Science and Education Publishing American Journal of Medical Case Reports 2374-216X 4 2 2016 3 11 Cyclic Cushing Syndrome, an Enigma in Diagnosis- A Case Report 65 70 EN Sharmin Jahan Department of Endocrinology, Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh Hasanat MA Md Enayet Hussain Reazuddin Danesh Nusrat Sultana Mashfiqul Hasan Fariduddin M AJMCR2016429 10.12691/ajmcr-4-2-9 2015 10 1 2016 2 14 2016 3 9 Cyclic Cushing syndrome is a rare disorder, characterized by repeated episodes of cortisol excess interspersed by periods of normal cortisol secretion. We report a 15-year-old boy with clinical Cushing syndrome and intermittent central Adrenocorticotropic hormone(ACTH) hypersecretion for a period of 8 years. Periods of hypercotisolemia as evidenced clinically and/or biochemically alternated with periods of eucortisolemia leading to much diagnostic dilemma. Ultimately, we were able to demonstrate the episodes of three peaks and two troughs of cortisol secretion favoring our diagnosis. His initial sellar MRI was negative, later high resolution dynamic sellar MRI unmasked a Pituitary micro-adenoma. In the absence of consensus for trans-sphenoidal adenomectomy (TSA) medical management in the form of sodium valproate was prescribed. At present he is on regular follow-up with marked clinical improvement.