Cerebellar pilocytic astrocytoma in adults: a management paradigm for a rare tumour

Rare vermian pilocytic astrocytoma with recurrent spontaneous hemorrhage in the elderly: A case report and review of literature

Background

Pilocytic astrocytoma (PA) is a benign glial tumor predominately seen in pediatrics and early adolescence with associated overall good outcomes. Very few cases of elderly PA have been reported in the literature, and they are known to display unique anatomic, histologic, and genetic peculiarities distinct from pediatric disease. We report a rare case of vermian PA in an octogenarian with recurrent spontaneous intratumoral hemorrhage as a presenting symptom. Furthermore, a review of the literature on the peculiarities of PA in the elderly will be discussed.

Case Description

An 81-year-old woman presented with features suggestive of repeated posterior fossa hemorrhages characterized by headaches, diplopia, and alteration in sensorium occurring about 5 months apart. Brain neuroimaging showed a cerebellar vermian tumor with features suggestive of repeated intratumoral bleeding. She had an initial ventriculoperitoneal shunting for acute hydrocephalus and subsequently had a suboccipital craniotomy and subtotal tumor excision due to morbid adherence to the brainstem. The histologic diagnosis was PA with Ki-67 <1% and negative for isocitrate dehydrogenase-1. There was a slow but progressive clinical improvement, and she has remained symptom-free for 4 years on follow-up.

Conclusion

PA in the elderly is a rare disease with distinct histologic and genetic peculiarities. This case review showed one of the oldest cases of cerebellar vermian PA presenting with recurrent spontaneous intratumoral hemorrhage, an extremely rare occurrence in benign glioma. Although complete surgical excision is recommended, partial resection is advocated for morbidly adherent tumors. Overall prognosis is worse in elderly PA.

MR dynamic-susceptibility-contrast perfusion metrics in the presurgical discrimination of adult solitary intra-axial cerebellar tumors

OBJECTIVES

Adult solitary intra-axial cerebellar tumors are uncommon. Their presurgical differentiation based on neuroimaging is crucial, since management differs substantially. Comprehensive full assessment of MR dynamic-susceptibility-contrast perfusion-weighted imaging (DSC-PWI) may reveal key differences between entities. This study aims to provide new insights on perfusion patterns of these tumors and to explore the potential of DSC-PWI in their presurgical discrimination.

METHODS

Adult patients with a solitary cerebellar tumor on presurgical MR and confirmed histological diagnosis of metastasis, medulloblastoma, hemangioblastoma, or pilocytic astrocytoma were retrospectively retrieved (2008-2023). Volumetric segmentation of tumors and normal-appearing white matter (for normalization) was semi-automatically performed on CE-T1WI and coregistered with DSC-PWI. Mean normalized values per patient tumor-mask of relative cerebral blood volume (rCBV), percentage of signal recovery (PSR), peak height (PH), and normalized time-intensity curves (nTIC) were extracted. Statistical comparisons were done. Then, the dataset was split into training (75%) and test (25%) cohorts and a classifier was created considering nTIC, rCBV, PSR, and PH in the model.

RESULTS

Sixty-eight patients (31 metastases, 13 medulloblastomas, 13 hemangioblastomas, and 11 pilocytic astrocytomas) were included. Relevant differences between tumor types' nTICs were demonstrated. Hemangioblastoma showed the highest rCBV and PH, pilocytic astrocytoma the highest PSR. All parameters showed significant differences on the Kruskal-Wallis tests (p < 0.001). The classifier yielded an accuracy of 98% (47/48) in the training and 85% (17/20) in the test sets.

CONCLUSIONS

Intra-axial cerebellar tumors in adults have singular and significantly different DSC-PWI signatures. The combination of perfusion metrics through data-analysis rendered excellent accuracies in discriminating these entities.

CLINICAL RELEVANCE STATEMENT

In this study, the authors constructed a classifier for the non-invasive imaging presurgical diagnosis of adult intra-axial cerebellar tumors. The resultant tool can be a support for decision-making in the clinical practice and enables optimal personalized patient management.

KEY POINTS

• Adult intra-axial cerebellar tumors exhibit specific, singular, and statistically significant different MR dynamic-susceptibility-contrast perfusion-weighted imaging (DSC-PWI) signatures. • Data-analysis, applied to MR DSC-PWI, could provide added value in the presurgical diagnosis of solitary cerebellar metastasis, medulloblastoma, hemangioblastoma, and pilocytic astrocytoma. • A classifier based on DSC-PWI metrics yields excellent accuracy rates and could be used as a support tool for radiologic diagnosis with clinician-friendly displays.

Rare Neuronal, Glial and Glioneuronal Tumours in Adults

Rare glial, neuronal and glioneuronal tumours in adults form a heterogeneous group of rare, primary central nervous system tumours. These tumours, with a glial and/or neuronal component, are challenging in terms of diagnosis and therapeutic management. The novel classification of primary brain tumours published by the WHO in 2021 has significantly improved the diagnostic criteria of these entities. Indeed, diagnostic criteria are nowadays multimodal, including histological, immunohistochemical and molecular (i.e., genetic and methylomic). These integrated parameters have allowed the specification of already known tumours but also the identification of novel tumours for a better diagnosis.

Fluorescein-guided surgery for the resection of pilocytic astrocytomas: A multicentric retrospective study

Objective

Pilocytic astrocytomas (PAs) are relatively benign tumors, usually enhancing on post-contrast MRI and often characterized by a mural nodule within a cystic component. Surgical resection represents the mainstay of treatment, and extent of resection (EOR) is associated with improved survival. In this study, we analyzed the effect of sodium fluorescein (SF) on the visualization and resection of these circumscribed astrocytic gliomas.

Methods

Surgical databases at two neurosurgical departments (Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy and Department of Neurosurgery, University Medical Center Regensburg, Regensburg, Germany) were retrospectively reviewed to identify the cohort of patients with pilocytic astrocytoma who had undergone fluorescein-guided tumor resection at any of the centers between March 2016 and February 2022. SF was intravenously injected (5 mg/kg) immediately after the induction of general anesthesia. Tumors were removed using a microsurgical technique with the YELLOW 560 filter (Carl Zeiss Meditec, Oberkochen, Germany).

Results

Forty-four patients (25 males and 19 females; 26 pediatric patients, mean age of 9.77 years, range 2 to 17 years; and 18 adult patients, mean age of 34.39 years, range 18 to 58 years) underwent fluorescein-guided surgery. No side effects related to SF occurred. In all tumors, contrast enhancement on preoperative MRI was correlated with intense, heterogeneous yellow fluorescence with bright fluorescent cystic fluid. Fluorescein was considered helpful in distinguishing tumors from viable tissue in all cases except three patients due to faint fluorescein enhancement. Biopsy was intended in two operations, and partial resection was intended in three operations. Gross total resection was achieved in 24 cases out of 39 patients scheduled for tumor removal (61.54%), in five cases a minimal residual volume was highlighted by postoperative MRI despite the intraoperative subjective evaluation of complete tumor removal (12.82%); in the other 10 cases, the resection was subtotal with fluorescent residual spots to avoid neurological worsening (25.64%).

Conclusions

The use of SF is a valuable method for safe fluorescence-guided tumor resection. Our data showed a positive effect of fluorescein-guided surgery on intraoperative visualization during resection of Pas, suggesting a possible role in improving the extent of resection of these lesions.

Adult-Onset Pilocytic Astrocytoma Predilecting Temporal Lobe: A Brief Review

(1) Introduction: Adult-onset pilocytic astrocytoma (APA) accounts for only 1.5% of all brain tumors, and studies regarding APA are limited. This review is focused on the history, clinical course, cytogenetics, neuroimaging features, management, and outcome of APAs. (2) Methods: Using a systematic search protocol in Google Scholar, PubMed, and Science Direct databases, the authors extracted cases of APA predilecting the temporal lobe from inception to December 2020. Articles lacking necessary data were excluded from this study. Data were analyzed using IBM SPSS 23 statistical package software. (3) Results: A total of 32 patients, 14 (43.8%) males and 18 (56.2%) females, with a male/female ratio of 0.77/1, were grouped. The mean age of the patients was 34.22 ± 15.17 years, ranging from 19 to 75. The tumors were predominantly located in the left side. We have also discussed the clinical presentation, and headache was the most common complaint, followed by visual disturbance. Preoperative neuroimaging features demonstrated cystic lesions in 16 patients, with mural nodule in 5 patients; intracerebral hemorrhage was present in 1 patient, and solid enhancing mass was observed in 3 patients. Only our reported case presented as a solid calcified mass. Most of the patients (78.1%) underwent a gross total resection (GTR), only 5 (21.9%) underwent subtotal resection (STR). The outcome and prognosis history were excellent, and no recurrence was observed. (4) Conclusion: Most of the APAs of the temporal lobe follow benign clinical courses, but some patients exhibit aggressive clinical behavior. There was no history of recurrence after treatment at up to 27 years of follow-up.

Typical Pediatric Brain Tumors Occurring in Adults-Differences in Management and Outcome

Adult brain tumors mostly distinguish themselves from their pediatric counterparts. However, some typical pediatric brain tumors also occur in adults. The aim of this review is to describe the differences between classification, treatment, and outcome of medulloblastoma, pilocytic astrocytoma, and craniopharyngioma in adults and children. Medulloblastoma is a WHO IV posterior fossa tumor, divided into four different molecular subgroups, namely sonic hedgehog (SHH), wingless (WNT), Group 3, and Group 4. They show a different age-specific distribution, creating specific outcome patterns, with a 5-year overall survival of 25–83% in adults and 50–90% in children. Pilocytic astrocytoma, a WHO I tumor, mostly found in the supratentorial brain in adults, occurs in the cerebellum in children. Complete resection improves prognosis, and 5-year overall survival is around 85% in adults and >90% in children. Craniopharyngioma typically occurs in the sellar compartment leading to endocrine or visual field deficits by invasion of the surrounding structures. Treatment aims for a gross total resection in adults, while in children, preservation of the hypothalamus is of paramount importance to ensure endocrine development during puberty. Five-year overall survival is approximately 90%. Most treatment regimens for these tumors stem from pediatric trials and are translated to adults. Treatment is warranted in an interdisciplinary setting specialized in pediatric and adult brain tumors.

Pilocytic Astrocytoma: A Review of General, Clinical, and Molecular Characteristics

Pilocytic astrocytomas are the primary tumors most frequently found in children and adolescents, accounting for approximately 15.6% of all brain tumors and 5.4% of all gliomas. They are mostly found in infratentorial structures such as the cerebellum and in midline cerebral structures such as the optic nerve, hypothalamus, and brain stem. The present study aimed to list the main characteristics about this tumor, to better understand the diagnosis and treatment of these patients, and was conducted on search of the published studies available in NCBI, PubMed, MEDLINE, Scielo, and Google Scholar. It was possible to define the main histologic findings observed in these cases, such as mitoses, necrosis, and Rosenthal fibers. We described the locations usually most affected by tumor development, and this was associated with the most frequent clinical features. The comparison between the molecular diagnostic methods showed great use of fluorescent in situ hybridization, polymerase chain reaction (PCR), and reverse transcriptase-PCR, important techniques for the detection of BRAF V600E mutation and BRAF-KIAA1549 fusion, characteristic molecular alterations in pilocytic astrocytomas.

A biphasic tumor in posterior cranial fossa and the pineal region in young adult

Background:

Biphasic tumors of the central nervous system are rarely described and mainly consisted out of the glial and mesenchymal component. The tumor originated out of both astrocytes and pinealocytes, best to our knowledge, has not been described. We present a case of a brain tumor consisted out of pilocytic astrocytoma (PA) and pineocytoma as components situated in the pineal region and posterior cranial fossa in young adult.

Case Description:

We present a 21-year-old patient with a history of intermittent headache, followed by nausea and vomiting, double vision, and dextropulsion. Magnetic resonance imaging revealed an extensive cystic-solid expansive formation in the posterior cranial fossa with a solid part in the area of the pineal gland. The patient underwent surgical resection. The pathohistological analysis showed two types of tumor cells; the major part of tumor showed features of PA, while minor part corresponded to pineocytoma.

Conclusion:

PA accounts for 5% of all gliomas and is most common in children and young adults. It usually occurs in the cerebellum, the optic pathway, third ventricular region, etc. Pineocytomas are rare, accounting up to 1% of all intracranial tumors. Since tumors origin is different, there must be complex molecular events or mutations that can lead to cell rearrangements and generation of two histologically different tissues in the same tumor mass. The course of treatment options is different for PA and pineocytoma; therefore, the case of brain mass consisted out of two different tissues can be helpful when deciding about the treatment of tumors in posterior cranial fossa and pineal region.

Adult Pilocytic Astrocytoma: An Institutional Series and Systematic Literature Review for Extent of Resection and Recurrence

INTRODUCTION

Pilocytic astrocytoma is a classically benign tumor that most often affects pediatric patients. Rarely, it occurs during adulthood. We present a case series and systematic literature review of adult pilocytic astrocytoma (APA) to examine the clinical presentation, extent of resection, and recurrence rate associated with this tumor in this population.

MATERIALS AND METHODS

Our institutional records were retrospectively reviewed for cases of pilocytic astrocytoma in adults. A PubMed search identified English-language studies of pathology-proven APA. A meta-analysis was performed to determine the relationship between extent of tumor resection and recurrence.

RESULTS

Forty-six patients with APA were diagnosed at our institution (mean age 33.6 ± 13.3; 24 [52%] female). Twenty-four patients (52%) underwent gross total resection, 11 (24%) subtotal resection, 4 (9%) near total resection, 4 (9%) observation after biopsy, and 3 (6%) radiotherapy alone. Tumors recurred or progressed in 6 (13%) patients, of whom 4 were treated by STR and 2 were treated by radiotherapy alone. Thirty-nine (95%) patients were still alive at last follow-up. A systematic literature review identified 415 patients with APA in 38 studies. Including our case series, 7 studies reported extent of resection, follow-up, and recurrence. Of 254 patients with a weighted mean follow-up of 77.7 ± 49.6 (31-250) months, 129 (51%) were treated with gross total resection, and 125 (49%) underwent subtotal resection. Tumor recurred in 79 (31%) patients, 22 (27%) after gross total resection and 57 (73%) after subtotal resection (P < 0.001).

CONCLUSIONS

Pilocytic astrocytoma rarely presents during adulthood. Overall, prognosis is favorable and survival rates are high. APA recurrence is more likely after STR, and the goal of surgery should always be GTR when feasible.

Cranial Pilocytic Astrocytoma With Spinal Drop Metastasis in an Adult: Case Report and Literature Review

BACKGROUND

Pilocytic astrocytoma (PA) is a benign neoplasm that typically occurs in the brain within the pediatric and adolescent age groups and is uncommon in adults. It rarely occurs within the ventricles, and the overall prognosis is favorable. A PA of the brain with spinal metastasis at presentation has never been reported in an adult.

CASE DESCRIPTION

We report a case of a 47-year-old man presenting with sudden-onset frontal headache associated with nausea and lethargy in addition to a background of a longer history of back pain and headache. Radiologic imaging revealed an acute intraparenchymal hemorrhage in the right parieto-occipital lobes with intraventricular extension within a peripherally enhancing heterogeneous lesion. Magnetic resonance imaging of the spine revealed a sacral intradural tumor. The patient underwent surgical resection of the intracranial mass followed by debulking of the spinal lesion. Histopathologic study revealed that both the cranial and spinal tumors were PA.

CONCLUSIONS

This case illustrates a unique instance of hemorrhage into a cerebral PA with a spinal metastasis. To our knowledge, this is the first such case reported in an adult. We review the literature on the subject.

Pilocytic astrocytomas

Pilocytic astrocytoma (PA) is the most common pediatric brain tumor in children. PAs are a distinct histologic and biologic subset of glioma that have a slow growth rate and may even spontaneously regress. These tumors tend to arise in the cerebellum and chiasmatic/hypothalamic region, but can also occur in other regions of the central nervous system. Dissemination is uncommon, but may occur in newly diagnosed PAs. Alterations in the Ras/RAF/mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) pathway (Ras/ERK) have been discovered in a majority of PAs, with KIAA1549-BRAF fusions being the most commonly identified alteration. Children with neurofibromatosis 1 are predisposed to developing PAs, primarily within the optic pathway. When required, treatment consists of surgery, chemotherapy, and/or radiation, although new molecular agents targeting the Ras/ERK and related signaling pathways are promising new approaches. The 10-year survival rates are greater than 90% in pediatric patients; however, they are poorer in adults. Tumors that are amenable to complete resection (i.e., cerebellum and cortex) have the best overall survival.

Posterior Fossa Intra-Axial Tumors in Adults

BACKGROUND

The posterior fossa is the site of many types of tumors, and brain metastases are the most common malignancies in that location among adults. Other brain tumors, such as ependymomas, medulloblastomas, and juvenile pilocytic astrocytomas, mostly occur during childhood and are relatively rare in adults. Most primary malignant brain tumors, such as gliomas and lymphomas, tend to be located in the supratentorial compartment.

METHODS

This review summarizes prognostic factors, therapeutic management, and molecular data of intra-axial posterior fossa tumors in adults, including ependymomas, medulloblastomas, and pilocytic astrocytomas.

RESULTS

The literature on intra-axial posterior fossa tumors in adults relies mainly on limited retrospective clinical studies, and such studies employ a wide range of treatment approaches that are usually based on therapies developed specifically for children or for supratentorial brain tumors.

CONCLUSIONS

The clinical course and surgical outcome of adult patients with intra-axial brain tumors in the posterior fossa are summarized in this review. The prognostic factors and therapeutic management of patients with these tumors are controversial because of their rarity, their heterogeneity, and the lack of sufficient data in the literature.

Adult patients with supratentorial pilocytic astrocytoma: long-term follow-up of prospective multicenter clinical trial NCCTG-867251 (Alliance)

BACKGROUND

Pilocytic astrocytoma is a rare tumor in adults. This report is of a prospective clinical trial with long-term follow-up.

METHODS

Between 1986 and 1994, 20 eligible adults with supratentorial pilocytic astrocytomas were enrolled in a prospective intergroup trial of radiotherapy (RT) after biopsy (3 patients) or observation after gross (11 patients) or subtotal (6 patients) resection.

RESULTS

At the time of analysis (median follow-up, 20.8 years), 2 patients (10%) have died and 18 patients (90%) are alive. Neurologic and cognitive function were stable or improved over time for the majority of patients. No toxic effects of treatment or malignant transformations have been recorded at last follow-up. For the entire cohort the 20-year time to progression and overall survival rates are 95% and 90% respectively. The cause of death (2.2 and 16.1 years after enrollment) in both patients was unrelated to tumor although both were biopsy-only patients. One subtotally resected tumor progressed 1 month after enrollment requiring P32 injection into an enlarging cyst. Because of further progression this patient required RT 18 months later. This patient is alive without evidence of progression 18 years after RT.

CONCLUSION

The long-term follow-up results of this prospective trial confirm that adults with pilocytic astrocytomas have a favorable prognosis with regard to survival and neurologic function. Close observation is recommended for adults with pilocytic astrocytomas, reserving RT for salvage, as the majority remain stable after gross or subtotal resection and no adjuvant therapy.

Pure Neuroendoscopic Resection of Cystic Cerebellar Tumors

BACKGROUND

We describe the resection of cerebellar cystic tumors using pure neuroendoscopy. This technique consists of performing all of the procedures under an endoscopic view, with the instruments introduced into the operative field coaxially to the endoscope through a trocar.

CASE DESCRIPTION

Three cases of cerebellar cystic lesions (two pilocytic astrocytomas and one hemangioblastoma) were approached using the pure neuroendoscopic technique. Under general anesthesia and prone positioning, a suboccipital burr hole was created. The endoscope was introduced into the tumor cavity, and a reddish nodule was identified. The monopolar electrode was used to coagulate and dissect the surrounding nodular tissue. Grasping forceps were used to remove the nodule. There were no complications related to tumor removal, and the patients recovered from their symptoms. The follow-up images showed reduction of the cavity with no contrast enhancement.

CONCLUSION

The pure neuroendoscopic technique was shown to be minimally invasive and a successful and secure method to treat cystic cerebellar tumors.

The expression of Wnt-1 inducible signaling pathway protein-2 in astrocytoma: Correlation between pathological grade and clinical outcome

Wnt-1 inducible signaling pathway protein-2 (WISP-2) is a member of the CCN family, which is critical for the control of cell morphology, motion, adhesion and other processes involved in tumorigenesis. The expression pattern and clinical significance of WISP-2 in astrocytomas remains unclear. In this study, reverse transcription-polymerase chain reaction was performed to systematically investigate the expression of WISP-2 in 47 astrocytoma tissues of different pathological grades and 10 normal brain tissues. The mRNA expression levels of WISP-2 in the astrocytoma tissues were observed to be significantly higher than those in the normal brain tissues. Furthermore, the upregulation of WISP-2 was found to be associated with astrocytomas of higher pathological grades. Subsequently, 154 astrocytoma and 15 normal brain tissues were analyzed using immunohistochemistry and similar results were obtained. Univariate and multivariate survival analyses were used to determine the correlations between WISP-2 expression and overall survival (OS) and progression-free survival (PFS). The results indicated that the expression of WISP-2 was found to negatively correlate with patient PFS and OS. These results demonstrated that the WISP-2 protein is involved in the pathogenesis and progression of human astrocytomas and may serve as a malignant biomarker of this disease.

Gliomas of the posterior fossa in adults

Infratentorial gliomas are relatively rare tumors compared to their supratentorial counterparts. As such they have not been extensively characterized as a group and are usually excluded from clinical studies. Using our database we aimed to characterize adult gliomas involving the posterior fossa with respect to their clinical behavior and prognostic factors. We reviewed our neurosurgical and neuro-oncological data bases for adult patients diagnosed with gliomas involving the posterior fossa between 1996 and 2010. Of 1,283 glioma patients, 57 patients with gliomas involving the posterior fossa were identified (4.4 %). Tumors were further classified by location as primary brainstem (n = 21) and primary cerebellar (n = 18) tumors. On univariate analysis survival was correlated to tumor grade and KPS. In addition we have identified a unique group of patients (n = 18) with previously diagnosed supratentorial gliomas who subsequently developed noncontiguous secondary infratentorial extension of their tumors with subsequent rapid clinical deterioration. Gliomas of the posterior fossa comprise a heterogeneous group of tumors. Histological grade of the tumor was found to be the main prognostic factor. Survival of primary cerebellar gliomas is comparable to supra-tentorial gliomas, while brainstem gliomas in adults fare better than in the pediatric population. Secondary extension of supratentorial gliomas to the posterior fossa signifies a grave prognosis.