Indications and pitfalls of immunohistochemistry in head and neck cancer.

UNLABELLED Immunohistochemistry (IHC) has been employed in the differential diagnosis of tumors. OBJECTIVE To assess the use of IHC in cases of head and neck tumor. METHOD This is a retrospective study of the cases included in the Cancer Registry of the institution. RESULTS IHC was used in 76 (11%) of 704 pathology tests. Most cases were carcinomas (85.80%), and 83.66% of them were squamous cell carcinomas. All tests were done with diagnostic purposes. The most frequently used antibodies were 34BE12 (37.18%), AE1/AE3 (35.9%), 35BH11 (28.21%), CD45 (25.64%), CD20 (24.36%), CD30 (24.36%), CK7 (23.08%) and CD3 (23.08%). CONCLUSIONS IHC was used in 10.67% of the head and neck tumor cases submitted to pathology testing, mostly for carcinoma (5.26%). In the determination of squamous cell carcinoma, IHC accounted for 18.42% of all tumors.