Primary and Recurrent Intraosseous Adenoid Cystic Carcinoma-Analysis of Two Cases and Literature Review

Adenoid cystic carcinoma (ACC) is a rare malignant tumor that mostly occurs in minor glands, especially in the palate. Intraosseous adenoid cystic carcinoma (IACC) is rarer. There is no clear conclusion on the clinical, radiologic and pathological characteristics of IACC because of few reported IACC cases, leading to insufficient understanding of IACC. We reviewed 52 previous reports of primary IACC (PIACC) and analyzed the clinical features of those patients involved, attempting to provide a better understanding of PIACC. Moreover, we present a case of primary PIACC and a case of recurrent IACC (RIACC). The two patients showed similarities in clinical and pathological results, along with slight differences in radiological and immunohistochemical results. The patient of case 1 seemed to display a worse prognosis, which can only be proved after long term follow-up.