Diencephalic syndrome as sign of tumor progression in a child with neurofibromatosis type 1 and optic pathway glioma: a case report

Treatment of NF1-associated Optic Pathway/Hypothalamic Gliomas in Patients With Diencephalic Syndrome

Diencephalic syndrome is usually associated with tumors in the hypothalamic region, rarely occurring in patients with neurofibromatosis type 1 (NF1)-associated gliomas. We describe the clinical presentation and response to treatment in 3 patients with NF1 presenting with diencephalic syndrome as first symptom of optic pathway/hypothalamic glioma (OPHG). Because of the rarity of this constellation, knowledge about the clinical course and best treatment options for patients with NF1-associated OPHG and diencephalic syndrome is still limited. All 3 patients showed good response to treatment with normalization of body mass index and decrease in tumor volume within 6 months.

Diencephalic Syndrome Due to Optic Pathway Gliomas in Pediatric Patients: An Italian Multicenter Study

Diencephalic syndrome (DS) is a rare pediatric condition associated with optic pathway gliomas (OPGs). Since they are slow-growing tumors, their diagnosis might be delayed, with consequences on long-term outcomes. We present a multicenter case series of nine children with DS associated with OPG, with the aim of providing relevant details about mortality and long-term sequelae. We retrospectively identified nine children (6 M) with DS (median age 14 months, range 3–26 months). Four patients had NF1-related OPGs. Children with NF1 were significantly older than sporadic cases (median (range) age in months: 21.2 (14–26) versus 10 (3–17); p = 0.015). Seven tumors were histologically confirmed as low-grade astrocytomas. All patients received upfront chemotherapy and nutritional support. Although no patient died, all of them experienced tumor progression within 5.67 years since diagnosis and were treated with several lines of chemotherapy and/or surgery. Long-term sequelae included visual, pituitary and neurological dysfunction. Despite an excellent overall survival, PFS rates are poor in OPGs with DS. These patients invariably present visual, neurological or endocrine sequelae. Therefore, functional outcomes and quality-of-life measures should be considered in prospective trials involving patients with OPGs, aiming to identify “high-risk” patients and to better individualize treatment.

Transition From Diencephalic Syndrome to Hypothalamic Obesity in Children With Suprasellar Low Grade Glioma: A Case Series

BACKGROUND

Children with suprasellar low grade glioma (LGG) frequently develop problems to maintain their body weight within the normal range, due to hypothalamic dysfunction. Hypothalamic damage may result in the diencephalic syndrome (DS), characterized by underweight or failure to thrive, but also in hypothalamic obesity (HO). Children with LGG presenting with DS at young age often develop HO later in life. The underlying pathophysiology for this change in body mass index (BMI) is not understood. Previous hypotheses have focused on the tumor or its treatment as the underlying cause. To better understand its etiology, we aimed to relate changes in BMI over time in children with suprasellar LGG presenting with DS to age, tumor progression, treatment, and endocrine function. We hypothesize that the development of HO in children with LGG presenting with DS is related to maturation status of the hypothalamus at time of injury and thus age.

METHODS

In this retrospective case series, all cases diagnosed in the Netherlands with suprasellar located LGG, currently treated or followed, with a history of DS developing into HO were included.

RESULTS

In total, 10 children were included. Median age at LGG diagnosis was 1.5 years (range 0.4-5.5), median BMI SDS was -2.64. The children developed overweight at a median age of 4.5 years (2.2-9.8). The median total difference in BMI SDS between underweight and obesity was +5.75 SDS (4.5-8.7). No association could be found between transition of DS to HO and onset of a pituitary disorder (present in 70.0%), surgery, chemotherapy, or tumor behavior. Two had developed central precocious puberty (CPP), both while having underweight or normal weight.

CONCLUSION

The shift from DS to HO in children with hypothalamic LGG may be associated with age and not to tumor behavior, treatment characteristics or pituitary function. The development of CPP in these children seems not to be related to obesity. Our findings may indicate that the clinical picture of hypothalamic dysfunction reflects the maturation state of the hypothalamus at time of lesioning. Future prospective studies are needed to better understand underlying causative mechanisms of the morbid changes in body weight.

Pretreatment Endocrine Disorders Due to Optic Pathway Gliomas in Pediatric Neurofibromatosis Type 1: Multicenter Study

CONTEXT

Up to 20% of children with neurofibromatosis type 1 (NF1) develop low-grade optic pathway gliomas (OPGs) that can result in endocrine dysfunction. Data on prevalence and type of endocrine disorders in NF1-related OPGs are scarce.

OBJECTIVES

The aim of the study was to determine the prevalence of endocrine dysfunctions in patients with NF1 and OPGs and to investigate predictive factors before oncological treatment.

DESIGN

Multicenter retrospective study.

SETTINGS AND PATIENTS

Records were reviewed for 116 children (64 females, 52 males) with NF1 and OPGs followed at 4 Italian centers.

MAIN OUTCOME MEASURES

We evaluated endocrine function and reviewed brain imaging at the time of OPG diagnosis before radio- and chemotherapy and/or surgery. OPGs were classified according to the modified Dodge classification.

RESULTS

Thirty-two children (27.6%) with a median age of 7.8 years had endocrine dysfunctions including central precocious puberty in 23 (71.9%), growth hormone deficiency in 3 (9.4%), diencephalic syndrome in 4 (12.5%), and growth hormone hypersecretion in 2 (6.2%). In a multivariate cox regression analysis, hypothalamic involvement was the only independent predictor of endocrine dysfunctions (hazard ratio 5.02 [1.802-13.983]; P = .002).

CONCLUSIONS

Endocrine disorders were found in approximately one-third of patients with Neurofibromatosis type 1 and OPGs before any oncological treatment, central precocious puberty being the most prevalent. Sign of diencephalic syndrome and growth hormone hypersecretion, although rare, could be predictive of optic pathway gliomas in NF1. Tumor location was the most important predictor of endocrine disorders, particularly hypothalamic involvement.

[A rare case of diencephalic cachexia in an adult female with cranio-pharyngioma]

Diencephalic cachexia (DС) is progressive weight loss despite a normal caloric intake and a satisfactory state of health, which is caused by hypothalamic lesions. This is a rare (about 100 cases were reported) and potentially fatal disorder of unknown pathogenesis. At present, there is no effective pharmacological therapy for the disorder. Cachexia may regress only if the tumor reduces in size, therefore the timely diagnosis and treatment are of vital importance for the patient. DС is typical of early childhood, and only a few cases have been reported in adults. We present a rare case of DС in a 24-year-old female with papillary craniopharyngioma.

Endocrine implications of neurofibromatosis 1 in childhood

In 1882, von Recklinghausen described a group of patients with multiple tumors arising from the 'endoneurium' of peripheral nerves, and called them 'neurofibromas'. The term von Recklinghausen disease was used up to the end of the 20th century, when the gene of neurofibromatosis (NF1) was cloned on chromosome 17q11.2. The gene product is a cytoplasmic protein termed neurofibromin, regulating proliferation and maturation of both glial and neuronal progenitors during embryogenesis. Loss of neurofibromin function determines the hyperactivation of the proto-oncogene RAS, leading to an increased risk of tumor formation, predominantly affecting the skin, bone and the nervous system. NF1 is clinically and genetically distinct from neurofibromatosis type 2, characterized by bilateral vestibular schwannomas and other nervous system tumors. An increased incidence of central precocious puberty, diencephalic syndrome, GH deficiency and GH hypersecretion has been described in NF1 children. These conditions are commonly complications of optic pathway gliomas (OPG) involving the hypothalamic and sellar region. Nevertheless, these endocrine disorders have been observed also in children without evidence of OPG at magnetic resonance imaging. Clinical and laboratory follow-up is crucial in all children with NF1, particularly in those with an OPG, aiming at the early identification of signs suggestive of secondary endocrine alterations.