Endocrine Abstracts

Pituitary stalk interruption syndrome (PSIS) is a rare clinical entity characterised by an absent or thin pituitary stalk, hypoplasia of the anterior pituitary gland, and ectopic location of the posterior pituitary on magnetic resonance imaging (MRI). Presentation is on early childhood or puberty and the most common hormonal deficiencies are growth hormone (GH) and gonadotropines. We present the case of a 28-year-old female patient who consulted after 2 years in secondary amenorrhea with menarche at 13 years old and previous regular menses; her family doctor prescribed oral contraceptives (restoring regular menses) and patient was referred to endocrinology consultation. She was as well in treatment with Levetiracetam for epilepsy. She didnt have any other familiar or personal pathological antecedents. The anamnesis showed 6–7 liter/day polidipsia, polyuria and nighttime thirst in the last 3 years, with no other symptoms. At physical exploration, her weight was 58.6 kg, height 160 cm (mid parental height: 158 cm) and had a Tanner stage V phenotype; she didnt have any midline craniofacial malformation. One month after contraceptives withdrawal, analysis revealed: glucose 86 mg/dl, creatinine 0.72 mg/dl, sodium 140 mmol/L, potassium 4.6 mmol/L, serum osmolality 290 mOsm/kg (N 275–295), thyrotropin 1.9 μUI/mL (N 0.4–4.2), free T4 0.91 ng/dl (N 0.93–1.7), GH 3.29 ng/mL (N 0.3–9.8), IGF-1 171 ng/ml (N 100–310), prolactin 7.65 ng/Ml (N 6–30), follistatin 3.6 mUI/mL, luteinizing hormone 0.47 mUI/mL, progesterone 0.05 ng/mL, estradiol 37 pg/mL, total testosterone 0.08 ng/mL, corticotropin 13.9 pg/mL, basal cortisol 14.6 μg/dL. Urine test: 6000 ml diuresis, urine osmolality 137 mOsm/kg. Water deprivation test: serum osmolality 273 mOsm/kg and urine osmolality 281 mOsm/kg, after 11 hours of fluid deprivation. Urine osmolality 719 and 756 mOsm/kg, before and after 1 subcutaneous μg desmopressin respectively. Synacthen test: cortisol basal levels 17.1 μg/dl, at 30 minutes 21.1 μg/dl and 25.3 μg/dl at 60 minutes. Propanolol-exercise provocative test: basal GH 4.91 ng/ml, 4.4 ng/ml at 30 minutes. MRI was performed: hypoplastic adenohypophysis (image). Patient was diagnosis with partial central diabetes insipidus (CDI), hypothyroidism, GH deficit and hypogonadism. Nowadays our patient is receiving treatment with 100 μg/day levothyroxine, 0.1 mg/24 hours oral desmopressin and contraceptives. Our case is uncommon due to SPIS presentation at adult age, normal sexual development and initial normal somatotropic axis, as well as partial CDI.