Always biopsy your periapical lesions and make sure you send them to an oral pathologist. Past two weeks I came across 3 cases that was sent to Temple university oral pathology department that ended up being malignant. Unfortunately, one was diagnosed as diffuse B-cell lymphoma. This is very rare but it happens. The treatment of localized disease consist of radiation plus chemotherapy. Although the response rate of many lesions is good and much progress has been made in this area, the cure rate is not high. Higher grade lymphomas are associated with a 60% mortality rate at 5 years after diagnosis and treatment.