Clinical Differential Diagnosis between Nonodontogenic and Endodontic Radiolucent Lesions in Periapical Location: A Critical Review.

In endodontics, accurate diagnoses are important for the selection of appropriate and successful therapy. Several nonendodontic entities in periapical location may resemble those of inflammatory endodontic origin and impact therapeutic approaches. The aim of this study was to review noninflammatory entities mimicking dentoalveolar abscesses or apical periodontitis and to discuss clinical and pathological features. In this review study, the authenticated search engine in PubMed (MEDLINE) database was used to find articles by using "Nonvital Pulp Dentoalveolar Abscess", "Nonvital Pulp And Apical Periodontitis", "Periapical Abscess", "Chronic Dentoalveolar Abscess", "Chronic Apical Periodontitis", "Periapical Granuloma", And "Radicular Cyst". Each of these predefined keywords were combined with the terms "Misdiagnosed", "Mimicking", "Masquerading", or "Simulating" to search for reported cases indexed from 1978 to 2020. All case reports fulfilling the selection criteria were reviewed to identify radiolucent nonendodontic periapical lesions focused on the questions: "Which pathological entities mimick radiolucent endodontic lesions in periapical location? Based on endodontic clinical parameters, what are the contrasting features?" Out of 426 articles, 111 were relevant to the subject, including a series of cases and case reports. Only well-documented English and recent papers were considered. A total of 30 noninflammatory entities appeared clinically as radiolucent endodontic lesion in periapical location. Lesions simulating chronic apical periodontitis represented 83.3% and dentoalveolar abscess 16.7%. Interestingly, primary malignancies and metastasis counted 43.3% and pain was a typical symptom. Swelling was a noncontributory clinical feature in distinguishing periapical lesions. Lack of pulp response was registered in 68.4% of nonedodontic lesions. A flowchart was generated to summarize clinicopathological aspects of radiolucent nonendodontic entities appearing as dentoalveolar abscesses or apical periodontitis In relation to clinical practice, it is very important for us to note that, a group of pathological entities may simulate radiolucencies of endodontic origin in periapical location, especially malignancies and non-inflammatory odontogenic lesions.