Adenoid cystic carcinoma(ACC) is an uncommon tumor of the head and neck. It is one of the most common malignant tumor of the salivary glands. Although ACC has clear pathologic features, it can be diagnosed as a benign lesion in terms of cytological and radiologic aspects. In this paper, we report a rare case of ACCACC on tongue that is diagnosed as ACC but appears as a benign lesion in cytological and radiologic views.

There are many case reports about cysts within the bones of the jaws associated with impacted third molars. When osmotic pressure is introduced into a cyst, the cyst expands and displaces the third molar. If continuity of cyst wall is lost, cystic expansion cannot occur, and the cyst cannot displace the third molar. This study analyzed four cases of pathologic migration of the third molar in ruptured cystic lesions that had formed bone tunnels and intraoral fistulas to identify the causes and factors contributing to this migration. Authors hypothesized that closure of fistulas repeated generation of pressure, it may temporarily increase the osmotic pressure within a cyst that has lost its continuity, causing displacement of the third molar. A cyst that has lost its continuity due to fistula formation within the oral cavity can cause ectopic displacement of the adjacent impacted teeth.

Malignant tumor of the paranasal sinus is a rare, occurring most frequently in the maxillary sinus. Carcinomas of the maxillary sinus are usually diagnosed at the advanced stage because most tumors have no symptom or nonspecific symptoms such as pain, nasal obstruction, rhinorrhea, and epistaxis. In addition to these features, it is difficult to distinguish carcinoma from inflammatory or cystic lesion on imaging study until the carcinoma destroys the surrounding structures. Therefore, the diagnosis is prone to be delayed. Here, we report a case of an 83‐year‐old male with nonkeratinizing carcinoma on the maxillary sinus, which was initially misdiagnosed as a cystic lesion. The aim of this study is to emphasize the effort for early diagnosis in order to improve prognosis and avoid inadequate treatment