Pituitary microadenoma in the posterior pituitary gland - Case Details

MRI

MRI shows a pituitary microadenoma (yellow arrow) in the posterior pituitary.

Title: Pituitary Microadenoma in the Posterior Pituitary Gland
Diagnosis Title: Coexisting Bartter Syndrome and Cushing's Disease due to Pituitary Microadenoma
Disease Specialty: Nephrology
Ease of Diagnosis: Difficult
Certainty: Certain
Ethnicity: Asian
Segment: Adult Female
Image Quality: Medium
Clinical Examination: The patient exhibited proximal muscle weakness in all limbs, cushingoid facies, emotional lability, and was normotensive and euvolemic on presentation.
Patient Age: 38 year
Patient Gender: Female

A 38-year-old female presented with vertigo, abdominal distension, weakness in all limbs, and facial edema. She had recurrent quadriparesis, polyuria, and new-onset T2DM. Labs showed hypokalemia (1.9 meq/L), metabolic alkalosis (pH 7.51, HCO₃ 35.8), normotension (BP 100/64 mmHg), and cushingoid facies. Urine tests indicated kaliuresis and hypercalciuria, confirming adult-onset Bartter syndrome. Elevated cortisol (56.5 mcg/dL) and ACTH (138 pg/mL) with pituitary microadenoma on MRI suggested Cushing's disease. Treated with K⁺ supplements, spironolactone, indomethacin, and transsphenoidal surgery. Genetic testing revealed Bartter syndrome type 4b (CLCNKA and CLCNKB mutations).