In the cases reviewed, physicians performed deep tonsil biopsies in 95 patients and tonsillectomy in 27 patients- 11 bilateral tonsillectomies and 16 unilateral tonsillectomies. The procedures themselves-endoscopies, biopsies, and tonsillectomies-did not appear to carry any additional complications in this series.
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June 2009Among the 95 patients in whom the deep tonsil biopsy was performed, the primary cancer was identified in 11 cases-about 12% of these patients; among the 27 patients in whom partial or complete tonsillectomy was performed, the primary tumor was identified in 11 cases-about 41% of these patients (p = 0.013), Dr. Waltonen reported.
Primary tumors in the tonsils were identified in three patients who had biopsies of the tonsil, and in eight patients who underwent tonsillectomies (p < 0.0002). Dr. Waltonen said that the series of cases he reviewed appears to be similar in its findings to several other studies reported in the literature, which indicate the yield of locating the primary tumor in these cases is about 30% if tonsillectomy is performed.
All the primary tonsil cancers identified were ipsilateral to the presenting neck metastases, he said. In 100 patients, doctors could not determine the primary tumor location prior to initiating treatment. After completion of treatment, three of those primaries emerged: one in the lung, one in the nasal cavity, and one in the tonsil-and that individual had undergone a tonsil biopsy, which was negative.
Implications
The situation in which we are faced with treating patients with unknown primary cancer is common, he said. These occult tumors represent about 3 to 5 percent of head and neck cancer population. A great deal of effort is put forth in identifying the primary tumor site.
In patients with primary tumors that remain occult despite thorough diagnostic workup, the likelihood of successful identification of tonsillar primary tumor is improved by performing tonsillectomy, Dr. Waltonen said.
Given that half the primary tumors we discovered were outside the tonsils, we continue to advocate directed biopsies of other potential mucosal sites, especially the tongue base, he said. In his series, eight primary tumors of the tongue base were identified.
Limitations
I believe this is an important finding, though the study suffers from small size and its retrospective nature, said Mark Weissler, MD, the Joseph P. Riddle Distinguished Professor of Otolaryngology and Chief of the Division of Head and Neck Oncology at the University of North Carolina in Chapel Hill.