Integrated Genomic Characterization of a Pineal Parenchymal Tumor of Intermediate Differentiation

A Pineal Parenchymal Tumor of Intermediate Differentiation in an Octogenarian Contains a Rare KBTBD4 Insertion

Pineal parenchymal tumors are rare central nervous system tumors that pose diagnostic challenges for surgical pathologists. Due to their paucity, their clinicopathologic features are still being defined. We report an 86-year-old woman with a remote history of breast lobular carcinoma who presented with a 2-month neurologic history that included gait instability, blurry vision, and headaches. Magnetic resonance imaging revealed a lobular, heterogeneously enhancing pineal region mass compressing the aqueduct of Sylvius. A biopsy performed concomitant with endoscopic third ventriculostomy consisted of small sheets of cells with eosinophilic to clear cytoplasm, multipolar processes, and ovoid nuclei with stippled chromatin. Whole exome sequencing revealed a small in-frame insertion (duplication) in exon 4 of KBTBD4 (c.931_939dup, p.P311_R313dup/ p.R313_M314insPRR), which has very recently been reported in 2 pineal parenchymal tumors of intermediate differentiation (PPTID). Additionally, variants of uncertain significance in CEBPA (c.863G > C, p.R288P) and MYC (c.655T > C, p.S219P) were identified. Although PPTID is considered a disease of young adulthood, review of 2 institutional cohorts of patients with pineal region tumors revealed that 25% of individuals with PPTID were over 65 years of age. In conclusion, PPTID should be considered in the differential diagnosis of pineal region tumors in older adults.

Pineal Parenchymal Tumors of Intermediate Differentiation: A Case Report and Literature Review

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.

Diagnosis and Treatment of Pineal Region Tumors in Adults: A EURACAN Overview

Simple Summary

Pineal region tumors are rare intracranial tumors. A deeper knowledge of these tumors’ molecular mechanisms has been gained in recent years, which has led to a new classification and new potential systemic treatments. Surgery remains the mainstay of treatment, while radiotherapy and systemic therapy depend on histological, molecular, and clinical characteristics. This paper highlights recent developments in the diagnosis and treatment of these tumors.

Abstract

Pineal region tumors are rare intracranial tumors, accounting for less than 1% of all adult intracranial tumor lesions. These lesions represent a histologically heterogeneous group of tumors. Among these tumors, pineal parenchymal tumors and germ cell tumors (GCT) represent the most frequent types of lesions. According to the new WHO 2021 classification, pineal parenchymal tumors include five distinct histotypes: pineocytoma (PC), pineal parenchymal tumors of intermediate differentiation (PPTID), papillary tumor of the pineal region (PTPR), pinealoblastoma (PB), and desmoplastic myxoid tumor of the pineal region, SMARCB1-mutant; GCTs include germinoma, embryonal carcinoma, yolk sac tumor, choriocarcinoma, teratoma, mixed GCTs. Neuroradiological assessment has a pivotal role in the diagnostic work-up, surgical planning, and follow-up of patients with pineal masses. Surgery can represent the mainstay of treatment, ranging from biopsy to gross total resection, yet pineal region tumors associated with obstructive hydrocephalus may be surgically managed via ventricular internal shunt or endoscopic third ventriculostomy. Radiotherapy remains an essential component of the multidisciplinary treatment approach for most pineal region tumors; however, treatment volumes depend on the histological subtypes, grading, extent of disease, and the combination with chemotherapy. For localized germinoma, the current standard of care is chemotherapy followed by reduced-dose whole ventricular irradiation plus a boost to the primary tumor. For pinealoblastoma patients, postoperative radiation has been associated with higher overall survival. For the other pineal tumors, the role of radiotherapy remains poorly studied and it is usually reserved for aggressive (grade 3) or recurrent tumors. The use of systemic treatments mainly depends on histology and prognostic factors such as residual disease and metastases. For pinealoblastoma patients, chemotherapy protocols are based on various alkylating or platinum-based agents, vincristine, etoposide, cyclophosphamide and are used in association with radiotherapy. About GCTs, their chemosensitivity is well known and is based on cisplatin or carboplatin and may include etoposide, cyclophosphamide, or ifosfamide prior to irradiation. Similar regimens containing platinum derivatives are also used for non-germinomatous GCTs with very encouraging results. However, due to a greater understanding of the biology of the disease’s various molecular subtypes, new agents based on targeted therapy are expected in the future. On behalf of the EURACAN domain 10 group, we reviewed the most important and recent developments in histopathological characteristics, neuro-radiological assessments, and treatments for pineal region tumors.

Pineal parenchymal tumor of intermediate differentiation: a systematic review and contemporary management of 389 cases reported during the last two decades

Pineal parenchymal tumor of intermediate differentiation (PPTID) is a WHO grade II and III tumor arising from pineal parenchymal cells. PPTID is a rare tumor accounting for less than 1% of all primary central nervous system neoplasms. Therefore, reports describing the clinical characteristics and biological features of PPTID are lacking. Moreover, the therapeutic strategy remains controversial. The current study aimed to evaluate treatment results and problems of contemporary therapeutic modalities of PPTID based on its features compared with other pineal parenchymal tumors. A comprehensive systematic literature review of 69 articles was performed, including articles on PPTID (389 patients) and similar tumors. Patient demographics, disease presentation, imaging characteristics, biological features, and current therapeutic options and their results were reviewed. We found that histopathological findings based on current WHO classification are well associated with survival; however, identifying and treating aggressive PPTID cases with uncommon features could be problematic. A molecular and genetic approach may help improve diagnostic accuracy. Therapeutic strategy, especially for grade III and aforementioned uncommon and aggressive tumors, remains controversial. A combination therapy involving maximum tumor resection, chemotherapy, and radiotherapy could be the first line of treatment. However, although challenging, a large prospective study would be required to identify ways to improve the clinical results of PPTID treatment.

Clinical Features of Pineal Parenchymal Tumors of Intermediate Differentiation (PPTID): A Single-Institution Series

OBJECTIVE

Pineal parenchymal tumors of intermediate differentiation (PPTID) are rare tumors of the pineal gland. Their treatment is often heterogeneous due to the lack of literature to compile standardized treatments. Although no single institution has large numbers of cases, our experience has been that the clinical course is more varied and complicated than reported.

METHODS

We reviewed the clinical data for all patients with pathology found to be consistent with PPTID at our institution between the years 2006 and 2019.

RESULTS

Nine patients were identified. At initial diagnosis, all were treated with surgery and 4 of 9 patients underwent gross total resection. Adjuvant radiation therapy to the resection bed was administered in 6 of 9 patients. Mean follow-up time was 95.3 months. Mean progression-free survival was 50.5 months, with a tendency to be longer for male sex and after gross total resection. Seven patients developed a recurrence. Five of 6 known locations of first recurrences had either distant metastases or dissemination of disease. First recurrences were treated with radiation alone in 5 patients, craniospinal radiation with multiagent chemotherapy in 1 patient, and surgery with radiation therapy in 1. At last follow-up, 2 patients had died.

CONCLUSIONS

Herein, we report clinical patterns of disease progression and treatment patterns of PPTID. Many patients progressed during the follow-up period. Disseminated disease was the most common presentation at recurrence. Ultimately, given the risk of recurrence and dissemination at recurrence, more aggressive treatment strategies should be considered. Specifically, our series suggests a benefit of adjuvant radiation at initial diagnosis for grade II patients.

Genomic alterations underlying spinal metastases in pediatric H3K27M-mutant pineal parenchymal tumor of intermediate differentiation: case report

Pediatric midline tumors are devastating high-grade lesions with a dismal prognosis and no curative surgical options. Here, the authors report the clinical presentation, surgical management, whole-exome sequencing (WES), and clonality analysis of a patient with a radically resected H3K27M-mutant pineal parenchymal tumor (PPT) and spine metastases consistent with PPT of intermediate differentiation (PPTID). They identified somatic mutations in H3F3A (H3K27M), FGFR1, and NF1 both in the original PPT and in the PPTID metastases. They also found 12q amplification containing CDK4/MDM2 and chromosome 17 loss of heterozygosity overlapping with NF1 that resulted in biallelic NF1 loss. They noted a hypermutated phenotype with increased C>T transitions within the PPTID metastases and 2p amplification overlapping with the MYCN locus. Clonality analysis detected three founder clones maintained during progression and metastasis. Tumor clones present within the PPTID metastases but not the pineal midline tumor harbored mutations in APC and TIMP2.While the majority of H3K27M mutations are found in pediatric midline gliomas, it is increasingly recognized that this mutation is present in a wider range of lesions with a varied morphological appearance. The present case appears to be the first description of H3K27M mutation in PPTID. Somatic mutations in H3F3A, FGFR1, and NF1 have been suggested to be driver mutations in pediatric midline gliomas. Their clonality and presence in over 80% of tumor cells in our patient's PPTID are consistent with similarly crucial roles in early tumorigenesis, with progression mediated by copy number variations and chromosomal aberrations involving known oncogenes and tumor suppressors. The roles of APC and TIMP2 mutations in progression and metastasis remain to be investigated.

ATRX Mutations in Pineal Parenchymal Tumors of Intermediate Differentiation

Pineal parenchymal tumors are rare neoplasms, ranging from WHO Grade I to IV. There are few studies characterizing the molecular profiles of these tumors. ATRX alterations are strongly associated with the presence of the alternative lengthening of telomeres (ALT) phenotype, and within the central nervous system they tend to occur in subsets of gliomas, including those with IDH, NF1, or histone (H3 K27M or G34) mutations. Here, we identified ATRX frameshift mutations by next generation sequencing associated with corresponding protein loss in 2 cases of pineal parenchymal tumors of intermediate differentiation (PPTID) developing in a 21-year-old woman and a 64-year-old man. In contrast, we identified partial ATRX loss in 1 pineoblastoma, among 14 pineal parenchymal tumors of various grades (6 pineoblastomas, 4 pineocytomas, and 4 PPTID) using tissue microarrays; ALT was absent in these cases. Evaluating the cBioPortal database, an ATRX mutation was identified in one (of 3 total) PPTIDs analyzed. Thus, ATRX mutations associated with protein loss and ALT develop in a small subset of pineal parenchymal tumors and may be limited to those with intermediate differentiation. The clinical significance of these alterations requires further study.

Pineal Parenchymal Tumors of Intermediate Differentiation: A long-Term Follow-Up Study in Helsinki Neurosurgery

BACKGROUND

Pineal parenchymal tumors of intermediate differentiation (PPTIDs) are rare lesions with particular features compared with other pineal parenchymal tumors.

METHODS

We present a retrospective review of patients with histologically confirmed PPTIDs who were operated on in our department between 1997 and 2015. A demographic analysis and an evaluation of preoperative status, surgical treatment, as well as immediate and long-term clinical and radiologic outcomes were conducted.

RESULTS

Fifteen patients with PPTIDs were operated on between 1997 and 2015. Gross total removal was achieved in 11 cases; 2 patients underwent near-total resection, 1 partial resection, and 1 received brachytherapy after an endoscopic biopsy. Nine patients required external radiation therapy (4 due to a pleomorphic histology of their lesion including pineoblastoma features in 3 of them; 3 after a subtotal resection; and 2 for tumor recurrence). No patient received chemotherapy. The survival rate of our patients was 57.1% at a mean follow-up of 137.2 ± 77.6 months (39-248 months).

CONCLUSIONS

A proper multidisciplinary management of PPTIDs based on a gross total removal of the lesion, and an adjuvant radiotherapy in selected cases, may improve the overall survival of these aggressive tumors.