Pituitary macroadenomas in childhood and adolescence: a clinical analysis of 7 patients.

BACKGROUND: Pituitary adenomas (PPAs) are uncommon in childhood and adolescence, accounting for 2-6% of all intracranial neoplasms. Delayed puberty, growth retardation, galactorrhea and weight gain are common features at presentation in pediatric patients. Functional tumors constitute a vast majority (90%) of PPAs, with the most frequent being prolactinomas. CASE PRESENTATION: A retrospective review of the clinical features and outcomes of 7 pediatric patients with pituitary macroadenomas was conducted. We included PPAs in patients under 18 years at diagnosis with diameters larger than 10 mm by magnetic resonance (MRI). Six patients were males (85%), with age at diagnosis ranging from 8 to 15 (median 14 ± 2.8SDS). The primary symptoms that led to medical attention were growth retardation, gigantism and secondary amenorrhea. The visual field was reduced in three cases (42%). Suprasellar extension was present in 3 subjects, and one had a giant adenoma. Adenomas were clinically functioning in 6 patients (85%) (three prolactinomas, two somatropinomas, one secreting FSH and one no-producer). The prolactinomas responded to treatment with cabergoline. For the rest, one required transsphenoidal surgery and the other three both surgery and radiotherapy. All patients undergoing radiotherapy had secondary panhypopituitarism. In relation to the genetic studies, two patients presented a pathogenic mutation of the AIP gene and one of the MEN1. DISCUSION AND CONCLUSION: Pediatric pituitary macroadenomas are a distinct entity, mostly found in males and with a predominance of functional tumors leading to detrimental effects on growth and puberty in addition to neuro-ophthalmological manifestations. It is important to perform genetic studies in patients with macroadenomas appearing under the age of 18 years as genetic and syndromic associations are more frequent in this age group.

Delineating the neurological phenotype in children with defects in the ECHS1 or HIBCH gene.

The neurological phenotype of 3-hydroxyisobutyryl-CoA hydrolase (HIBCH) and short-chain enoyl-CoA hydratase (SCEH) defects is expanding and natural history studies are necessary to improve clinical management. From 42 patients with Leigh syndrome studied by massive parallel sequencing, we identified five patients with SCEH and HIBCH deficiency. Fourteen additional patients were recruited through collaborations with other centres. In total, we analysed the neurological features and mutation spectrum in 19 new SCEH/HIBCH patients. For natural history studies and phenotype to genotype associations we also included 70 previously reported patients. The 19 newly identified cases presented with Leigh syndrome (SCEH, n = 11; HIBCH, n = 6) and paroxysmal dystonia (SCEH, n = 2). Basal ganglia lesions (18 patients) were associated with small cysts in the putamen/pallidum in half of the cases, a characteristic hallmark for diagnosis. Eighteen pathogenic variants were identified, 11 were novel. Among all 89 cases, we observed a longer survival in HIBCH compared to SCEH patients, and in HIBCH patients carrying homozygous mutations on the protein surface compared to those with variants inside/near the catalytic region. The SCEH p.(Ala173Val) change was associated with a milder form of paroxysmal dystonia triggered by increased energy demands. In a child harbouring SCEH p.(Ala173Val) and the novel p.(Leu123Phe) change, an 83.6% reduction of the protein was observed in fibroblasts. The SCEH and HIBCH defects in the catabolic valine pathway were a frequent cause of Leigh syndrome in our cohort. We identified phenotype and genotype associations that may help predict outcome and improve clinical management.

Pediatric minor head injury imaging practices: results from an ESPR survey.

PURPOSE: Computed tomography (CT) for minor head injury exposes a large number of children to ionizing radiation, with an associated increased lifetime risk of malignancy. To study imaging practices for children with minor head injury and the level of awareness of radiologists of the current clinical decision rules for minor traumatic brain injury (TBI). METHODS: A questionnaire consisting of 17 questions was distributed electronically to 472 ESPR members. The questionnaire covered demographic information, employment status, years of experience and the current practice setting of the participants, the number of CTs performed for pediatric head trauma, awareness of clinical decision rules and use of shielding, pediatric CT protocol and MRI. RESULTS: The response rate was 18.4%. The majority of participants was aged over 50 years and was full-time consultants. Regarding decision rules, 73.8% of respondents cited the NICE head injury guidelines, and 79% reported that the decision to perform CT was agreed between specialists. Shielding was used by 58.3% and 67.4% applied a specific pediatric protocol. MRI was not used for pediatric head trauma by 70.6% of respondents, although always available in 68.6% of cases. The reported obstacles to MRI use were machine availability (42.7%), the long acquisition time (39%) and patients' intolerance (18.3%), and less frequently the cost and the need for sedation. CONCLUSION: There is room for decreasing the use of CT for pediatric minor TBI. The use of shielding and application of pediatric CT protocols constitute areas for improvement.

Mutations in the mitochondrial complex I assembly factor NDUFAF6 cause isolated bilateral striatal necrosis and progressive dystonia in childhood.

AIM: To perform a deep phenotype characterisation in a pedigree of 3 siblings with Leigh syndrome and compound heterozygous NDUFAF6 mutations. METHOD: A multi-gene panel of childhood-onset basal ganglia neurodegeneration inherited conditions was analysed followed by functional studies in fibroblasts. RESULTS: Three siblings developed gait dystonia in infancy followed by rapid progression to generalised dystonia and psychomotor regression. Brain magnetic resonance showed symmetric and bilateral cytotoxic lesions in the putamen and proliferation of the lenticular-striate arteries, latter spreading to the caudate and progressing to cavitation and volume loss. We identified a frameshift novel change (c.554_558delTTCTT; p.Tyr187AsnfsTer65) and a pathogenic missense change (c.371T>C; p.Ile124Thr) in the NDUFAF6 gene, which segregated with an autosomal recessive inheritance within the family. Patient mutations were associated with the absence of the NDUFAF6 protein and reduced activity and assembly of mature complex I in fibroblasts. By functional complementation assay, the mutant phenotype was rescued by the canonical version of the NDUFAF6. A literature review of 14 NDUFAF6 patients showed a consistent phenotype of an early childhood insidious onset neurological regression with prominent dystonia associated with basal ganglia degeneration and long survival. INTERPRETATION: NDUFAF6-related Leigh syndrome is a relevant cause of childhood onset dystonia and isolated bilateral striatal necrosis. By genetic complementation, we could demonstrate the pathogenicity of novel genetic variants in NDUFAF6.

Measurements of signal intensity of globus pallidus and dentate nucleus suggest different deposition characteristics of macrocyclic GBCAs in children.

INTRODUCTION: The safety of using GBCAs to enhance the visibility of body structures is currently discussed due to possible gadolinium retention in brain structures. The aim of the study was to evaluate the effect of multiple exposures to macrocyclic GBCAs in children. MATERIALS AND METHODS: This retrospective, single-center study included data from 43 patients who had received ≥4 injections of macrocyclic GBCAs during MRI examinations over performed over 8 to 84 months. Signal intensity was measured on unenhanced T1-weighted MRI, and globus pallidus to thalamus (GP/Th) and dentate nucleus to pons (DN/P) ratios were calculated. The differences in ratios were tested with the Student's t-test or the Wilcoxon rank sum test. For categorical data, Pearson's chi-squared test was used. Relationships were analyzed with the Spearman's rank correlation coefficient. RESULTS: Patients with the mean age of 7.5 years (SD = 4.2) received 8.19 (SD = 3.63) injections of GBCAs on average. Differences in GP/Th and DN/P ratios between the first and the last measurement were insignificant. Children before the end of myelination process (≤2 years of age) had the first GP/Th ratio values significantly lower than those >2 years of age (p = 0.0284), which than increased at the final scan and reached the level similar to values obtained in the group of >2 years of age. CONCLUSIONS: Maturation of the brain may affect both signal intensity of brain structures and susceptibility to GBCAs; thus, assessment of signal intensity of the brain structures should be conducted taking into account the age of a child.

Recommendations for the radiological diagnosis and follow-up of neuropathological abnormalities associated with tuberous sclerosis complex.

Tuberous sclerosis complex (TSC) is a genetic condition with multisystem involvement, characterized by the development of tumors and other abnormalities in organs such as the brain, retina, skin, heart, kidneys, and lungs. Most patients have neuropathological abnormalities such as cortical tubers, white matter radial migration lines, subependymal nodules, and subependymal giant cell astrocytomas (SEGAs). These lesions are associated with different neurological manifestations that are frequently associated with TSC. These manifestations consist of epilepsy, intellectual disability, and neurobehavioral and psychiatric problems, including autism spectrum disorder. Hydrocephalus may also develop in patients with SEGAs due to ventricular obstruction, when this usually slow-growing tumor reaches sufficient size. Surgery has been the classical approach to treat SEGAs, although this treatment is associated with substantial morbidity and does not completely prevent tumor recurrence. Recently, the mammalian target of rapamycin (mTOR) inhibitor, everolimus, has been approved by the Food and Drug Administration and the European Medicines Agency for the treatment of patients with SEGAs associated with TSC. However, the treatment of SEGAs with these agents requires the development of guidelines that establish a differential diagnosis between SENs and SEGAs, in which neuroradiological examinations play an essential role. With the aim of improving the neuroradiological diagnosis and follow-up of the neuropathological abnormalities associated with TSC, a group of experts in this field has reviewed different aspects related to these issues and put together, a series of statements and recommendations intended to provide guidance to specialists involved in the management of TSC.

Intracystic gadolinium-enhanced MRI in the evaluation of residual giant-cystic craniopharyngiomas in children: report of four cases.

Residual giant-cystic craniopharyngiomas are amenable to intracavitary bleomycin treatment. Radiologic identification of potential cyst leaks is of paramount for treatment decisions. This report describes our experience in the use of intracystic Gadolinium (Gd)-enhanced MR imaging to determine potential communications between the tumoral cysts and other intra-axial spaces in 4 pediatric patients with residual giant-cystic craniopharyngiomas in whom intracavitary bleomycin treatment was planned after the injection of .1-.2 mL of gadopentetate dimeglumine (Gd-DTPA). In three cases no leaks were found. In one case, whose previous water-soluble iodinated contrast-enhanced CT cystography was negative for leaks, intracystic Gd-enhanced MR showed intraventricular Gd enhancement. We conclude that MR imaging after intracystic administration of Gd-based contrast paramagnetic agents is useful in the detection of potential leaks in cases of giant residual craniopharyngiomas.

Evolution of fetal subependymal cysts throughout gestation.

Subependymal cysts are secondary to brain germinal matrix hemorrhage or infarction and are associated with fetal chromosomal and metabolic conditions, as well as infections. They are found in 1-3% of neonates in the first days of life and have been described in fetuses, although much less frequently. We report the prenatal diagnosis of a case of subependymal cysts first visualized at 12 weeks' gestation and its evolution throughout pregnancy and after birth. As far as we know, this is the first time that such a condition is described before 16 weeks' gestation as well as its longitudinal evolution. Knowledge that subependymal cysts can be seen as early as 12 weeks' gestation and their natural evolution is important to avoid equivocal diagnoses. The prognosis of isolated subependymal cysts remains uncertain.

Side effects of oncologic therapies in the pediatric central nervous system: update on neuroimaging findings.

The need for early, accurate diagnosis of central nervous system (CNS) complications occurring during and after pediatric cancer treatment is growing because of the improvement in overall survival rates related to innovative and aggressive oncologic therapies. An elevated degree of suspicion is needed to recognize the radiologic features of these CNS complications. Radiologists need familiarity with the early and late side effects of cancer therapy in the pediatric CNS (eg, toxic effects, infection, endocrine or sensory dysfunction, neuropsychologic impairment, second malignancies), in order to accelerate the imaging diagnosis and minimize as much as possible the associated morbidity. Acquisition of knowledge about these complications will enable the development of more appropriate therapeutic trials and more effective patient surveillance and will lead to an improved quality of life by decreasing the long-term sequelae in survivors.

Macroorchidism and panhypopituitarism: two different forms of presentation of FSH-secreting pituitary adenomas in adolescence.

BACKGROUND: FSH-secreting pituitary adenomas are extremely rare in children and are seldom associated with clinical manifestations of high serum gonadotrophin levels. Thus, most patients have a late presentation, usually as macroadenomas. CASE REPORTS: Two different clinical forms of presentation of FSH-secreting pituitary adenomas are reported: one in a 12-year-old boy with macroorchidism due to a pituitary microadenoma, probably FSH-secreting, and the other in a 15-year-old boy with panhypopituitarism due to an FSH-producing macroadenoma. Both patients presented slightly high or high FSH with low LH and high inhibin B levels. In the first case, the microadenoma was treated medically with cabergoline, which failed to reduce FSH and inhibin B levels. No radiological progression has been observed despite increasing testicular volume. In the second case, surgery was performed on the macroadenoma, leading to a decrease in FSH and inhibin B levels. The patient developed severe hypothalamic obesity and is currently under treatment with somatostatin. CONCLUSIONS: FSH-secreting pituitary tumors have an extremely variable clinical expression. The discrepancy between normal or slightly increased FSH and low LH values, together with high inhibin B levels, strongly suggests FSH hypersecretion which should be studied.

Congenital tumours involving the head, neck and central nervous system.

Congenital intracranial tumours are uncommon and differ from those occurring in older children in clinical presentation, imaging characteristics and prognosis. These tumours are often detected incidentally on routine prenatal US and/or fetal MRI. Hence, the paediatric radiologist should be familiar with the features of those lesions that should be included in the differential diagnosis. In general, the prognosis of these conditions is poor owing to large tumour size and the limitations of adjuvant therapy at such a young age. Congenital lesions involving the head and neck region require a meticulous imaging approach using both US and MRI techniques to better guide prenatal planning and fetal or neonatal surgical procedures.

Developmental abnormalities of temporal lobe in children.

A review of neuroimaging findings in diverse pathologies involving the temporal lobe in children is undertaken. Illustrative images of the developmental disorders that may cause temporal epilepsy in the pediatric context are provided. Brain malformations associated with hippocampal dysgenesis and related conditions such as epilepsy-associated tumors will be discussed with representative examples. Neurocutaneous syndromes that can involve the temporal lobe producing epilepsy or learning defects will be also discussed. Some other miscellaneous disorders occurring preferentially in the pediatric age such as hippocampal damage secondary to hypoxia or radiotherapy will be briefly exposed at the end of the article.

Posterior fontanelle sonography: an acoustic window into the neonatal brain.

BACKGROUND AND PURPOSE: Sonographic brain studies are classically performed through the anterior fontanelle, but visualization of posterior supratentorial and infratentorial structures is poor with this approach. Posterior fontanelle sonography is recommended for better assessment of these structures. Our purpose was 1) to determine whether sonography of the brain through the posterior fontanelle (PF) improves visualization of brain lesions when added to the routine anterior fontanelle (AF) approach and 2) to describe standardized PF coronal and sagittal sections. METHODS: In this prospective study (conducted from February 1999 to January 2001), PF sonography was added to AF sonography in 165 consecutive premature neonates with a birth weight of < 2000 g. Sonograms were recorded in digital format for re-evaluation at the end of the study. Lesions were grouped as congenital, infectious, hemorrhagic, or hypoxic-ischemic. The chi2 test for paired data and the kappa coefficient were used to compare diagnoses with AF alone and diagnoses with AF plus PF. RESULTS: PF sonography was performed in 164 of 165 patients. Results were normal in 86 and abnormal in 78. The single posterior fossa malformation detected in this series was best delineated with the PF approach. PF sonography increased the diagnostic rate of grade II hemorrhage by 32%. Cerebellar hemorrhage (two patients) and cerebellar abscesses (one patient) were diagnosed by using the PF approach. PF sonography did not contribute to the diagnosis of periventricular leukomalacia. CONCLUSION: Study of the neonatal brain with the addition of PF sonography afforded greater accuracy in detecting intraventricular hemorrhage compared with AF sonography alone, especially when the ventricle was not dilated. The PF approach better defines posterior fossa malformations.

Second malignancies in pediatric patients: imaging findings and differential diagnosis.

Therapeutic advances in the treatment of pediatric neoplasms have improved the prognosis but have also increased the risk of developing rare second malignant neoplasms (SMNs). Primary neoplasms that are often associated with SMNs include lymphoma, retinoblastoma, medulloblastoma, neuroblastoma, and leukemia. The most common SMNs are central nervous system (CNS) tumors, sarcomas, thyroid and parotid gland carcinomas, and leukemia, particularly acute myeloblastic leukemia. Genetic predisposition, chemotherapy, and especially radiation therapy are implicated as pathogenic factors in SMN. All survivors of childhood cancer should have lifelong follow-up, preferably with magnetic resonance imaging, which does not require ionizing radiation and provides greater anatomic detail and resolution in the head and neck region and the CNS. A new or progressive lesion may represent recurrence of the primitive neoplastic process, late radiation injury, or, more infrequently, an SMN. Differential diagnosis can be very difficult, and outcome is often fatal. Treatment protocols should be modified to reduce the risk for SMN without compromising the effectiveness of initial therapy. Clinicians should individualize treatment for patients who are genetically predisposed to SMN. In addition, radiologists should be familiar with the long-term consequences of antineoplastic therapy to facilitate diagnosis and anticipate adverse outcomes.

Neuroimaging in pediatric leukemia and lymphoma: differential diagnosis.

Recent advances in therapy for pediatric hematologic neoplasms have greatly improved the prognosis but have resulted in an increased incidence of associated complications and toxic effects. The main neuroimaging features in pediatric patients with leukemia or lymphoma treated with chemotherapy or radiation therapy were retrospectively reviewed. To simplify the approach and facilitate differential diagnosis, the neuroimaging features have been classified into three main categories: central nervous system manifestations of primary disease, side effects of therapeutic procedures (radiation therapy, chemotherapy, bone marrow transplantation), and complications due to immunosuppression, particularly infections. Manifestations of primary disease include cerebrovascular complications (hemorrhage, cerebral infarction) and central nervous system involvement (infiltration of the meninges, parenchyma, bone marrow, orbit, and spine). Effects of radiation therapy include white matter disease, mineralizing microangiopathy, parenchymal brain volume loss, radiation-induced cryptic vascular malformations, and second neoplasms. Effects of chemotherapy and bone marrow transplantation include hemorrhage, dural venous thrombosis, white matter disease, reversible posterior leukoencephalopathy syndrome, and anterior lumbosacral radiculopathy. Both the underlying malignancy and antineoplastic therapy can cause immunosuppression. Fungi are the most frequent causal microorganisms in immunosuppressed patients with infection. Familiarity with the imaging findings is essential for proper diagnosis of neurologic symptoms in pediatric patients with oncohematologic disease.