P-075 A CASE OF LATE DIAGNOSIS OF PITUITARY STALK INTERRUPTION SYNDROME IN A 27-YEAR-OLD GIRL

Abstract Introduction Pituitary stalk interruption syndrome (PSIS) is an uncommon congenital disorder marked by a distinct triad of features: interruption of the pituitary stalk, hypoplasia of the anterior pituitary gland, and the absence or ectopic positioning of the posterior pituitary gland. This condition can lead to a range of endocrine dysfunctions due to the integral role the pituitary gland plays in hormone regulation. Clinical Case A 27-year-old woman from a rural area near Kirkuk city, Iraq. presented to us with hypotension after she received a cabergoline tablet 0.5mg prescribed by her gynecologist for mildly elevated prolactin 67ng/dl in addition to OCP that she was taking irregularly since age 16 for secondary amenorrhea. Secondary sexual characteristics appeared between the ages of 13 and 14. Her first cycle started at the age of 14 years; she had two periods 6 months apart. Then, she was amenorrheic for 1 year. Because of this, she sought medical advice from a gynecologist and was treated with hormonal replacement therapy irregularly. On physical examination, her vital signs were as follows: a blood pressure of 88/60 mmHg, a pulse rate of 109 beats/min, a height of 154 cm, a weight of 77 kg, and a BMI of 32.4. Evaluation started by sending for the pituitary function test, and the results showed hypopituitarism with low LH, FSH, and estradiol, slightly elevated TSH, but low free T4, low GH, and as shown in the table, an ultrasound of the abdomen and pelvis were normal. Imaging studies (MRI pituitary) revealed a thin (non-enhancing) pituitary stalk, hypoplastic anterior pituitary, and an ectopic posterior pituitary located as a very small (3.5 mm) T1WI hyperintense nodule at the median eminence just inferior to the optic chiasm and projecting into the suprasellar cistern. The patient was diagnosed with PSIS and started on hormone replacement therapy, leading to a significant improvement in symptoms. PSIS is a rare congenital condition with an estimated incidence rate of 0.5/1,000,000 births. PSIS is typically diagnosed in childhood, with male predominance, with a male: female ratio of 2.3-6.9:1 pointing to X-linked inheritance, and the mean age at diagnosis is 9.4 ± 11.6 years. Usual presentation is as growth retardation or other symptoms. However, our case highlights the possibility of late presentation in adulthood, often with non-specific symptoms. This case emphasizes the importance of considering PSIS in the differential diagnosis of hypopituitarism, even in adults. Conclusion Late presentation of PSIS can occur, and clinicians should be aware of this rare condition. Early diagnosis and hormone replacement therapy can significantly improve patient outcomes. Our case powerfully highlights the importance of recognizing PSIS and underscores the diverse presentations associated with this condition.Figure 1:Pituitary MRISagittal view T1WI of pituitary MRI, yellow arrow shows a small hypoplastic anterior pituitary gland, and blue one shows a hyperintense nodule at the median eminence just inferior to the optic chiasm and projecting into the suprasellar cistern. Table 1:Laboratory data of the patient