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

Optic Pathway–Hypothalamic Glioma Apoplexy: A Report of Two Cases and Systematic Review of the Literature

Background

Hemorrhage into optic pathway–hypothalamic glioma (OPHG) is rare. Variable clinical presentations and outcomes are associated with such pathology. We aim to present two infants presented with OPHG and a systematic review of the literature.

Methods

We describe two cases of infants presenting with sudden decreased vision, poor feeding, and irritability due to OPHG. Both patients underwent urgent craniotomy and subtotal resection followed by chemotherapy. We systematically reviewed the literature using PubMed, Google Scholar, and Embase. In addition, we included all English published reports for all ages discussing the optic pathway (optic nerve and optic chiasm) or hypothalamic glioma associated with hemorrhage from the year of the first reported case (1970) to January 2022.

Results

Of 17,949, 44 articles met the inclusion criteria of this review. A total of 56 cases were described with a mean of 21.35 years (0.5–70), with the male gender 52% and the female gender 45%. The hemorrhage location was sellar/suprasellar in 43% cases. Histopathology of included cases was pilocytic astrocytoma in 41%, followed by pilomyxoid astrocytoma in 16% cases. The outcome was unfavorable; 37.5% cases showed improvement, whereas 18% cases resulted in death.

Conclusion

Apoplexy of the OPHG can be fatal and associated with poor outcomes. A systematic review of the literature has shown that younger age, pilocytic or pilomexyoid astrocytoma histopathology, and chiasmal/hypothalamic locations are associated with a higher risk of intertumoral hemorrhage and poor prognosis. Further genetic studies for OPHG may provide information for high-risk patients.

Optic pathway-hypothalamic glioma hemorrhage: a series of 9 patients and review of the literature

OBJECTIVEHemorrhage (also known as apoplexy) in optic pathway gliomas (OPGs) is rare. Because of the variable presentations and low incidence of OPG hemorrhages, little is known about their clinical course and the best treatment options. The aim of this work was to review risk factors, clinical course, and treatment strategies of optic glioma hemorrhages in the largest possible number of cases.METHODSA total of 34 patients were analyzed. Nine new cases were collected, and 25 were identified in the literature. Data regarding demographics, radiological and histological features, treatment, and outcome were retrospectively reviewed.RESULTSThe majority of patients were younger than 20 years. Only 3 patients were known to have neurofibromatosis. The histopathological diagnosis was pilocytic astrocytoma in the majority of cases. Five patients had intraorbital hemorrhages, whereas 29 patients had intracranial hemorrhage; the majority of intracranial bleeds were treated surgically. Six patients, all with intracranial hemorrhage, died due to recurrent bleeding, hydrocephalus, or surgical complications. No clear risk factors could be identified.CONCLUSIONSIntracerebral OPG hemorrhages have a fatal outcome in 20% of cases. Age, hormonal status, neurofibromatosis involvement, and histopathological diagnosis have been suggested as risk factors for hemorrhage, but this cannot be reliably established from the present series. The goals of surgery should be patient survival and prevention of further neurological and ophthalmological deterioration.

Hemorrhagic presentation of frontal partially calcified pilocytic astrocytoma in an 18-year-old woman: A case report and literature review as "clinical case"

We report an unusual case of a frontal partially calcified pilocytic astrocytoma (PA) (WHO grade 1) in an 18-year-old woman who presented with acute, spontaneous intracerebral hemorrhage. Histopathology revealed the PA was mixed with psammoma bodies and areas of vascular proliferation responsible for a hypervascular pattern. The patient underwent a total gross resection. MRI showed no residual tumor at the 18-month follow-up and her neurological deficits improved after rehabilitation. Only 20 cases, including ours, of hemorrhagic presentation of PA in adults have been reported to date with enough radiological data. Furthermore, hemorrhagic presentation of a calcified PA is extremely rare. To date only two other cases of calcified PA with hemorrhagic presentation have been reported, one in an adult and one in an infant as described by Shibao et al. (2012) and Kapoor et al. (2015) respectively. Endothelial proliferation may be the main cause of bleeding in these lesions. In our case, a hypervascular pattern was exhibited by histopathological findings. A diagnosis of PA should be considered, especially when calcifications are present within a hemorrhagic tumor lesion.

Adult Pilomyxoid Astrocytoma with Hemorrhage in an Atypical Location

Pilomyxoid astrocytomas (PMAs) are generally seen in young children and tend to occur in the hypothalamic-chiasmatic region. Their presence in other parts of the brain in the nonpediatric age group is uncommon. In addition, hemorrhage in such low-grade tumors is an occasional event. We describe a case of PMA that presented with spontaneous bleed in an atypical location (temporoparietal region) in an adult. A concise literature of the cases of PMA which were associated with bleed is also presented. Occasionally, low-grade tumors such as PMA may present with bleed. These benign looking neoplasms behave differently from the commonly occurring pilocytic astrocytomas (PAs) and should be considered as a differential. It is important to differentiate these from PA, as the management and prognosis differs.

Repeat Bleeding 18 Years After Hemorrhagic Pilocytic Astrocytoma: Prognostic Implications of Conservative Management-Case Report and Literature Review

BACKGROUND

Acute hemorrhagic occurrence of pilocytic astrocytomas is extremely rare but has become increasingly recognized and often presents in clinically emergent situations. The precise significance of hemorrhage in these tumors and its pathogenetic mechanisms have not yet been defined. Nothing is known about the natural history of bleeding pilocytic astrocytomas.

CASE DESCRIPTION

A 21-year-old man presented with acute biventricular hydrocephalus for repeat bleeding of a midbrain lesion that had been diagnosed 18 years earlier after a similar acute hemorrhagic episode. The patient had been initially treated conservatively, considering the high risk of surgery. He underwent urgent biventricular external shunt surgery and, subsequently, total removal of the lesion. Histopathological analysis revealed pilocytic astrocytoma. Including the present case, 59 cases were analyzed and reviewed, including 5 cases with a pilomyxoid variant. Different pathogenetic mechanisms have been proposed, including histological characteristics, rupture of the bridging veins torn by the neoplastic mass, and vascular instability determined by overexpression of vascular endothelial growth factor.

CONCLUSIONS

To the best of our knowledge, the presented case is completely unique owing to the long-term observational follow-up data available. The hemorrhagic potential did not decrease over time, representing a specific feature of this tumor. The occurrence of bleeding might not reflect either malignancy or aggressiveness. However, the worse prognosis is related to the clinical behavior, with life-threatening complications often associated. Surgery remains the standard treatment and will influence the final prognosis.

[Chiasm and optic nerve glioma manifested as hemorrhage (two clinical cases and a literature review)]

The article presents two rare clinical cases of low-grade (WHO grade I-II) glioma of the anterior visual pathway structures, the chiasm and optic nerves, in adults. The feature of these cases was the benign nature of a chiasm and optic nerve glioma in adults as well as its presentation in the form of hemorrhage to the tumor and parenchymal and subarachnoid space, which to some extent complicated making the correct diagnosis. Removal of an intracerebral hematoma and open tumor biopsy were performed in one case, and removal of a hematoma and partial tumor resection followed by radiotherapy were performed in the other case.

Posterior fossa pilomyxoid astrocytoma with spontaneous hemorrhage in pediatric patients

OBJECT

The tumor described in this report was unique because of its involvement with a posterior fossa spontaneous hemorrhage in a pediatric patient; such a case has never been previously described in cases of pilomyxoid astrocytomas and also rarely found in those of pilocytic astrocytomas.

METHODS

This report studied a rare case of posterior fossa pilomyxoid astrocytoma (PMA) with critical and dangerous spontaneous hemorrhage. A 7-year-old girl appeared at the outpatient clinic with sudden headache and vomiting.

RESULTS

The patient underwent gross total tumor resection via suboccipital Medline approach, and no evidence of residual or recurrent tumor was found on magnetic resonance images at two follow-up examinations which were respectively conducted 1 and 5 months after resection.

CONCLUSION

In this report, the authors reviewed the literature and discussed the clinical features and treatment of pilomyxoid astrocytoma. It is important to distinguish this tumor variant from the more indolent pilocytic astrocytoma.

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.

Spontaneous hemorrhages in pediatric supratentorial pilocytic astrocytomas. Malignant presentation of a benign entity

BACKGROUND

Hemorrhage as a presenting feature in pilocytic astrocytoma is an extremely rare phenomenon. When seen in children, most of such tumors exist in the cerebellum. Rarely, a supratentorial pilocytic astrocytoma can present with bleeding.

RESULTS

We present similar two cases and discuss the pathophysiology of such hemorrhage and histopathological changes in thinned hyalinised vessels of this tumor.

CONCLUSION

The presence of calcifications in the peri-hemorrhagic areas and the presence of mass effect disproportionate to the size of the bleeding are harbingers of the presence of a benign neoplasm that may have bled.

High accuracy of arterial spin labeling perfusion imaging in differentiation of pilomyxoid from pilocytic astrocytoma

INTRODUCTION

Pilomyxoid astrocytoma (PMA) is a relatively new tumor entity which has been added to the 2007 WHO Classification of tumors of the central nervous system. The goal of this study is to utilize arterial spin labeling (ASL) perfusion imaging to differentiate PMA from pilocytic astrocytoma (PA).

METHODS

Pulsed ASL and conventional MRI sequences of patients with PMA and PA in the past 5 years were retrospectively evaluated. Patients with history of radiation or treatment with anti-angiogenic drugs were excluded.

RESULTS

A total of 24 patients (9 PMA, 15 PA) were included. There were statistically significant differences between PMA and PA in mean tumor/gray matter (GM) cerebral blood flow (CBF) ratios (1.3 vs 0.4, p < 0.001) and maximum tumor/GM CBF ratio (2.3 vs 1, p < 0.001). Area under the receiver operating characteristic (ROC) curves for differentiation of PMA from PA was 0.91 using mean tumor CBF, 0.95 using mean tumor/GM CBF ratios, and 0.89 using maximum tumor/GM CBF. Using a threshold value of 0.91, the mean tumor/GM CBF ratio was able to diagnose PMA with 77 % sensitivity, 100 % specificity, and a threshold value of 0.7, provided 88 % sensitivity and 86 % specificity. There was no statistically significant difference between the two tumors in enhancement pattern (p = 0.33), internal architecture (p = 0.15), or apparent diffusion coefficient (ADC) values (p = 0.07).

CONCLUSION

ASL imaging has high accuracy in differentiating PMA from PA. The result of this study may have important applications in prognostication and treatment planning especially in patients with less accessible tumors such as hypothalamic-chiasmatic gliomas.

Sustained response to weekly vinblastine in 2 children with pilomyxoid astrocytoma associated with diencephalic syndrome

Diencephalic syndrome (DS) related to hypothalamic/chiasmatic region tumor has mainly been reported with low-grade glioma. We described 2 young children with DS related to pilomyxoid astrocytoma. Despite the recognized more agressive clinical behavior of this histologic subtype, we report successful resolution of DS and sustained tumor response with prolonged use of single-agent vinblastine.

Surgical management of thalamic gliomas: case selection, technical considerations, and review of literature

This study aimed to identify (1) the thalamic gliomas suitable for surgical resection and (2) the appropriate surgical approach based on their location and the displacement of the posterior limb of the internal capsule (PLIC). A retrospective study over a 5-year period (from 2006 to 2010) was performed in 41 patients with thalamic gliomas. The mean age of these patients was 20.4 years (range, 2-65 years). Twenty (49 %) tumors were thalamic, 19 (46 %) were thalamopeduncular, and 2 (5 %) were bilateral. The PLIC, based on T2-weighted magnetic resonance axial sections, was displaced anterolaterally in 23 (56 %) cases and laterally in 6 (14 %) cases. It was involved by lesion in eight (20 %) cases and could not be identified in four (10 %) cases. Resection, favored in patients with well-defined, contrast-enhancing lesions, was performed in 34 (83 %) cases, while a biopsy was resorted to in 7 (17 %) cases. A gross total resection or near total resection (>90 %) could be achieved in 26 (63 %) cases. The middle temporal gyrus approach, used when the PLIC was displaced anterolaterally, was the commonly used approach (63.5 %). Common pathologies were pilocytic astrocytoma (58 %) in children and grade III/IV astrocytomas (86 %) in adults. Preoperative motor deficits improved in 64 % of the patients with pilocytic lesions as compared to 0 % in patients with grade III/IV lesions (P value, 0.001). Postoperatively, two patients (5 %) had marginal worsening of motor power, two patients developed visual field defects, and one patient developed a third nerve paresis. Radical resection of thalamic gliomas is a useful treatment modality in a select subset of patients and is the treatment of choice for pilocytic astrocytomas. Tailoring the surgical approach, depending on the relative position of the PLIC, has an important bearing on outcome.

Temporal and optic pathway pilomyxoid astrocytoma mimicking dural-based lesion: case report and review of the literature

Pilomyxoid astrocytomas (PMAs) are low-grade tumors that share many common traits with pilocytic astrocytomas. However, PMAs have a more worrisome clinical course, with a higher recurrence rate, lower survival rate, and higher risk of leptomeningeal spread compared to pilocytic tumors. These tumors tend to occur in younger children and are typically located in the area of the optic chiasm or hypothalamus. There are few studies examining the radiographic appearance of these lesions. In this case report, the authors present an unusual radiographic appearance of a PMA in an 11-year-old child. Preoperative images suggested a dural-based, homogenously enhancing lesion coupled with an enlarged optic nerve. Surgery revealed an intraparenchymal lesion of the right temporal lobe. There was hyperintensity on T2 MRI sequences, suggesting infiltration of the tumor along the optic tracts.

Clinico-pathological feature of pilomyxoid astrocytomas: three case reports

Pilomyxoid astrocytoma (PMA) is a newly identified variant of pilocytic astrocytoma (PA). We report three cases of PMA with comparison to seven cases of PA in terms of their clinicopathological features. The three cases occurred at the ages of 2, 36 and 6 years, and their tumors were located in the left basal ganglia, the pineal gland, and the cerebellum, respectively. They were diagnosed PMA by surgical specimens that showed a characteristic monomorphous architecture with an angiocentric growth pattern and myxoid background. One patient developed localized relapse at 6 months after the surgery, but the other patients remained alive without tumor progression more than 5 years after treatment. In analysis of the immunohistochemical association in PMA and PA, no specific staining was found to be useful for differential diagnosis of PMA from PA. The expression of biomarkers including O-6-methylguanine-DNA methyltransferase, p53, MIB-1, and EGF receptor neither distinguished PMA from PA nor correlated with outcome. But almost all PMA and PA that demonstrated prominent positivity for nestin showed a high MIB-1 labelling index (LI), and four of these five patients suffered a relapse in the early phase. These results suggest that immunohistochemical expression of nestin and MIB-1 LI may correlate with the aggressiveness of the tumor in PA and PMA.

Pilomyxoid astrocytoma of the cerebellum

Pilomyxoid astrocytomas (PMAs) are low-grade (WHO Grade II) tumors for which the imaging features are similar to pilocytic astrocytomas (PAs), but for which histological features and the clinical course differ. They are classified as a variant of PA. They have only been recently recognized, and they behave more aggressively than PAs. Most cases occur in the hypothalamic-chiasmatic area, although they may be located in any part of the neuraxis. Posterior fossa PMAs are very rare. The authors report a case of a 2-year-old girl with cerebellar PMA.

Synchronous occurrence of a hemorrhagic hypothalamic hamartoma and a suprasellar teratoma

Hypothalamic hamartomas have been reported to coexist with lesions like Rathke's cleft cyst and arachnoid cysts in the suprasellar or temporo-sylvian regions. This is the first report in indexed literature describing its association with a suprasellar teratoma. A 7-year-old girl presented with long-standing precocious puberty and generalized tonic-clonic seizures and recent-onset raised intracranial pressure. MRI done prior to the onset of symptomatic raised intracranial pressure revealed 2 distinct lesions in the suprasellar region. One was a midline, pedunculated lesion arising from the hypothalamus, with evidence of an old bleed within it. A separate lesion, with a wide base near the tuberculum sellae and a posteriorly directed conical tip, was noted in an adjacent sagittal cut. CT scan done at the time of admission demonstrated a re-bleed in the suprasellar region with blood in the lateral and third ventricles and gross hydrocephalus. The child was taken up for a ventriculoperitoneal shunt followed by complete excision of the lesions. Histopathologic examination confirmed the pedunculated lesion to be a hypothalamic hamartoma with evidence of hemorrhage, and the other to be a mature teratoma. Postoperative MRI confirmed complete excision of both the lesions. The child reported regression of precocious puberty and remained seizure-free until the last follow-up 6 months after surgery. A hypothesis based on a dysontogenetic mechanism is discussed to explain the unusual occurrence of the dual, seemingly unrelated pathologies. Hemorrhage into the hamartoma was an added oddity in this case.

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.

Hemorrhagic onset of pilocytic astrocytoma and pilomyxoid astrocytoma

The incidence of hemorrhagic onset in pilocytic astrocytoma and pilomyxoid astrocytoma, and the clinical and histological characteristics, were compared to other types of neuroepithelial tumors or nonhemorrhagic pilocytic astrocytoma by retrospective review of 445 consecutive neuroepithelial tumors treated at our institute. Hemorrhagic onset was observed in 4 of 35 (11.4%) patients with pilocytic astrocytoma and pilomyxoid astrocytoma, with higher incidence than in glioblastoma (3.9%), anaplastic oligodendroglioma (7.7%), and anaplastic ependymoma (7.1%). The hemorrhagic onset occurred in 2 patients with sporadic pilocytic astrocytoma, 1 with pilocytic astrocytoma associated with neurofibromatosis type 1, and 1 with pilomyxoid astrocytoma. There was no correlation between hemorrhagic onset and clinical features, including age, sex, tumor location, proliferative activity, or microvascular proliferation. Hemorrhagic onset of pilocytic astrocytoma and pilomyxoid astrocytoma is not as uncommon as was previously thought, so pilocytic astrocytoma or pilomyxoid astrocytoma should be considered in the differential diagnosis of patients with brain tumors manifesting as hemorrhagic onset.

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.