A case of recurrent non-small-cell lung carcinoma and paraneoplastic Cushing's syndrome.

Secretion of ectopic adrenocorticotropic hormone (ACTH) with consequently Cushing's syndrome is a rare paraneoplastic phenomenon. It has been described in a variety of malignancies, like bronchial carcinoids, small-cell lung carcinoma, thymoma, pancreatic carcinoma and other. In many cases of suspected ectopic ACTH secretion, it is difficult to histologically or cytochemically confirm the diagnosis. We present a 63-year-old woman with a recurrent poorly differentiated squamous cell lung carcinoma with clinical and biochemical features consistent with ectopic Cushing's syndrome. Immunocytochemical staining confirmed the secretion of ACTH by tumour cells.