Significance of multiple carcinoid tumors and tumorlets in surgical lung specimens: analysis of 28 patients.

Background: The clinical significance of multiple carcinoid tumorlets in surgical lung specimens has not been systematically analyzed. We reviewed our experience to determine the range of clinical circumstances associated with this finding.
Methods: We reviewed clinical records, available imaging, and pathology materials from patients evaluated at Mayo Clinic Rochester (from 1987 to 2000) with two or more carcinoid tumors or tumorlets in lung specimens.
Results: Twenty-eight of 294 patients with a diagnosis of carcinoid tumor or tumorlet had two or more lesions. Twenty-six patients (93%) were women; mean age was 65 years. Patients were categorized into three groups: multiple nodules (n = 17), solitary lung nodules on preoperative imaging (n = 7), and airflow limitation (n = 4). Approximately half of patients with multiple nodules had respiratory complaints; two patients had Cushing syndrome. Ten patients (58.8%) were suspected of having pulmonary metastases, including 7 patients with previously diagnosed malignancies. Intrathoracic lymph node metastases were present in three patients, none of whom had recurrent disease. One patient had a carcinoid tumor resected 8 years later. Extrathoracic metastases developed in another patient 3 years after presentation, and the patient was alive with disease 2 years later. Only one patient with airflow limitation had a syndrome resembling diffuse idiopathic pulmonary neuroendocrine cell hyperplasia.
Conclusions: Our series represents the largest compilation of multiple carcinoid tumors or tumorlets. Our analysis reveals that multiple carcinoid tumors or tumorlets occur most commonly in patients with multiple nodules resembling metastatic disease. Significant airflow limitation is rare. Long-term survival is excellent, although patients have persistent disease.