Successful chemotherapeutic treatment of diencephalic syndrome with continued tumor presence

[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.

Diencephalic syndrome: a frequently neglected cause of failure to thrive in infants

Purpose

Diencephalic syndrome is an uncommon cause of failure to thrive in early childhood that is associated with central nervous system neoplasms in the hypothalamic-optic chiasmatic region. It is characterized by complex signs and symptoms related to hypothalamic dysfunction; such nonspecific clinical features may delay diagnosis of the brain tumor. In this study, we analyzed a series of cases in order to define characteristic features of diencephalic syndrome.

Methods

We performed a retrospective study of 8 patients with diencephalic syndrome (age, 5-38 months). All cases had presented to Seoul National University Children's Hospital between 1995 and 2013, with the chief complaint of poor weight gain.

Results

Diencephalic syndrome with central nervous system (CNS) neoplasm was identified in 8 patients. The mean age at which symptoms were noted was 18±10.5 months, and diagnosis after symptom onset was made at the mean age of 11±9.7 months. The mean z score was -3.15±1.14 for weight, -0.12±1.05 for height, 1.01±1.58 for head circumference, and -1.76±1.97 for weight-for-height. Clinical features included failure to thrive (n=8), hydrocephalus (n=5), recurrent vomiting (n=5), strabismus (n=2), developmental delay (n=2), hyperactivity (n=1), nystagmus (n=1), and diarrhea (n=1). On follow-up evaluation, 3 patients showed improvement and remained in stable remission, 2 patients were still receiving chemotherapy, and 3 patients were discharged for palliative care.

Conclusion

Diencephalic syndrome is a rare cause of failure to thrive, and diagnosis is frequently delayed. Thus, it is important to consider the possibility of a CNS neoplasm as a cause of failure to thrive and to ensure early diagnosis.

The role of leptin in diencephalic syndrome

Diencephalic syndrome is a rare condition associated with central nervous system tumors. The most common presentation is secondary failure to thrive with proper caloric intake and no statural impairment. Despite the importance of this syndrome, little is known of its pathophysiology. Some reports have documented changes in human growth hormone and insulin levels at the onset, whereas others have described endocrine disorders of hypothalamic insufficiency resulting from surgery of the tumor. It has been suggested that the hormonal changes described, such as increased human growth hormone and ghrelin or decreased insulin and leptin levels, are related to a patient's BMI. These findings support the role of these 4 hormones as indicators of the patient's nutritional status but not as mediators or potential therapeutic targets of the disease. We report the case of an infant who initially presented with tumor progression and, after chemotherapy, progressive weight gain and reduced tumor size. Because he presented no hormonal deficiencies or obesity after therapy, we were able to analyze his hormonal status uninfluenced by effects of metabolic treatment or excess weight. Although ghrelin and leptin levels have been related to nutritional status, our patient's leptin levels fell when tumor size decreased and weight increased: an extraordinary finding because leptin concentration is expected to increase with weight gain. This paradoxical response suggests that leptin may be dysregulated in diencephalic syndrome or that the diencephalic astrocytoma may have had an effect on leptin secretion.

Improvement of diencephalic syndrome after partial surgery of optic chiasm glioma

A 10-month-old male presented with sudden growth failure and cachexia. MRI showed a chiasma of the hypothalamic mass. Biopsy was avoided due to operative risks. Three cycles of chemotherapy were given, resulting in stable disease on MRI, but growth failure despite attempts at enteral feeding. Surgical biopsy was then performed. A 30% tumor reduction was observed on post-operative imaging. Pathological examination revealed a pilocytic astrocytoma. After surgery, the child gained weight and his growth curve returned to normal. Enteral feeding was discontinued. After 4-year of follow-up, neurological development remains normal, with no residual or endocrine abnormalities.

Astrocitoma de vías ópticas: una causa infrecuente de retraso ponderal en el lactante

Failure to thrive is a frequent cause of consultation in pediatric services. The main objective in these patients is the early detection of an organic cause, if present. We report a case of low-grade astrocytoma of the optic pathway in a 2-month-old child whose main symptoms at diagnosis were failure to thrive and anorexia. Unfortunately, despite therapeutic efforts, the tumor showed local and metastatic progression refractory to chemotherapy. The patient died 3 months after diagnosis. We conclude that diencephalic tumors must be considered in the differential diagnosis of failure to thrive during the first year of life, especially when, after initial investigations, a cause is not found.