AIMS: Human Papillomavirus (HPV) is known as causative for squamous cell carcinoma (SCC) of the oropharynx, but is also not infrequently found in carcinomas of the sinonasal tract. Recently, a subset of these carcinomas was recognized to harbour HPV33 and have a significant morphological overlap with adenoid cystic carcinoma (ACC), a rare and aggressive carcinoma originating in the minor salivary glands. Termed HPV-related carcinoma with ACC-like features, only 9 cases have been reported. To clarify the occurrence of these tumours we screened a large material for presence of HPV-related ACC-like carcinoma. The identified tumours were characterized immunohistochemically and with fluorescence in situ hybridization and clinicopathologic information for all cases is presented.

METHODS AND RESULTS: Forty-seven candidate cases were screened for presence of HPV. Six cases were identified and genotyped as HPV types 33, 35 and 56. All six cases had areas of dysplastic mucosal lining and showed remarkable heterogeneous morphologies. MYB, MYBL1, and NFIB genes were intact and, interestingly, staining for MYB protein was largely negative in contrast to what was found in ACC. One patient experienced a local recurrence 11 years after initial treatment and the remaining five patients were alive without evidence of disease.

CONCLUSION: We report six new cases of HPV-related ACC-like carcinoma and found that, although in a small material, the prognosis for these patients seems more favourable than for ACC. For the distinction between ACC and HPV-related ACC-like carcinoma, p16, MYB immunohistochemistry, or investigation of MYB, MYBL1, and NFIB gene status are valuable. This article is protected by copyright. All rights reserved.