Radiological classification of optic pathway gliomas: experience of a modified functional classification system.

Optic pathway gliomas (OPGs) in childhood are associated with neurofibromatosis type 1 (NF1) and since 1958 have been classified anatomically using the Dodge classification (DC). MR scanning permits a more detailed anatomical description than can be classified by this historical system. A modified Dodge classification (MDC) has been applied to MRI scans from a cohort of 72 patients (36.1% NF1-positive) from 4 centres participating in an international clinical trial. The MDC was feasible, applicable and more detailed than the original DC. NF1-positive cases more commonly involved both optic nerves (p = 0.021) and other multiple locations (p = 0.001). NF1-negative tumours more commonly involved the central chiasm (p = 0.005) and hypothalamus (p = 0.003). Fewer hypothalamus-positive tumours were associated with optic nerve involvement (p = 0.009), whereas more were associated with central chiasm involvement (p<0.001). From diagnosis to follow-up, there was concordance between DC and MDC in 51/72 cases (70.8%). The MDC is therefore proposed for use in clinical trials of new treatments for OPGs.

Pediatric craniopharyngiomas: classification and treatment according to the degree of hypothalamic involvement.

OBJECT: The current treatment of craniopharyngiomas is evolving into one of a multimodal approach in which the aim is disease control and improved preservation of quality of life (QOL). To date, an appropriate classification system with which to individualize treatment is absent. The objectives of this study were to identify preoperative prognostic factors in patients with craniopharyngiomas and to develop a risk-based treatment algorithm. METHODS: The authors reviewed data obtained in a retrospective cohort of 66 children (mean age 7.4 years, mean follow-up period 7 years) who underwent resection between 1984 and 2001. Postoperative recurrence rates, vision status, and endocrine function were consistent with those reported in the literature. The postoperative morbidity was related to hypothalamic dysfunction. The preoperative magnetic resonance imaging grade, clinically assessed hypothalamic function, and the sugeon's operative experience (p = 0.007, p = 0.047, p = 0.035, respectively) significantly predicted poor outcome. Preoperative hypothalamic grading was used in a prospective cohort of 22 children (mean age 8 years, mean follow-up period 1.2 years) treated between 2002 and 2004 to stratify patients according to whether they underwent gross-total resection (GTR) (20%), complete resection avoiding the hypothalamus (40%), or subtotal resection (STR) (40%). In cases in which residual disease was present, the patient underwent radiotherapy. There have been no new cases of postoperative hyperphagia, morbid obesity, or behavioral dysfunction in this prospective cohort. CONCLUSIONS: For many children with craniopharyngiomas, the cost of resection is hypothalamic dysfunction and a poor QOL. By using a preoperative classification system to grade hypothalamic involvement and stratify treatment, the authors were able to minimize devastating morbidity. This was achieved by identifying subgroups in which complete resection or STR, performed by an experienced craniopharyngioma surgeon and with postoperative radiotherapy when necessary, yielded better overall results than the traditional GTR.

Newly defined central nervous system neoplasms.

In recent years, numerous new entities or variants of recognized central nervous system tumors have been described in the literature, and the morphologic spectrum of these neoplasms is delineated incompletely. The accurate diagnosis and classification of these lesions is important to ensure that patients receive adequate therapy and prognostic information. The clinicopathologic features and differential diagnosis of 4 new entities, including the chordoid glioma of the third ventricle, cerebellar liponeurocytoma, atypical teratoid/rhabdoid tumor, and papillary glioneuronal tumor, are discussed in this review.