Regression of microcephaly as a protective factor of neuropsychomotor development in fetal surgery for occipital encephalocele.

PURPOSE: Encephaloceles are neural tube closure defects characterized by herniation of intracranial contents through the skull, with a mortality rate of 33.3%. Approximately 50% of patients who survived have some degree of neuropsychomotor developmental impairment or seizures. This study aimed to analyze the relationship between good neuropsychomotor development (NPMD) in patients undergoing fetal occipital encephalocele correction and the reversal of microcephaly, comparing these outcomes with those observed in patients who underwent postnatal surgery. METHODS: The 22 participants were categorized into two groups: 10 in the fetal group (FG) and 12 in the postnatal group (PNG). During the study, 1 patient was excluded from the FG and 2 patients were excluded from the PNG, totaling 19 patients in the study. All patients were diagnosed, evaluated, and monitored by the same healthcare service between July 2012 and July 2018. All participants were subjected to a careful developmental assessment using the Bayley Scale of Infant Development, Second Edition (BSID-II), up to 2 years and 11 months of age. Additionally, CP measurements were taken during the first year of life to monitor their progress. The relationship between microcephaly reversal and NPMD was studied. RESULTS: The CP adjusted for gestational age showed a tendency toward the reversal of progressive microcephaly after correction of encephaloceles in the FG. We found a statistically significant difference in the median BSID-II score between the PNG and FG. Patients in the FG maintained normal CP development in the first year of life, whereas those in the PNG remained microcephalic. CONCLUSION: The reversal of microcephaly in the FG directly influences good NPMD and can be considered a protective factor.

Prognostic factors of pediatric pineal region tumors at a single institution.

PURPOSE: This study aimed to identify factors of a worse prognosis among different histological types of pineal region tumors in pediatric patients treat at a single institution in a 30-year period. MATERIAL AND METHODS: Pediatric patients (151; < 18 years of age) treated between 1991 and 2020 were analyzed. Kaplan-Meyer survival curves were created, and the log-rank test was used to compare the main prognostic factors in the different histological types. RESULTS: Germinoma was found in 33.1%, with an overall 60-month survival rate of 88%; the female sex was the only factor of a worse prognosis. Non-germinomatous germ cell tumors were found in 27.1%, with an overall 60-month survival rate of 67.2%; metastasis upon diagnosis, residual tumor, and the absence of radiotherapy were associated with a worse diagnosis. Pineoblastoma was found in 22.5%, with an overall 60-month survival rate of 40.7%; the male sex was the only factor of a worse prognosis; a tendency toward a worse outcome was found in patients < 3 years of age and those with metastasis upon diagnosis. Glioma was identified in 12.5%, with an overall 60-month survival rate of 72.6%; high-grade gliomas were associated with a worse prognosis. Atypical teratoid rhabdoid tumors was found in 3.3%, and all patients died within a 19-month period. CONCLUSION: Pineal region tumors are characterized by the heterogeneity of histological types, which exert an influence on the outcome. Knowledge of the prognostic factors for each histological types is of extreme importance to the determination of guided multidisciplinary treatment.

Mansonic neuroschistosomiasis in the childhood: an undiagnosed pathology?

Schistosomiasis is an endemic parasitic disease in several tropical countries. In Brazil, the only prevalent species of parasite responsible for schistosomiasis is Schistosoma mansoni. Neuroschistosomiasis is the second most frequent form of infection and the primary ectopic manifestation, with predominant involvement of the lower thoracic spinal cord and lumbar and lumbosacral regions. The frequent contact of children with contaminated ponds and the immaturity of their immune systems make this age group especially susceptible to infection by this parasite. Therefore, neuroschistosomiasis mansoni should always be considered in cases of transverse myelitis in children from endemic regions. The treatment for this condition is quite simple and effective, resulting in total recovery of neurological deficits if the diagnosis is made early.

Training model for the fetal myelomeningocele correction with multiportal endoscopic technique.

PURPOSE: The recent history of myelomeningocele has shown that treatment during the fetal life may reduce the risk of developing hydrocephalus in individuals by approximately 50%. Thus, a significant advancement involves fetal surgery performed through an endoscopic technique in which portals are placed to introduce the forceps and laparoscopic instruments. However, the development of this technique requires training; therefore, this study aimed to develop a training model for fetal myelomeningocele repair technique with multi-portal endoscopy. METHODS: Two stages of endoscopic technique development were performed. The first stage consisted of exercises in order to familiarize the surgeon with 2D-vision endoscopic surgery, associated with the application of exercises focused on surgical skills, such as the development of laparoscopic knots in a synthetic model. The second stage involved the creation and application of the stages of myelomeningocele closure with a non-living animal model consisting of a chicken breast to simulate the myelomeningocele and a basketball to simulate the gravid uterus, in which perforations were made to introduce vascular introducers (portals) that, as in vivo, are used as portals (trocars) for the introduction of laparoscopic instruments. Overall, two different scenarios with three portals and two portals were tested. RESULTS: In three-portal simulator, the triangular apex trocar was used for the introduction of 4-mm 0° or 30° optics or even Minop type neurodoscope (Aesculap®, Germany) that was operated by the assistant surgeon; the other two portals are used for the introduction of laparoscopic instruments. Thus, the surgeon is able to perform maneuvers bimanually since dissection to laparoscopic sutures. In two-portal simulator, the surgeon and assistant stay side by side and one of the portals is used for the optic and the other for the laparoscopic instruments. There is no possibility of bimanual dissection in this method. CONCLUSION: Realistic simulation models for endoscopic fetal surgery for myelomeningocele correction are easily performed and help develop the necessary skills for fetal surgery teams.

Fluorescein-guided resection for pediatric low-grade gliomas: institutional experience on two cases and a narrative literature review.

PURPOSE: Low-grade gliomas compose 30% of pediatric central nervous system tumors and outcomes of disease-free progression, and survival is directly correlated to the extent of resection. The use of sodium fluorescein (Na-Fl) is an intraoperative method in the localization of tumor cells in adult patients to optimize resection. Our purpose is to describe the use of Na-Fl in pediatric low-grade gliomas and its outcomes. METHODS: Patients under 18 years of age with low-grade gliomas at the author's institution underwent resection with the use of Na-Fl, with review of preoperative imaging findings, intraoperative results, and follow-up. Then, a comprehensive, narrative literature review of the use of Na-Fl in pediatric low-grade glioma was performed. RESULTS: Our single-institution use of Na-Fl in pediatric patients with suspected low-grade glioma demonstrated excellent results of intraoperative enhancement of tumor cells as well as gross total resection. The literature demonstrated 84% Na-Fl staining and 59.2% of gross total resection in pediatric low-grade gliomas with few small case studies, a range of reported findings, and few side effects. CONCLUSION: Na-Fl has a promising use in low-grade glioma resection in the pediatric patient population. Further research is warranted, such as randomized controlled studies, to assess Na-Fl as a potential tool in improving resection and long-term favorable outcomes.

Risk for hydrocephalus, hygroma, and tumor dissemination after ventricular opening during resection of supratentorial neoplasms in children.

PURPOSE: The possibility that ventricular opening generates postoperative complications after surgical tumor treatment often restricts the degree of tumor resection. This study aims to determine whether the ventricular opening is associated with more complications in surgeries for resectioning supratentorial intra-axial brain tumors in the pediatric population. METHODS: A retrospective review analysis was performed of patients treated at IOP/GRAACC between 2002 and 2020 under 19 years of age and underwent surgery for supratentorial intra-axial primary brain tumor resection. Data were collected from 43 patients. RESULTS: Glial tumor was more common than non-glial (65% vs. 35%, p = 0.09). The ventricular opening was not related to neoplastic spreads to the neuroaxis (6% vs. 0, p > 0.9) or leptomeningeal (3% vs. 0, p > 0.9). Of the patients whose ventricle was opened, 10% developed hydrocephalus requiring treatment, while none of the patients in the group without ventricular opening developed hydrocephalus (p = 0.5). There was also no statistical difference regarding ventriculitis. Postoperative subdural hygroma formation correlated with the ventricular opening (43% vs. 0, p = 0.003). The survival at 1, 5, and 10 years of cases with the ventricular opening was 93.2%, 89.7%, and 75.7%, respectively, while in cases without ventricular opening, it was 100%, 83%, and 83%, respectively, respectively, with no statistical difference between the mortality curves. CONCLUSION: Our study demonstrated that ventricular violation was not associated with the occurrence of significant complications. It was related to the formation of subdural hygroma, which did not require additional treatment.

Fetal neurosurgery.

Among fetal surgical procedures, neurosurgery stands out due to the number of cases and the possibility of developing new procedures that can be performed in the fetal period. To perform fetal neurosurgical procedures, there is a need for specialized centers that have experts in the diagnosis of fetal pathologies and a highly complex obstetrics service with specialized maternal-fetal teams associated with a pediatric neurosurgery center with expertise in the diverse pathologies of the fetus and the central nervous system that offers multidisciplinary follow-up during postnatal life. Services that do not have these characteristics should refer their patients to these centers to obtain better treatment results. It is essential that the fetal neurosurgical procedure be performed by a pediatric neurosurgeon with extensive experience, as he will be responsible for monitoring these patients in the postnatal period and for several years. The objective of this manuscript is to demonstrate the diagnostic and treatment possibilities, in the fetal period, of some neurosurgical diseases such as hydrocephalus, tumors, occipital encephalocele, and myelomeningocele.

Reduction in the cerebrospinal fluid protein level after bevacizumab treatment in patients with optic pathway low-grade gliomas.

Optic pathway gliomas (OPG) can cause elevated cerebrospinal fluid (CSF) protein concentrations. We report on two patients with suprasellar low-grade gliomas and high CSF protein levels (590 and 551 mg/dl) that precluded shunt implantation. After two and three doses of bevacizumab, respectively, the levels dropped dramatically to 191 and 178 mg/dl, respectively. Bevacizumab treatment was associated with a decrease in CSF protein level, allowing successful shunt placement. Our results are consistent with the pharmacological mechanism of bevacizumab, which decreases protein leakage from blood vessels to the ventricles.

Medullary neuroschistosomiasis in adolescence: case report and literature review.

INTRODUCTION: Medullary neuroschistosomiasis is a severe complication of gastrointestinal infection by Schistosoma. There are several endemic areas, wherein the only causative species present is Schistosoma mansoni, which is responsible for the clinical manifestations of all cases in those areas. METHODS: We report the case of a 13-year-old female with lumbar pain and progressive lower limb weakness, with a delayed diagnosis of medullary involvement by the parasite. We also reviewed the literature on the disease. CONCLUSIONS: Although it is related to the less severe forms of schistosomiasis, one should pay attention to the diagnosis of neuroschistosomiasis in cases of transverse myelitis in patients who traveled to endemic areas. The delay in diagnosis and, consequently, the introduction of treatment may result in irreversible neurological sequelae.

Alterations in skull base anatomy in intrauterine and postnatal repaired myelomeningoceles.

PURPOSE: The aim of this study was to analyze the skull base anatomy of patients who underwent intrauterine or postnatal myelomeningocele repair and to determine its relationship with hydrocephalus. METHODS: This was a retrospective cross-sectional study that analyzed three groups: the postnatal group, 57 patients who underwent myelomeningocele repair up to 48 h after birth; the fetal group, 70 patients who underwent myelomeningocele repair between 19 and 27 weeks of gestation; and a control group (65). We compared the rate of hydrocephalus treatment, the clivus-supraocciput angle (CSA), and the Welcher angle. RESULTS: The mean CSA in the fetal group was 87.6°, and the postnatal group was significantly different at 78.3° (p < 0.0001). The control group (89.1°) was significantly different from the postnatal group but not from the fetal group. The mean Welcher angle was not significantly different between the groups. There was an 8.5% rate of surgical treatment for hydrocephalus in the fetal group, compared with 73.6% in the postnatal group. CONCLUSIONS: The CSA in the fetal group was larger than that in the postnatal group, which may explain the decrease in the prevalence of hydrocephalus in the fetal group.

Surgical approaches for brainstem tumors in pediatric patients.

PURPOSE: To analyze the pathways to brainstem tumors in childhood, as well as safe entry zones. METHOD: We conducted a retrospective study of 207 patients less than 18 years old who underwent brainstem tumor resection by the first author (Cavalheiro, S.) at the Neurosurgical Service and Pediatric Oncology Institute of the São Paulo Federal University from 1991 to 2011. RESULTS: Brainstem tumors corresponded to 9.1 % of all pediatric tumors operated in that same period. Eleven previously described "safe entry zones" were used. We describe a new safe zone located in the superior ventral pons, which we named supratrigeminal approach. The operative mortality seen in the first 2 months after surgery was 1.9 % (four patients), and the morbidity rate was 21.2 %. CONCLUSIONS: Anatomic knowledge of intrinsic and extrinsic brainstem structures, in association with a refined neurosurgical technique assisted by intraoperative monitoring, and surgical planning based on magnetic resonance imaging (MRI) and tractography have allowed for wide resection of brainstem lesions with low mortality and acceptable morbidity rates.

Outcomes and surgical approaches for pineal region tumors in children: 30 years' experience.

OBJECTIVE: Pineal region tumors account for 2.7%-11% of all CNS tumors in children. In this series, the authors present their surgical results and long-term outcomes from a pediatric pineal region tumor cohort. METHODS: A total of 151 children aged 0-18 years were treated from 1991 to 2020. Tumor markers were collected in all patients; if positive, chemotherapy was performed, and if negative, biopsy was performed, preferably endoscopically. Resection was performed when there was a residual germ cell tumor (GCT) lesion after chemotherapy. RESULTS: The distribution based on histological type, as verified by markers, biopsy, or surgery, was germinoma (33.1%), nongerminomatous GCT (NGGCT) (27.2%), pineoblastoma (22.5%), glioma (12.6%), and embryonal tumor (atypical teratoid rhabdoid tumor) (3.3%). A total of 97 patients underwent resection, and gross-total resection (GTR) was achieved in 64%; the highest GTR rate (76.6%) was found in patients with GCTs, and the lowest (30.8%) was found in those with gliomas. The supracerebellar infratentorial approach (SCITA) was the most common, performed in 53.6% of patients, followed by the occipital transtentorial approach (OTA), performed in 24.7% of patients. Lesions were biopsied in 70 patients, and the diagnostic accuracy was 91.4. The overall survival (OS) rates at 12, 24, and 60 months as stratified by histological type were 93.7%, 93.7%, and 88% for patients with germinomas; 84.5%, 63.5%, and 40.7% for patients with pineoblastomas; 89.4%, 80.8%, and 67.2% for patients with NGGCTs; 89.4%, 78.2%, and 72.6% for patients with gliomas; and 40%, 20%, and 0% for patients with embryonal tumors, respectively (p < 0001). The OS at 60 months was significantly higher in the group with GTR (69.7%) than in the group with subtotal resection (40.8%) (p = 0.04). The 5-year progression-free survival was 77% for patients with germinomas, 72.6% for patients with gliomas, 50.8% for patients with NGGCTs, and 38.9% for patients with pineoblastomas. CONCLUSIONS: The efficacy of resection varies by histological type, and complete resection is associated with higher OS rates. Endoscopic biopsy is the method of choice for patients presenting with negative tumor markers and hydrocephalus. For tumors restricted to the midline and with extension to the third ventricle, a SCITA is preferred, whereas for lesions with extension toward the fourth ventricle, an OTA is preferred.

Endoscopic Laser Fenestration to Treat a Bobble-Head Doll Syndrome Caused by Suprasellar Cyst.

The bobble-head doll syndrome (BHDS) is a rare acquired head movement disorder characterized by up and down or side-to-side movement, most commonly seen in the first decade of life. The syndrome occurs more often in lesions causing third ventricle dilatation such as suprasellar or third ventricle cyst, but it is also found in other pathologies associated with hydrocephalus like shunt dysfunctions, trapped fourth ventricle, congenital aqueductal stenosis, Dandy-Walker syndrome, and cerebellar malformations. The pathophysiology of this head movement has different origins theories; one states that this stereotyped movements empties the cyst and move the dome away from the foramina of Monro, which relieves the symptoms of hydrocephalus; the other suggests that the extrapyramidal tracts (rubrotegmentospinal and reticulospinal) are stimulated by the compression of dorsomedial nucleus of the thalamus by the cyst, whose tracts innervate the neck muscles resulting in the bobbling head movements. This video (Video 1) presents a clinical case of BHDS caused by suprasellar cyst in a 10- year-old boy treated by endoscopic procedure. A ventricular-cyst-cisternostomy was performed resulting in complete improvement of the head movements and uneventful recovery. Postoperative images demonstrate decreasing of the cyst lesion and resolution of the hydrocephalus.

Functional Motor Skills in Children Who Underwent Fetal Myelomeningocele Repair: Does Anatomic Level Matter?

BACKGROUND: In this study, we evaluated children who underwent prenatal myelomeningocele (MMC) repair to investigate the influence of the anatomical level of the lesion on functional motor skills and congenital orthopedic malformations. METHODS: This cross-sectional study evaluated children who underwent prenatal correction. The anatomical level of the lesion was classified by observing the magnetic resonance of the spine. The sensory/motor assessment was performed by physical examination to classify the status of ambulation, functional level, and functional performance according to chronological age using the Pediatric Evaluation of Disability Inventory (PEDI-CAT) scale. RESULTS: One hundred cases were evaluated; for 60%, lesions were located in the upper lumbar region and for 40%, they were located in the lower lumbar and sacral regions. The functionality, measured by the PEDI-CAT scale, showed a normal average according to age (mean 50), with 71% of children being community ambulators. Congenital orthopedic malformations were also unrelated to the injury levels, except for knee dislocation in relation to upper lumbar injury. At the functional level, we observed that for the majority, the levels of function of at least 2 vertebrae were below the anatomical level. CONCLUSIONS: There were no differences in functional motor skills, walking pattern, or congenital orthopedic malformation when compared with the anatomical level of injury in patients who underwent prenatal repair of MMC, except for congenital knee dislocation.

Fetal surgery for occipital encephalocele.

OBJECTIVE: In this study, the authors retrospectively reviewed two cohorts of patients with occipital encephalocele (OE) and demonstrate the technical aspects of an innovative and unprecedented method for fetal OE correction. METHODS: This was a cross-sectional retrospective study of 22 patients who underwent surgery from July 2012 to July 2018. The inclusion criteria for participants were a gestational age between 19 weeks and 27 weeks, a maternal age ≥ 18 years, a normal fetal karyotype, the presence of microcephaly, and a cystic hernial sac with the cystic component accounting for more than 80% of the total volume, which was larger than 10 ml. The fetuses with OE and microcephaly underwent intrauterine repair. The exclusion criteria were the presence of a fetal anomaly not associated with OE, chromosomopathy, presence of the brainstem inside the hernial sac or venous sinuses inside the herniated content, the risk of premature birth, placenta previa, and maternal conditions that would constitute an additional risk for fetal and maternal health, as well as refusal for fetal surgery. The authors reviewed the potential for microcephaly reversal and the long-term neurocognitive development. RESULTS: The authors report the cases of 9 fetuses with OE and microcephaly who underwent intrauterine OE repair at gestational ages of less than 27 weeks (fetal group). One case selected for fetal surgery also presented with placental abruption. All patients who underwent the fetal operation had microcephaly reversal, and 3 patients required ventriculoperitoneal shunting in the 1st year of life. The authors reviewed the cases of 12 patients who underwent postnatal repair. In 10 cases, fetal surgery was refused (postnatal group), and in 2 cases, the inclusion criteria for fetal surgery were not met. The authors evaluated the neurocognitive development of the patients with the Bayley Scales of Infant Development II. The median score for the fetal group was 98.7, and that for the postnatal group was 27.8. CONCLUSIONS: The intrauterine repair of OE may stop the progression of encephalocele sac herniation and result in microcephaly reversal. The fetal group had a better cognitive outcome than the postnatal group. The technique required to correct this defect is feasible for those with previous experience in the correction of fetal myelomeningocele. However, more studies are needed to ensure the efficacy of this procedure.

High-grade gliomas in children and adolescents: is there a role for reoperation?

OBJECTIVE: Tumors of the CNS are the main causes of childhood cancer and have an incidence that exceeds that of leukemia. In addition, they are the leading causes of cancer-related death in childhood. High-grade gliomas account for 11% of such neoplasms and are characterized by aggressive clinical behavior and high morbidity and mortality. There is a lack of studies focusing on the factors that can prolong survival in these patients or guide therapeutic interventions. The authors aimed to investigate the factors related to longer survival durations, with a focus on reoperation for gross-total resection (GTR). METHODS: In this retrospective cohort study, the authors analyzed 78 patients diagnosed with high-grade gliomas occurring across all CNS locations except diffuse intrinsic pontine gliomas. Patients 0 to < 19 years of age were followed up at the Pediatric Oncology Institute. Overall survival (OS) and progression-free survival (PFS) were analyzed in the context of various prognostic factors, such as age, sex, histology, extent of tumor resection, reoperation for GTR, adjuvant treatment, and treatment initiation from 2010 onward. RESULTS: With a mean age at diagnosis of 8.7 years, 50% of the patients were female and approximately 39% underwent GTR at some point, which was already achieved in approximately 46% of them in the first surgery. The median OS was 17 months, and PFS was 10 months. In terms of median OS, the authors found no significant difference between those with reoperation for GTR and patients without GTR during treatment. Significant differences were observed in the OS in terms of the extent of resection in the first surgery, age, sex, Ki-67 expression, adjuvant treatment, and treatment initiation from 2010 onward. Furthermore, the PFS values significantly differed between those with GTR in the first surgery and Ki-67 expression ≥ 50%. CONCLUSIONS: This study demonstrates the importance of GTR for these neoplasms, highlights the role of surgeons in its achievement in the first attempt, and questions the role of reoperation for this purpose. Finally, this study further supports the use of combined adjuvant treatment for the improvement of OS and PFS.

New therapeutic target for pediatric anaplastic ependymoma control: study of anti-tumor activity by a Kunitz-type molecule, Amblyomin-X

EPNs comprise a heterogeneous group of neuroepithelial tumors, accounting for about 10% of all intracranial tumors in children and up to 30% of brain tumors in those younger than 3 years. Actually, the pattern therapy for low-grade EPNs includes complete surgical resection followed by radiation therapy. Total surgical excision is often not possible due to tumor location. The aim of this study was to evaluate, for the first time, the anti-tumor activity of Amblyomin-X in 4 primary cultures derived from pediatric anaplastic posterior fossa EPN, Group A (anaplastic, WHO grade III) and one primary culture of a high grade neuroepithelial tumor with MN1 alteration, which was initially misdiagnosed as EPN: i) by in vitro assays: comparisons of temozolomide and cisplatin; ii) by intracranial xenograft model. Amblyomin-X was able to induce cell death in EPN cells in a more significant percentage compared to cisplatin. The cytotoxic effects of Amblyomin-X were not detected on hFSCs used as control, as opposed to cisplatin-treatment, which promoted a substantial effect in the hAFSCs viability. TEM analysis showed ultrastructural alterations related to the process of cell death: mitochondrial degeneration, autophagosomes and aggregate-like structures. MRI and histopathological analyzes demonstrated significant tumor mass regression. Our results suggest that Amblyomin-X has a selective effect on tumor cells by inducing apoptotic cell death and may be a therapeutic option for Group AEPNs.

New therapeutic target for pediatric anaplastic ependymoma control: study of anti-tumor activity by a Kunitz-type molecule, Amblyomin-X

EPNs comprise a heterogeneous group of neuroepithelial tumors, accounting for about 10% of all intracranial tumors in children and up to 30% of brain tumors in those younger than 3 years. Actually, the pattern therapy for low-grade EPNs includes complete surgical resection followed by radiation therapy. Total surgical excision is often not possible due to tumor location. The aim of this study was to evaluate, for the first time, the anti-tumor activity of Amblyomin-X in 4 primary cultures derived from pediatric anaplastic posterior fossa EPN, Group A (anaplastic, WHO grade III) and one primary culture of a high grade neuroepithelial tumor with MN1 alteration, which was initially misdiagnosed as EPN: i) by in vitro assays: comparisons of temozolomide and cisplatin; ii) by intracranial xenograft model. Amblyomin-X was able to induce cell death in EPN cells in a more significant percentage compared to cisplatin. The cytotoxic effects of Amblyomin-X were not detected on hFSCs used as control, as opposed to cisplatin-treatment, which promoted a substantial effect in the hAFSCs viability. TEM analysis showed ultrastructural alterations related to the process of cell death: mitochondrial degeneration, autophagosomes and aggregate-like structures. MRI and histopathological analyzes demonstrated significant tumor mass regression. Our results suggest that Amblyomin-X has a selective effect on tumor cells by inducing apoptotic cell death and may be a therapeutic option for Group AEPNs.

Cystic craniopharyngioma: intratumoral chemotherapy with alpha interferon.

OBJECTIVE: To assess whether the cystic craniopharyngiomas can be controlled with the use of intratumoral applications of interferon alpha. METHOD: Nineteen patients with the diagnosis of cystic craniopharyngioma were treated with intratumoral chemotherapy with interferon alpha from January 2002 to April 2006. All patients underwent placement of an intracystic catheter connected to an Ommaya reservoir. Through this reservoir were made applications during chemotherapy cycles. Each cycle corresponded to application of 3,000,000 units of interferon alpha three times per week on alternate days totalizing 36,000,000 units. Response to treatment was evaluated by calculating the tumor volume on MRI control after one, three and six months after the end of each cycle. Patients who developed worsening of symptoms or who had insignificant reduction in tumor volume during follow-up underwent repeat cycle chemotherapy. RESULTS: Four patients received four cycles of chemotherapy, three patients received three cycles, six patients received two cycles and six patients received one. The lower percentage of reduction in tumor volume was 60% and the bigger reduction was 98.37%. Eleven patients had a reduction greater than 90%. Five patients had a tumor reduction between 75 and 90% and in three patients the tumors were reduced by less than 75%. No deaths occurred during treatment and side effects of interferon alpha were well tolerated. No treatment was discontinued. Follow-up after the last application ranged from one year and five months to three years and nine months. CONCLUSION: The intratumoral chemotherapy with interferon alpha decreases the volume of cystic craniopharyngiomas and so far can be considered a new therapeutic alternative.