ESPE Abstracts

Background: PSIS results in thin or absent pituitary stalk, adenohypophysis hypoplasia or aplasia, and ectopic neurohypophysis, confirmable by MRI. PSIS is a common cause of panhypopituitarism, often presenting with hypoglycemia in infancy or growth failure in childhood. Patients can present variable degrees of pituitary hormone deficiency and a large spectrum of clinical manifestations. Here, we report a unique case of PSIS presenting with absence of secondary sexual characteristics and hyperprolactinemia.

Case report: The patient, M., is a 16-year-old boy with delayed puberty. M. was born at 36 weeks via emergency cesarean section due to PROM, requiring ventilatory support at birth (APGAR 7 at 1'). He was followed for delayed psychomotor development and giant subcortical heterotopia, without epilepsy. At 15 years and 7 months, an endocrinological assessment showed height 158.5 cm (-1.82 SDS), lower than his target of 173 cm (+0.48 SDS), weight 55.5 kg (-0.84 SDS). His growth chart showed a notable deceleration in growth velocity. Physical examination revealed Tanner stage G1, testicular volume 3 ml bilaterally, and no axillary or pubic hair. His vital signs and cardiovascular and digestive systems were normal. Blood tests showed low IGF1, cortisol and FT4, with slightly elevated TSH. Basal gonadotropins were FSH 1.4 mIU/mL, LH 1.1 mIU/mL, and low total testosterone, with normal AMH and Inhibin B. MRI revealed complex brain malformations: pituitary gland hypoplasia, absent pituitary stalk, ectopic posterior pituitary, corpus callosum and optic chiasm hypoplasia, and giant subcortical heterotopia. The pituitary-adrenal axis was evaluated. Although the ACTH-cortisol rhythm was abnormal, the ACTH level at 8 a.m. was normal. An ACTH stimulation test with 250 mg IV showed a cortisol level of 11.71 ug/dL, indicating hypoadrenocorticism. Pathological levels of GH secretion were observed after an arginine stimulation test. A clonidine stimulation test will confirm GH deficiency. To assess the pituitary-thyroid axis, TSH, FT4, and FT3 levels were measured. TSH elevation was less than expected for the FT4 lowering, suggesting central hypothyroidism. Hyperprolactinemia was found, likely due to dopaminergic pathway disconnection. Hand X-ray indicated a bone age of 14 years, compared to the chronological age of 16 years. In addition, abdominal ultrasound revealed hepatic steatosis. Further investigations yielded normal results. Clinical exome and CGH array results are pending.

Conclusion: PSIS is a rare congenital malformation with unknown etiology and pathogenesis. Early diagnosis and appropriate hormone replacement therapy are crucial to prevent adverse effects on long-term growth and development.