significant difference in age (p < .05) among the three groups of pineoblastoma (mean age ± standard deviation 7.0 ± 8.7years), PPTID, and pineocytoma (53.7 ± 11.4years) and germinoma (19.1 ± 8.1years). Sex also showed significant differences between PPTs and germinomas (p = .039). Exploded pattern of calcification was found in 9 of 11 PPT patients and engulfed pattern in 7 of 9 patients with germinomas. No reverse pattern was observed, and the patterns of calcification were considered highly specific of tumor types. None of the quantitative imaging values could differentiate PPTs from germinomas. Age, sex, and calcification patterns were confirmed useful in differentiating these tumors to some degree.

Pineal parenchymal tumor of intermediate differentiation (PPTID) is rare. The WHO first classified PPTID in 2000 as a pineal parenchymal tumor (PPT) with an intermediate prognosis between pineocytoma (PC) and pineoblastoma (PB). It is considered an intermediate-grade tumor and divided into WHO grade II or III.The number of available reports about PPTID is presently limited, and the appropriate management for this tumor has not yet been determined.The authors report a rare case of PC in a 63-year-old woman who presented with lower-extremity weakness and gait disturbance. A pineal mass lesion was detected on MRI. A diagnosis of PC was established after microsurgical gross-total tumor resection, and the patient received no adjuvant therapy after surgery. Two years after surgery, a partial recurrence was recognized and Gamma Knife radiosurgery was performed. Fours years later, the patient developed diffuse leptomeningeal dissemination. She was successfully treated with craniospinal irradiation. Leptomeningeal dissemination may develop 6 years after the initial diagnosis of PC. A histopathological study of the recurrent tumor revealed a malignant change from PC to PPTID.The present case shows the importance of long-term follow-up of patients with PPTs following resection and the efficacy of craniospinal irradiation in the treatment of leptomeningeal dissemination.

Pineal region tumours are rare and mainly arise at a younger age. They can be categorized into various types: germ cell tumours (GCT), pineal parenchymal tumours (PPT), meningiomas, gliomas, pineoblastoma, pineal parenchymal tumours of intermediate differentiation, papillary tumours of the pineal region, and SMARCB1- mutant desmoplastic myxoid tumour. Within GCT, germinomas are the most prevalent, comprising the majority of tumours in this region, while nongerminomatous GCTs are also present. In rare instances, metastases from other sites may manifest. These tumours often lead to obstructive hydrocephalus and commonly exhibit symptoms related to mass effect, including headache, nausea, vomiting, and impaired gait stability. Different subtypes of pineal region tumours exhibit distinct radiological characteristics, thus imaging remains the primary diagnostic tool. Histologic diagnosis necessitates biopsy, unless in cases of germ cell tumours, particularly germinomas, which can be identified through elevated levels of tumour markers like alpha-fetoprotein (AFP) and human chorionic gonadotropin (HCG) in both cerebrospinal fluid (CSF) and serum. While benign tumours might be effectively treated with radical resection alone, malignant tumours demand additional chemotherapy and radiotherapy following surgical removal.