SUN-287 A Case of Ectopic Neurohypophysis

Pituitary stalk interruption syndrome (PSIS) is a congenital disorder of the pituitary gland. Symptoms at presentation may vary widely as this disease presents along a spectrum which includes; ectopic posterior pituitary, interrupted pituitary stalk or aplasia and hypoplasia of the pituitary gland. It is a heterogeneous disorder in terms of radiologic and clinical presentation. It can present clinically as an isolated pituitary hormone deficiency (most common being growth hormone deficiency) or as multihormonal deficiencies. CASE PRESENTATION Patient is a 34-year-old woman with history of primary amenorrhea who was evaluated by a gynecologist and was prescribed oral contraceptive pills which lead to her having a menstrual bleed for the first time in her life. She denied any difficulty with smell. She had undergone normal psychomotor milestones and highest level of education was high school. She had normal puberty with normal pubic and axillary hair growth, normal breast development but no menarche. Of note, patient has a short stature, height is 4 feet and 11 inches, and her biological parents are of normal adult height On evaluation, patient had normal am cortisol, prolactin and thyroid function tests. IGF-1 was significantly low for her age, FSH and LH were inappropriately low for her low estradiol level suggesting hypogonadotropic hypogonadism. Patient subsequently had an MRI of the pituitary and DXA scan. MRI findings were suggestive of ectopic neurohypophysis. DXA scan showed significant reduction in bone mineral density for age. Patient is currently being treated with hormonal replacement which is the main modality of treatment for ectopic neurohyphysis. She will need long term follow up as disease progression to pan-hypopituitarism is common. CONCLUSION PSIS is a rare syndrome with different phenotypic presentation depending on when the diagnosis is made; therefore, adequate follow up is indicated as the disease can progress from a single hormonal deficiency to pan-hypopituitarism.