Sudden Clinical Development Of Ectopic Cushing's Syndrome Due To A Non-Catecholamine Producing Pheochromocytoma Sudden Clinical Development Of Ectopic Cushing's Syndrome Due To A Non-Catecholamine Producing Pheochromocytoma

To our knowledge, there is only one previous report of a patient with Cushing's syndrome caused by a nonsecreting adrenal pheochromocytoma. We now present a 54 year old female who developed sudden ectopic Cushing's syndrome in a previously diagnosed but apparently nonfunctioning adrenal incidentaloma. The incidentaloma was noted one year prior to her presentation with Cushing's syndrome. She was also evaluated by the authors in endocrine clinic four months after discovery of this lesion. Despite a search for signs and symptoms of Cushing's syndrome, none were identified. Seven months later the patient presented to an outlying hospital with rapid onset and worsening of swelling in her face, neck, and abdomen accompanied by a syncopal episode. Hypokalemia, hypertension, hyperglycemia, and Cushingoid habitus were noted. Her cortisol was 119 mcg/dl; her ACTH was 518 pg/dl (nl 9-52 pg/ml). A 24-hour urine free cortisol was elevated to 8479 ug/24 hr (nl 0-50 ug/24 hr). MRI of pituitary was negative and inferior petrosal sinus sampling did not reveal an elevated central to peripheral ratio after CRH stimulation. The ACTH appeared ectopic in origin. A CT scan chest/abdomen/pelvis was repeated and the mass had increased in size to 3.7 cm and the opposite adrenal was now noted to be hypertrophic. Urinary metanephrines and catecholamines were collected and levels were all within normal limits. During testing her clinical condition deteriorated rapidly with refractory hypertension and the development of psychosis. The patient underwent left adrenalectomy and a 3.5 cm tumor was removed. Pathologic examination was consistent with a pheochromocytoma. Immunostaining of the tumor showed focal staining for ACTH, and ACTH levels were undetectable on postoperative day one. Her hypokalemia, hyperglycemia,hypertension, edema, and psychosis all resolved within one week. In conclusion, we present a case of Cushing's syndrome due to a noncatecholamine secreting, ACTH producing pheochromocytoma. Her rapid clinical presentation implies that the biologic behavior of the tumor had changed from when it was first discovered and 2.5 cm in size. The explanation for this apparent transformation is unclear. One should be aware that while ACTH producing tumors of the adrenal are rare, it is possible that they can present without the usual biochemical markers for pheochromocytoma.