A 65-year-old man complains of muscle weakness and a dry cough for 4 months. He has smoked two packs of cigarettes daily for 45 years. A chest X-ray shows a 4-cm central, left lung mass. Laboratory studies reveal hyperglycemia and hypertension. A transbronchial biopsy is diagnosed as small cell carcinoma. Metastases to the liver are detected by CT scan. Which of the following might account for the development of hyperglycemia and hypertension in this patient?

Cancers may produce remote effects, collectively termed paraneoplastic syndromes. For example, the secretion of corticotropin (ACTH) by a tumor leads to clinical features of Cushing syndrome, including hyperglycemia and hypertension. Corticotropin production is most commonly seen with cancers of the lung, particularly small cell carcinoma. Adrenal and pituitary metastases (choices A and D) would lead to loss of adrenal function (Addison disease). Although pituitary adenoma (choice C) is a possible cause of Cushing syndrome, this choice would be unlikely in a patient with lung cancer.Diagnosis: Small cell carcinoma of lung, paraneoplastic syndrome