Department of Medicine, King Faisal Specialist Hospital & Research Centre, Riyadh, Saudi Arabia.
Endocr Pract. 2010 Mar-Apr;16(2):249-54. doi: 10.4158/EP09243.CR.
To report a rare cause of ectopic adrenocorticotropic hormone (ACTH) secretion leading to severe Cushing syndrome.
We describe the clinical presentation and management of a case of Cushing syndrome attributable to ectopic ACTH secretion from small cell cancer of the prostate.
In a 70-year-old man with hypertension and diabetes, congestive heart failure developed. He was found to have severe hypokalemia (serum potassium, 1.7 mEq/L) and a huge pelvic mass on a computed tomographic scan performed because of a complaint of urinary retention. Transurethral biopsy of the prostate showed features of small cell prostate cancer. Hormonal evaluation revealed a high urine free cortisol excretion of 6,214.5 microg/d (reference range, 36 to 137), confirming the diagnosis of Cushing syndrome. A serum ACTH level was elevated at 316 ng/dL (reference range, 10 to 52). An overnight high-dose (8 mg orally) dexamethasone suppression test was positive (serum cortisol levels were 43.2 and 41 microg/dL before and after suppression, respectively), and magnetic resonance imaging of the pituitary gland disclosed no abnormalities. A prostate biopsy specimen showed small cell prostate cancer with positive staining for ACTH. The tumor was found to be unresectable, and the poor condition of the patient did not allow for bilateral adrenalectomy. He was treated with ketoconazole and metyrapone, which yielded good temporary control of his Cushing syndrome (24-hour urine free cortisol decreased to 55.2 microg/d). He received 1 cycle of chemotherapy (etoposide and cisplatin), but he died 6 months later as a result of sepsis.
Small cell prostate cancer is a rare subtype that can be associated with ectopic secretion of ACTH and severe Cushing syndrome. With this subtype of prostate cancer, Cushing syndrome should be considered and appropriately managed.
报告一种罕见的异位促肾上腺皮质激素（ACTH）分泌导致严重库欣综合征的病因。
我们描述了一例归因于前列腺小细胞癌异位 ACTH 分泌的库欣综合征的临床表现和治疗。
一名 70 岁男性患有高血压和糖尿病，出现充血性心力衰竭。他被发现严重低钾血症（血清钾 1.7 mEq/L），计算机断层扫描显示骨盆内有巨大肿块，因为他抱怨尿潴留。前列腺经尿道活检显示前列腺小细胞癌的特征。激素评估显示尿游离皮质醇排泄量高，为 6,214.5 mcg/d（参考范围为 36 至 137），证实了库欣综合征的诊断。血清 ACTH 水平升高至 316 ng/dL（参考范围为 10 至 52）。过夜高剂量（8 mg 口服）地塞米松抑制试验阳性（抑制前后血清皮质醇水平分别为 43.2 和 41 mcg/dL），垂体磁共振成像无异常。前列腺活检标本显示前列腺小细胞癌，ACTH 染色阳性。肿瘤无法切除，患者状况不佳，无法进行双侧肾上腺切除术。他接受了酮康唑和米托坦治疗，暂时很好地控制了他的库欣综合征（24 小时尿游离皮质醇降至 55.2 mcg/d）。他接受了 1 个周期的化疗（依托泊苷和顺铂），但 6 个月后因败血症去世。
前列腺小细胞癌是一种罕见的亚型，可伴有异位 ACTH 分泌和严重的库欣综合征。对于这种亚型的前列腺癌，应考虑并适当治疗库欣综合征。
