Proliferative characteristics of juvenile pilocytic astrocytomas determined by bromodeoxyuridine labeling

Bromodeoxyuridine (BUdR) labeling studies were performed to characterize the biological and clinical behavior of 50 juvenile pilocytic astrocytomas (JPAs) from 47 patients. Each patient received an i.v. infusion of BUdR before tumor resection; the excised tumor specimens were stained by the immunoperoxidase method with anti-BUdR monoclonal antibody to determine the BUdR labeling index (LI), or percentage of S-phase cells. The BUdR LI ranged from 0.22 to 4.3% (less than 1% in 34 and greater than or equal to 1% in 16; mean +/- SE, 1.05 +/- 0.13%). Tumors from younger patients often had higher LIs, but as the age of the patients increased, the frequency of tumors with LIs greater than or equal to 1% decreased. Tumors from male patients had higher LIs than those from female patients (1.36 +/- 0.20% [SE] vs. 0.75 +/- 0.13%; P less than 0.01), and tumors in the cerebellum had higher LIs than those in the hypothalamus (1.39 +/- 0.24% vs. 0.87 +/- 0.15%; P less than 0.05). The LI did not correlate with the gross appearance of the tumor (solid or cystic) or with outcome after the initial diagnosis. Overall, there was no difference in the LIs of primary and recurrent tumors. Four tumors (3 primary and 1 recurrent) that recurred after subtotal resection had a higher mean LI than 32 tumors that did not recur after subtotal resection (2.6 +/- 0.7% vs. 0.74 +/- 0.09%; P less than 0.005). None of 14 totally resected tumors (mean LI, 1.3 +/- 0.2%) has recurred.(ABSTRACT TRUNCATED AT 250 WORDS)

Cell kinetics of medulloblastomas

BACKGROUND

Cell kinetics and clinical behavior were correlated for 22 primary and 10 recurrent or metastatic medulloblastomas from 30 patients.

METHODS

Twenty-six patients received bromodeoxyuridine (BUdR) intravenously during craniotomy; excised specimens were stained by the immunoperoxidase method. The BUdR labeling index (LI) was calculated. Four patients received a pulse of tritiated thymidine; LI was calculated autoradiographically.

RESULTS

The mean LI for 32 tumors (11.7 +/- 1.3% standard error) indicated high proliferative potential. LI appeared higher in tumors from younger patients and those in the cerebellar hemisphere as compared with those in the cerebellar vermis. LI did not correlate with survival time. In six BUdR-labeled tumors labeled with iododeoxyuridine, the S-phase duration was 6.1-11.3 hours (mean, 8.0 +/- 0.8 hours); the potential doubling time was 25-82 hours. The actual doubling time, estimated in three cases from serial imaging, was 20-24 days. A cell loss factor of approximately 0.90 was assumed.

CONCLUSION

A high LI may reflect rapid medulloblastoma growth, but survival seemed more dependent on sensitivity to radiation therapy.

Predicting the recurrence of ependymomas from the bromodeoxyuridine labeling index

The usefulness of histopathological grading in predicting the prognosis of patients with ependymomas is controversial. To clarify the discrepancy between the histological malignancy and the prognosis of these tumors, we estimated the proliferative potential of 32 intracranial and intraspinal ependymomas and correlated the findings with the clinical behavior. Each patient received an intraoperative infusion of bromodeoxyuridine (BUdR, 200 mg/m2 i.v.) before tumor removal; the BUdR labeling index (LI), or percentage of BUdR-labeled cells, was determined immunohistochemically in excised specimens. The mean BUdR LI (+/- SD) of intracranial malignant ependymomas was 4.1 +/- 2.8%. Nonmalignant intracranial and intraspinal ependymomas and subependymomas had mean LIs of 1.5 +/- 0.9%, 1.1 +/- 0.3%, and less than 1%, respectively. Overall, 44% of the tumors recurred. There were no statistically significant differences in the recurrence rates of intracranial and intraspinal ependymomas, including subependymomas (43% and 44%, respectively), or of intracranial ependymomas with LIs greater than 1.0% and less than 1.0% (67% and 44%, respectively). However, the early recurrence rate (within 24 months after treatment) of tumors with LIs greater than 1.0% was higher than that of tumors with LIs of less than 1.0% (100% vs. 25%, P less than 0.05). The BUdR LI also showed a statistically significant inverse correlation with the time to recurrence. These findings indicate that BUdR LI reflects the proliferative potential of individual ependymomas and can be used to help predict the recurrence and estimate the prognosis of these tumors.

Evolution of white matter lesions in neurofibromatosis type 1: MR findings

To characterize further the evolution of white matter lesions in neurofibromatosis type 1, we reviewed 68 MR images in 43 patients (age, 1-31 years), including 25 follow-up studies (mean interval, 27 months). Lesion number, location, morphology, signal characteristics, and contrast enhancement were assessed. Lesion characteristics and changes thereof were correlated with the patients' ages. Thirty-four patients (79%) had white matter lesions. These lesions were hyperintense on T2-weighted images, were isointense on T1-weighted images, and showed no mass effect or contrast enhancement in 31 patients; in three patients, T1-prolongation was observed (one with significant mass effect). None of the lesions evolved into a glioma. The most common locations were the cerebellum (49%), brainstem (22%), and internal capsule (19%). Nineteen patients had white matter lesions and follow-up studies. Lesions decreased in size or number in seven patients (average age, 13 years), showed no change in three (average age, 12 years), increased in size or number in four (average age, 5 years), and showed a mixed pattern (increased/decreased size/number) in four (average age, 7 years). White matter lesions in neurofibromatosis type 1 frequently increase in size or number early in childhood; this did not indicate neoplasia in our study. The lesions tend to resolve with increasing age. Lesion progression in a child more than 10 years old warrants close follow-up to rule out a neoplasm.

Proliferative potential and outcome in pediatric astrocytic tumors

In 43 pediatric patients (29 male, 14 female) with primary astrocytic tumors of the central nervous system (CNS), the correlation was evaluated between outcome and proliferative potential, measured by the bromodeoxyuridine (BrdU) labeling index (LI). Twenty-five patients had low-grade gliomas, 13 had anaplastic gliomas, and 5 had glioblastomas multiforme (GBM). All patients underwent surgery; 37 also had chemotherapy, radiation therapy, or both. The median BrdU LIs were less than 1% (range 0-9.3%) in low-grade gliomas, 2.3% (range 0-21.2%) in anaplastic gliomas, and 7.7% (range 0-21.3%) in GBM. Seven of eight patients with BrdU LI greater than 5% have died (median survival 29 weeks). Median survival has not been reached in patients with BrdU LI less than 1% (19/22 alive) or between 1% and 5% (12/13 alive) after median follow-up periods of 165 and 120 weeks, respectively. A high BrdU LI correlated with short survival (p = 0.0001); the association between malignant histology and short survival was weaker (p = 0.019). BrdU LI is therefore a significant predictor of outcome in patients with primary CNS astrocytomas and appears to be a stronger predictor than histology in patients with low-grade and anaplastic gliomas. More patients need to be studied to confirm these preliminary observations.

Neurocutaneous melanosis in association with the Dandy-Walker complex

An infant had a giant congenital nevus, neurocutaneous melanosis (NCM), and a Dandy-Walker malformation of the brain. The diagnosis of NCM was suspected at 6 weeks of age when macrocephaly was noted, resulting in the discovery of hydrocephalus and a Dandy-Walker malformation. Serial magnetic resonance imaging scans demonstrated so-called T1 shortening in the pia or subarachnoid spaces surrounding the cerebellar vermis and in the temporal lobes anterior to the temporal horns. Eventually, a biopsy-proved melanoma developed in the anterior temporal lobe, in an area previously noted to have T1 shortening. Since meningeal cells have been shown experimentally to play a critical role in cerebellar development, we hypothesize that the association of NCM with a Dandy-Walker malformation may be due to meningeal melanosis disrupting the normal development of the cerebellum and fourth ventricle.

Involvement of multiple chromosome 17p loci in medulloblastoma tumorigenesis

Loss of heterozygosity for sequences located on chromosome 17p in several tumor types is often associated with mutations in the tumor suppressor gene p53. We previously showed consistent deletion of chromosome 17p12-13.1 in medulloblastoma, a common childhood brain tumor. Using denaturing gradient gel electrophoresis and direct sequencing, we have detected p53 mutations in only two of 20 medulloblastoma specimens. Moreover, additional RFLP studies of these 20 specimens showed loss of heterozygosity at a more distal and distinct site, 17p13.3. Deletion of 17p almost invariably signified a negative prognosis. Our results suggest that p53 mutations may contribute to the pathogenesis of medulloblastoma in relatively few cases. The consistent deletion of other discrete loci on 17p suggests that additional or alternative tumor suppressor genes may contribute to the tumor's phenotype.

Applications of neuroimaging in hydrocephalus

Hydrocephalus is a common problem in pediatric neurological and neurosurgical practices. In this manuscript, the common imaging appearances of hydrocephalus are discussed in relation to the underlying causes of the hydrocephalus. Moreover, specific findings seen on magnetic resonance imaging (MR) examinations are discussed and contrasted with those on computed x-ray tomography (CT) and ultrasound. Finally the imaging findings associated with treatment of hydrocephalus are discussed. In particular, analysis of shunt function, the diagnosis of shunt failure, and the complications of shunting are stressed.

Report on Gardnerella vaginitis

Gardnerella vaginitis is one of the most common diagnoses in our outpatient clinic. From January 1, 1989 through July 30, 1989 we had 230 positive cultures for G. vaginitis. Eighty-three compliant patients in this group had unabated symptoms with documented positive cultures for Gardnerella after treatment with metronidazole. This led to the use of alternative regimens of ceftriaxone or clindamycin. A survey of antibiotic choice and post-treatment culture obtained 103 entries from 34 active duty women soldiers and 60 women dependents. This paper presents the results of the survey after an introduction beginning with a 1953 article in U.S. Armed Forces Medical Journal.

Hyperfractionated radiation therapy for gliomas of the brainstem in children and in adults

Between February 1984 and September 1990, 60 patients with brainstem gliomas were treated with hyperfractionated radiotherapy in the Department of Radiation Oncology at the University of California, San Francisco. Forty-one children (< or = 18 years) and 19 adults were treated with 100 cGy twice daily with 4-8 hr between doses. Thirty-one patients (21 children and 10 adults) received total doses of 66-72 Gy and 29 patients (20 children and nine adults) received 74-78 Gy. Median follow-up was 208 weeks for all patients (214 weeks for children, 157 weeks for adults). Twenty-three patients (14 children and nine adults) were alive at the time of analysis, surviving 59-359 weeks following treatment. Median actuarial survival was 73.6 weeks overall (72 weeks for children, 190 weeks for adults; p = 0.43). Survival at 12 and 24 months was 65% and 38%, respectively (63% and 32%, for children; 68% and 53% for adults). All patients had pretreatment magnetic resonance imaging by which tumors were classified as either focal or diffuse. No significant pretreatment prognostic factors for adults were identified. In children, significant favorable prognostic factors on univariate analysis were older age (p = 0.001), tumor location in thalamus or midbrain (p = 0.002), focal appearance on MRI scan (p < 0.001) and duration of symptoms > 2 months prior to treatment (p < 0.001). Thirty-five patients had tumor biopsies, leading to a diagnosis in 33 (22 children and 11 adults). Children with moderately anaplastic astrocytomas survived significantly longer than those with glioblastoma multiforme or unbiopsied tumors (p < 0.001). Only duration of symptoms > 2 months remained significant as a favorable prognostic indicator for children on multivariate analysis (p < 0.001). Survival was not significantly different for patients receiving < or = 72 Gy and those receiving > 72 Gy (p = 0.18). No subgroup of patients showed significantly better survival with the higher dose. These findings indicate that hyperfractionated radiotherapy is effective treatment for adults and a subgroup of better prognosis children with brainstem gliomas. There is a subgroup of pediatric patients with extremely poor prognosis for whom even this aggressive treatment does little to extend survival. We conclude that there is no benefit to increasing total dose above 72 Gy for any of the groups analyzed.

Metastatic juvenile pilocytic astrocytoma. Case report

The authors report the case of a metastatic juvenile pilocytic astrocytoma of the hypothalamic region in a 10-year-old boy. Eight years after craniotomy and radiation therapy, the tumor spread via cerebrospinal fluid pathways to the left cerebellar tonsil and the lumbosacral region. Histological evaluation of both the original hypothalamic and the new lumbosacral masses showed features of a slow-growing juvenile pilocytic astrocytoma with no evidence of malignant transformation. The clinical implications and possible mechanisms of metastatic spread are discussed.

Ultrasound-guided aspiration of a neonatal brain abscess

The authors successfully treated a Serratia marcescens brain abscess in the right parieto-occipital region of a newborn infant born at 27 weeks' gestation and weighing 800 g. Bedside ultrasound-guided aspiration techniques and local anesthesia were used to treat the abscess.

Identification of a germ-line mutation in the p53 gene in a patient with an intracranial ependymoma

We detected a germ-line mutation of the p53 gene in a patient with a malignant ependymoma of the posterior fossa. This mutation, which was found at codon 242, resulted in an amino acid substitution in a highly conserved site of exon 7 of the p53 gene; the same mutation was found in both the germ-line and the tumor tissue. This is the most common region of previously described somatic p53 mutations in tumor specimens and of the germ-line p53 mutations in patients with the Li-Fraumeni cancer syndrome. Evaluation of the patient's family revealed several direct maternal and paternal relatives who had died at a young age from different types of cancer. The association of a germ-line p53 mutation with an intracranial malignancy and a strong family history of cancer suggests that p53 gene mutations predispose a person to malignancy and, like retinoblastoma mutations, may be inherited.

Role of neutrophil receptors in opsonophagocytosis of coagulase-negative staphylococci

The role of neutrophil complement receptors in the opsonophagocytosis of 10 strains of coagulase-negative staphylococci was investigated. Polymorphonuclear leukocytes from adults as well as term and premature newborn infants were tested with normal human serum, adult hypogammaglobulinemic serum, and pooled premature infant serum in an opsonophagocytic assay. Neutrophils from premature infants demonstrated significantly lower killing capacity (62%) than neutrophils from adults (86%) or term infants (84%; P less than 0.02). Maximum inhibition of opsonophagocytosis by adult or infant neutrophils occurred with an FcIII receptor blockade (80%), whereas a blockade of complement receptors produced minimal inhibition. Opsonophagocytic activity for the coagulase-negative staphylococci was not influenced by the serum source but was influenced by reducing the serum concentration below 5%. Abrogation of the complement activity of normal human serum by heating or the addition of ethylenediamine tetraacetate reduced opsonophagocytosis by 100 and 96%, respectively, whereas selective inhibition of the classical complement pathway reduced opsonophagocytosis by only 40%. Thus, opsonophagocytosis of coagulase-negative staphylococci by human sera appears to be mediated primarily by neutrophil Fc receptors, but complement is also required. The inefficiency of these interactions with neutrophils from premature infants may partially explain the enhanced susceptibility of very-low-birth-weight neonates to disseminated, coagulase-negative staphylococcal infections.

Deposition and degradation of C3 on type III group B streptococci

Antibody to the polysaccharide capsule of type III group B streptococci (GBS) and complement are essential to host defense against systemic infection in neonates. Interactions between C3 degradation products and specific neutrophil receptors mediate the attachment and ingestion of these organisms. To evaluate the influence of capsule on C3 disposition, we compared the C3 fragments released from a highly encapsulated clinical isolate (M861) with those from an unencapsulated mutant (COH 31-15) and an asialo mutant (COH 31-21) of type III GBS after opsonization with hypogammaglobulinemic serum. Upon sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blot (immunoblot) analysis, the three strains displayed similar patterns of C3 degradation; both C3b and iC3b were detectable. However, as the duration of opsonization increased, C3 fragment bands became more prominent on the encapsulated strain. The capsule, and specifically sialylation of the capsular polysaccharide of type III GBS, promotes C3 fragment deposition. However, C3 was deposited and degraded to iC3b in the absence of capsule. Opsonization of strain M861 with serum containing antibody specific for the polysaccharide capsule facilitated C3 fragment deposition in the early phases of opsonization. Because iC3b is one of the C3 fragments on an encapsulated strain of type III GBS, the relative deficiency of neonatal neutrophil receptors for this ligand may contribute to the virulence of this organism. Sufficient concentrations of antibody may enhance opsonization by facilitating C3 deposition as well as by interacting with Fc receptors on neutrophils.

Management of chiasmal and hypothalamic gliomas of infancy and childhood with chemotherapy

Between March, 1983, and February, 1989, 19 infants or children with chiasmal/hypothalamic gliomas were treated with chemotherapy after either surgical or radiological diagnosis. The patients ranged in age from 15 weeks to 15.6 years (median 3.2 years) at the start of therapy. Twelve patients were treated immediately after diagnosis because of progressive symptoms, and seven received chemotherapy after either radiographic progression or clinical deterioration, including progressive visual loss or intracranial hypertension. Based on biopsy results, seven of these tumors were classified as juvenile pilocytic astrocytomas, two as astrocytomas, two as highly anaplastic astrocytomas, and one as a subependymal giant-cell astrocytoma. There was associated neurofibromatosis in four patients. The two initial patients were treated with either actinomycin D and vincristine or 5-fluorouracil, hydroxyurea, and 6-thioguanine. The remaining patients received nitrosourea-based therapy; 15 evaluable patients were treated with a five-drug regimen that included 6-thioguanine, procarbazine, dibromodulcitol, 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea (CCNU), and vincristine and one received 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) and 5-fluorouracil. Fifteen of the 18 evaluable patients initially managed with chemotherapy either responded to therapy or their condition stabilized. Median time to tumor progression has not been reached at a median follow-up period of 79 weeks (range 6.6 to 303 weeks), and no tumor-related death has occurred with a median follow-up period of 79 weeks (range 18 to 322 weeks) from the initiation of therapy. The four patients who failed therapy or whose disease progressed after chemotherapy were treated satisfactorily with radiation therapy. Initial improvement or stabilization of visual function was obtained in 16 patients. Endocrine function remained stable in all patients during treatment, although three patients required pharmacological treatment for endocrinopathy that was present at diagnosis. These preliminary results suggest that nitrosourea-based cytotoxic regimens are useful for the initial treatment of children with chiasmal/hypothalamic gliomas, and allow potentially harmful radiation therapy to be deferred until progression of disease.

Hyperfractionated irradiation for adults with brainstem gliomas

Hyperfractionated irradiation appears to have improved survival for pediatric patients with brainstem gliomas. However, the efficacy and safety of this technique are less well established for adults with brainstem tumors. In 1984 the UCSF Department of Radiation Oncology began treating adults with brainstem gliomas using 100 cGy fractions given twice daily to total doses ranging between 6600-7800 cGy (median dose 7200 cGy). By the end of 1989, a total of 14 patients had been irradiated with follow-up times for surviving patients ranging between 4-69 months (median follow-up 33 months). Tumor histologies included five moderately anaplastic astrocytomas, one highly anaplastic astrocytoma, and eight which were unbiopsied. At the time of this analysis, six patients had failed locally, with five dying as a result of recurrent tumor. There were no deaths caused by complications or intercurrent illness. The 3-year actuarial survival rate was 59%, with a corresponding 3-year actuarial local control rate of 48%. The projected median survival was in excess of 5 years, whereas the actuarial median time to progression was 31 months (134 weeks). The treatments were well tolerated: the mean pretreatment Karnofsky Performance Status was 74% (range 60-90%); at the end of treatment the mean KPS was 78% (range 60-100%). In terms of neurologic status, six patients improved by the end of treatment, seven were stable, and one experienced only minor deterioration without change in KPS. There were no significant long-term complications (specifically, no instances of either radiation brain necrosis or myelitis). Seven patients required prolonged steroid administration after completing radiotherapy; six of these eventually recurred locally. These results appear to be substantially better than those achieved using conventional radiotherapy regimens, and suggest that this technique merits further investigation.

Low-dose craniospinal radiation therapy for medulloblastoma

At the University of California, San Francisco, 65 children with medulloblastoma of the posterior fossa were treated postoperatively with craniospinal irradiation; the dose to the posterior fossa was 54 Gy. The 26 children initially treated had only radiation therapy, receiving 30 to 40 Gy to the spine and 40 to 50 Gy to the brain. Subsequently, 39 children were treated with low-dose craniospinal irradiation and chemotherapy; 24 to 30 Gy was directed to the whole brain and 24 to 26 Gy to the spinal axis. Chemotherapy generally consisted of procarbazine just before, and hydroxyurea during, radiation therapy. Poor-risk and good-risk patients (defined by tumor resection less than 75% or greater than 75%, positive or negative myelogram, positive or negative cerebrospinal fluid analysis, age less than or greater than 2 years, respectively) were evenly distributed between the low-dose and high-dose craniospinal radiation therapy groups. Median follow-up was 51 months (range, 24 to 228 months). Kaplan-Meier actuarial survival for all patients was 73% at 5 years, 70% at 10 years. Freedom from disease progression was 68% at 5 years, 65% at 10 years. Whereas poor-risk patients treated with low-dose craniospinal irradiation and chemotherapy had a 5-year survival of 58% and a 5-year freedom from disease progression of 39%, those figures in the comparable good-risk patients were 83% and 77%, respectively. For both good-risk and poor-risk patients, the posterior fossa was the primary site of recurrence. Tumors recurred in the frontal region, probably under blocks, in three patients receiving low-dose irradiation and in two receiving the higher dose. Reducing the dose of whole-brain and spinal irradiation and giving chemotherapy did not result in a higher rate of recurrence in the brain or spinal cord. Intellectual and social function appeared better in patients receiving the lower dose. We did not study whether chemotherapy benefitted good-risk patients. Craniospinal axis irradiation at a lower dose than conventionally used does not compromise local control or survival in patients with medulloblastoma, and may reduce toxicity.

Bilateral retinal hamartomas in neurofibromatosis type 2

We report a case of bilateral retinal hamartomas in a child with neurofibromatosis type 2. This unique case demonstrates that a diversity of retinal changes can occur in this disease.

Intracranial arachnoid cysts in children. A comparison of the effects of fenestration and shunting

The best operative intervention for children with arachnoid cysts remains the subject of controversy. Recent reports stress that craniotomy for cyst fenestration is associated with a low incidence of morbidity and mortality and may leave the child shunt-independent. The cases of 40 pediatric patients with arachnoid cysts treated between 1978 and 1989 are reported. Five children with mild symptoms and small cysts that remained stable on follow-up studies have not required surgical intervention. Of 15 patients with cysts initially treated by fenestration, 10 (67%) showed no clinical or radiographic improvement postoperatively and have undergone cyst-peritoneal (eight patients) or ventriculoperitoneal (VP) shunting (one patient), or revision of a VP shunt placed for hydrocephalus before cyst fenestration (one patient). Two other patients with existing VP shunts required no further procedures. Thus, only three (20%) of 15 patients initially treated by fenestration remain shunt-independent after a median follow-up period of 8 years. The 20 other patients were initially treated by cysts shunting and all improved postoperatively; shunt revision has been necessary in six (30%) of these 20 patients because of cysts recurrence. Cyst location influenced the success of shunt treatment; none of the seven middle cranial fossa cysts treated by shunting have required revision, but results with cysts in other locations were less favorable. In all locations, though, shunting was more successful than fenestration. It is concluded that cyst-peritoneal or cyst-VP shunting is the procedure of choice for arachnoid cysts in most locations, including those in the middle cranial fossa.

Magnetic resonance analysis of suprasellar tumors of childhood

A retrospective analysis of the magnetic resonance (MR) images in 53 pediatric patients with pathologically proven suprasellar tumors was performed, in an attempt to identify the characteristic MR features of these tumors and assess the capability of MR to predict a histologic differentiation. The tumors analyzed included 29 astrocytomas, 11 craniopharyngiomas, 4 germinomas, 3 pituitary adenomas with suprasellar extension, 2 teratomas, 1 spindle cell tumor, 1 primitive neuroectodermal tumor, 1 arachnoid cyst and 1 chordoma of the clivus with suprasellar extension. Thirty patients received intravenous Gd-DTPA as part of their MR exam. Certain MR features, while not pathognomonic, are quite helpful in the differentiation of craniopharyngiomas from chiasmatic/hypothalamic astrocytomas. Presence of a high signal intensity component on T1-weighted images, cyst formation with macrocystic predominance, irregular, heterogeneous solid portion, and smooth ring cyst wall enhancement represent the key characteristics of craniopharyngiomas. Solid predominance with microcysts, long T1 and T2 relaxation times, intense enhancement after contrast administration and extension along the posterior optic pathways are the typical MR findings of chiasmatic/hypothalamic astrocytomas. Presence of diabetes insipidus in correlation with the MR findings of a well-marginated, round or lobular tumor with prolonged T1 and T2 relaxation times, which enhances strongly after Gd-DTPA administration may be the clue in the diagnosis of suprasellar germinomas. Teratomas can be separated from other pediatric suprasellar neoplasms on the basis of internal heterogeneity with presence of fat, calcium and various soft tissue densities. Tumors invading the suprasellar cistern by extension are easily differentiated by identification of the primary site of origin. The above features, while not pathognomonic, are quite helpful in making a specific diagnosis.