Microscopic detection of occult malignancy in the adult tonsil.

Microscopic evaluation of all adult tonsillar specimens has been considered essential despite the low incidence of unsuspected pathologic conditions. We evaluate whether routine histologic examination of clinically benign adult tonsillar specimens is indicated. We retrospectively reviewed pathology results from all tonsillectomies performed on patients ages 18 years or older at our institution from 1989 through 1996. Three groups were created on the basis of indications for tonsillectomy: (1) routine tonsillectomies for benign disease, (2) asymmetric tonsils, and (3) search for unknown primary lesions. Demographic data and pathologic findings in each group were analyzed. In 1280 tonsillectomies performed for benign disease there were no malignancies (0%) and 32 cases (2.50%) with clinically unsuspected benign pathologic conditions. In 31 cases of tonsillar asymmetry, two cases with malignant lymphoma (6.5%) and three cases with benign pathology (9.7%) were identified. In nine patients with squamous cell carcinoma metastatic to the neck, two occult primary lesions were identified in the ipsilateral tonsil. Our results suggest that histologic evaluation of adult tonsils removed for benign disease may be clinically unnecessary. The elimination of microscopic examination of tonsils removed from patients whose clinical presentation is entirely consistent with benign disease poses minimal risk of missing clinically significant pathologic conditions. Substantial costs for negative examinations may be avoided.