Hyaline ring granuloma: a distinct oral entity. Hyaline ring granuloma (HRG) is a distinct oral entity. In this study, 64 cases from the literature are analyzed and two new cases are reported. The lesions could be classified by location as central hyaline ring granuloma (42%) and peripheral hyaline ring granuloma (53%). Radiographically, a radiolucent area irregularly outlined by well-formed trabeculae of bone was found in central HRG, and a poorly defined erosion at the crest of the alveolar ridge was often found in peripheral HRG. Occasionally, the lesion occurred in the connective tissue wall of cysts (5%). The etiology of this condition is controversial, but most lesions were in edentulous areas and most patients had a history of tooth extraction or other trauma. The majority of cases (83%) occurred in the mandible, usually posterior to the premolar. The mean age of patients at diagnosis was 43 years, and the male/female ratio was 1.9:1. Pain was not a symptom, although local discomfort, such as recurrent swelling and tenderness, was noted in many cases. Hyaline rings with giant cell inclusions are the significant features for histopathologic diagnosis. HRG is treated by curettage or surgical excision, care being taken to remove the entire lesion. The removal of a peripheral HRG in an edentulous jaw should be followed by careful smoothing of the bone surface, since the lesion tends to infiltrate and is not well demarcated. Recurrence, probably due to incomplete excision, is uncommon. 