Cushing's syndrome and nocardiosis associated with a pulmonary carcinoid tumor: report of a case and review of the literature.

Ectopic hormone production is an uncommon complication of neoplastic lung disease. Rarely, patients may present with signs and symptoms of systemic endocrine dysfunction related to a hormone-secreting tumor. Bronchopulmonary carcinoids are the most common neoplasm implicated in ectopic ACTH-dependent Cushing's syndrome. Persistent hypercortisolism, such as that which occurs in Cushing's syndrome, causes immunosuppression and makes patients vulnerable to opportunistic infections. We present a case of a 42-year-old woman diagnosed with ACTH-dependent Cushing's syndrome which was originally thought to stem from a pituitary lesion as interpreted on magnetic resonance imaging. Her symptoms persisted after undergoing hypophysectomy, and further work-up involving a fine needle aspiration of the left lung revealed an ACTH-producing carcinoid tumor. Before treatment could be administered, the patient developed several new suspicious nodules in the left lung that were shown by fine needle aspiration to be infectious in nature. A Gram stain revealed numerous Gram positive branching organisms, and culture of the specimen grew Nocardia asteroides. Her pulmonary infection was treated with antibiotics and she underwent successful ablation of the carcinoid tumor.