Pancreatic neuroendocrine tumor in a child with a tuberous sclerosis complex 2 (TSC2) mutation.

OBJECTIVE: Pancreatic neuroendocrine tumors (PanNETs) are rare in children with tuberous sclerosis complex (TSC). The objective of this report is to describe a case of PanNET in a boy with TSC. METHODS: We describe the patient's clinical presentation, biochemical workup, and laboratory tests. RESULTS: A 10-year-old boy with a TSC2 mutation presented with a nonsecretory PanNET discovered during routine annual abdominal ultrasound. Surgical distal pancreatectomy with spleen preservation was undertaken. The excised tumor appeared nodular, whitish, and encapsulated. The tumor was composed of pancreatic endocrine monomorphic cells, and the solid appearance of the tumor was interrupted by areas of cystic degeneration. Mitoses were rare; the proliferation index was estimated around 4%. Local lymph nodes showed hyperplasia but were free of metastatic disease. Immunohistochemical examinations were positive for the neuroendocrine markers chromogranin, neurospecific enolase, synaptophysin, CAM52, and vimentin and were negative for CD10 and alpha-1 antitrypsin. The immunohistochemistry also showed a lack of hyperactivation of mammalian target of rapamycin (mTOR) mTOR pathway. All data supported the diagnosis of a grade II well-differentiated neuroendocrine neoplasm, according to the World Health Organization (WHO). CONCLUSIONS: Thirteen non-secretory PanNET cases associated with TSC have been reported, including our patient (9 men and 4 women; 7 with TSC2 mutation). These tumors are usually asymptomatic and can be associated with metastasis; therefore, early diagnosis is crucial for prompt treatment. It is still unclear whether PanNETs should be considered a feature of TSC; however due to this association, we suggest that pancreas investigation should be included in routine examinations in men with TSC2 mutation.

Long-term neurological outcome in children with early-onset epilepsy associated with tuberous sclerosis.

In tuberous sclerosis complex, early seizure onset is associated with high risk of intractable epilepsy and cognitive/behavioral impairment. We retrospectively evaluated the long-term outcome of 44 infants presenting with seizures in the first 12 months who received vigabatrin, and were followed up for at least 3.5 years. At the final evaluation 55% of patients were still having seizures, 80% had intellectual disability, and 30% had autism. Sixty-five percent of children who had been treated earlier with vigabatrin after seizure onset achieved seizure freedom, compared with 24% of subjects who received vigabatrin treatment later (P<0.01). Intellectual disability was present in 61% of the children treated early (group A) and in 100% of the children treated later (group B). Nine percent of group A and 52% of group B had autism (P≈0.001). A shorter gap between seizure onset and start of treatment could reduce the risk of epileptic encephalopathy, minimizing the deleterious effect of seizures, but is not able to completely reverse the tuberous sclerosis complex-associated cognitive impairment.

The management of subependymal giant cell tumors in tuberous sclerosis: a clinician's perspective.

BACKGROUND: Tuberous sclerosis (TSC) is a genetic multisystem disorder associated with hamartomas in several organs including subependymal giant cell tumors (SGCT). SGCT have the potential to grow and therefore to become symptomatic and are one of the main causes of death in TSC individuals. Surgical resection is the procedure of choice for SGCT. However, the discovery of mTOR pathway upregulation in TSC-associated tumors and recent evidence that mTOR inhibitors may induce regression of SGCT open up new treatment strategies. Based on a review of the currently available literature and on personal experience, current options for the management of TSC patients and appropriate indications, taking into account benefits and risks of surgery and pharmacotherapy, are discussed. DISCUSSION: An earlier diagnosis of SGCT in neurologically asymptomatic children may allow a precocious surgical removal of the tumor, thus minimizing surgery-related morbidity and mortality. Biologically targeted pharmacotherapy with mTOR inhibitors such as sirolimus and everolimus provides a safe and efficacious treatment option for patients with SGCT and has the potential to change the clinical management of these tumors. However, whether pharmacotherapy is sufficient to control growth or if it only delays the need for surgical removal of symptomatic SGCT remains unclear. Further studies are needed to determine the optimal levels of mTOR inhibitors that preserve maximal anti-tumor efficacy while minimizing side effects.

Early control of seizures improves long-term outcome in children with tuberous sclerosis complex.

Epilepsy associated with tuberous sclerosis complex (TSC) is characterized by early onset and intractable seizures in the majority of children. There is a solid evidence of clinical efficacy of vigabatrin in interrupting infantile spasms associated with TSC. Due to an early diagnosis we were able to start vigabatrin at the very early onset of seizures in 10 children, who subsequently underwent a long-term neurodevelopmental follow-up. At the final evaluation, a seizure free status was achieved in 50% of patients; 30% of individuals had a normal or borderline mental development, with no patients developing severe mental retardation and/or autism. Early control of seizures has a crucial role in preventing subsequent epileptic encephalopathy, and in reducing the cognitive/behavioural consequences of seizures, but does not guarantee for a normal mental outcome in children with TSC.

Abnormal parieto-motor connectivity in Tuberous Sclerosis Complex.

Abnormal connectivity might be involved in the pathophysiology of Tuberous Sclerosis Complex (TSC). We used twin-coil Transcranial Magnetic Stimulation protocol to investigate connectivity between posterior parietal cortex (PPC) and motor cortex (M1) in TSC patients. In comparison with healthy subjects and TSC patients treated with antiepileptic drugs, non-medicated TSC patients exhibited abnormal excitability of PPC-M1 connection. Such altered connectivity might play a role in TSC epileptic phenotype.

Tuberous sclerosis.

Tuberous sclerosis is a genetic multisystem disorder characterised by widespread hamartomas in several organs, including the brain, heart, skin, eyes, kidney, lung, and liver. The affected genes are TSC1 and TSC2, encoding hamartin and tuberin respectively. The hamartin-tuberin complex inhibits the mammalian-target-of-rapamycin pathway, which controls cell growth and proliferation. Variations in the distribution, number, size, and location of lesions cause the clinical syndrome to vary, even between relatives. Most features of tuberous sclerosis become evident only in childhood after 3 years of age, limiting their usefulness for early diagnosis. Identification of patients at risk for severe manifestations is crucial. Increasing understanding of the molecular abnormalities caused by tuberous sclerosis may enable improved management of this disease.

Massive hepatic angiomyolipoma in a young woman with tuberous sclerosis complex: significant clinical improvement during tamoxifen treatment.

BACKGROUND/AIMS: Isolated liver angiomyolipomas (AMLs) occur in about 40% of TSC patients. Because of their slow growth, these tumors are often asymptomatic. Since AMLs express estrogen and progesteron receptors we suggest the possible benefits of tamoxifen for the treatment of liver AMLs. METHODS: We report the case of a 26-year-old female affected by tuberous sclerosis (TSC2) with cerebral, renal and hepatic involvement admitted to the Liver Unit for severe malnutrition, anorexia and abdominal pain. MRI showed a grossly enlarged liver, causing severe gastric compression. The liver was entirely filled with multiple nodular lesions of different sizes. Liver biopsy showed tumoral tissue with microscopic and ultrastructural features of angiomyolipoma. All liver function tests were repeatedly normal. Prior to considering the patient for partial hepatectomy, she was administered tamoxifen (20mg b.i.d). RESULTS: After 6 months of tamoxifen treatment a greatly improved quality of life and a significant weight gain were observed. After 12 months the clinical conditions further improved and the MRI showed a significant reduction of the largest lesion with a liquid central area and a diminished compression of the stomach. CONCLUSIONS: This is to our knowledge the first report in which tamoxifen has been successfully used in a TSC patient with multiple liver angiomyolipomas.

Anophthalmia-Waardenburg syndrome with expanding phenotype: does neural crest play a role?

We describe a child with bilateral anophthalmia, limb anomalies, skin lesions, cerebral malformations, epilepsy, and mental retardation. This patient, according to eponymous classification, should fit into the Anophthalmia-Waardenburg syndrome, although he also presents cutaneous and cerebral manifestations never reported in this syndrome until now. These clinical findings could be explained by the new classification of brain malformations, which takes into account the role of neural crest in Waardenburg syndrome.

Current role of vigabatrin in infantile spasms.

Vigabatrin (VGB), a selective irreversible inhibitor of gamma-aminobutyric acid transaminase, has proved to be effective against cryptogenic and symptomatic infantile spasms (IS). Unfortunately, reports of serious visual field defects have led to a drastic reduction in the use of the drug. This review is based on a systematic search in the literature for evidence regarding efficacy and safety of VGB in IS. Based on a specific mechanism of action, there is a solid evidence of clinical efficacy of VGB in children with Tuberous Sclerosis. Similarly, VGB could represent a potential effective therapy also for spasms due to focal cortical dysplasia. In infants with spasms due to other causes, the risk of ophthalmologic toxicity should be carefully weighted against the benefit of controlling spasms.

Deletion of the long arm of chromosome 6: report on a new case with intractable epilepsy.

Interstitial deletions in the terminal region of chromosome 6 are rare. The deletion most often occurs de novo. Mental retardation is always described. The most characteristic manifestations are microcephaly, micrognathia, hypotonia, typical facial appearance, strabismus, and congenital heart defects. Although this chromosomal syndrome does not appear to have a distinctive phenotype, epileptic seizures are uncommon in affected individuals. We report on a novel finding in a patient with the 46 XX karyotype and del(6)(q25-q26) who developed intractable epilepsy.

Hypohidrosis during topiramate treatment: a rare and reversible side effect.

Topiramate is an antiepileptic drug with a beneficial clinical effect on various seizure types. Topiramate does not seem to be associated with serious adverse effects and is also well tolerated in pediatric patients. Only few cases of hypohidrosis have been described. This report presents one young patient with complex partial seizures who was medicated with topiramate when she developed fatigue, headache, intermittent hyperthermia, inability to produce sweat secretion, and dryness of the skin. Reduced sweat response was determined using the Wescor Macroduct collection procedure. Topiramate was discontinued, and within 3 weeks a repeat sweat test was completely normal. At that time, clinical signs had also disappeared. Hypohidrosis is an uncommon and reversible side effect reported in association with topiramate therapy. It is rare in patients on monotherapy. Although a definite causal relationship still needs to be established, this side effect might be attributed to an autonomic dysfunction by inhibition of isoenzymes of carbonic anhydrase localized in human eccrine sweat glands.

Current management for epilepsy in tuberous sclerosis complex.

PURPOSE OF REVIEW: This article reviews the most significant advances in the field of epilepsy associated with tuberous sclerosis complex, with emphasis on new advances in the knowledge of the pathophysiological mechanisms of epileptogenicity, progress in identifying the epileptogenic zone, and the rationale for surgical management in individuals with intractable seizures. RECENT FINDINGS: Advances in our understanding of the mechanisms and genetics underlying infantile spasms and catastrophic epilepsy associated with tuberous sclerosis complex may facilitate more effective interventions. Early effective seizure control could significantly reduce the adverse developmental effects of chronic epilepsy in tuberous sclerosis. Vigabatrin is the first choice in the short-term treatment of infantile spasms. Some individuals, however, develop seizures that remain highly intractable. The factors that influence the intractability of epilepsy associated with tuberous sclerosis complex remain poorly understood. Multimodality neuroimaging has improved detection of epileptogenic foci, allowing an increased number of individuals to be evaluated for resective surgery. Epilepsy surgery is often associated with significant improvement of the neurologic outcome. SUMMARY: Epilepsy in tuberous sclerosis seems to arise from the interaction between multiple areas, all of which have increased excitability and reduced inhibition. Understanding the mechanisms of epileptogenesis might increase the availability of development of a more specific and efficacious treatment. New evidence suggests that it is possible to noninvasively identify children with tuberous sclerosis who are highly likely to become seizure free following surgical treatment.

Intractable seizures in tuberous sclerosis complex: from molecular pathogenesis to the rationale for treatment.

Tuberous sclerosis complex is a multisystem autosomal dominant genetic disorder resulting from mutations in one of two genes, TSC1 and TSC2. Pathologically, tuberous sclerosis complex is characterized by abnormal cellular differentiation and proliferation, as well as abnormal neuronal migration. Epilepsy occurs in about 90% of patients, with onset frequently in the first year of life. In a sizable proportion of individuals, seizures tend to be refractory to antiepileptic drug treatment. This article reviews the progress in understanding drug-resistant seizures in tuberous sclerosis complex, from molecular pathogenesis to the pathophysiologic mechanisms of epileptogenesis, and the rationale for appropriate medical and surgical treatment.

Tuberous sclerosis complex: a review of neurological aspects.

Tuberous sclerosis complex is characterized by hamartomatous lesions involving skin, brain, kidneys, eyes and heart. Pathologically, tuberous sclerosis is a disorder of cell migration, proliferation and differentiation. Cell lineage and cell migration disorders in the developing cortex of tuberous sclerosis complex patients might produce very different neurological phenotypes including epilepsy, cognitive impairment and autism. Cortical tubers constitute the hallmark of the disease and are pathognomonic of cerebral tuberous sclerosis. Epilepsy is the most common neurological feature, occurring in 96% of patients. Seizures often begin in the first months of life and are frequently severe and intractable. The treatment of seizures has recently benefited from the advent of the new anti-epileptic drugs. Selected drug-resistant patients with tuberous sclerosis complex could be considered for surgical treatment. Clear localization of the most active epileptogenic focus and the zone of the cortical abnormality may lead to tuberectomy and improved seizure control in selective drug-resistant patients. The finding of multiple areas of cerebral involvement should not automatically preclude epilepsy surgery in a child with intractable seizures and a well defined seizure origin.