Cushings syndrome (CS) remains a diagnostic challenge due to an overlap with other clinical conditions such as pseudo-Cushing, which can be triggered by major depression, alcoholism, and metabolic syndrome. The most prevalent cause of CS is iatrogenic. When Cushings syndrome is caused by endogenous cortisol secretion, most often an ACTH-secreting pituitary adenoma is the culprit and the syndrome is hence referred to as Cushings disease. In very rare cases CS is caused by a cortisol-producing ACC. The prognosis of this extremely rare disease is generally poor but depends on the stage at diagnosis. Here, we present the case of a 40-year- old female who, as a result of an acute psychotic episode in the presence of severe hypokalemia and metabolic alkalosis, was diagnosed with liver-metastasized ACC. Despite treatment with ketoconazole, followed by adrenalectomy, and adjuvant therapy with mitotane, the patient showed rapid clinical deterioration and eventually palliative care was initiated. The patient died several weeks after her discharge. We address the current literature on the epidemiology, underlying causes, clinical presentation, diagnosis, treatment, and prognosis of CS. In the presence of (therapy-resistant) arterial hypertension, impaired glucose tolerance or diabetes, and psychiatric symptoms, screening for CS should be readily considered. Concomitant hypokalemia and metabolic alkalosis, which are caused by stimulation of the aldosterone receptor, should further increase clinical suspicion for CS.