Diagnostics and treatment of lesions located in apical periodontium constitutes an important clinical issue in contemporary endodontics. Such lesions are often diagnosed accidentally during other diagnostic procedures. If they are left untreated, their development may lead to extensive tissue destruction within the head and neck. According to their aetiology, they can be classified into odontogenic and non-odontogenic lesions. The paper discusses contemporary state of knowledge concerning pathology within periapical tissues, and differential diagnostics (clinical and radiographic) of vascular non-odontogenic lesions that may mimic chronic apical periodontitis.

Key words: endodontics, periapical diseases, head and neck neoplasms.