Guillain-Barre syndrome as a manifestation of Cushing’s disease secondary to Crooke’s cells tumor

Background: Guillain–Barré syndrome (GBS) is an inflammatory disease that affects the peripheral nervous system. Cushing’s disease (CD) is the most common type of endogenous Cushing syndrome (CS). Few literature reports are available on the coexistence between both diseases. We present a patient who developed Guillain–Barré syndrome-compatible polyneuropathy as a manifestation of Cushing's disease secondary to a Crooke cell tumor. Objective: To recognize that most cases of hypercortisolism lack typical clinical features, healthcare personnel must maintain a high level of suspicion to ensure early diagnosis. Case presentation: We present the case of a 64-year-old female patient with type 2 diabetes mellitus, hypertension, major depressive disorder, and a suicide attempt in the last year, who consulted the emergency department by exacerbation of her mood disorder after a fall with traumatic brain injury without loss of consciousness. She presented symmetrical, progressive, distal to proximal progressive weakness due to Guillain-Barré syndrome. However, hypokalemia secondary to Cushing’s disease caused by a pituitary adenoma was documented. Treatment with intravenous immunoglobulin and transsphenoidal surgery were carried out. Histopathological study confirmed ACTH-producing Crooke’s cell adenoma. Both mobility, electrolytes, and the mood disorder improved after treatment. Discussion: This case highlights a patient with nonspecific symptoms, an unusual presentation of a known pathology, and a rare etiopathological origin, making it valuable to examine and discuss. Conclusions: Guillain-Barré syndromes are usually sporadic. There are few cases documenting concomitance between Cushing’s and Guillain-Barré syndromes, this being the first case describing Crooke cell-type ACTH-producing pituitary tumor.