Spindle-cell carcinoid tumors of the lung: a clinicopathologic study of 35 cases.

Thirty-five cases of spindle-cell carcinoid tumors of the lung were studied. Fifteen patients were male and 20 female, and they ranged in age from 33 to 78 years, with a mean of 57.6 years. Eleven neoplasms were located in the left lung and 23 in the right lung; a disproportionately large number of neoplasms were present in the right middle lobe. The tumors were most commonly encountered as an incidental finding on chest roentgenogram. None of the patients had unequivocal evidence of the carcinoid or any other endocrine syndrome. All but two of the lesions were located n the periphery of the lung and most were subpleural. They ranged in size from 0.7 to 4 cm, with 82% of the neoplasms having a maximum dimension of 2 cm or less. Microscopically, the neoplasms were composed predominantly or entirely of spindle cells which were fairly uniform in length in any single lesion, but showed moderate variation from case to case. The shorter spindle cells were often arranged in an "organoid" pattern, while the neoplasms composed of larger spindle cells were more "mesenchymal" in appearance. Silver stains were performed on 12 cases and all were argyrophil-positive. Cytoplasmic dense-core granules were identified in all four neoplasms examined ultrastructurally. Twelve cases were treated by wedge resection or segmental resection, and 18 cases by lobectomy. Hilar lymph nodes were removed from seven patients, and in two there were microscopic lymph node metastases. One other patient had a single microscopic bony metastasis. Follow-up information was available for 22 patients and ranged from 1 to 13 years with a mean of 5.4 years. None of the patients have had metastases other than those described above and none of the patients had died of their disease.