Low-grade astrocytomas: prognosis factors and elements of management

Primary adult unilateral thalamic pilocytic astrocytoma with von Recklinghausen's disease mimicking lymphoma: A case report

Thalamic astrocytomas are rare central nervous system tumors that account for 1%-1.5% of all brain tumors. Their Clinical features depend on anatomical involvement. For these tumors, gross total resection is so difficult due to their deep location and also the infiltration of the optic pathway or brain stem. Unilateral adult thalamic locations are rarely described in the literature. Their radiological features often suggest lymphoma. The authors report here a new case of a primary unilateral thalamic pilocytic astrocytoma mimicking lymphoma diagnosed after a stereotactic core biopsy in a 62-year-old male patient with von Recklinghausen's disease and which is responsible for Dejerine-Roussy syndrome. The authors will proceed with a comprehensive review of literature regarding this rare entity.

Low-grade astrocytoma associated with abscess formation: case report and literature review

A rare case of low-grade astrocytoma associated with abscess formation occurred in a 52-year-old man presenting with Broca's aphasia. He underwent craniotomy and tumor removal under the impression of brain tumor with necrotic cystic change. Abscess accumulation within the intra-axial tumor was found intraoperatively. Literature related to brain abscess with brain tumor is reviewed, with an emphasis on abscesses with astrocytoma. We discuss the common brain tumors that are associated with abscess, pathogens that coexist with brain tumor, and the pathogeneses of coexisting brain abscess and tumor. It is very important to know how to differentiate between and diagnose a brain abscess and tumor, or brain abscess with tumor, preoperatively from clinical presentation and through the use of computed tomography, conventional magnetic resonance imaging, diffusion-weighted imaging or magnetic resonance spectroscopy.

Les astrocytomes pilocytiques du diencéphale de l’enfant

BACKGROUND AND PURPOSE

Pilocytic astrocytoma (PA) is a WHO grade I tumor of the central nervous system mostly arising in children and young adults. Management of diencephalic PA is a difficult challenge. Surgical treatment has to cope with both the difficulties of deep location and eloquent area tumors.

MATERIALS AND METHODS

We retrospectively reviewed seven pediatric cases (female: 4, male: 3) of diencephalic PA. Opto-chiasmatic tumors were excluded from the series. Mean age at diagnosis was 108 months (9 years) (range: 4 month-18 years), median age was 111 months. Median follow-up for the series was 125 months. Tumor locations were as followed: right thalamus: 2, both thalami: 1, hypothalamus: 3, and right basal ganglia: 1. At the onset, the first symptom was mostly raised intracranial pressure. The delay in diagnosis ranged from 48 hours up to 6 years.

TREATMENT

a shunting procedure was performed in 3 patients, a direct surgical approach in 5 patients (gross total removal: 2; partial removal: 3) and one patient had only a biopsy. Three children were re-operated. Three patients were treated by radiationtherapy (RT) after surgery. Chemotherapy was delivered for 4 children.

RESULTS

The overall survival rate was 71.4 months (almost 6 years) (range: 3-184 months). Median survival rate was 42 months (3.5 years). Three children died, two by tumor progression and one death related to late side-effects of RT. Four patients have a good quality of life with GOS I (n = 3) or II (n = 1). We observed tumor regression in two patients at 1 and 17 years after the beginning of treatment. Correct diagnosis was only made for two cases at the initial pathological examination.

CONCLUSION

The course of diencephalic PA is still unpredictable. The tumor can be controlled by a partial surgical removal, and a residual tumor can sometimes decrease in size after surgery. Gross total removal of these tumors, although difficult, may be performed. With cranial navigation systems, the risk is low. Pathological diagnosis is sometimes difficult to assess.

Neurosurgical treatment of brain tumors in children

Primary brain tumors are the most common solid neoplasms of childhood. The diagnosis of brain tumors in the general pediatric population remains challenging. Nevertheless, it is clear that refinements in imaging, surgical technique, and adjunctive therapies have led to longer survival and an improving quality of life in children with brain tumors.

Oligodendroglioma: an appraisal of recent data pertaining to diagnosis and treatment

OBJECTIVE

This article reviews and summarizes recent data on the diagnosis, prognosis, and treatment of oligodendroglial tumors.

METHODS

Histological criteria for optimized diagnosis and grading of oligodendroglial tumors are described and discussed. The therapeutic approaches are analyzed in light of the results of recent series.

RESULTS

Oligodendroglial tumors may be more common than is generally thought. Perinuclear halo and "chicken-wire" pattern, although considered classic histological features of oligodendrogliomas, are unreliable as sole criteria for diagnosis. Nuclear regularity and roundness and an eccentric rim of eosinophilic cytoplasm lacking obvious cell processes are more constant features. Grading should be accomplished using a composite of radiological and histopathological relevant features. The allelic loss of chromosome arms 1p and 19q might be a marker for both chemosensitivity and longer survival after chemotherapy. Oligodendrogliomas are notably chemosensitive when compared with other gliomas. For aggressive lesions, chemotherapy should be used upfront, after surgery.

CONCLUSION

Oligodendrogliomas are underdiagnosed. One unfortunate implication is that a large number of patients may be receiving suboptimal care. A simplification in grading of oligodendroglioma to two grades would reduce the confusion surrounding the classification and better define prognosis and response to treatment modalities. A better definition of the so-called mixed tumor should also allow a better classification of these lesions in an intermediate prognostic class between astrocytic and oligodendroglial lesions. Loss of 1p and 19q could be used as a cytogenetic marker in assisting grading. New concepts emerging in the recent literature should help optimize the diagnosis of these lesions and reduce interobserver variability.

p53 protein expression in grade II astrocytomas: immunohistochemical study of 100 cases with long-term follow-up

p53 protein expression was evaluated by immunohistochemistry in a homogeneous series of 100 supratentorial grade II astrocytomas with long-term follow-up. The staining was positive in 72 cases. The proportion of p53 positive tumors was slightly higher in younger patients. The tumor regrowths which derived from p53 positive tumors were themselves p53 positive, and this p53 immunopositivity was often stronger than in the initial tumors. All of the 10 gemistocytic astrocytomas included in our series were p53 positive, and age more than histological type appeared decisive in prognosis. p53 protein expression did not quite reach statistical significance as an independent predictive variable in multivariate analysis, whereas survival was related with age, mass effect, surgery and tumor location. Only a tendency to a longer survival was observed on the curves in younger patients with mildly positive tumors.