Primary extranodal non-Hodgkin lymphoma of the gingiva initially misdiagnosed as dental abscess.

Oral non-Hodgkin lymphomas are uncommon, and those arising on the gingiva are rare. A case of non-Hodgkin lymphoma of the gingiva that was erroneously diagnosed and treated as a dental abscess is presented. Clinical examination showed a firm and ulcerated mass extending from the mandibular right first premolar region to the retromolar trigone.