1 | INTRODUCTION
Adenoid cystic carcinoma (ACC) is a rare primary neoplasm of salivary glands which is 1% of all head and neck cancers and 10% of all salivary gland neoplasms. ACC arises in both major and minor salivary glands. The parotid gland accounts for 25% of origin in head and neck which is the most common site. 1 Occasionally it arises in the nose, the paranasal sinuses, the lachrymal glands, the ceruminous glands of the external auditory canal, the larynx, the nasopharynx, and the palate.
Anatomically, ACC of hypopharynx is an extremely rare disease. The most common histologic type of hypopharyngeal malignancy is squamous cell carcinoma (SCC), which originates very differently from ACC. Moreover, treatment backbone of ACC is surgery while the role of radiation and systemic therapy are still controversial, unlike the treatment strategy of SCC.
We report the case of a hypopharyngeal ACC presenting several months after a previous diagnosis of SCC. The rare incidence and a short time earlier history of SCC could pose a diagnostic challenge for ACC in hypopharynx.