Bronchopulmonary carcinoid tumors associated with Cushing's syndrome: a more aggressive variant of typical carcinoid

Our objectives were to delineate the clinicopathologic characteristics of adrenocorticotropin-secreting bronchopulmonary carcinoid tumors causing Cushing's syndrome and to derive from these findings a rational approach to diagnosis and surgical management of this unusual condition.

We conducted a retrospective, chart-review analysis of seven consecutive patients treated at the Massachusetts General Hospital over a 16-year period.

The patients uniformly had symptoms of marked hypercortisolism, and the underlying lung lesions remained clinically occult for a mean of 24 months. Standard endocrine testing was misleading in 83% of patients, reinforcing the need for an alternative diagnostic strategy based on petrosal sinus catheterization and computed tomography of the chest. Although 72% of the tumors were typical carcinoids by standard criteria, 57% demonstrated microscopic evidence of local invasiveness, and 43% were associated with mediastinal lymph node metastases. Eighty-six percent of patients have been cured by pulmonary resection a mean of 59 months after the operation, but 50% of these required a second operation for resection of involved lymph nodes after an initial relapse.

These data suggest that adrenocorticotropin-secreting bronchopulmonary carcinoid tumors represent a distinct, more aggressive subtype of the usual, typical carcinoid. The high rate of lymphatic and local spread demands a surgical approach consisting of anatomic resection and routine mediastinal lymph node dissection.