After 4,186 visual or "gross" exams, pathologists found no cases of disease.
And after 1,066 microscopic exams, pathologists found only 18 cases of malignant disease, all of which were previously suspected either because the patients had previously received organ transplants, and were thus at higher risk, or because a surgeon had noticed the tissue appeared suspicious.
Nevertheless, wrote Marc C. Thorne, MD, assistant professor of otolaryngology at the U-M Medical School, hospital pathologists still routinely perform these two types of exams on removed tonsils even though neither produces significant cases of disease unless performed in high-risk patients.
For gross or visual pathology exams, he wrote, "Exploration of the cost implications suggests that such a practice is not a cost-effective use of limited healthcare resources." The second test, which looks for diseased tissue with a microscope, "is appropriate for post-transplantation patients and in cases of surgeon suspicion," a minority of those undergoing tonsillectomy.
McHugh's study, authored with U-M colleagues, is published in this month's issue of the American Academy of Otolaryngology-Head and Neck Surgery.
In a sample of 4,186 tonsillectomies at the hospital between 1996 and 2008, he wrote, the cost of both tests was $250,000. The paper also looked at other research papers examining the same topic, and concluded that the cost of finding an unsuspected lymphoma in a child through microscopic evaluation is $766,500 per found case.