Adrenocorticotropin-producing pulmonary tumorlets with lymph node metastasis.

A case of pulmonary tumorlets with ectopic adrenocorticotropin (ACTH) production and lymph node metastasis in a bronchiectatic patient is reported. A 65-year-old man underwent right lower lobe lobectomy because of a sudden attack of cough and hemoptysis. Histological study revealed multiple discrete uniform small nests of tumor cells surrounding dilated bronchioles. Tumor nests were also found in the hilar lymph node. Immunohistochemically, the proliferating cells were confirmed to be neuroendocrine in origin with ectopic ACTH production, despite being clinically silent. The findings in the present case suggest that the clinical behavior of pulmonary tumorlets may be like a carcinoid, and need to be treated as tumor-like lesions. Ectopic hormonal production in the present case suggests pulmonary tumorlets should be considered in the differential diagnosis of Cushing's syndrome.