Primary adenocarcinoma of the arytenoid: an ultrastructural study.

Primary adenocarcinoma of the larynx is a rare neoplasm that tends to spread to both regional lymph nodes and distant sites. A case of primary adenocarcinoma of the arytenoid in a 74-year-old man is presented. The tumor was evaluated by light and electron microscopy. A high percentage of intranuclear pseudoinclusions (more than 20% of the neoplastic cells) was a peculiar characteristic of the tumor. To the best of our knowledge, such a feature has not been reported previously and should be considered a hallmark of more aggressive behavior.