**5.3. Endocrinopathy at diagnosis and during treatment of brain tumor**

Tumors of suprasellar and pineal region show various endocrine abnormalities even before the start of any treatment. Endocrinal symptoms in midline tumors include diabetes insipi‐ dus; changes in weight, height, and growth velocity; precocious puberty; or delayed sexual development. These symptoms less often lead to diagnosis, despite being present long before diagnosis [59]. Hypothalamic and pituitary endocrinopathies occur commonly in children following ≥24 Gy whole brain or localized cranial RT that included these structures in the radiation field. Hypothalamic-pituitary axis dysfunction gives rise to endocrinal abnormali‐ ties. This could be permanent or transient and the pituitary gland may regain its ability to secrete hormones after treatment. Therapeutic modalities, including surgery and radiothera‐ py, can damage pituitary cells leading to worsening of preexisting hypopituitarism [60]. Careful history and clinical examination, as well as timely reevaluation of children with abnormal body mass index (BMI) or BMI progression, as the presence of other neurological, ophthalmologic, and endocrine signs and symptoms may be indicative of the presence of an underlying hypothalamic-pituitary lesion [59, 60].
