7667 Cushing’s Puzzle: Echinococcal Pituitary Cyst In A Rare Encounter

Abstract Disclosure: E. Sari: None. F. Erenler: None. Introduction: Echinococcus is a rare parasitic infection endemic in the Mediterranean, Middle East, South America and Africa, which can cause cystic disease in several organs. Central nervous system involvement is known to comprise 1-2% of all cystic echinococcal disease. Hereby, we report a case of an opportunistic pituitary echinococcus infection in a patient with hypercortisolism due to adrenocortical adenoma with initial misdiagnosis of Cushing’s disease. Clinical Case: A 40-year-old South American female with poorly controlled T2DM on oral agents and hypertension presented to the ER with abdominal pain and subsequent CT of the abdomen with contrast showed a right adrenal mass measuring up to 2.8 cm. A follow up CT with adrenal protocol confirmed 3.3 cm right adrenal mass, 46 HU in precontrast images with >50% washout. Review of records revealed that a recent MRI brain with contrast was performed for headache evaluation and showed an incidental 5x7x4 mm lesion in the pituitary gland. Endocrinology evaluation revealed 24-hour urine volume 1800 mL, elevated free cortisol levels 277.6 mcg/24hr (RR: 4.0-50.0 mcg/24hr), creatinine of 0.67g/24hr (RR: 0.50-2.15g/24hr). 1 mg dexamethasone suppression test showed AM cortisol of 28.7 mcg/dL. ACTH was elevated at 67 pg/mL (RR: 6-50 pg/mL). FSH, LH, and GH were normal. Presumed diagnosis of ACTH-dependent hypercortisolism was made and she underwent bilateral inferior petrosal sinus sampling with confirmed successful cannulation but this was inconclusive due to low ACTH levels. Follow-up MRI of the pituitary gland showed T1 bright, T2 isointense circumscribed lesion measuring 7x6x3 mm at anterior pituitary gland with a thin rim of peripheral enhancement consistent with cystic features. She underwent transsphenoidal resection of the pituitary lesion and the pathology specimen showed parasites consistent with echinococcosis. Infectious disease was consulted, and the patient started on albendazole. Post-operative laboratory evaluation was notable for persistently elevated AM cortisol, 24-hour urine free cortisol levels, and low ACTH levels, confirming ACTH independent hypercortisolism. She underwent right adrenal nodule resection and pathology was consistent with adrenocortical adenoma. Post-adrenalectomy AM cortisol levels were < 2 mcg/dL, indicating the resolution of hypercortisolism along with substantiating the diagnosis of primary adrenocortical hyperfunction. Conclusion: To the best of our knowledge, this is the first case report of an opportunistic echinococcus infection presenting as a pituitary lesion in the setting of Cushing Syndrome. We would like to highlight the importance of recognizing opportunistic infections, including Echinococcus as a potential etiology in the setting of hypercortisolism, especially for patients from endemic regions. Presentation: 6/2/2024