Pediatric Cushing's Disease: Dichotomy in Lateralization between Imaging and Inferior Petrosal Sinus Sampling with Review of Literature.

Inferior petrosal sinus sampling (IPSS) is a minimally invasive method done in adrenocorticotrophic hormone (ACTH)-dependent pituitary adenoma cases where magnetic resonance imaging (MRI) either gives equivocal results or fails to localize it. A 12-year-girl with cushingoid features and raised ACTH levels presented to us with two consecutive MRI's done outside showing gross change in the morphology of a left-sided pituitary adenoma. Hence, a bilateral IPSS was done which showed a higher IPS/periphery ACTH ratio on the right side as compared to left. Transsphenoidal endoscopic excision of the left pituitary adenoma along with right hemihypophysectomy was performed. ACTH levels fell postoperatively. This case stands distinct in highlighting the discordance in lateralization of pituitary adenoma on MRI and IPSS. Review of literature tells us that while IPSS is more sensitive in accurately diagnosing Cushing's disease, MRI provides better accuracy in lateralizing the site of adenoma.