Tracheobronchial adenoid cystic carcinoma - A clinicopathologic study of 14 cases

Study objectives: To investigate the clinicopathologic features of primary tracheobronchial adenoid cystic carcinoma (ACC), and to examine kit protein (CD117) expression, and a possible correlation between the histologic grade and Ki-67 positivity. Design: Retrospective 10-year study (from 1992 to 2001). Setting: Referral center for interventional pulmonology. Patients: Fourteen patients referred to our institution for laser resection of tracheal or endobronchial tumors. Interventions: Twelve patients were treated primarily by laser resection via bronchoscopy with subsequent radiation therapy. The remaining two patients had tracheal resection with postoperative radiation and radiation therapy alone. Results: Fourteen patients (5 men and 9 women) had an average age of 44 years at diagnosis (age range, 29 to 57 years). Five of 14 patients were smokers (average smoking history, 28.5 pack-years), 8 were nonsmokers, and the smoking history was unknown in 1 patient. Major symptoms at presentation included cough (57.1%), dyspnea (71.4%), and hoarseness (14.3%). Two patients (14.3%) presented with respiratory failure. Eleven patients (78.6%) had one or more recurrences, and 4 patients (28.6%) had metastases, primarily to the lungs. The average time to either recurrence or metastasis was 4.6 years after the initial diagnosis. Five patients (35.7%), all of whom had recurrences and/or metastasis during the course of their disease, died of their disease (average time, 8.2 years). Thirteen of 13 cases stained for CD117 were positive in the tumor cell cytoplasm with membranous accentuation. Our cases included 8 grade I tumors, 4 grade II tumors, and 2 grade III tumors, which did not correlate with the degree of Ki-67 positivity. Conclusions: Tracheobronchial ACCs in our study were more common in women and nonsmokers who presented with nonspecific respiratory symptoms and followed a clinical course generally comparable to that of tumors in the salivary glands. CD117 expression was present in all cases tested, and Ki-67 stain results did not correlate with the tumor grade.