Assessing the value of bilateral inferior petrosal sinus sampling in the diagnosis and treatment of a complex case of Cushing's disease.

A 41-year-old female visited Ruijin Hospital because her face was swollen for more than 2 months. The patient was initially diagnosed with Cushing's disease (CD). Several examinations, including a dexamethasone suppression test (DST) at 2 mg and 8 mg, pituitary MRI, abdominal CT, punch biopsy of adrenal masses, and bilateral inferior petrosal sinus sampling (BIPSS), were performed, but the findings were not consistent with the clinical presentation. Ultimately, the patient underwent surgery and recovered. In this case, BIPSS was a useful way to diagnosis CD and suggested the exact location of a pituitary adenoma to Neurosurgery. BIPSS should be a required test for cases of CD that cannot be definitively diagnosed with just an MRI and 8 mg DST before surgery.