Juvenile pilocytic astrocytoma `pilomyxoid variant' with spinal metastases

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.

Spontaneous intratumoural and intraventricular haemorrhage associated with a pilomyxoid astrocytoma in the hypothalamic/chiasmatic region

Pilomyxoid astrocytoma (PMA) is a rare, low-grade glioma that is recognised as a variant of pilocytic astrocytoma. There have been few reports on this pathologic entity presenting with spontaneous haemorrhage. In this study, we report a rare case of PMA in the hypothalamic/chiasmatic region presenting with intratumoural and intraventricular haemorrhage. An external ventricular drain was urgently inserted. A ventriculo-peritoneal shunt (VP) was undergone 4weeks thereafter. The patient received fractionated Gamma Knife radiosurgery in another hospital 3weeks after the VP shunt. Three months later, subtotal resection of the tumour was performed in our hospital via a pterional approach. The pathological diagnosis was PMA. Postoperatively, no adjuvant therapy was given, and the neurologic deficits were improved. However, the presentation of endocrine deficits remained. Notably, PMAs in the hypothalamic/chiasmatic region presenting with massive intratumoural and intraventricular haemorrhage may result in a severe condition and long-term impairment of endocrine function. Long-term follow-up is required to monitor the recurrence of the tumour and endocrinopathy.

Metastatic Low-Grade Gliomas in Children: 20 Years' Experience at St. Jude Children's Research Hospital

BACKGROUND

Patients with low-grade gliomas (LGG), which are the most common childhood brain tumors, have excellent long-term survival. Dissemination of LGG is rare. Robust data on the incidence, presentation, patterns of dissemination, disease behavior, outcome, and best-management approaches do not exist. We describe 20 years of follow-up of children with metastatic LGG.

PROCEDURE

Data collected during the period 1990-2010 were retrospectively reviewed for the following inclusion criteria: diagnosis of metastatic LGG, age younger than 21 years at initial diagnosis, and magnetic resonance imaging of the brain and/or spine at diagnosis and/or follow-up. Patient demographics, pathology, treatment modalities, and outcome were reviewed.

RESULTS

Of 599 patients with LGG, 38 (6%) had metastatic disease at either diagnosis or follow-up. Most tumors (87%) were located in the brain, and half of the patients had metastatic disease at presentation. The most common diagnosis was pilocytic astrocytoma (55%). Chemotherapy was the most common initial treatment modality. Median survival of the group was 6.2 years (range, 0.1-16.9 years). Fifteen (40%) patients died at a median of 6 years from diagnosis (range, 0.8-15 years). Overall survival at 5, 10, and 15 years was 80.7 ± 6.6%, 63.0 ± 10.2%, and 50.9 ± 16.0%, respectively.

CONCLUSION

This study describes the longest follow-up of children with metastatic LGG. LGG is underestimated and entails major morbidity and mortality. Prospective studies are needed to learn the true incidence, study the biology, and determine the best approaches to diagnosis, treatment, and follow-up.

Probing the mechanical properties of brain cancer cells using a microfluidic cell squeezer device

Despite being invasive within surrounding brain tissues and the central nervous system, little is known about the mechanical properties of brain tumor cells in comparison with benign cells. Here, we present the first measurements of the peak pressure drop due to the passage of benign and cancerous brain cells through confined microchannels in a "microfluidic cell squeezer" device, as well as the elongation, speed, and entry time of the cells in confined channels. We find that cancerous and benign brain cells cannot be differentiated based on speeds or elongation. We have found that the entry time into a narrow constriction is a more sensitive indicator of the differences between malignant and healthy glial cells than pressure drops. Importantly, we also find that brain tumor cells take a longer time to squeeze through a constriction and migrate more slowly than benign cells in two dimensional wound healing assays. Based on these observations, we arrive at the surprising conclusion that the prevailing notion of extraneural cancer cells being more mechanically compliant than benign cells may not apply to brain cancer cells.

Impact of chemotherapy on disseminated low-grade glioma in children and adolescents: report from the HIT-LGG 1996 trial

BACKGROUND

We describe demographic data of disseminated childhood low-grade glioma (DLGG) prospectively recruited in the HIT-LGG 1996 study and evaluate the impact of primary chemotherapy (CT) on the outcome of these tumors, which have previously only been described in small and retrospective series.

PATIENTS AND METHODS

The multicenter study HIT-LGG 1996 accrued 1181 children and adolescents with low-grade glioma. 61 patients (5.2%) had tumor dissemination, with 2.8% being present at diagnosis. Frequencies of dissemination for different subgroups were calculated. Efficiency of first-line CT with vincristine/carboplatin was defined in 24 children with dissemination prior to first-line non-surgical-treatment.

RESULTS

Incidence of dissemination was high among infants (16%) with hypothalamic-chiasmatic-glioma (HCG) and diencephalic syndrome. A relevant percentage of HCG showed isolated spinal dissemination. CT achieved objective and overall response rates of 25% and 79% of the primary tumor and a similar response of disseminated lesions. Clinical stabilization or improvement could be achieved in the majority of patients during treatment. However, 20 of 24 patients experienced further progression and 5-year PFS was 6%. Dissemination prior to CT was a negative prognostic factor for PFS within the study (P = 0.005). Overall-survival of primary DLGG was inferior compared to LGG without dissemination at diagnosis (P < 0.001).

CONCLUSION

Complete MRI scan should be a standard diagnostic procedure in young children with hypothalamic-chiasmatic tumors especially if presenting with diencephalic syndrome. Dissemination in childhood LGG relates to impaired PFS. CT delays progression for responders. Multicenter studies have to evaluate the efficacy of extended treatment strategies in DLGG to improve outcome.

Pilomyxoid astrocytoma of the cervical spinal cord in a child with rapid progression into glioblastoma: case report and literature review

INTRODUCTION

Pilomyxoid astrocytoma (PMA) is a recently described glial tumor with similarities to pilocytic astrocytomas, yet with distinct histopathological characteristics and a more aggressive behavior. It occurs predominantly in the hypothalamic/chiasmatic region. Only four patients with spinal cord PMA have been reported in the pediatric population. The 2007 WHO Working Group recognized PMA as a new variant and recommended an assignment to WHO grade II.

OBJECTIVE

The purpose of this paper was to report a rare location, address the aggressive behavior and rapid progression, and based on the specific patient, to review the literature and discuss current treatment strategies.

CASE PRESENTATION

A 12-year-old girl presented with motor and sensory deficits of the left side as well as gait disturbance. Imaging revealed an intramedullary tumor extending from C2 to C7. The patient improved impressively after surgical resection. Histopathological findings were consistent with PMA. Three months later, the patient presented with rapid neurological deterioration. Histopathology after the second operation was consistent with glioblastoma. The outcome was fatal 12 months after initial diagnosis, despite adjuvant therapy.

CONCLUSIONS

This is the fifth pediatric spinal cord PMA in literature. Furthermore, it is the only documented patient with rapid recurrence and progression within 3 months into a glioblastoma. The question of a sampling error affecting initial pathology is raised. Based on contemporary literature data, we discuss the further treatment options, as there are no guidelines yet. Efforts towards registries should be encouraged, as the documentation of PMA might lead to more evidence based treatment strategies.

Imaging characteristics of pilomyxoid astrocytomas in comparison with pilocytic astrocytomas

PURPOSE

Pilomyxoid astrocytoma (PMA) is a recently described astrocytic tumor that has been previously diagnosed as pilocytic astrocytoma (PA). The purpose of this study was to describe the imaging features of PMAs in comparison with PAs.

MATERIALS AND METHODS

We retrospectively reviewed CT/MR images and medical records of 10 patients with PMA and 38 patients with PA. The mean ages of patients with PMA and PA were 10 and 15 years, respectively. Imaging features including location, composition, enhancement pattern, presence of calcification, hemorrhage, and leptomeningeal dissemination were compared in patients with two tumor types.

RESULTS

Six PMAs (60%) occurred at the suprasellar area and the cerebellum was the most common (45%) site of PA. Solid component was dominant in eight PMAs (80%) and in 19 PAs (50%). All of the PMAs containing solid mass (n=8) included non-enhancing portion while 12/37 (32%) PAs included non-enhancing solid portion (p<0.05). Leptomeningeal dissemination was noted in five PMAs (50%) and one PA (3%) (p<0.05). Other imaging findings were not significantly different.

CONCLUSION

A younger age, more frequent occurrence at the suprasellar area, mainly solid mass containing non-enhancing portion, and more frequent leptomeningeal dissemination are helpful differential features of PMAs as compared to PAs.

Pilomyxoid astrocytoma: expanding the imaging spectrum

BACKGROUND AND PURPOSE

Pilomyxoid astrocytoma (PMA) is a recently described variant of pilocytic astrocytoma (PA) with unique clinical and histopathologic characteristics. Because the histopathology of PMA is distinct from that of PA, we hypothesized that PMAs would display distinctive imaging characteristics. We retrospectively reviewed the imaging findings in a large number of patients with PMA to identify these characteristics.

MATERIALS AND METHODS

CT and MR images, pathology reports, and clinical information from 21 patients with pathology-confirmed PMA from 7 institutions were retrospectively reviewed. CT and MR imaging findings, including location, size, signal intensity, hemorrhage, and enhancement pattern, were tabulated.

RESULTS

Patients ranged in age from 9 months to 46 years at initial diagnosis. Sex ratio was 12:9 (M/F). Twelve of 21 (57%) tumors were located in the hypothalamic/chiasmatic/third ventricular region. Nine (43%) occurred in other locations, including the parietal lobe (2/21), temporal lobe (2/21), cerebellum (2/21), basal ganglia (2/21), and fourth ventricle (1/21). Ten (48%) tumors showed heterogeneous rim enhancement, 9 (43%) showed uniform enhancement, and 2 (9%) showed no enhancement. Five (24%) masses demonstrated intratumoral hemorrhage.

CONCLUSION

This series expands the clinical and imaging spectrum of PMA and identifies characteristics that should suggest consideration of this uncommon diagnosis. One third of patients were older children and adults. Almost half of all tumors were located outside the typical hypothalamic/chiasmatic region. Intratumoral hemorrhage occurred in one quarter of patients. PMA remains a histologic diagnosis without definitive imaging findings that distinguish it from PA.

Pilomyxoid astrocytoma in a patient presenting with fatal hemorrhage. Case report

The authors report on a rare case of pilomyxoid astrocytoma in a patient presenting with fatal hemorrhage. This 5-year-old boy presented to the outpatient clinic with headache and vomiting. Computed tomography and magnetic resonance imaging studies revealed a mass lesion with partial hemorrhage in the suprasellar region extending into the third ventricle. Partial resection via a transcallosal approach was performed. Because the pathological diagnosis was pilomyxoid astrocytoma, chemotherapy was administered. However, 4 months after the first operation, during chemotherapy, the boy presented with massive intratumoral and intraventricular hemorrhage with hydrocephalus. Although emergent external ventricular drainage was performed, the patient died. In this report, the authors review the literature and discuss the clinical features and treatment of pilomyxoid astrocytoma.

Magnetic resonance imaging and spectroscopy of pilomyxoid astrocytomas: case reports and comparison with pilocytic astrocytomas

BACKGROUND AND PURPOSE

Pilomyxoid astrocytomas (PMAs) have been described only recently. They appear as low-grade tumors sharing imaging features similar to pilocytic astrocytomas (PAs). However, pilomyxoid astrocytomas have different histological features and behave more aggressively than PAs. We present the imaging and proton spectroscopic (magnetic resonance spectroscopy; MRS) findings in 3 patients with PMA and compare them with those of PA arising in other sites.

METHODS

Three patients who later proved to harbor PMA were studied with MR imaging and multivolume MRS. We analyzed the imaging findings, with attention to location, size, signal intensities, pattern of enhancement, and edema. In addition, we analyzed the MRS, with attention to the peaks of choline (Cho), creatine (Cr), N-acetyl aspartate, lipids, lactate, and myoinositol, and ratios between these metabolites. We compared the MRS studies of PMA with those of PA located in the hypothalamus and brain stem.

RESULTS

In 2 patients, the PMAs were located in the chiasmatic-hypothalamic and third-ventricular-hypothalamic regions, showing solid enhancement, high T2 signal intensity, and hydrocephalus. One PMA was found in the right parietal lobe showing a well-defined mass without enhancement and high T2 signal intensity. The 2 PMAs showed high Cho/Cr ratios in peritumoral regions at long echo time in comparison with PA. A third PMA showed slight elevation of Cho/Cr ratio in peritumoral regions and no elevation of Cho/Cr ratios within the mass when compared with a PA. Short echo time MRS obtained in 2 PMAs showed low myoinositol/Cr ratios in tumoral regions in comparison with PA.

CONCLUSIONS

Our 2 PMAs showed imaging features similar to those described in the literature. Magnetic resonance spectroscopy showed elevated Cho/Cr outside their enhancing margins, which may be related to their more aggressive behavior when compared with PA. The third PMA was different to those previously reported in the literature because it was hemispheric rather than hypothalamic in location in addition to having low intratumoral ratios of Cho/Cr.

Pilomyxoid astrocytoma: neuroimaging with clinicopathologic correlates in 4 cases followed over time

Pilomyxoid astrocytoma (PmA) is a recently identified tumor type characteristically located in the hypothalamus and occurring in young children (<2 y). PmAs were formerly included in large series of pilocytic astrocytomas (PA) until it was realized in 1999 that this differing phenotype tended to manifest a more aggressive biologic course. PmA is defined by its pathologic features of a monomorphous architectural pattern, abundant myxoid background, and absence of features seen in classic PA. We present 4 histologically definite cases of PmA seen at our institution over a minimum 5-year follow-up time: one was rapidly fatal after initial treatment and 2 recurred during therapy. No singular neuroimaging feature can reliably diagnose PmA. However, PmAs tend to be solid, are more commonly necrotic and show extension of abnormal signal intensity into adjacent structures. Cysts, calcification, and perilesional edema are more common in classic PA. Serial neuroimaging in PmA shows early progression of predominantly solid, and later progression of predominantly cystic component. Radiologists should consider this diagnosis particularly in young children with hypothalamic tumors that lack the typical cystic appearance seen in PA.

Dissemination patterns of pilocytic astrocytoma

Two patients with multifocal pilocytic astrocytoma diagnosed by magnetic resonance imaging (MRI) and confirmed by histopathological examination are reported. They presented distinct sites and mechanisms of metastasis: to distant ventricles through the cerebral spinal fluid (CSF) in patient 1 and to contralateral parenchyma, possibly through white matter tracts, in patient 2, a pathway not so far reported in pilocytic astrocytoma. Early detection of multifocal pilocytic astrocytoma by MRI may change treatment strategies and improve prognosis.

Neuropathological spectrum of pilocytic astrocytoma: an Indian series of 120 cases

Pilocytic astrocytomas (PAs) are generally well circumscribed, slowly growing, cystic tumors, occurring in the pediatric age group. Our aims were to retrospectively analyze the neuropathological spectrum of PA, and correlate it with various clinicopathological features. A total of 120 PAs, diagnosed and managed at this center during a 5-year period, were included. The study population had a mean age of 18.9 years, with male predominance (68.3%), and demonstrated predilection for posterior fossa (61.7%). On histopathology, biphasic pattern (89.2%) along with Rosenthal fibers (66.7%) and eosinophilic granular bodies (60%) were present in the majority of cases. Vascular features were characterized by perivascular hyalinization (51.7%), angiomatous proliferation (21.7%) and glomeruloid changes (21.7%). Hemosiderin-laden macrophages were noted in 37.1% of cases. Further, 60.8% showed lymphoplasmacytic infiltration, while atypia and necrosis were present in 25.8% and 1.7% of cases, respectively. Statistical evaluation revealed significant correlation of angiomatous proliferation with age (< or =12 and >12-year age groups) (p=0.011); and of hemosiderin deposition with angiomatous proliferation (p=0.006), perivascular hyalinization (p=0.035), and age (< or =12 and >12-year age groups) (p=0.028). This study emphasizes that though PAs generally display classical histomorphology, diagnosis may be challenging in patients with unusual clinicopathological features, e.g. in older patients, uncommon location, absence of biphasic pattern, or presence of nuclear atypia, mitotic figures and necrosis, and also in cases of small biopsies. In the absence of diagnostic histology enumerated above, vascular features like angiomatous proliferation, glomeruloid changes and perivascular hyalinization, along with hemosiderinladen macrophages and perivascular lymphocytic infiltration should be considered as surrogate histological markers of PA.