Vol. 6, Issue 1, Part A (2024)

Pituitary stalk interruption syndrome presents with a combination of a thin or disrupted pituitary stalk, underdeveloped or absent anterior pituitary, and a missing or ectopic posterior pituitary (EPP) as observed on magnetic resonance imaging (MRI). This condition, a congenital pituitary anomaly, lacks a precise prevalence estimate. In certain instances, the anomaly manifests solely as EPP or pituitary stalk interruption. Common indicators include tertiary hypothyroidism characterized by reduced thyroid stimulating hormone levels, hyperprolactinemia, and deficiencies in other pituitary hormones. 
Case presentation: A 5-day-old newborn was admitted due to poor feeding, lethargy, and hypoglycemic seizure. Upon examination, he was found to have undescended testes on one side with a micropenis (SPL 0.8cm). Laboratory investigations revealed low cortisol levels at 0.49ug/dl (normal range: 4-20ug/dl) alongside decreased growth hormone levels (0.94ng/ml) during hypoglycemia. Additionally, on day 10 of life, serum LH was 0.100 mIU/ml (normal range: 0.3-4.9mU/ml), testosterone was 0.025ng/dl (normal range: 75-400ng/dl), Free T4 was 0.64ng/dl (normal range: 0.93-1.7ng/dl), TSH was 5.24uUI/mL (normal range: 0.58-5.57uUI/mL), and Prolactin was significantly elevated at 201.8ng/ml (normal range: 10-20 ng/mL). Given the markedly high prolactin levels, the possibility of Pituitary stalk interruption syndrome was considered, which was subsequently confirmed by MRI imaging. Whole exome sequencing was done which revealed PROP 1 gene mutation. Treatment commenced with hydrocortisone replacement initially, followed by thyroid and testosterone replacement. 
Conclusion: Given the relatively rare occurrence of pituitary stalk interruption syndrome, it is advisable to include magnetic resonance imaging (MRI) of the pituitary when evaluating a patient with suspected pituitary deficiency to ensure timely diagnosis and treatment. Hormone replacement therapy serves as the cornerstone of treatment for pituitary stalk interruption syndrome and should be initiated promptly. The correlation between neuroimaging findings and endocrine data is crucial for enhancing our comprehension of the condition and establishing a foundation for molecular diagnosis, genetic counselling, and improved patient management.