Diseases of the Larynx, Hypopharynx and Trachea

We have reviewed our experience in 38 patients with adenoid cystic carcinoma of the upper airway seen between 1963 and 1995. The mean age was 44.8 years (15 to 80 years) with a male/female ratio of 1:1.1. Thirty-two of the 38 patients were treated by resection and reconstruction (primary anastomosis 28; Marlex mesh prosthesis 4). Twenty-six of the 32 patients undergoing resection received adjuvant radiotherapy. Six patients with unresectable tumors were treated primarily with radiotherapy only. Pathologic examination revealed local invasion beyond the wall of the trachea in all patients. In a majority, microscopic extension was found in submucosal and perineural lymphatics, well beyond the grossly visible or palpable limits of the tumor. Lymphatic metastases were relatively uncommon, occurring in only five of 32 (19%) patients undergoing resection. Metachronous hematogenous metastases occurred in 17 of 38 patients (44%). Thirteen of these 38 patients (33%) had pulmonary metastases. Sixteen of 32 resections were complete and potentially curative. There were two deaths within 30 days of operation. The mean survival in the 14 patients undergoing complete resection was 9.8 years (12 months to 29 years). Sixteen of 32 resections were incomplete (residual tumor at the airway margin on final pathologic examination), with one operative death occurring in this group. The mean survival in the 15 surviving patients was 7.5 years (4 months to 21 years). Six patients were treated with primary radiation only and had a mean survival of 6.2 years (2 months to 14.3 years). In the patients with pulmonary metastases, mean survival was 37 months (4 months to 7 years) from the time of diagnosis of the pulmonary metastasis until their death. Adenoid cystic carcinoma of the upper airway is a rare tumor, which is locally invasive and frequently amenable to resection. Although late local recurrence after resection is a feature of this tumor (up to 29 years), excellent long-term palliation is commonly achieved after both complete and incomplete resection. There was a small difference in survival between patients having complete and incomplete resection. Long periods of control can be obtained with radiotherapy alone. The best results, in this series of patients, were obtained by resection. Adjuvant radiotherapy is assumed to favorably influence survival.

Adenoid cystic carcinoma is an indolent salivary gland malignancy that is associated with a poor long-term prognosis. The distinction of adenoid cystic carcinoma from other head and neck neoplasms can occasionally be problematic, particularly in small biopsies. Recent studies suggest that KIT (CD117) might be useful as an ancillary marker for adenoid cystic carcinoma; however, the expression of KIT in other benign and malignant head and neck neoplasms, including those that might mimic adenoid cystic carcinoma, has not been well studied. Here we use two different antibodies against KIT to evaluate its expression in a series of 66 adenoid cystic carcinomas compared with its expression in 98 other neoplasms of the head and neck. Overall, 94% (n = 62) of adenoid cystic carcinomas from various anatomic sites and of various histologic subtypes were positive for at least one of the KIT antibodies, and 77% (n = 50) of adenoid cystic carcinoma cases were positive for both antibodies. This contrasted with only 8% (n = 8) of other head and neck neoplasms that were positive for both KIT antibodies (P .05). The overall sensitivity of the two KIT antibodies for adenoid cystic carcinoma was 82-89%, and the specificity was 87-88%. The findings in this study support the potential use of KIT immunoexpression for distinguishing adenoid cystic carcinoma from many other benign and malignant head and neck neoplasms.