A Case of Cushing's Syndrome Associated with Ectopic Corticotropin Production in Patient with Small-Cell Lung Cancer

이소성 ACTH 생산에 의해 야기된 Cushing 증후군이 동반된 소세포 폐암 1예

Small cell lung cancer(SCLC) is frequently associated with paraneoplastic syndromes, which occur in approximately 20% of patients at presentation. Clinical Cushing's syndrome secondary to ectopic ACTH production is uncommon, occurring in approximately 5% of all SCLC patients. However, biochemical evidence of hypercortisolism can be detected in up to 50% of patients. Patients with Cushing's syndrome from ectopic ACTH production show hypertension, weakness, hyperglycemia, and hypokalemic metabolic alkalosis, but differ from patients with classic Cushing's disease in that symptoms develop more rapidly. Ectopic ACTH production is associated with a poor response to chemotherapy, short survival, and a high risk of treatment-related complications. We report a case of Cushing's syndrome associated with ectopic corticotropin production in 59-year-old male patient with extensive stage of SCLC.

기침, 호흡곤란 및 성한 전신 쇄약감을 주소로 내원하여 기관지 내시경 및 경부 림프절 생검을 통한 조직검사로 소세포 폐암을 확진하고, 병력상 심한 전신무력감 및 체중감소를 호소해며, 검사상 성한 저칼륨혈증 및 대사성 알칼리증의 소견이 있으며, 최근 발생된 고혈당, 고혈압 등의 증상이 있어 시행한 내분비학적 생화학 검사상 혈중 cortisol이 상승하고, cortisol의 일간 변동(diurnal variation)이 소실되었으며, 24시간 뇨 free cortisol의 현저한 상승으로 Cushing 증후군이 paraneoplastic syndrome으로 소세포 폐암에서 동반되었음을 확인한 1예를 경험하였기에 보고하는 바이다.